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Sample records for breakdown spectroscopy libs

  1. Overview of applications of Laser-Induced Breakdown Spectroscopy (LIBS)

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) is a method of performing elemental analyses of solids, liquids, and gases using the microplasma produced by a focused laser pulse. Because the microplasma is formed by optical radiation, LIBS has some important advantages compared to conventional laboratory based analytical methods. Three applications are discussed which use the LIBS method. 6 refs., 8 figs., 2 tabs

  2. Laser-Induced Breakdown Spectroscopy (LIBS): specific applications

    Science.gov (United States)

    Trtica, M. S.; Savovic, J.; Stoiljkovic, M.; Kuzmanovic, M.; Momcilovic, M.; Ciganovic, J.; Zivkovic, S.

    2015-12-01

    A short overview of Laser Induced Breakdown Spectroscopy (LIBS) with emphasis on the new trends is presented. Nowadays, due to unique features of this technique, LIBS has found applications in a great variety of fields. Achievements in the application of LIBS in nuclear area, for hazardous materials detection and in geology were considered. Also, some results recently obtained at VINCA Institute, with LIBS system based on transversely excited atmospheric (TEA) CO2 laser, are presented. Future investigations of LIBS will be oriented toward further improvement of the analytical performance of this technique, as well as on finding new application fields.

  3. Progress in fieldable laser-induced breakdown spectroscopy (LIBS)

    Science.gov (United States)

    Miziolek, Andrzej W.

    2012-06-01

    In recent years there has been great progress in the Laser Induced Breakdown Spectroscopy (LIBS) technology field. Significant advances have been made both in fundamental and applied research as well as in data processing/chemometrics. Improvements in components, most notably lasers/optics and spectrometers are enabling the development of new devices that are suitable for field use. These new commercial devices recently released to the marketplace, as well as ones currently under development, are bringing the potential of LIBS for CBRNE threat analysis into real-world applications.

  4. Laser induced breakdown spectroscopy (LIBS) applied to plutonium analysis

    International Nuclear Information System (INIS)

    A Laser Induced Breakdown Spectroscopy (LIBS) system has been developed specifically for the quantitative analysis of gallium in plutonium dioxide in support of the MOX fuel development program. The advantage of this system is no sample preparation and the capability to analyze extremely small samples. Success in this application has prompted an expansion of the technique to other areas, including determination of plutonium isotopic ratios. This paper will present recent results for gallium content in PuO2 after processing via thermally induced gallium removal (TIGR). Data will also be presented for the determination of the plutonium 239/240 isotopic ratio

  5. A Simple LIBS (Laser-Induced Breakdown Spectroscopy) Laboratory Experiment to Introduce Undergraduates to Calibration Functions and Atomic Spectroscopy

    Science.gov (United States)

    Chinni, Rosemarie C.

    2012-01-01

    This laboratory experiment introduces students to a different type of atomic spectroscopy: laser-induced breakdown spectroscopy (LIBS). LIBS uses a laser-generated spark to excite the sample; once excited, the elemental emission is spectrally resolved and detected. The students use LIBS to analyze a series of standard synthetic silicate samples…

  6. The effect of the laser wavelength on collinear double pulse laser induced breakdown spectroscopy (DP-LIBS)

    Science.gov (United States)

    Wang, Qi; Lin, Yanqing; Liu, Jing; Fan, Shuang; Xu, Zhuopin; Huang, Qing; Wu, Yuejin

    2016-05-01

    The pulsed lasers at wavelengths of 532 nm and 1064 nm were used as two beams of light for collinear double pulse laser induced breakdown spectroscopy (DP-LIBS). By changing the time sequence of two beams of different lasers, we studied the effect of the interval of two pulses of DP-LIBS on spectral signals compared with single pulsed (SP) LIBS.

  7. Eye-safe infrared laser-induced breakdown spectroscopy (LIBS) emissions from energetic materials

    Science.gov (United States)

    Brown, Ei E.; Hömmerich, Uwe; Yang, Clayton C.; Jin, Feng; Trivedi, Sudhir B.; Samuels, Alan C.

    2016-05-01

    Laser-induced breakdown spectroscopy is a powerful diagnostic tool for detection of trace elements by monitoring the atomic and ionic emission from laser-induced plasmas. Besides elemental emissions from conventional UV-Vis LIBS, molecular LIBS emission signatures of the target compounds were observed in the long-wave infrared (LWIR) region in recent studies. Most current LIBS studies employ the fundamental Nd:YAG laser output at 1.064 μm, which has extremely low eye-damage threshold. In this work, comparative LWIR-LIBS emissions studies using traditional 1.064 μm pumping and eye-safe laser wavelength at 1.574 μm were performed on several energetic materials for applications in chemical, biological, and explosive (CBE) sensing. A Q-switched Nd: YAG laser operating at 1.064 μm and the 1.574 μm output of a pulsed Nd:YAG pumped Optical Parametric Oscillator were employed as the excitation sources. The investigated energetic materials were studied for the appearance of LWIR-LIBS emissions (4-12 μm) that are directly indicative of oxygenated breakdown products as well as partially dissociated and recombination molecular species. The observed molecular IR LIBS emission bands showed strong correlation with FTIR absorption spectra of the studied materials for 1.064 μm and 1.574 μm pump wavelengths.

  8. Application of Handheld Laser-Induced Breakdown Spectroscopy (LIBS) to Geochemical Analysis.

    Science.gov (United States)

    Connors, Brendan; Somers, Andrew; Day, David

    2016-05-01

    While laser-induced breakdown spectroscopy (LIBS) has been in use for decades, only within the last two years has technology progressed to the point of enabling true handheld, self-contained instruments. Several instruments are now commercially available with a range of capabilities and features. In this paper, the SciAps Z-500 handheld LIBS instrument functionality and sub-systems are reviewed. Several assayed geochemical sample sets, including igneous rocks and soils, are investigated. Calibration data are presented for multiple elements of interest along with examples of elemental mapping in heterogeneous samples. Sample preparation and the data collection method from multiple locations and data analysis are discussed. PMID:27170779

  9. Detection of Anomalies in Citrus Leaves Using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Sankaran, Sindhuja; Ehsani, Reza; Morgan, Kelly T

    2015-08-01

    Nutrient assessment and management are important to maintain productivity in citrus orchards. In this study, laser-induced breakdown spectroscopy (LIBS) was applied for rapid and real-time detection of citrus anomalies. Laser-induced breakdown spectroscopy spectra were collected from citrus leaves with anomalies such as diseases (Huanglongbing, citrus canker) and nutrient deficiencies (iron, manganese, magnesium, zinc), and compared with those of healthy leaves. Baseline correction, wavelet multivariate denoising, and normalization techniques were applied to the LIBS spectra before analysis. After spectral pre-processing, features were extracted using principal component analysis and classified using two models, quadratic discriminant analysis and support vector machine (SVM). The SVM resulted in a high average classification accuracy of 97.5%, with high average canker classification accuracy (96.5%). LIBS peak analysis indicated that high intensities at 229.7, 247.9, 280.3, 393.5, 397.0, and 769.8 nm were observed of 11 peaks found in all the samples. Future studies using controlled experiments with variable nutrient applications are required for quantification of foliar nutrients by using LIBS-based sensing. PMID:26163130

  10. Laser induced spectroscopy breakdown (LIBS) application to heavy metal detection in soils; Applicazioni della tecnica Laser induced breakdown spectroscopy (LIBS) alla determinazione dei metalli pesanti nei suoli

    Energy Technology Data Exchange (ETDEWEB)

    Barbini, R.; Fantoni, R.; Palucci, A.; Ribezzo, S.; Colao, F. [ENEA, Centro Ricerche Frascati, Frascati, RM (Italy). Div. Fisica Applicata; Capitelli, F. [Bari, Univ., Bari (Italy). Dipt. di Biologia e Chimica Agroforestale ed Ambientale

    2000-07-01

    LIBS (Laser induced breakdown spectroscopy) is a new spectroscopic technique suitable to the use in the analysis of samples of environmental interest, such as soils and rocks, and of industrial interest, such as alloys. Results dealing with the application of the technique to heterogeneous soil samples certified by Ispra Joint Research Centre in the contest of heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) with an agronomical interest are presented in this report. In the LIBS technique, a high power laser beam is focused onto the sample in order to generate a small volume of plasma at its surface. Emissions from single atomic species are collected by a lens system coupled to an optical fiber bundle, dispersed on a monochromator and analyzed by an iCCD. the identification and the assignment of emission lines relevant to single atomic species allows to determine the sample elemental composition and, after calibration against reference samples, to perform quantitative analysis for a large number of species. This technique requires no sample pre-treatment, a part from eventually compacting powders by mechanical press. This is a considerable advantage with respect to traditional spectroscopic techniques, such as the ICP (Inductively Coupled Plasma) which needs sample mineralization by acid attack. Measurements performed on soil samples by means of the LIBS technique at ENEA Frascati were compared with the results obtained by ICP, which is considered a traditional technique for this kind of analysis. Results showed a general overestimation of the LIBS values with respect to the ICP ones, probably due to differences in lytologic matrix between the analyzed samples and the standard. The phenomenon is usually referred to the matrix effect, which is held responsible for the deviation from linearity between single element concentration and its row intensity. The effect is due to local plasma density variations and limit the correlation between the plasma elemental composition

  11. Temperature and Electron Density Determination on Laser-Induced Breakdown Spectroscopy (LIBS) Plasmas: A Physical Chemistry Experiment

    Science.gov (United States)

    Najarian, Maya L.; Chinni, Rosemarie C.

    2013-01-01

    This laboratory is designed for physical chemistry students to gain experience using laser-induced breakdown spectroscopy (LIBS) in understanding plasma diagnostics. LIBS uses a high-powered laser that is focused on the sample causing a plasma to form. The emission of this plasma is then spectrally resolved and detected. Temperature and electron…

  12. Application of laser-induced breakdown spectroscopy (LIBS) analysis to molten alloy production process

    International Nuclear Information System (INIS)

    We applied laser-induced breakdown spectroscopy (LIBS) analysis to the molten alloy production process, in which simulated metals (Zr, Cu, Sm, Ce) are used instead of nuclear metallic fuels containing minor actinide (MA). Our aim is in-situ monitoring of the elementary composition of a molten alloy's surface in a chamber and the vapor particles generated from that surface. We successfully observed the variation in the ratio of the elementary composition of the molten alloy's surface in the crucible by depending on the crucible's temperature. The elementary composition of the vapor particles in the molten alloy chamber was also measured. Practical experimental results show that the LIBS technique is very useful for investigating elementary composition in the molten alloy production process and understanding molten alloy behavior in crucibles. (author)

  13. Performance evaluation of Laser Induced Breakdown Spectroscopy (LIBS) for quantitative analysis of rare earth elements in phosphate glasses

    Science.gov (United States)

    Devangad, Praveen; Unnikrishnan, V. K.; Nayak, Rajesh; Tamboli, M. M.; Muhammed Shameem, K. M.; Santhosh, C.; Kumar, G. A.; Sardar, D. K.

    2016-02-01

    In the current study, we have determined the elemental compositions of synthesized rare earth doped phosphate glasses using a laboratory Laser-Induced Breakdown Spectroscopy (LIBS) system. LIBS spectra of this rare earth (samarium (Sm), thulium (Tm) and ytterbium (Yb)) doped glass samples with known composition are recorded using a highly sensitive detector. Major atomic emission lines of Sm, Tm and Yb found in LIBS spectra are reported. By considering the atomic emission line of phosphorous as an internal standard, calibration curves were constructed for all the rare earth concentrations. Very good linear regression coefficient (R2) values were obtained using this technique. Analytical predictive skill of LIBS was studied further using leave-one-out method. Low values of the reported correlation uncertainty between measured LIBS concentration ratio and certified concentration ratio confirms that LIBS technique has great potential for quantitative analysis of rare earth elements in glass matrix.

  14. Rapid Analysis of Ash Composition Using Laser-Induced Breakdown Spectroscopy (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Tyler L. Westover

    2013-01-01

    Inorganic compounds are known to be problematic in the thermochemical conversion of biomass to syngas and ultimately hydrocarbon fuels. The elements Si, K, Ca, Na, S, P, Cl, Mg, Fe, and Al are particularly problematic and are known to influence reaction pathways, contribute to fouling and corrosion, poison catalysts, and impact waste streams. Substantial quantities of inorganic species can be entrained in the bark of trees during harvest operations. Herbaceous feedstocks often have even greater quantities of inorganic constituents, which can account for as much as one-fifth of the total dry matter. Current methodologies to measure the concentrations of these elements, such as inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS) are expensive in time and reagents. This study demonstrates that a new methodology employing laser-induced breakdown spectroscopy (LIBS) can rapidly and accurately analyze the inorganic constituents in a wide range of biomass materials, including both woody and herbaceous examples. This technique requires little or no sample preparation, does not consume any reagents, and the analytical data is available immediately. In addition to comparing LIBS data with the results from ICP-OES methods, this work also includes discussions of sample preparation techniques, calibration curves for interpreting LIBS spectra, minimum detection limits, and the use of internal standards and standard reference materials.

  15. Composition analysis of medieval ceramics by laser-induced breakdown spectroscopy (LIBS)

    Science.gov (United States)

    Genc Oztoprak, B.; Sinmaz, M. A.; Tülek, F.

    2016-05-01

    Laser-induced breakdown spectroscopy (LIBS) technique is expected to be one of the most preferred techniques in archaeology research since it does not disrupt the structural and chemical form of archaeological samples, and it is considered virtually nondestructive analysis method. In this work, LIBS is used for analyses of glaze, paint, and clay of medieval ceramics collected from East Plain Cilicia, Osmaniye Province during archaeological survey. Transparent glazed and colour-painted ceramics of the Islam and Byzantine pottery traditions are analysed to detect distinctive and common features of the chemical compositions of their glazes. The spectral lines of Islamic and Byzantine glazes indicate that their structures are same. However, strontium (Sr) is determined in the transparent glaze of Islamic ceramics. Elemental composition and homogeneity of paint on one of the sample are determined by LIBS analysis. Colour changes are related with composition differences of the paint content in the archaeological ceramic. In addition, the clay classification of archaeological ceramics taken from the Yapılıpınar mounds, Taşlıhöyük mounds, and Örenşehir ancient sites is done using PCA and PLS-DA chemometric techniques. According to the results of the classification, Yapılıpınar mounds terracotta ceramics differ from those of Taşlıhöyük and Örenşehir ancient sites.

  16. Laser induced spectroscopy breakdown (LIBS) application to heavy metal detection in soils

    International Nuclear Information System (INIS)

    LIBS (Laser induced breakdown spectroscopy) is a new spectroscopic technique suitable to the use in the analysis of samples of environmental interest, such as soils and rocks, and of industrial interest, such as alloys. Results dealing with the application of the technique to heterogeneous soil samples certified by Ispra Joint Research Centre in the contest of heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) with an agronomical interest are presented in this report. In the LIBS technique, a high power laser beam is focused onto the sample in order to generate a small volume of plasma at its surface. Emissions from single atomic species are collected by a lens system coupled to an optical fiber bundle, dispersed on a monochromator and analyzed by an iCCD. the identification and the assignment of emission lines relevant to single atomic species allows to determine the sample elemental composition and, after calibration against reference samples, to perform quantitative analysis for a large number of species. This technique requires no sample pre-treatment, a part from eventually compacting powders by mechanical press. This is a considerable advantage with respect to traditional spectroscopic techniques, such as the ICP (Inductively Coupled Plasma) which needs sample mineralization by acid attack. Measurements performed on soil samples by means of the LIBS technique at ENEA Frascati were compared with the results obtained by ICP, which is considered a traditional technique for this kind of analysis. Results showed a general overestimation of the LIBS values with respect to the ICP ones, probably due to differences in lytologic matrix between the analyzed samples and the standard. The phenomenon is usually referred to the matrix effect, which is held responsible for the deviation from linearity between single element concentration and its row intensity. The effect is due to local plasma density variations and limit the correlation between the plasma elemental composition

  17. Application of laser induced breakdown spectroscopy (LIBS) instrumentation for international safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Barefield Ii, James E [Los Alamos National Laboratory; Clegg, Samuel M [Los Alamos National Laboratory; Lopez, Leon N [Los Alamos National Laboratory; Le, Loan A [Los Alamos National Laboratory; Veirs, D Kirk [Los Alamos National Laboratory; Browne, Mike [Los Alamos National Laboratory

    2010-01-01

    Advanced methodologies and improvements to current measurements techniques are needed to strengthen the effectiveness and efficiency of international safeguards. This need was recognized and discussed at a Technical Meeting on 'The Application of Laser Spectrometry Techniques in IAEA Safeguards' held at IAEA headquarters (September 2006). One of the principal recommendations from that meeting was the need to pursue the development of novel complementary access instrumentation based on Laser Induced Breakdown Spectroscopy (UBS) for the detection of gaseous and solid signatures and indicators of nuclear fuel cycle processes and associated materials'. Pursuant to this recommendation the Department of Safeguards (SG) under the Division of Technical Support (SGTS) convened the 'Experts and Users Advisory Meeting on Laser Induced Breakdown Spectroscopy (LIBS) for Safeguards Applications' also held at IAEA headquarters (July 2008). This meeting was attended by 12 LlBS experts from the Czech Republic, the European Commission, France, the Republic of South Korea, the United States of America, Germany, the United Kingdom of Great Britain, Canada, and Northern Ireland. Following a presentation of the needs of the IAEA inspectors, the LIBS experts agreed that needs as presented could be partially or fully fulfilled using LIBS instrumentation. Inspectors needs were grouped into the following broad categories: (1) Improvements to in-field measurements/environmental sampling; (2) Monitoring status of activities in Hot Cells; (3) Verify status of activity at a declared facility via process monitoring; and (4) Need for pre-screening of environmental samples before analysis. The primary tool employed by the IAEA to detect undeclared processes and activities at special nuclear material facilities and sites is environmental sampling. One of the objectives of the Next Generation Safeguards Initiative (NGSI) Program Plan calls for the development of advanced

  18. A Simple Laser Induced Breakdown Spectroscopy (LIBS) System for Use at Multiple Levels in the Undergraduate Chemistry Curriculum

    Science.gov (United States)

    Randall, David W.; Hayes, Ryan T.; Wong, Peter A.

    2013-01-01

    A LIBS (laser induced breakdown spectroscopy) spectrometer constructed by the instructor is reported for use in undergraduate analytical chemistry experiments. The modular spectrometer described here is based on commonly available components including a commercial Nd:YAG laser and a compact UV-vis spectrometer. The modular approach provides a…

  19. Laser-induced breakdown spectroscopy (LIBS) for carbon single shot analysis of micrometer-sized particles

    International Nuclear Information System (INIS)

    The purpose of this work is to study the ability of the laser-induced breakdown spectroscopy (LIBS) technique to perform in situ (without sample preparation) detection of graphite particles circulating in a gas loop used to simulate the cooling gas circuit of a helium-cooled nuclear reactor. Results obtained with a laboratory scale set up are presented. The experiments were performed in nitrogen with micrometer-sized particles containing carbon (glucose particles and sodium hydrogeno-carbonate particles). Statistical shot to shot analysis was used to determine the concentration of the analyte. The variation of LIBS signal as a function of glucose particle diameter showed an underestimation of the signal of particles of diameters larger than 5 μm. This phenomenon is likely to be correlated to an incomplete vaporization in the laser-induced plasma of particles of sizes above 5 μm. Analytical measurements were performed with glucose particles and sodium hydrogeno-carbonate particles, and the concentration-based limit of detection of carbon was evaluated to be about 60 μg m-3. (authors)

  20. Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

    Energy Technology Data Exchange (ETDEWEB)

    Clegg, Sanuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Humphries, Seth D [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Vaniman, D. T. [Los Alamos National Laboratory; Sharma, S. K. [UNIV OF HAWAII; Misra, A. K. [UNIV OF HAWAII; Dyar, M. D. [MT. HOLYOKE COLLEGE; Smrekar, S. E. [JET PROPULSION LAB.

    2010-12-13

    The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to

  1. Analysis of geological materials containing uranium using laser-induced breakdown spectroscopy (LIBS)

    Science.gov (United States)

    Barefield, James E.; Judge, Elizabeth J.; Campbell, Keri R.; Colgan, James P.; Kilcrease, David P.; Johns, Heather M.; Wiens, Roger C.; McInroy, Rhonda E.; Martinez, Ronald K.; Clegg, Samuel M.

    2016-06-01

    Laser induced breakdown spectroscopy (LIBS) is a rapid atomic emission spectroscopy technique that can be configured for a variety of applications including space, forensics, and industry. LIBS can also be configured for stand-off distances or in-situ, under vacuum, high pressure, atmospheric or different gas environments, and with different resolving-power spectrometers. The detection of uranium in a complex geological matrix under different measurement schemes is explored in this paper. Although many investigations have been completed in an attempt to detect and quantify uranium in different matrices at in-situ and standoff distances, this work detects and quantifies uranium in a complex matrix under Martian and ambient air conditions. Investigation of uranium detection using a low resolving-power LIBS system at stand-off distances (1.6 m) is also reported. The results are compared to an in-situ LIBS system with medium resolving power and under ambient air conditions. Uranium has many thousands of emission lines in the 200-800 nm spectral region. In the presence of other matrix elements and at lower concentrations, the limit of detection of uranium is significantly reduced. The two measurement methods (low and high resolving-power spectrometers) are compared for limit of detection (LOD). Of the twenty-one potential diagnostic uranium emission lines, seven (409, 424, 434, 435, 436, 591, and 682 nm) have been used to determine the LOD for pitchblende in a dunite matrix using the ChemCam test bed LIBS system. The LOD values determined for uranium transitions in air are 409.013 nm (24,700 ppm), 424.167 nm (23,780 ppm), 434.169 nm (24,390 ppm), 435.574 nm (35,880 ppm), 436.205 nm (19,340 ppm), 591.539 nm (47,310 ppm), and 682.692 nm (18,580 ppm). The corresponding LOD values determined for uranium transitions in 7 Torr CO2 are 424.167 nm (25,760 ppm), 434.169 nm (40,800 ppm), 436.205 nm (32,050 ppm), 591.539 nm (15,340 ppm), and 682.692 nm (29,080 ppm). The LOD values

  2. Characterization of laser-induced breakdown spectroscopy (LIBS) for application to space exploration

    International Nuclear Information System (INIS)

    Early in the next century, several space missions are planned with the goal of landing craft on asteroids, comets, the Moon, and Mars. To increase the scientific return of these missions, new methods are needed to provide (1) significantly more analyses per mission lifetime, and (2) expanded analytical capabilities. One method that has the potential to meet both of these needs for the elemental analysis of geological samples is laser-induced breakdown spectroscopy (LIBS). These capabilities are possible because the laser plasma provides rapid analysis and the laser pulse can be focused on a remotely located sample to perform a stand-off measurement. Stand-off is defined as a distance up to 20 m between the target and laser. Here we present the results of a characterization of LIBS for the stand-off analysis of soils at reduced air pressures and in a simulated Martian atmosphere (5-7 torr pressure of CO2) showing the feasibility of LIBS for space exploration. For example, it is demonstrated that an analytically useful laser plasma can be generated at distances up to 19 m by using only 35 mJ/pulse from a compact laser. Some characteristics of the laser plasma at reduced pressure were also investigated. Temporally and spectrally resolved imaging showed significant changes in the plasma as the pressure was reduced and also showed that the analyte signals and mass ablated from a target were strongly dependent on pressure. As the pressure decreased from 590 torr to the 40-100 torr range, the signals increased by a factor of about 3-4, and as the pressure was further reduced the signals decreased. This behavior can be explained by pressure-dependent changes in the mass of material vaporized and the frequency of collisions between species in the plasma. Changes in the temperature and the electron density of the plasmas with pressure were also examined and detection limits for selected elements were determined. (c) 2000 Society for Applied Spectroscopy

  3. Remote Raman - Laser Induced Breakdown Spectroscopy (LIBS) Geochemical Investigation under Venus Atmospheric Conditions

    Science.gov (United States)

    Clegg, S. M.; Barefield, J. E.; Humphries, S.; Wiens, R. C.; Vaniman, D. T.; Sharma, S. K.; Misra, A. K.; Dyar, M. D.; Smrekar, S. E.

    2010-12-01

    The extreme Venus surface temperatures (~740 K) and atmospheric pressures (~93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. [1] and Sharma et al. [2] demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic [3] with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachy-andesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to

  4. Remote Laser Induced Breakdown Spectroscopy (LIBS) Geochemical Investigation under Venus Atmospheric Conditions

    Science.gov (United States)

    Clegg, S. M.; Barefield, J. E.; Humphries, S.; Wiens, R. C.; Vaniman, D.; Dyar, M. D.; Tucker, J. M.; Sharma, S. K.; Misra, A. K.

    2009-12-01

    The extreme Venus surface temperature (740 K) and atmospheric pressure (93 atm) creates a challenging environment for future lander missions. Scientific investigations capable of Venus geochemical observations must be completed within several hours of landing before the lander is overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. [1] and Sharma et al. [2] have demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with LIBS and demonstrate the quantitative analysis under Venus surface conditions. The LIBS experiment involves focusing a Nd:YAG laser operating at 1064 nm onto the surface of the sample. The laser ablates material from the surface, generating a plasma containing electronically excited atoms, ions and small molecules. Some of this emission is collected with an 89 mm diameter telescope. The light is directed into a Princeton Instruments f/4 0.25 m dispersive spectrometer and recorded with an ICCD detector. The powdered and pelletized samples are placed in a pressure vessel containing supercritical CO2 at 93 atm and at least 423 K and the vessel is placed at least 1.6 m from the telescope and laser. A range of Venus-analog basaltic rock types [3] was chosen for this study to reproduce compositions identified by Soviet Venera and VEGA landers, including several standards: four basalts (BCR-2, BIR-1, GUWBM, JB-2), granite (GBW 07015), andesite (JA-1), carbonate (SARM-40), and Kauai volcanic (KV04-17, KV04-25). We also added a good Venus analog, TAP 04, which is an alkali-rich rock from an olivine minette in the Ayutla volcanic field (Righter and Rosas-Elguera [4]). Our goal was to study samples with a

  5. Laser-induced breakdown spectroscopy (LIBS) to measure quantitatively soil carbon with emphasis on soil organic carbon. A review.

    Science.gov (United States)

    Senesi, Giorgio S; Senesi, Nicola

    2016-09-28

    Soil organic carbon (OC) measurement is a crucial factor for quantifying soil C pools and inventories and monitoring the inherent temporal and spatial heterogeneity and changes of soil OC content. These are relevant issues in addressing sustainable management of terrestrial OC aiming to enhance C sequestration in soil, thus mitigating the impact of increasing CO2 concentration in the atmosphere and related effects on global climate change. Nowadays, dry combustion by an elemental analyzer or wet combustion by dichromate oxidation of the soil sample are the most recommended and commonly used methods for quantitative soil OC determination. However, the unanimously recognized uncertainties and limitations of these classical laboursome methods have prompted research efforts focusing on the development and application of more advanced and appealing techniques and methods for the measurement of soil OC in the laboratory and possibly in situ in the field. Among these laser-induced breakdown spectroscopy (LIBS) has raised the highest interest for its unique advantages. After an introduction and a highlight of the LIBS basic principles, instrumentation, methodologies and supporting chemometric methods, the main body of this review provides an historical and critical overview of the developments and results obtained up-to-now by the application of LIBS to the quantitative measurement of soil C and especially OC content. A brief critical summary of LIBS advantages and limitations/drawbacks including some final remarks and future perspectives concludes this review. PMID:27619082

  6. Partial Least Squares and Neural Networks for Quantitative Calibration of Laser-induced Breakdown Spectroscopy (LIBs) of Geologic Samples

    Science.gov (United States)

    Anderson, R. B.; Morris, Richard V.; Clegg, S. M.; Humphries, S. D.; Wiens, R. C.; Bell, J. F., III; Mertzman, S. A.

    2010-01-01

    The ChemCam instrument [1] on the Mars Science Laboratory (MSL) rover will be used to obtain the chemical composition of surface targets within 7 m of the rover using Laser Induced Breakdown Spectroscopy (LIBS). ChemCam analyzes atomic emission spectra (240-800 nm) from a plasma created by a pulsed Nd:KGW 1067 nm laser. The LIBS spectra can be used in a semiquantitative way to rapidly classify targets (e.g., basalt, andesite, carbonate, sulfate, etc.) and in a quantitative way to estimate their major and minor element chemical compositions. Quantitative chemical analysis from LIBS spectra is complicated by a number of factors, including chemical matrix effects [2]. Recent work has shown promising results using multivariate techniques such as partial least squares (PLS) regression and artificial neural networks (ANN) to predict elemental abundances in samples [e.g. 2-6]. To develop, refine, and evaluate analysis schemes for LIBS spectra of geologic materials, we collected spectra of a diverse set of well-characterized natural geologic samples and are comparing the predictive abilities of PLS, cascade correlation ANN (CC-ANN) and multilayer perceptron ANN (MLP-ANN) analysis procedures.

  7. Preliminary results of the characterization of pre-hispanic archaeological ceramics through Laser Induced Breakdown Spectroscopy (LIBS)

    International Nuclear Information System (INIS)

    This work describes the procedure performed to do the analysis of fragments of archaeological ceramic from the pre-Hispanic era in Cajamarquilla (southeast of Lima, Peru). Laser Induced Breakdown Spectroscopy (LIBS) was the technique used for the analysis giving excellent results with respect to reproducibility, sensitivity, non destructiveness, rapid elemental analysis, and depth-profile analysis. In this work, elements contained in pigments from pre-Hispanic ceramics of Cajamarquilla were identified. It also presents in detail, the equipment required for the implementation of the technique in the laboratory of X-ray fluorescence in the Nuclear Centre RACSO. (author)

  8. Detection of calculus by laser-induced breakdown spectroscopy (LIBS) using an ultra-short pulse laser system (USPL)

    Science.gov (United States)

    Schelle, F.; Brede, O.; Krueger, S.; Oehme, B.; Dehn, C.; Frentzen, M.; Braun, A.

    2011-03-01

    The aim of this study was to assess the detection of calculus by Laser Induced Breakdown Spectroscopy (LIBS). The study was performed with an Nd:YVO4 laser, emitting pulses with a duration of 8 ps at a wavelength of 1064 nm. A repetition rate of 500 kHz at an average power of 5 W was used. Employing a focusing lense, intensities of the order of 1011 W/cm2 were reached on the tooth surface. These high intensities led to the generation of a plasma. The light emitted by the plasma was collimated into a fibre and then analyzed by an echelle spectroscope in the wavelength region from 220 nm - 900 nm. A total number of 15 freshly extracted teeth was used for this study. For each tooth the spectra of calculus and cementum were assessed separately. Comprising all single measurements median values were calculated for the whole spectrum, leading to two specific spectra, one for calculus and one for cementum. For further statistical analysis 28 areas of interest were defined as wavelength regions, in which the signal strength differed regarding the material. In 7 areas the intensity of the calculus spectrum differed statistically significant from the intensity of the cementum spectrum (p Laser Induced Breakdown Spectroscopy is well suited as method for a reliable diagnostic of calculus. Further studies are necessary to verify that LIBS is a minimally invasive method allowing a safe application in laser-guided dentistry.

  9. Line selection and parameter optimization for trace analysis of uranium in glass matrices by laser-induced breakdown spectroscopy (LIBS).

    Science.gov (United States)

    Choi, Inhee; Chan, George C-Y; Mao, Xianglei; Perry, Dale L; Russo, Richard E

    2013-11-01

    Laser-induced breakdown spectroscopy (LIBS) has been evaluated for the determination of uranium in real-world samples such as uraninite. NIST Standard Reference Materials were used to evaluate the spectral interferences on detection of uranium. The study addresses the detection limit of LIBS for several uranium lines and their relationship to non-uranium lines, with emphasis on spectral interferences. The data are discussed in the context of optimizing the choice of emission lines for both qualitative and quantitative analyses from a complex spectrum of uranium in the presence of other elements. Temporally resolved spectral emission intensities, line width, and line shifts were characterized to demonstrate the parameter influence on these measurements. The measured uranium line width demonstrates that LIBS acquired with moderately high spectral resolution (e.g., by a 1.25 m spectrometer with a 2400 grooves/mm grating) can be utilized for isotope shift measurements in air at atmospheric pressure with single to tens of parts per million (ppm) level detection limits, as long as an appropriate transition is chosen for analysis. PMID:24160879

  10. Classification of red wine based on its protected designation of origin (PDO) using Laser-induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Moncayo, S; Rosales, J D; Izquierdo-Hornillos, R; Anzano, J; Caceres, J O

    2016-09-01

    This work reports on a simple and fast classification procedure for the quality control of red wines with protected designation of origin (PDO) by means of Laser Induced Breakdown Spectroscopy (LIBS) technique combined with Neural Networks (NN) in order to increase the quality assurance and authenticity issues. A total of thirty-eight red wine samples from different PDO were analyzed to detect fake wines and to avoid unfair competition in the market. LIBS is well known for not requiring sample preparation, however, in order to increase its analytical performance a new sample preparation treatment by previous liquid-to-solid transformation of the wine using a dry collagen gel has been developed. The use of collagen pellets allowed achieving successful classification results, avoiding the limitations and difficulties of working with aqueous samples. The performance of the NN model was assessed by three validation procedures taking into account their sensitivity (internal validation), generalization ability and robustness (independent external validation). The results of the use of a spectroscopic technique coupled with a chemometric analysis (LIBS-NN) are discussed in terms of its potential use in the food industry, providing a methodology able to perform the quality control of alcoholic beverages. PMID:27343593

  11. Laser-Induced Breakdown Spectroscopy (LIBS) for the Measurement of Spatial Structures and Fuel Distribution in Flames.

    Science.gov (United States)

    Kotzagianni, Maria; Kakkava, Eirini; Couris, Stelios

    2016-04-01

    Laser-induced breakdown spectroscopy (LIBS) is used for the mapping of local structures (i.e., reactants and products zones) and for the determination of fuel distribution by means of the local equivalence ratio ϕ in laminar, premixed air-hydrocarbon flames. The determination of laser threshold energy to induce breakdown in the different zones of flames is employed for the identification and demarcation of the local structures of a premixed laminar flame, while complementary results about fuel concentration were obtained from measurements of the cyanogen (CN) band Β(2)Σ(+)--Χ(2)Σ(+), (Δυ = 0) at 388.3 nm and the ratio of the atomic lines of hydrogen (Hα) and oxygen (O(I)), Hα/O. The combination of these LIBS-based methods provides a relatively simple to use, rapid, and accurate tool for online and in situ combustion diagnostics, providing valuable information about the fuel distribution and the spatial variations of the local structures of a flame. PMID:26865582

  12. Heavy metal concentrations in soils as determined by laser-induced breakdown spectroscopy (LIBS), with special emphasis on chromium.

    Science.gov (United States)

    Senesi, G S; Dell'Aglio, M; Gaudiuso, R; De Giacomo, A; Zaccone, C; De Pascale, O; Miano, T M; Capitelli, M

    2009-05-01

    Soil is unanimously considered as one of the most important sink of heavy metals released by human activities. Heavy metal analysis of natural and polluted soils is generally conducted by the use of atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) on adequately obtained soil extracts. Although in recent years the emergent technique of laser-induced breakdown spectroscopy (LIBS) has been applied widely and with increasing success for the qualitative and quantitative analyses of a number of heavy metals in soil matrices with relevant simplification of the conventional methodologies, the technique still requires further confirmation before it can be applied fully successfully in soil analyses. The main objective of this work was to demonstrate that new developments in LIBS technique are able to provide reliable qualitative and quantitative analytical evaluation of several heavy metals in soils, with special focus on the element chromium (Cr), and with reference to the concentrations measured by conventional ICP spectroscopy. The preliminary qualitative LIBS analysis of five soil samples and one sewage sludge sample has allowed the detection of a number of elements including Al, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Si, Ti, V and Zn. Of these, a quantitative analysis was also possible for the elements Cr, Cu, Pb, V and Zn based on the obtained linearity of the calibration curves constructed for each heavy metal, i.e., the proportionality between the intensity of the LIBS emission peaks and the concentration of each heavy metal in the sample measured by ICP. In particular, a triplet of emission lines for Cr could be used for its quantitative measurement. The consistency of experiments made on various samples was supported by the same characteristics of the laser-induced plasma (LIP), i.e., the typical linear distribution confirming the existence of local thermodynamic equilibrium (LTE) condition, and similar excitation

  13. A brief history of laser-induced breakdown spectroscopy: From the concept of atoms to LIBS 2012

    Energy Technology Data Exchange (ETDEWEB)

    Radziemski, Leon, E-mail: ljrbwr@comcast.net [Tucson, AZ (United States); Cremers, David [Applied Research Associates Inc., Albuquerque, NM (United States)

    2013-09-01

    LIBS did not appear de novo in 1962, but was built upon accomplishments of the past. These started with very old concepts of indivisible units (atomos), chemical and physical experiments and theoretical advances that took place in the late 19th and early 20th centuries, the development of the laser, the discovery of gas breakdown, and the realization of the application to spectrochemistry. We sketch the historical developments and focus as well on the advances in LIBS methodology and instrumentation over the past 50 years, culminating with a synopsis of the LIBS 2012 Conference in Luxor, Egypt.

  14. A brief history of laser-induced breakdown spectroscopy: From the concept of atoms to LIBS 2012

    International Nuclear Information System (INIS)

    LIBS did not appear de novo in 1962, but was built upon accomplishments of the past. These started with very old concepts of indivisible units (atomos), chemical and physical experiments and theoretical advances that took place in the late 19th and early 20th centuries, the development of the laser, the discovery of gas breakdown, and the realization of the application to spectrochemistry. We sketch the historical developments and focus as well on the advances in LIBS methodology and instrumentation over the past 50 years, culminating with a synopsis of the LIBS 2012 Conference in Luxor, Egypt

  15. STUDI PERBANDINGAN ANALISIS UNSUR PLUMBUM (PB DARI HASIL ELEKTROLISIS ANTARA METODE LASER- INDUCED BREAKDOWN SPECTROSCOPY (LIBS DENGAN METODE KONVENSIONAL

    Directory of Open Access Journals (Sweden)

    H. S. Suyanto

    2014-07-01

    Full Text Available Penelitian ini bertujuan menganalisis unsur Pb hasil proses elektrolisis dengan metode alternatif laser-induced breakdown spectroscopy (LIBS dan metode konvensional. Elektrolisis menggunakan tembaga (Cu sebagai katoda dan karbon sebagai anoda. Unsur Pb yang terdeposisi pada katoda diirradiasi laser Nd-YAG (model CFR 200, 1064nm dan emisinya (Pb I 405.7 nm ditangkap spektrometer HR 2500++ yang kemudian ditampilkan dalam intensitas fungsi panjang gelombang. Hasil penelitian menunjukkan bahwa energi laser, arus listrik dan waktu deposisi proses elektrolisis yang optimum untuk karakterisasi unsur Pb masing - masing adalah 100 mJ, 5,28 mA dan 15 menit. Aplikasi metode ini untuk analisis kuantitatif larutan Pb dengan membuat kurva kalibrasi dari kosentrasi 300 ppm sampai kosentrasi terendah yaitu 0,5 ppm, serta diperoleh deteksi limit sebesar 0,44 ppm. Sebagai perbandingan metode deteksi dengan LIBS ini telah dilakukan analisis dengan metode konvensional dengan menentukan selisih massa katoda sebelum dan sesudah elektrolisis dan diperoleh hasil yang sebanding.ABSTRACTThe aim of this research was to compare between a method of laser-induced breakdown spectroscopy (LIBS and the conventional one to analyse of Plumbum (Pb element resulted from electrolysis process. Electrolysis used copper (Cu and carbon (C as cathode and anode respectively. Plumbum element which was deposited on cathode was irradiated by Nd-YAG laser (model CFR 200, 1064nm and its emission intensity of neutral Pb I 405.7 nm in the plasma was captured by HR 2500++ spectrometer and displayed in a form of intensity as a function of wavelength. The experiment result showed that the optimum condition parameters of electrolysis: laser energy, electric current and electrolysis time duration were 100 mJ, 5.28 mA and 15 minutes respectively. An application of these conditions was done to make calibration curve of Pb element in liquid sample from 300 ppm to 0.5 ppm and resulted a limit of

  16. Raman and Laser-Induced Breakdown Spectroscopy (LIBS) Remote Geochemical Analysis Under Venus Atmospheric Pressure

    Science.gov (United States)

    Clegg, S.; Sharma, S. K.; Misra, A. K.; Dyar, M. D.; Dallmann, N.; Wiens, R. C.; Vaniman, D. T.; Speicher, E. A.; Smrekar, S. E.; Wang, A.; Maurice, S.; Esposito, L.

    2012-03-01

    A remote Raman-LIBS spectrometer (RLS) is a rapid method to determine Venus surface chemistry and mineralogy without collecting samples and bringing them into the lander. The RLS results from 18 synthetic samples will be presented.

  17. Recent development of double pulse laser induced breakdown spectroscopy (DP-LIBS) setup

    OpenAIRE

    David Prochazka; Jozef Kaiser; Karel Novotny; Michaela Galiova; Radomir Malina*

    2010-01-01

    Single pulse (SP) LIBS setup was modified to DP setup to achievemore accurate analytical sensitivity and spatial resolution. Allparameters, like interpulse delay, acquisition delay or energy ofablation and excitation laser pulses were optimized.

  18. Homogeneity testing and quantitative analysis of manganese (Mn in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS

    Directory of Open Access Journals (Sweden)

    V. K. Unnikrishnan

    2014-09-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS, an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.7×109 W/cm2. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.

  19. Homogeneity testing and quantitative analysis of manganese (Mn) in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Unnikrishnan, V. K.; Nayak, Rajesh; Kartha, V. B.; Santhosh, C., E-mail: santhosh.cls@manipal.edu, E-mail: unnikrishnan.vk@manipal.edu [Department of Atomic and Molecular Physics, Manipal University, Manipal (India); Sonavane, M. S. [Nuclear Recycle Board, Bhabha Atomic Research Centre, Mumbai (India); Yeotikar, R. G. [Process Development Division, Bhabha Atomic Research Centre, Mumbai (India); Shah, M. L.; Gupta, G. P.; Suri, B. M. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-09-15

    Laser-induced breakdown spectroscopy (LIBS), an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn) in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.7×10{sup 9} W/cm{sup 2}. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX) surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations.

  20. Analysis of heterogeneous gallstones using laser-induced breakdown spectroscopy (LIBS) and wavelength dispersive X-ray fluorescence (WD-XRF).

    Science.gov (United States)

    Jaswal, Brij Bir S; Kumar, Vinay; Sharma, Jitendra; Rai, Pradeep K; Gondal, Mohammed A; Gondal, Bilal; Singh, Vivek K

    2016-04-01

    Laser-induced breakdown spectroscopy (LIBS) is an emerging analytical technique with numerous advantages such as rapidity, multi-elemental analysis, no specific sample preparation requirements, non-destructiveness, and versatility. It has been proven to be a robust elemental analysis tool attracting interest because of being applied to a wide range of materials including biomaterials. In this paper, we have performed spectroscopic studies on gallstones which are heterogeneous in nature using LIBS and wavelength dispersive X-ray fluorescence (WD-XRF) techniques. It has been observed that the presence and relative concentrations of trace elements in different kind of gallstones (cholesterol and pigment gallstones) can easily be determined using LIBS technique. From the experiments carried out on gallstones for trace elemental mapping and detection, it was found that LIBS is a robust tool for such biomedical applications. The stone samples studied in the present paper were classified using the Fourier transform infrared (FTIR) spectroscopy. WD-XRF spectroscopy has been applied for the qualitative and quantitative analysis of major and trace elements present in the gallstone which was compared with the LIBS data. The results obtained in the present paper show interesting prospects for LIBS and WD-XRF to study cholelithiasis better. PMID:26886588

  1. Homogeneity testing and quantitative analysis of manganese (Mn) in vitrified Mn-doped glasses by laser-induced breakdown spectroscopy (LIBS)

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS), an atomic emission spectroscopy method, has rapidly grown as one of the best elemental analysis techniques over the past two decades. Homogeneity testing and quantitative analysis of manganese (Mn) in manganese-doped glasses have been carried out using an optimized LIBS system employing a nanosecond ultraviolet Nd:YAG laser as the source of excitation. The glass samples have been prepared using conventional vitrification methods. The laser pulse irradiance on the surface of the glass samples placed in air at atmospheric pressure was about 1.7×109 W/cm2. The spatially integrated plasma emission was collected and imaged on to the spectrograph slit using an optical-fiber-based collection system. Homogeneity was checked by recording LIBS spectra from different sites on the sample surface and analyzing the elemental emission intensities for concentration determination. Validation of the observed LIBS results was done by comparison with scanning electron microscope- energy dispersive X-ray spectroscopy (SEM-EDX) surface elemental mapping. The analytical performance of the LIBS system has been evaluated through the correlation of the LIBS determined concentrations of Mn with its certified values. The results are found to be in very good agreement with the certified concentrations

  2. LIBSLog: Laser Induced Breakdown Spectroscopy (LIBS) based logging tool for exploration of boreholes

    Science.gov (United States)

    Zacny, K.; Chu, P.

    2012-12-01

    We present a novel downhole instrument, currently under development at Honeybee Robotics with SBIR funding from NASA. The device is designed to characterize elemental composition as a function of depth in terrestrial and non-terrestrial geological formations. The instrument consists of a miniaturized LIBS analyzer integrated in a 2" diameter drill string. While the drill provides subsurface access, the LIBS analyzer provides information on the elemental composition of the borehole wall. This instrument has a variety of space applications ranging from exploration of the Moon for which it was originally designed, to Mars and Europa. The system can also be deployed in a wireline configuration as a logging probe, called LIBSLog. The LIBSLog could be lowered into existing boreholes and scan the borehole wall with depth. Subsurface analysis is usually performed by sample acquisition through a drill or excavator, followed by sample preparation and subsequent sample presentation to an instrument or suite of instruments. An alternative approach consisting in bringing a miniaturized version of the instrument to the sample has many advantages over the traditional methodology, as it allows faster response, reduced probability of cross-contamination and a simplification in the sampling mechanisms. The results for lunar simulant NU-LHT-2M show a value for the concentration of iron ranging between 2.29% and 3.05% depending on the atomic line selected. The accepted value for the sample analyzed is 2.83%, showing the capability for the system in development to provide qualitative and semi-quantitative analysis in real-time.

  3. Qualitative analysis of Pb liquid sample using laser-induced breakdown spectroscopy (LIBS)

    International Nuclear Information System (INIS)

    Qualitative analysis of liquid sample containing 1,000 ppm of Pb was performed by using LIBS technique. In order to avoid splashing off of the liquid sample during laser irradiation, a sample pretreatment was done, namely the liquid sample was absorbed by using commercial available stomach medicine. Two kinds of absorbent materials were chosen in this experiment, first containing 125 mg activated carbon and second 600 mg activated attapulgite. These absorbent materials were used since carbon sample gives better absorption of infrared laser irradiation used in this experiment. In order to characterize the absorption process, three treatments were conducted in this experiment; first, without heating the sample but varying the absorption time before laser irradiation; second by varying the heating temperature after certain time of absorption process and third by varying the temperature only. The maximum emission intensity of Pb I 405.7 nm was found in the second treatment of heating the sample till 85°C after 30 minutes absorption of the liquid sample in both absorbent materials

  4. Effect of Sample Preparation on the Discrimination of Bacterial Isolates Cultured in Liquid Nutrient Media Using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Gamble, Gary R; Park, Bosoon; Yoon, Seung-Chul; Lawrence, Kurt C

    2016-03-01

    Laser-induced breakdown spectroscopy (LIBS) is used as the basis for discrimination between two genera of gram-negative bacteria and two genera of gram-positive bacteria representing pathogenic threats commonly found in poultry processing rinse waters. Because LIBS-based discrimination relies primarily upon the relative proportions of inorganic cell components including Na, K, Mg, and Ca, this study aims to determine the effects of trace mineral content and pH found in the water source used to isolate the bacteria upon the reliability of the resulting discriminant analysis. All four genera were cultured using tryptic soy agar (TSA) as the nutrient medium, and were grown under identical environmental conditions. The only variable introduced is the source water used to isolate the cultured bacteria. Cultures of each bacterium were produced using deionized (DI) water under two atmosphere conditions, reverse osmosis (RO) water, tap water, phosphate buffered saline (PBS) water, and TRIS buffered water. After 3 days of culture growth, the bacteria were centrifuged and washed three times in the same water source. Bacteria were then freeze dried, mixed with microcrystalline cellulose, and a pellet was made for LIBS analysis. Principal component analysis (PCA) was used to extract related variations in LIBS spectral data among the four bacteria genera and six water types used to isolate the bacteria, and Mahalanobis discriminant analysis (MDA) was used for classification. Results indicate not only that the four genera can be discriminated from each other in each water type, but that each genus can be discriminated by water type used for isolation. It is concluded that in order for LIBS to be a reliable and repeatable method for discrimination of bacteria grown in liquid nutrient media, care must be taken to insure that the water source used in purification of the culture be precisely controlled regarding pH, ionic strength, and proportionate amounts of mineral cations

  5. Comparison of Laser Induced Breakdown Spectroscopy (LIBS) on Martian Meteorite NWA 7034 to ChemCam Observations at Gale Crater, Mars

    Science.gov (United States)

    Gordon, S.; Newsom, H. E.; Agee, C. B.; Santos, A. R.; Clegg, S. M.; Wiens, R. C.; Lasue, J.; Sautter, V.

    2014-12-01

    The ChemCam instrument on board the Mars Science Laboratory (MSL) Curiosity rover uses laser-induced breakdown spectroscopy (LIBS) to analyze rock and soil targets on Mars from up to 7 m away. The Nd:KGW laser can shoot up to 1000 shots at one location and profile up to 1 mm depth into a rock. Identical LIBS instrumentation is located at Los Alamos National Laboratory and was used to analyze martian meteorite NWA 7034, a non-SNC basaltic breccia whose bulk composition matches the martian surface. Initial LIBS analysis of NWA 7034 included observations on two basaltic clasts in the meteorite. Electron microprobe analysis (EPMA) was performed on the two clasts for comparison with elemental compositions measured using LIBS. The two instruments give similar compositions of major oxides within the error of both techniques. EPMA analysis was also completed on three light-toned clasts and a dark-toned clast in the meteorite. The light-toned clasts have Al/Si vs. (Fe+Mg)/Si compositions ranging from felsic to mafic, and the dark-toned clast shows a mafic composition. A Sammon's map was created to compare LIBS data for NWA 7034 and ChemCam targets Stark, Crestaurum, Link, Portage, Jake_M, Mara, Thor_Lake, Coronation, Pearson, and Prebble. This nonlinear statistical mapping technique is used for clustering assessment of LIBS data in two dimensions. The map shows NWA 7034 clustering in its own location, and the closest similar ChemCam rock targets are La_Reine and Ashuamipi, which are both coarse grained targets that have a mafic component consistent with augite. The most similar ChemCam soil targets are the Crestaurum and Portage. Creation of maps with a greater number of targets will show more of the similarities between NWA 7034 and ChemCam target rocks and soils. Further analysis will compare NWA 7034 LIBS data, data from the paired meteorite NWA 7533, and a variety of ChemCam targets that are similar in morphology and texture.

  6. Secondary plasma formation after single pulse laser ablation underwater and its advantages for laser induced breakdown spectroscopy (LIBS).

    Science.gov (United States)

    Gavrilović, M R; Cvejić, M; Lazic, V; Jovićević, S

    2016-06-01

    In this work we present studies of spatial and temporal plasma evolution after single pulse ablation of an aluminium target in water. The laser ablation was performed using 20 ns long pulses emitted at 1064 nm. The plasma characterization was performed by fast photography, the Schlieren technique, shadowgraphy and optical emission spectroscopy. The experimental results indicate the existence of two distinct plasma stages: the first stage has a duration of approximately 500 ns from the laser pulse, and is followed by a new plasma growth starting from the crater center. The secondary plasma slowly evolves inside the growing vapor bubble, and its optical emission lasts over several tens of microseconds. Later, the hot glowing particles, trapped inside the vapor cavity, were detected during the whole cycle of the bubble, where the first collapse occurs after 475 μs from the laser pulse. Differences in the plasma properties during the two evolution phases are discussed, with an accent on the optical emission since its detection is of primary importance for LIBS. Here we demonstrate that the LIBS signal quality in single pulse excitation underwater can be greatly enhanced by detecting only the secondary plasma emission, and also by applying long acquisition gates (in the order of 10-100 μs). The presented results are of great importance for LIBS measurements inside a liquid environment, since they prove that a good analytical signal can be obtained by using nanosecond pulses from a single commercial laser source and by employing cost effective, not gated detectors. PMID:27180875

  7. Study and development of the laser induced breakdown spectroscopy (LIBS) for the realization of field measurements: application to analysis on-line of metals in liquids

    International Nuclear Information System (INIS)

    Metal contamination of water is a major public health issue. Controls and treatments are more drastic and performed on them for human consumption. It is essential for this to possess reliable and sensitive analytical tools adapted to the existing regulations and flexible enough to use. The technique of 'Laser Induced Breakdown Spectroscopy' (LIBS), proven for the analysis of solids, including exo-terrestrial explorations, this very interesting advantages for liquids including, for example, are multi-character elementary and the possibility of in-situ measurements of water contamination by metals. A first part of this study thesis allowed to explore the potential (LIBS) for the analysis of dissolved metals or suspensions in water. Study has found an important effect related to the particle size in the analysis of suspensions. A second prong is to look at the effects of organic matrix represented by humic acid and those natural minerals represented by the bentonite and alumina particles. The matrix effect observed was corrected by normalization by internal standard. (author)

  8. Qualitative analysis of black stone and its application for detecting Ag and Pb in liquid sample by laser-induced breakdown spectroscopy (LIBS)

    Science.gov (United States)

    Suyanto, Hery

    2016-03-01

    The aim of this research is to characterize black stone and also to know the capability to adsorb Ag and Pb elements in solution. All analysis in this research used laser-induced breakdown spectroscopy (commercial LIBS) method with laser energy of 120 mJ, accumulation 4, gate delay 1 µs and air surrounding gas at 1 atmosphere. Before soaked in 20 ml solution containing Ag and Pb of 40 ppm in 1 hour, the stone was analyzed by LIBS and it contains the main elements such as Ca, Mn, Si, K, Fe, Mg, Mo, H, O and Na until 16 laser shots. However, after immersed in solution, the stone contains impurities Ag and Pb elements with signal to noise ratio (SNR) of 9.5 and 1.2 respectively. Based on this data, the stone is predicted to be able to adsorb Ag element in solution till 12.7 ppm. The data also show that Ag element was adsorbed homogenously by stone till 16th laser shots, although it was washed with flowing demineralized water before it was analyzed.

  9. Recent advances in the use of laser-induced breakdown spectroscopy (LIBS) as a rapid point-of-care pathogen diagnostic

    Science.gov (United States)

    Rehse, Steven; Trojand, Daniel; Putnam, Russell; Gillies, Derek; Woodman, Ryan; Sheikh, Khadija; Daabous, Andrew

    2013-05-01

    There is a well-known and urgent need in the fields of medicine, environmental health and safety, food-processing, and defense/security to develop new 21st Century technologies for the rapid and sensitive identification of bacterial pathogens. In only the last five years, the use of a real-time elemental (atomic) analysis performed with laser-induced breakdown spectroscopy (LIBS) has made tremendous progress in becoming a viable technology for rapid bacterial pathogen detection and identification. In this talk we will show how this laser-based optical emission spectroscopic technique is able to sensitively assay the elemental composition of bacterial cells in situ. We will also present the latest achievements of our lab to fully develop LIBS-based bacterial sensing including simulation of a rapid urinary tract infection diagnosis and investigation of a variety of autonomous multivariate analysis algorithms. Lastly, we will show how this technology is now ready to be transitioned from the laboratory to field-portable and potentially man-portable instrumentation. The introduction of such a technology into popular use could very well transform the field of bacterial biosensing - a market valued at approximately 10 billion/year world-wide. Funding for this project was provided in part by a Natural Sciences and Engineering Research Council of Canada Discovery Grant.

  10. Compact High Sensitive Laser-Induced Breakdown Spectroscopy Instrument Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Laser induced breakdown spectroscopy (LIBS) is a versatile tool for in situ substance characterization. Existing LIBS instruments are not compact enough for space...

  11. Characterizing the economic value of an epithermal Au-Ag ore with Laser Induced Breakdown Spectroscopy (LIBS)

    NARCIS (Netherlands)

    Dalm, M.; Buxton, M.W.N.

    2016-01-01

    LIBS was applied to 19 Au-Ag ore samples to investigate if this technique can be used to distinguish between economic and sub-economic ore either by direct detection of these elements or by using other elements as indicators. However, the Au and Ag grades of the samples are below the detection limit

  12. Bulk measurement of copper and sodium content in CuIn(0.7)Ga(0.3)Se(2) (CIGS) solar cells with nanosecond pulse length laser induced breakdown spectroscopy (LIBS)

    CERN Document Server

    Kowalczyk, Jeremy M D; DeAngelis, Alexander; Kaneshiro, Jess; Mallory, Stewart A; Chang, Yuancheng; Gaillard, Nicolas

    2013-01-01

    In this work, we show that laser induced breakdown spectroscopy (LIBS) with a nanosecond pulse laser can be used to measure the copper and sodium content of CuIn(0.7)Ga(0.3)Se(2) (CIGS) thin film solar cells on molybdenum. This method has four significant advantages over methods currently being employed: the method is inexpensive, measurements can be taken in times on the order of one second, without high vacuum, and at distances up to 5 meters or more. The final two points allow for in-line monitoring of device fabrication in laboratory or industrial environments. Specifically, we report a linear relationship between the copper and sodium spectral lines from LIBS and the atomic fraction of copper and sodium measured via secondary ion mass spectroscopy (SIMS), discuss the ablation process of this material with a nanosecond pulse laser compared to shorter pulse duration lasers, and examine the depth resolution of nanosecond pulse LIBS.

  13. Alloying elemental change of SS-316 and Al-5754 during laser welding using real time laser induced breakdown spectroscopy (LIBS) accompanied by EDX and PIXE microanalysis

    Science.gov (United States)

    Jandaghi, M.; Parvin, P.; Torkamany, M. J.; Sabbaghzadeh, J.

    Experimental studies of pulsed laser welding of stainless steel 316 in keyhole mode was done to examine a vaporization model based on the kinetic theory of gases and the thermodynamic laws. A long pulsed Nd:YAG laser with variable duration of 1-12 ms and 9-17 Gw/cm2 was employed. The undesirable loss of volatile elements affects on the weld metal compositions and the alloy properties. The model predicts that the loss of alloying elements strongly takes place at higher peak powers and longer pulse durations. On the other hand, the model shows the rapid migration of Mn and Cr based on the pressure and concentration gradients from the molten pool. Accordingly, the concentrations of iron, chromium, nickel and manganese were determined in the weld pool by means of the energy dispersive x-ray analysis (EDX) and proton induced X ray characteristics (PIXE) microanalysis. The change of weld metal composition of aluminium alloy 5754 in keyhole mode laser welding, was investigated using the model and was supported by the successive measurements. The model predicts that the concentration of magnesium in the weld metal decreases, while the aluminium concentration increases. Moreover, the real time concentrations of aluminium and magnesium elements in the weld metal were determined by laser induced breakdown spectroscopy (LIBS) at different conditions. We conclude that variation of the Al to Mg concentration ratio is negligible with various laser power densities while it is strongly correlated to the pulse duration.

  14. Measuring H, O, li, B, and BE on Planetary Surfaces: Calibration of Laser-Induced Breakdown Spectroscopy (libs) Data Under Air, Vacuum, and CO2

    Science.gov (United States)

    Dyar, M. D.; Nelms, M.; Breves, E. A.

    2012-12-01

    Laser-induced breakdown spectrometer (LIBS), as implemented on the ChemCam instrument on Mars Science Lab and the proposed New Frontiers SAGE mission to Venus, can analyze elements from H to Pb from up to 7m standoff. This study examines the capabilities of LIBS to analyze H, O, B, Be, and Li under conditions simulating Earth, the Moon, and Mars. Of these, H is a major constituent of clay minerals and a key indicator of the presence of water. Its abundance in terrestrial materials ranges from 0 ppm up to 10's of wt.% H2O in hydrated sulfates and clays, with prominent emission lines occurring ca. 656.4 nm. O is an important indicator of atmospheric and magmatic coevolution, and has lines ca. 615.8, 656.2, 777.6, and 844.8 nm. Unfortunately there are very few geological samples from which O has been directly measured, but stoichiometry suggests that O varies from ca. 0 wt.% in sulfides to 21% in ferberite, 32% in ilmenite, 42% in amphiboles, 53% in quartz, 63% in melanterite, and 71% in epsomite. Li (lines at 413.3, 460.4, and 670.9 nm in vacuum), B (412.3 nm), and Be (313.1 nm) are highly mobile elements and key indicators of interaction with water. Local atmospheric composition and pressure significantly influence LIBS plasma intensity because the local atmosphere and the breakdown products from the atmospheric species interact with the ablated surface material in the plasma. Measurement of light elements with LIBS requires that spectra be acquired under conditions matching the remote environment. LIBS is critically dependent on the availability of well characterized, homogeneous reference materials that are closely matched in matrix (composition and structure) to the sample being studied. In modern geochemistry, analyses of most major, minor, and trace elements are routinely made. However, quantitative determination of light element concentrations in geological specimens still represents a major analytical challenge. Thus standards for which hydrogen, oxygen, and

  15. Direct spectral analysis of tea samples using 266 nm UV pulsed laser-induced breakdown spectroscopy and cross validation of LIBS results with ICP-MS.

    Science.gov (United States)

    Gondal, M A; Habibullah, Y B; Baig, Umair; Oloore, L E

    2016-05-15

    Tea is one of the most common and popular beverages spanning vast array of cultures all over the world. The main nutritional benefits of drinking tea are its anti-oxidant properties, presumed protection against certain cancers, inhibition of inflammation and possible protective effects against diabetes. Laser induced breakdown spectrometer (LIBS) was assembled as a powerful tool for qualitative and quantitative analysis of various brands of tea samples using 266 nm pulsed UV laser. LIBS spectra for six brands of tea samples in the wavelength range of 200-900 nm was recorded and all elements present in our tea samples were identified. The major toxic elements detected in several brands of tea samples were bromine, chromium and minerals like iron, calcium, potassium and silicon. The spectral assignment was conducted prior to the determination of concentration of each element. For quantitative analysis, calibration curves were drawn for each element using standard samples prepared in known concentration in the tea matrix. The plasma parameters (electron temperature and electron density) were also determined prior to the tea samples spectroscopic analysis. The concentration of iron, chromium, potassium, bromine, copper, silicon and calcium detected in all tea samples was between 378-656, 96-124, 1421-6785, 99-1476, 17-36, 2-11 and 92-130 mg L(-1) respectively. The limits of detection estimated for Fe, Cr, K, Br, Cu, Si, Ca in tea samples were 22, 12, 14, 11, 6, 1 and 12 mg L(-1) respectively. To further confirm the accuracy of our LIBS results, we determined the concentration of each element present in tea samples by using standard analytical technique like ICP-MS. The concentrations detected with our LIBS system are in excellent agreement with ICP-MS results. The system assembled for spectral analysis in this work could be highly applicable for testing the quality and purity of food and also pharmaceuticals products. PMID:26992530

  16. Cropland Field Monitoring: MMV Page 1 Montana Cropland Enrolled Farm Fields Carbon Sequestration Field Sampling, Measurement, Monitoring, and Verification: Application of Visible-Near Infrared Diffuse Reflectance Spectroscopy (VNIR) and Laser-induced Breakdown Spectroscopy (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Lee Spangler; Ross Bricklemyer; David Brown

    2012-03-15

    There is growing need for rapid, accurate, and inexpensive methods to measure, and verify soil organic carbon (SOC) change for national greenhouse gas accounting and the development of a soil carbon trading market. Laboratory based soil characterization typically requires significant soil processing, which is time and resource intensive. This severely limits application for large-region soil characterization. Thus, development of rapid and accurate methods for characterizing soils are needed to map soil properties for precision agriculture applications, improve regional and global soil carbon (C) stock and flux estimates and efficiently map sub-surface metal contamination, among others. The greatest gains for efficient soil characterization will come from collecting soil data in situ, thus minimizing soil sample transportation, processing, and lab-based measurement costs. Visible and near-infrared diffuse reflectance spectroscopy (VisNIR) and laser-induced breakdown spectroscopy (LIBS) are two complementary, yet fundamentally different spectroscopic techniques that have the potential to meet this need. These sensors have the potential to be mounted on a soil penetrometer and deployed for rapid soil profile characterization at field and landscape scales. Details of sensor interaction, efficient data management, and appropriate statistical analysis techniques for model calibrations are first needed. In situ or on-the-go VisNIR spectroscopy has been proposed as a rapid and inexpensive tool for intensively mapping soil texture and organic carbon (SOC). While lab-based VisNIR has been established as a viable technique for estimating various soil properties, few experiments have compared the predictive accuracy of on-the-go and lab-based VisNIR. Eight north central Montana wheat fields were intensively interrogated using on-the-go and lab-based VisNIR. Lab-based spectral data consistently provided more accurate predictions than on-the-go data. However, neither in situ

  17. Field deployment test of laser-induced breakdown spectroscopy (LIBS) technology at the Yucca Mountain Exploratory Studies Facility, Test Alcove No. 1, March 2-9, 1994: Milestone Report LA4047

    International Nuclear Information System (INIS)

    A field test in the Exploratory Studies Facility at Yucca Mountain, Nevada was performed to determine the feasibility of real-time elemental analysis of rock encountered in air core drilling using the technique of laser-induced breakdown spectroscopy (LIBS). Over the period March 2-9, 1994, hundreds of LIBS spectra were collected in real-time, reflecting the elemental composition of dust produced at the drill head of the second horizontal core hole in Test Alcove No. 1. The particle-laden, drill-coring effluent air stream served as the means to obtain a representative rock sample immediately surrounding the drill bit. LIBS spectra were taken with the spectral range centered at 250, 330, 410, and 500 nm so that representative, overlapping spectral coverage from 200 to 550 nm was obtained for the dust. Spectral lines for the major elements Si, Al, K, Na, and Fe and the minor elements Ca, Mg, Ti, and Mn were observed. Some simple engineering improvements to the cyclone separator were identified if this approach to dust analysis is pursued in the future

  18. Field deployment test of laser-induced breakdown spectroscopy (LIBS) technology at the Yucca Mountain Exploratory Studies Facility, Test Alcove No. 1, March 2-9, 1994: Milestone Report LA4047

    Energy Technology Data Exchange (ETDEWEB)

    Blacic, J.; Pettit, D.; Cremers, D.

    1996-01-01

    A field test in the Exploratory Studies Facility at Yucca Mountain, Nevada was performed to determine the feasibility of real-time elemental analysis of rock encountered in air core drilling using the technique of laser-induced breakdown spectroscopy (LIBS). Over the period March 2-9, 1994, hundreds of LIBS spectra were collected in real-time, reflecting the elemental composition of dust produced at the drill head of the second horizontal core hole in Test Alcove No. 1. The particle-laden, drill-coring effluent air stream served as the means to obtain a representative rock sample immediately surrounding the drill bit. LIBS spectra were taken with the spectral range centered at 250, 330, 410, and 500 nm so that representative, overlapping spectral coverage from 200 to 550 nm was obtained for the dust. Spectral lines for the major elements Si, Al, K, Na, and Fe and the minor elements Ca, Mg, Ti, and Mn were observed. Some simple engineering improvements to the cyclone separator were identified if this approach to dust analysis is pursued in the future.

  19. Infrared laser-induced breakdown spectroscopy emissions from energetic materials

    Science.gov (United States)

    Yang, Clayton S.; Brown, E.; Hommerich, Uwe; Trivedi, Sudhir B.; Samuels, Alan C.; Snyder, A. Peter

    2011-05-01

    Laser-induced breakdown spectroscopy (LIBS) has shown great promise for applications in chemical, biological, and explosives (CBE) sensing and has significant potential for real time standoff detection and analysis. We have studied LIBS emissions in the mid-infrared (MIR) spectral region for potential applications in CBE sensing. Detailed MIR-LIBS studies were performed for several energetic materials for the first time. In this study, the IR signature spectral region between 4 - 12 um was mined for the appearance of MIR-LIBS emissions that are directly indicative of oxygenated breakdown products as well as partially dissociated and recombination molecular species.

  20. Detection of rare earth elements in Powder River Basin sub-bituminous coal ash using laser-induced breakdown spectroscopy (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Phuoc [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United State; Mcintyre, Dustin [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United State

    2015-10-01

    We reported our preliminary results on the use of laser-induced breakdown spectroscopy to analyze the rare earth elements contained in ash samples from Powder River Basin sub-bituminous coal (PRB-coal). We have identified many elements in the lanthanide series (cerium, europium, holmium, lanthanum, lutetium, praseodymium, promethium, samarium, terbium, ytterbium) and some elements in the actinide series (actinium, thorium, uranium, plutonium, berkelium, californium) in the ash samples. In addition, various metals were also seen to present in the ash samples

  1. Europium migration in argilaceous rocks: On the use of micro Laser-Induced Breakdown Spectroscopy (micro LIBS) as a microanalysis tool

    International Nuclear Information System (INIS)

    Eu migration in a Callovo-Oxfordian argilite sample was studied using the micro LIBS technique. Quantitative elemental mapping were made by micro LIBS that showed the actual distribution of the various micro areas observed on the Callovo-Oxfordian sample's surface. Calcite, dolomite, alumino-silicates, quartz, pyrite and iron oxides were identified and their statistical distribution was determined. Experimental Eu profiles observed are consistent with diffusion process accompanied by heterogeneous sorption on alumino-silicate surface. (author)

  2. Medical Applications of Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Sedentary lifestyle of human beings has resulted in various diseases and in turn we require a potential tool that can be used to address various issues related to human health. Laser Induced Breakdown Spectroscopy (LIBS) is one such potential optical analytical tool that has become quite popular because of its distinctive features that include applicability to any type/phase of samples with almost no sample preparation. Several reports are available that discusses the capabilities of LIBS, suitable for various applications in different branches of science which cannot be addressed by traditional analytical methods but only few reports are available for the medical applications of LIBS. In the present work, LIBS has been implemented to understand the role of various elements in the formation of gallstones (formed under the empyema and mucocele state of gallbladder) samples along with patient history that were collected from Purvancal region of Uttar Pradesh, India. The occurrence statistics of gallstones under the present study reveal higher occurrence of gallstones in female patients. The gallstone occurrence was found more prevalent for those male patients who were having the habit of either tobacco chewing, smoking or drinking alcohols. This work further reports in-situ LIBS study of deciduous tooth and in-vivo LIBS study of human nail

  3. Medical Applications of Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Pathak, A. K.; Rai, N. K.; Singh, Ankita; Rai, A. K.; Rai, Pradeep K.; Rai, Pramod K.

    2014-11-01

    Sedentary lifestyle of human beings has resulted in various diseases and in turn we require a potential tool that can be used to address various issues related to human health. Laser Induced Breakdown Spectroscopy (LIBS) is one such potential optical analytical tool that has become quite popular because of its distinctive features that include applicability to any type/phase of samples with almost no sample preparation. Several reports are available that discusses the capabilities of LIBS, suitable for various applications in different branches of science which cannot be addressed by traditional analytical methods but only few reports are available for the medical applications of LIBS. In the present work, LIBS has been implemented to understand the role of various elements in the formation of gallstones (formed under the empyema and mucocele state of gallbladder) samples along with patient history that were collected from Purvancal region of Uttar Pradesh, India. The occurrence statistics of gallstones under the present study reveal higher occurrence of gallstones in female patients. The gallstone occurrence was found more prevalent for those male patients who were having the habit of either tobacco chewing, smoking or drinking alcohols. This work further reports in-situ LIBS study of deciduous tooth and in-vivo LIBS study of human nail.

  4. Laser-Induced Breakdown Spectroscopy to high-resolution analysis of ion distribution in cement-bound solid; Laser-induzierte Breakdown Spektroskopie (LIBS) zur hochaufloesenden Analyse der Ionenverteilung in zementgebundenen Feststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Molkenthin, Andre

    2009-06-03

    The Laser-Induced Breakdown Spectroscopy allows imaging and quantitative analysis of the ion distribution of all relevant elements on the surface of mineral building materials. The measuring system has been characterised by investigations on specimens of hardened cement paste, mortar and concrete. Transport and accumulation processes are visualised. Besides, results are introduced for the peripheral zone close to the surface and the extraction is shown. (orig.) [German] Die Laser-induzierte Breakdown Spektroskopie ermoeglicht eine bildgebende und quantitative Analyse der Ionenverteilung aller massgeblichen Elemente auf mineralischen Baustoffoberflaechen. Das Messsystem wurde durch verfahrenspezifische Untersuchungen an Proben aus Zementstein, -moerteln und Betonen charakterisiert, Transport- und Anlagerungsprozesse wurden visuell dargestellt. Zudem werden Ergebnisse fuer den Ionenhaushalt in der ungestoerten oberflaechenahen Randzone sowie bei deren Auslaugung bzw. Anreicherung vorgestellt.

  5. IMPLEMENTACIÓN DE TÉCNICAS ESPECTROQUÍMICAS EN LA INVESTIGACIÓN ZOOARQUEOLÓGICA. CUANTIFICACIÓN DE ESTRONCIO UTILIZANDO LASER INDUCED BREAKDOWN SPECTROSCOPY (LIBS/ Implementation of spectrochemical techniques in zooarchaeological research...

    Directory of Open Access Journals (Sweden)

    Gabriela Srur

    2012-11-01

    Full Text Available Los estudios químicos sobre restos zooarqueológicos se vienen desarrollando con mayor intensidad en las últimas décadas, especialmente aquellos dedicados a la identificación de huellas químicas o diversos tipos de isótopos y sus relaciones. El objetivo de este trabajo es el de presentar dos procedimientos utilizados para la caracterización química de huesos en base a datos espectrométricos obtenidos mediante la técnica LIBS (Laser Induced Breakdown Spectroscopy. El primero denominado Adición Estándar, consiste en un procedimiento destructivo, con un grado de error estimable, mientras que el segundo, Reemplazo de la Matriz Ósea, constituye un método no invasivo y con un grado de error relativamente bajo. Con esto se espera lograr el desarrollo de un corpus metodológico y analítico que permita caracterizar de un modo eficiente y económico las huellas químicas de diverso material arqueofaunístico. En este sentido se intenta lograr una caracterización química de huesos arqueológicos con el fin de dar respuesta a cuestiones relacionadas tanto a la alimentación como a la movilidad de los animales en el pasado. Abstract Chemical studies on zooarchaeological remains have been most extensively developed in recent decades, especially those focused on the identification of chemical fingerprints or types of isotopes and their relationships. This paper aims at showing two procedures used for chemical characterization of bones on the basis of spectrometric data obtained by LIBS technique (Laser Induced Breakdown Spectroscopy. One called Standard Addition, a destructive procedure, with a high error degree; the other called Bone Matrix Replacement, a noninvasive method with a relatively low error degree. We expect to gather a methodological and analytical corpus to characterize, efficiently and inexpensively, the chemical fingerprints of diverse archaeofaunal material. Hence, we intend to achieve chemical characterization of

  6. Elemental analysis of slurry samples with laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Direct analysis of wet slurry samples with laser induced breakdown spectroscopy (LIBS) is challenging due to problems of sedimentation, splashing, and surface turbulence. Also, water can quench the laser plasma and suppress the LIBS signal, resulting in poor sensitivity. The effect of water on LIBS spectra from slurries was investigated. As the water content decreased, the LIBS signal was enhanced and the standard deviation was reduced. To improve LIBS slurry analysis, dried slurry samples prepared by applying slurry on PVC coated slides were evaluated. Univariate and multivariate calibration was performed on the LIBS spectra of the dried slurry samples for elemental analysis of Mg, Si, and Fe. Calibration results show that the dried slurry samples give a good correlation between spectral intensity and elemental concentration.

  7. Laser induced breakdown spectroscopy stratigraphic characterization of multilayered painted surfaces

    Science.gov (United States)

    Staicu, A.; Apostol, I.; Pascu, A.; Iordache, I.; Damian, V.; Pascu, M. L.

    2012-08-01

    Laser spectroscopy techniques are modern and competitive methods for elemental analysis. Laser induced breakdown spectroscopy (LIBS), due to its advantages as minimally invasive method that provides real time monitoring and selectivity, is a suitable tool to analyze sample composition. Based on the known emission spectra of heavy metals such as Pb, Zn, Au, Ca, a stratigraphic study regarding the identification of the painting layers content of different mock-up samples was performed. LIBS was used to monitor the laser induced stepwise selective removal of the painting layers and to analyze their composition. The obtained LIBS spectra were correlated with profilometric measurements.

  8. Laser induced breakdown spectroscopy (LIBS) applied to stratigrafic elemental analysis and optical coherence tomography (OCT) to damage determination of cultural heritage Brazilian coins

    Science.gov (United States)

    M. Amaral, Marcello; Raele, Marcus P.; Z. de Freitas, Anderson; Zahn, Guilherme S.; Samad, Ricardo E.; D. Vieira, Nilson, Jr.; G. Tarelho, Luiz V.

    2009-07-01

    This work presents a compositional characterization of 1939's Thousand "Réis" and 1945's One "Cruzeiro" Brazilian coins, forged on aluminum bronze alloy. The coins were irradiated by a Q-switched Nd:YAG laser with 4 ns pulse width and energy of 25mJ emitting at 1064nm reaching 3.1010Wcm-2 (assured condition for stoichiometric ablation), forming a plasma in a small fraction of the coin. Plasma emission was collected by an optical fiber system connected to an Echelle spectrometer. The capability of LIBS to remove small fraction of material was exploited and the coins were analyzed ablating layer by layer from patina to the bulk. The experimental conditions to assure reproductivity were determined by evaluation of three plasma paramethers: ionization temperature using Saha-Boltzmann plot, excitation temperature using Boltzmann plot, plasma density using Saha-Boltzmann plot and Stark broadening. The Calibration-Free LIBS technique was applied to both coins and the analytical determination of elemental composition was employed. In order to confirm the Edict Law elemental composition the results were corroborated by Neutron Activation Analysis (NAA). In both cases the results determined by CF-LIBS agreed to with the Edict Law and NAA determination. Besides the major components for the bronze alloy some other impurities were observed. Finally, in order to determine the coin damage made by the laser, the OCT (Optical Coherence Tomography) technique was used. After tree pulses of laser 54μg of coin material were removed reaching 120μm in depth.

  9. Time-resolved laser-induced breakdown spectroscopy of aluminum

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-yun; ZHANG Wei-jun; WANG Zhen-ya; HAO Li-qing; HUANG Ming-qiang; ZHAO Wen-wu; LONG Bo; Zhao Wei

    2008-01-01

    We develop a system to measure the elemental composition of unprepared samples using laser-induced breakdown spectroscopy (LIBS) in our laboratory, which can be used for the determination of elements in solids, liquids and aerosols. A description of the instrumentation, including laser, sample chamber and detection, is followed by a brief discussion. The time-resolved LIBS of aluminum at atmospheric pressure is presented. At the end, the possibilities and later uses of this technique are briefly discussed.

  10. Laser induced breakdown spectroscopy stratigraphic characterization of multilayered painted surfaces

    International Nuclear Information System (INIS)

    Laser spectroscopy techniques are modern and competitive methods for elemental analysis. Laser induced breakdown spectroscopy (LIBS), due to its advantages as minimally invasive method that provides real time monitoring and selectivity, is a suitable tool to analyze sample composition. Based on the known emission spectra of heavy metals such as Pb, Zn, Au, Ca, a stratigraphic study regarding the identification of the painting layers content of different mock-up samples was performed. LIBS was used to monitor the laser induced stepwise selective removal of the painting layers and to analyze their composition. The obtained LIBS spectra were correlated with profilometric measurements. - Highlights: ► LIBS was used to analyze heavy metals in mock-up painting samples. ► LIBS data are correlated with profilometric and optical microscopy measurements. ► Appropriate analysis parameters are provided for some materials used in painting.

  11. Laser-induced breakdown spectroscopy expands into industrial applications

    International Nuclear Information System (INIS)

    This paper presents R and D activities in the field of laser-induced breakdown spectroscopy for industrial applications and shows novel LIBS systems running in routine operation for inline process control tasks. Starting with a comparison of the typical characteristics of LIBS with XRF and spark-discharge optical emission spectrometry, the principal structure of LIBS machines embedded for inline process monitoring will be presented. A systematic requirement analysis for LIBS systems following Ishikawa's scheme was worked out. Stability issues are studied for laser sources and Paschen-Runge spectrometers as key components for industrial LIBS systems. Examples of industrial applications range from handheld LIBS systems using a fiber laser source, via a set of LIBS machines for inline process control tasks, such as scrap analysis, coal analysis, liquid slag analysis and finally monitoring of drill dust. - Highlights: • New applications for LIBS realized within the last five years • Systematic requirement analysis for industrial LIBS systems • First long-term studies of key components • Demonstration of LIBS potential for inline chemical analysis

  12. Biomedical and environmental applications of laser-induced breakdown spectroscopy

    Indian Academy of Sciences (India)

    V K Unnikrishnan; K S Choudhari; Suresh D Kulkarni; Rajesh Nayak; V B Kartha; C Santhosh; B M Suri

    2014-02-01

    Laser-induced breakdown spectroscopy (LIBS) is an emerging analytical technique with numerous advantages such as rapidity, multi-elemental analysis, minimal sample preparation, minimal destruction, low cost and versatility of being applied to a wide range of materials. In this paper, we report the preliminary observations we obtained using LIBS for clinical and environmental samples. Elemental analysis has been done qualitatively in human teeth samples which show encouraging results. It has also been demonstrated in this paper that LIBS can be very well utilized in field applications such as plastic waste sorting and recycling.

  13. 基于原子和分子谱线分析的 LIBS 快速测量 CO2%Rapid Measurement of Carbon Dioxide with Laser-Induced Breakdown Spectroscopy Based on Atomic and Molecular Spectrum

    Institute of Scientific and Technical Information of China (English)

    徐嘉隆; 李越胜; 陆继东; 白凯杰; 卢伟业; 姚顺春

    2016-01-01

    s important to develop a rapid detection of CO2 for accurate control .There are amounts of methods to detect CO 2 at present ,including titration ,electrochemical method , gas chromatography ,infrared absorption spectroscopy and so on ,however ,t they still have the deficiency for online monitoring in industrial field .laser induced breakdown spectroscopy (LIBS) ,which is developing rapidly in recent few decades ,is a detec‐ting technology with characteristics of time‐saving and synchronous measuring of multicomponent .What’s more ,there is no need for sample pretreating .To develop the online monitoring technique of CO 2 emission in the industrial field ,LIBS was em‐ployed to measure CO2 in this study .The mass flow controller was used to adjust the flow of high purity CO 2 and N2 to obtain mixed gas with different CO2 concentrations .The mixed gas was firstly mixed in an air mixing chamber for thorough mixing and then sent to the sample cell for LIBS measurement .The evolution of C atomic spectral line and CN molecular band with different delay times were being studied ,which demonstrated parts of CO 2 react with air ambient to form CN molecular during the plasma generation ,the CN molecular band should be taken into consideration for quantitative analysis ,and the parameters were opti‐mized for synchronous measurement of C line and CN band :800 ns was the optimal delay time .During the plasma generation , many factors in the plasma may interact with others ,the analysis index had close relationship wih serval measuring parameters . With the consideration of the effect of C ,CN and the self‐absorption in high concentration ,multivariate calibration method was employed to establish calibration models of CO 2 .The results showed that the correlation coefficients R2 and the slope were 0.978 and 0.981 ,respectively .Compared with calibrated with single factor ,the multivariate method improved the reliability of the model .What’s more ,the feasibility of the

  14. Comparison of laser induced breakdown spectroscopy and spark induced breakdown spectroscopy for determination of mercury in soils

    International Nuclear Information System (INIS)

    Mercury is a toxic element found throughout the environment. Elevated concentrations of mercury in soils are quite hazardous to plants growing in these soils and also the runoff of soils to nearby water bodies contaminates the water, endangering the flora and fauna of that region. This makes continuous monitoring of mercury very essential. This work compares two potential spectroscopic methods (laser induced breakdown spectroscopy (LIBS) and spark induced breakdown spectroscopy (SIBS)) at their optimum experimental conditions for mercury monitoring. For LIBS, pellets were prepared from soil samples of known concentration for generating a calibration curve while for SIBS, soil samples of known concentration were used in the powder form. The limits of detection (LODs) of Hg in soil were calculated from the Hg calibration curves. The LOD for mercury in soil calculated using LIBS and SIBS is 483 ppm and 20 ppm, respectively. The detection range for LIBS and SIBS is discussed. - Highlights: • We compared SIBS and LIBS for mercury (Hg) measurements in soil. • Hg 546.07 nm line was selected for both LIBS and SIBS measurements. • Limit of detection for Hg was found to be 20 ppm with SIBS and 483 ppm with LIBS

  15. Laser-Induced Breakdown Spectroscopy and Chlorophyll a Flourescence Transients

    DEFF Research Database (Denmark)

    Frydenvang, Jens

    trustworthy results of a sufficient quality; something that remains a problem for many in-situ methods. In my PhD, I present my work with two such in-situ methods, Laser-Induced Breakdown Spectroscopy (LIBS) and OJIP transients, the rising part of chlorophyll a fluorescence transients from dark-adapted leaves....

  16. Double pulse laser-induced breakdown spectroscopy of explosives: Initial study towards improved discrimination

    Science.gov (United States)

    De Lucia, Frank C.; Gottfried, Jennifer L.; Munson, Chase A.; Miziolek, Andrzej W.

    2007-12-01

    Detecting trace explosive residues at standoff distances in real-time is a difficult problem. One method ideally suited for real-time standoff detection is laser-induced breakdown spectroscopy (LIBS). However, atmospheric oxygen and nitrogen contributes to the LIBS signal from the oxygen- and nitrogen-containing explosive compounds, complicating the discrimination of explosives from other organic materials. While bathing the sample in an inert gas will remove atmospheric oxygen and nitrogen interference, it cannot practically be applied for standoff LIBS. Alternatively, we have investigated the potential of double pulse LIBS to improve the discrimination of explosives by diminishing the contribution of atmospheric oxygen and nitrogen to the LIBS signal. These initial studies compare the close-contact (LIBS spectra of explosives using single pulse LIBS in argon with double pulse LIBS in atmosphere. We have demonstrated improved discrimination of an explosive and an organic interferent using double pulse LIBS to reduce the air entrained in the analytical plasma.

  17. Double pulse laser-induced breakdown spectroscopy of explosives: Initial study towards improved discrimination

    International Nuclear Information System (INIS)

    Detecting trace explosive residues at standoff distances in real-time is a difficult problem. One method ideally suited for real-time standoff detection is laser-induced breakdown spectroscopy (LIBS). However, atmospheric oxygen and nitrogen contributes to the LIBS signal from the oxygen- and nitrogen-containing explosive compounds, complicating the discrimination of explosives from other organic materials. While bathing the sample in an inert gas will remove atmospheric oxygen and nitrogen interference, it cannot practically be applied for standoff LIBS. Alternatively, we have investigated the potential of double pulse LIBS to improve the discrimination of explosives by diminishing the contribution of atmospheric oxygen and nitrogen to the LIBS signal. These initial studies compare the close-contact (< 1 m) LIBS spectra of explosives using single pulse LIBS in argon with double pulse LIBS in atmosphere. We have demonstrated improved discrimination of an explosive and an organic interferent using double pulse LIBS to reduce the air entrained in the analytical plasma

  18. Laser-induced breakdown spectroscopy theory and applications

    CERN Document Server

    Perini, Umberto

    2014-01-01

    This book deals with the Laser-Induced Breakdown Spectroscopy (LIBS), a widely used atomic emission spectroscopy technique for elemental analysis of materials. It is based on the use of a high-power, short pulse laser excitation. The book is divided into two main sections: the first one concerning theoretical aspects of the technique, the second one describing the state of the art in applications of the technique in different scientific/technological areas. Numerous examples of state of the art applications provide the readers an almost complete scenario of the LIBS technique. The LIBS theoretical aspects are reviewed. The book helps the readers who are less familiar with the technique to understand the basic principles. Numerous examples of state of the art applications give an almost complete scenario of the LIBS technique potentiality. These examples of applications may have a strong impact on future industrial utilization. The authors made important contributions to the development of this field.

  19. Development of the double-pulse technique to improve the analytical performance of Laser Induced Breakdown Spectroscopy (LIBS) on solids: Nuclear and geological applications

    International Nuclear Information System (INIS)

    The double-pulse technique has been developed to improve the analytical performance of Laser Ablation coupled to Optical Emission Spectroscopy (LA/OES). This approach relies on the addition of a second time-resolved laser pulse to the classical LA/OES system. It has been studied on aluminium alloys according to different geometries of the two laser beams (orthogonal and collinear geometries) before being applied to different materials (synthetic glass, rock, steel, sodium chloride). The increase in emission intensity depends on the temporal parameters, on the excitation energy level of the emission line, on the concentration of the studied element and on the analyzed matrix. The double-pulse LA/OES technique can be particularly interesting to improve the sensitivity towards vitreous matrices containing elements emitting lines with high excitation energy levels. (author)

  20. Characterization of Phyllosilicates by LIBS and Laser Raman Spectroscopy

    Science.gov (United States)

    Wang, A.; Sobron, P.

    2011-12-01

    NIR spectral signatures of phyllosilicates were recognized on Mars with wide distributions from orbit by OMEGA (on Mars Express orbiter) and CRISM (on Mars Reconnaissance Orbiter) observations. On the ground, geochemical and spectral features related to phyllosilicates were identified in rocks at two locations on Columbia Hill at Gusev crater using the data obtained by the Mars Exploration Rover (MER) Spirit. Furthermore, Opportunity rover is currently approaching the Cap of York at Endeavour crater on Meridiani Planum, where the signatures of phyllosilicates (and hydrous sulfates) were seen by CRISM. Laser-Induced Breakdown spectroscopy (LIBS) and Laser Raman spectroscopy will be used for the first time in rover missions in ChemCam on the NASA-MSL (Mars Science Laboratory) and in RLS on the ESA-ExoMars, respectively. As demonstrated by our previous studies, they are very powerful tools for characterizing the geochemistry and mineralogy aspects of the secondary minerals from aqueous alterations, especially hydrous sulfates. This study investigates the potential of LIBS and Raman spectroscopy for identifying and characterizing a variety of phyllosilicates, especially clays. Clay standards from the Clay Mineral Society were used. The LIBS measurements were made in a Planetary Environment and Analysis Chamber (PEACh) under Mars atmospheric pressure and composition, using 1064 nm as the excitation laser wavelength, same as ChemCam. The Raman measurements were made in ordinary laboratory environment using 532 nm as the excitation wavelength, same as RLS. The LIBS data were processed using custom automated software. We performed quantitative analysis of the spectra in order to evaluate the effectiveness of our method in: (a) discriminating between phyllosilicates and other silicates; (b) classifying different types of phyllosilicates (i.e., serpentine, chlorites, clays); and (c) correlating the LIBS-derived elemental abundances with the real chemical compositions of

  1. Micro spatial analysis of seashell surface using laser-induced breakdown spectroscopy and Raman spectroscopy

    Science.gov (United States)

    Lu, Yuan; Li, Yuandong; Li, Ying; Wang, Yangfan; Wang, Shi; Bao, Zhenmin; Zheng, Ronger

    2015-08-01

    The seashell has been studied as a proxy for the marine researches since it is the biomineralization product recording the growth development and the ocean ecosystem evolution. In this work a hybrid of Laser Induced Breakdown Spectroscopy (LIBS) and Raman spectroscopy was introduced to the composition analysis of seashell (scallop, bivalve, Zhikong). Without any sample treatment, the compositional distribution of the shell was obtained using LIBS for the element detection and Raman for the molecule recognition respectively. The elements Ca, K, Li, Mg, Mn and Sr were recognized by LIBS; the molecule carotene and carbonate were identified with Raman. It was found that the LIBS detection result was more related to the shell growth than the detection result of Raman. The obtained result suggested the shell growth might be developing in both horizontal and vertical directions. It was indicated that the LIBS-Raman combination could be an alternative way for the shell researches.

  2. Laser-induced breakdown spectroscopy fundamentals and applications

    CERN Document Server

    Noll, Reinhard

    2012-01-01

    This book is a comprehensive source of the fundamentals, process parameters, instrumental components and applications of laser-induced breakdown spectroscopy (LIBS). The effect of multiple pulses on material ablation, plasma dynamics and plasma emission is presented. A heuristic plasma modeling allows to simulate complex experimental plasma spectra. These methods and findings form the basis for a variety of applications to perform quantitative multi-element analysis with LIBS. These application potentials of LIBS have really boosted in the last years ranging from bulk analysis of metallic alloys and non-conducting materials, via spatially resolved analysis and depth profiling covering measuring objects in all physical states: gaseous, liquid and solid. Dedicated chapters present LIBS investigations for these tasks with special emphasis on the methodical and instrumental concepts as well as the optimization strategies for a quantitative analysis. Requirements, concepts, design and characteristic features of LI...

  3. Laser-induced breakdown spectroscopy based detection of lunar soil simulants for moon exploration

    Institute of Scientific and Technical Information of China (English)

    Rong Shu; Hongxing Qi; Gang Lü; Demin Ma; Zhiping He; Yongqi Xue

    2007-01-01

    A scientific goal of the moon exploration project is to perform elemental analysis on the moon surface.The assuming of using laser-induced breakdown spectroscopy (LIBS) for this goal has been put forward.The laser plasma used by LIBS is sensitive to the surrounding atmosphere and the moon has very low ambient gas pressure on the surface, so the study of the LIBS capabilities at the low pressure was carried out.

  4. Plasma temperature clamping in filamentation laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Harilal, Sivanandan S.; Yeak, J.; Phillips, Mark C.

    2015-10-19

    Ultrafast laser filament induced breakdown spectroscopy is a very promising method for remote material detection. We present characteristics of plasmas generated in a metal target by laser filaments in air. Our measurements show that the temperature of the ablation plasma is clamped along the filamentation channel due to intensity clamping in a filament. Nevertheless, significant changes in radiation intensity are noticeable, and this is essentially due to variation in the number density of emitting atoms. The present results also partly explains the reason for the occurrence of atomic plume during fs LIBS in air compared to long-pulse ns LIBS.

  5. Laser induced breakdown spectroscopy for the discrimination of Candida strains.

    Science.gov (United States)

    Manzoor, S; Ugena, L; Tornero-Lopéz, J; Martín, H; Molina, M; Camacho, J J; Cáceres, J O

    2016-08-01

    The present study reports the evaluation of Laser Induced Breakdown Spectroscopy (LIBS) and Neural Networks (NN) for the discrimination of different strains of various species of Candida. This genus of yeast was selected due to its medical relevance as it is commonly found in cases of fungal infection in humans. Twenty one strains belonging to seven species of Candida were included in the study. Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) was employed as a complementary technique to provide information about elemental composition of Candida cells. The use of LIBS spectra in combination with optimized NN models provided reliable discrimination among the distinct Candida strains with a high spectral correlation index for the samples analyzed, without any false positive or false negative. Therefore, this study indicates that LIBS-NN based methodology has the potential to be used as fast fungal identification or even diagnostic method. PMID:27216662

  6. [Joint Analyses of Na2SO4 Solution by Laser Induced Breakdown Spectroscopy and Raman Spectroscopy].

    Science.gov (United States)

    Guo, Jin-jia; Lu, Yuan; Liu, Chun-hao; Zheng, Rong-er

    2016-01-01

    Spectroscopic sensor is becoming an important issue for the deep-sea exploration due to the advantages of multi-specie, multi-phases and stand-off detection. Different approach have been developing in recent years based on LIBS (Laser Induced Breakdown Spectroscopy) and Raman spectroscopy since Raman-LIBS are complementary techniques with the similar components and the capability of molecular and elementary analysis. In this work, we built a LIBS-Raman system and detected Na2SO4 in aqueous solution to evaluate the potential ocean application. With the same laser, spectrometer and detector, a hybrid of Raman and LIBS system was developed to realize the detection of anions and cations in the seawater. The optics was composed by two parts. Raman channel and LIBS channel, and the signal was collected by a Y type optical fiber bundle. The signal from two channels was separated by imaging on different arrays of the CCD detector. The Raman spectra of SO4(2-) and LIBS spectra of Na was successfully detected simultaneously when the pulse energy was above 3.6 mJ. However, due to the strong bremsstrahlung radiation of LIBS, the signal to noise ratio of Raman was significantly decreased as the laser energy increasing. The results manifested the great potential of Raman-LIBS combination for the underwater detection. PMID:27228778

  7. Laser Induced Breakdown Sepctroscopy (LIBS) use in nuclear security and compliance

    International Nuclear Information System (INIS)

    Laser Induced Breakdown Spectroscopy (LIBS) uses optical emission spectroscopy of the induced plasma to identify elements. It is an analytical method that is growing in use by research groups and industry alike, because of its characteristics of requiring no sample preparation, small and rapid sample taking, real time results, in-situ and stand off analysis, and minimum operator training required. Because of these traits, the Canadian Safeguards Support Program (CSSP) recognized this technology could be used by lAEA inspectors and security staff in performing their duties. Laboratory results have shown the technology can identify nuclear indicators and signatures of nuclear clandestine activities, even will low intensity laser power. The findings, as well as the quick identification of yellowcake, U3O8, by using pattern recognition chemometric procedures arc reported within this paper. In addition, it will present the progression made in the development of a hand-held instrument for field operations by inspectors, nuclear security personnel and border crossing staff. (author)

  8. Analysis of organic vapors with laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor

  9. Analysis of organic vapors with laser induced breakdown spectroscopy

    Science.gov (United States)

    Nozari, Hadi; Rezaei, Fatemeh; Tavassoli, Seyed Hassan

    2015-09-01

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor.

  10. Analysis of organic vapors with laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nozari, Hadi; Tavassoli, Seyed Hassan [Laser and Plasma Research Institute, Shahid Beheshti University, G. C, 1983963113 Evin, Tehran (Iran, Islamic Republic of); Rezaei, Fatemeh, E-mail: fatemehrezaei@kntu.ac.ir [Department of Physics, K. N. Toosi University of Technology, 15875-4416 Shariati, Tehran (Iran, Islamic Republic of)

    2015-09-15

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor.

  11. Effect of atmosphere on collinear double-pulse laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Andrew J. Effenberger, Jr.; Jill R. Scott

    2010-09-01

    Double pulse laser induced breakdown spectroscopy (DP-LIBS) has been shown to enhance LIBS spectra. Several researches have reported significant increases in signal-to-noise and or spectral intensity [1-4]. In addition to DP-LIBS, atmospheric conditions can also increase spectra intensity. For example, Iida [5] found that He and Ar both increase LIBS intensity compared to air at one 1 atm. It was also found that as the pressure was decreased to 100 Torr, LIBS intensity increased in Ar and air for single pulse (SP) LIBS. In this study, a collinear DP-LIBS scheme is used along with manipulation of the atmospheric conditions. The DP-LIBS scheme consists of a 355 nm ablative pulse fired into a sample contained in a vacuum chamber. A second analytical 1064 nm pulse is then fired 100 ns to 10 µs after and along the same path of the first pulse. Ar, He and air at pressures ranging from atmospheric pressure (630 Torr at elevation) to 10-5 Torr are introduced during DP-LIBS and SP-LIBS experiments. For a brass sample, a significant increase in spectral intensity of Cu and Zn lines were observed in DP-LIBS under Ar compared to DP-LIBS in air (Figure 1). It was also found that Cu and Zn lines acquired with SP-LIBS in Ar are nearly as intense as DP-LIBS in air. Signal-to-noise for lines from various samples will be reported for both DP-LIBS and SP-LIBS in Ar, He, and air at pressures ranging from 630 Torr to 10-5 Torr.

  12. Mid-infrared Molecular Emission Studies from Energetic Materials using Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Brown, Ei; Hommerich, Uwe; Yang, Clayton; Trivedi, Sudhir; Samuels, Alan; Snyder, Peter

    2011-10-01

    Laser-induced breakdown spectroscopy (LIBS) is a powerful diagnostic tool for detection of trace elements by monitoring the atomic and ionic emission from laser-induced plasmas. The laser-induced plasma was produced by focusing a 30 mJ pulsed Nd:YAG laser (1064 nm) to dissociate, atomize, and ionize target molecules. In this work, LIBS emissions in the mid-infrared (MIR) region were studied for potential applications in chemical, biological, and explosives (CBE) sensing. We report on the observation of MIR emissions from energetic materials (e.g. ammonium compounds) due to laser-induced breakdown processes. All samples showed LIBS-triggered oxygenated breakdown products as well as partially dissociated and recombination molecular species. More detailed results of the performed MIR LIBS studies on the energetic materials will be discussed at the conference.

  13. Laser induced breakdown spectroscopy inside liquids: Processes and analytical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Lazic, V., E-mail: violeta.lazic@enea.it [ENEA (UTAPRAD-DIM), Via. E. Fermi 45, 00044 Frascati (RM) (Italy); Jovićević, S. [Institute of Physics, University of Belgrade, 11080 Belgrade (Serbia)

    2014-11-01

    This paper provides an overview of the laser induced breakdown spectroscopy (LIBS) inside liquids, applied for detection of the elements present in the media itself or in the submerged samples. The processes inherent to the laser induced plasma formation and evolution inside liquids are discussed, including shockwave generation, vapor cavitation, and ablation of solids. Types of the laser excitation considered here are single pulse, dual pulse and multi-pulse. The literature relative to the LIBS measurements and applications inside liquids is reviewed and the most relevant results are summarized. Finally, we discuss the analytical aspects and release some suggestions for improving the LIBS sensitivity and accuracy in liquid environment. - Highlights: • The paper reviews LIBS applications on bulk liquids and on submerged samples, using single, dual and multi pulse excitation. • The fundamentals about plasma in liquids are provided: beam transmission, breakdown, ablation, cavitation, and energy balance • Influence of the bubble’s optical properties on the plasma formation and detection after the second pulse is considered • The results obtained by various research groups and in different experimental conditions are reviewed and summarized • The analytical aspects are discussed, which include the experimental part, signal stability, data processing and calibration.

  14. Laser induced breakdown spectroscopy inside liquids: Processes and analytical aspects

    International Nuclear Information System (INIS)

    This paper provides an overview of the laser induced breakdown spectroscopy (LIBS) inside liquids, applied for detection of the elements present in the media itself or in the submerged samples. The processes inherent to the laser induced plasma formation and evolution inside liquids are discussed, including shockwave generation, vapor cavitation, and ablation of solids. Types of the laser excitation considered here are single pulse, dual pulse and multi-pulse. The literature relative to the LIBS measurements and applications inside liquids is reviewed and the most relevant results are summarized. Finally, we discuss the analytical aspects and release some suggestions for improving the LIBS sensitivity and accuracy in liquid environment. - Highlights: • The paper reviews LIBS applications on bulk liquids and on submerged samples, using single, dual and multi pulse excitation. • The fundamentals about plasma in liquids are provided: beam transmission, breakdown, ablation, cavitation, and energy balance • Influence of the bubble’s optical properties on the plasma formation and detection after the second pulse is considered • The results obtained by various research groups and in different experimental conditions are reviewed and summarized • The analytical aspects are discussed, which include the experimental part, signal stability, data processing and calibration

  15. Improvement of the sensitivity for the measurement of copper concentrations in soil by microwave-assisted laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    This study shows a 23-fold improvement of the sensitivity in the determination of copper in soil samples when using Microwave-Assisted Laser-Induced Breakdown Spectroscopy (MA-LIBS) compared with our conventional LIBS. This comparison between MA-LIBS and LIBS was performed with identical ablation conditions and detection geometry. The signal enhancement obtained with MA-LIBS allowed for the detection of spectral lines related to concentration values as low as 30 mg kg−1 for copper and 23.3 mg kg−1 for silver, which were not detected by LIBS. - Highlights: ► Application of Microwave-assisted LIBS for the analysis of soil samples. ► Quantitation of the sensitivity improvement by MA-LIBS over LIBS for copper in soil. ► Extension of the range of the calibration by MA-LIBS over LIBS for copper in soil.

  16. Multivariate analysis of laser-induced breakdown spectroscopy chemical signatures for geomaterial classification

    International Nuclear Information System (INIS)

    A large suite of natural carbonate, fluorite and silicate geological materials was studied using laser-induced breakdown spectroscopy (LIBS). Both single- and double-pulse LIBS spectra were acquired using close-contact benchtop and standoff (25 m) LIBS systems. Principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to identify the distinguishing characteristics of the geological samples and to classify the materials. Excellent discrimination was achieved with all sample types using PLS-DA and several techniques for improving sample classification were identified. The laboratory double-pulse LIBS system did not provide any advantage for sample classification over the single-pulse LIBS system, except in the case of the soil samples. The standoff LIBS system provided comparable results to the laboratory systems. This work also demonstrates how PCA can be used to identify spectral differences between similar sample types based on minor impurities.

  17. Elemental analysis of cotton by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schenk, Emily R.; Almirall, Jose R.

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) has been applied to the elemental characterization of unprocessed cotton. This research is important in forensic and fraud detection applications to establish an elemental fingerprint of U.S. cotton by region, which can be used to determine the source of the cotton. To the best of our knowledge, this is the first report of a LIBS method for the elemental analysis of cotton. The experimental setup consists of a Nd:YAG laser that operates at the fundamental wavelength as the LIBS excitation source and an echelle spectrometer equipped with an intensified CCD camera. The relative concentrations of elements Al, Ba, Ca, Cr, Cu, Fe, Mg, and Sr from both nutrients and environmental contributions were determined by LIBS. Principal component analysis was used to visualize the differences between cotton samples based on the elemental composition by region in the U.S. Linear discriminant analysis of the LIBS data resulted in the correct classification of >97% of the cotton samples by U.S. region and >81% correct classification by state of origin.

  18. Single shot depth sensitivity using femtosecond Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Depth profiling measurement using multiple pulse Laser Induced Breakdown Spectroscopy (LIBS) can be used to determine the characteristics of buried layers. However for femtosecond pulses the emission spectra does not necessarily reflect the average depth composition for the single shot case and instead has much higher sensitivity for the surface layer of the ablation region. We introduce a concept of “depth sensitivity” to characterize this behavior for single shot LIBS depth profiling. Experiments were carried out using 800 nm femtosecond laser pulses irradiating layered targets while monitoring the plasma emission with a spectrometer system. Laser induced plasma formed at the surface layer exhibits a strong LIBS signature while deeper ablated region contributes very little to the emission spectrum. The sensitive depth region, the source of the major part of the emission, is much less than the ablation crater depth and is shown to be of the order of 3 nm in the case of actual crater depths of 100's of nm. A two temperature model has been used to determine the lattice temperature profile versus depth which qualitatively predicts the observed behavior. - Highlights: • Depth dependence of LIBS emission within a single 800 nm femtosecond laser shot. • LIBS emission spectra dominated by only a thin surface layer. • Depth sensitivity, a new concept, is ∼3 nm when actual crater depth ∼100’s of nm. • Qualitative agreement with TTM model of lattice temperature versus depth and time

  19. Elemental analysis of cotton by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) has been applied to the elemental characterization of unprocessed cotton. This research is important in forensic and fraud detection applications to establish an elemental fingerprint of U.S. cotton by region, which can be used to determine the source of the cotton. To the best of our knowledge, this is the first report of a LIBS method for the elemental analysis of cotton. The experimental setup consists of a Nd:YAG laser that operates at the fundamental wavelength as the LIBS excitation source and an echelle spectrometer equipped with an intensified CCD camera. The relative concentrations of elements Al, Ba, Ca, Cr, Cu, Fe, Mg, and Sr from both nutrients and environmental contributions were determined by LIBS. Principal component analysis was used to visualize the differences between cotton samples based on the elemental composition by region in the U.S. Linear discriminant analysis of the LIBS data resulted in the correct classification of >97% of the cotton samples by U.S. region and >81% correct classification by state of origin.

  20. Lead determination in glasses by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Carmona, N. [Centro Nacional de Investigaciones Metalurgicas, CENIM-CSIC, Gregorio del Amo 8, 28040 Madrid (Spain)], E-mail: ncarmona@cenim.csic.es; Oujja, M.; Gaspard, S. [Instituto de Quimica Fisica Rocasolano, CSIC. Serrano 119, 28006 Madrid (Spain); Garcia-Heras, M. [Centro Nacional de Investigaciones Metalurgicas, CENIM-CSIC, Gregorio del Amo 8, 28040 Madrid (Spain); Instituto de Historia, CSIC. Serrano 13, 28001 Madrid (Spain); Villegas, M.A. [Centro Nacional de Investigaciones Metalurgicas, CENIM-CSIC, Gregorio del Amo 8, 28040 Madrid (Spain); Castillejo, M. [Instituto de Quimica Fisica Rocasolano, CSIC. Serrano 119, 28006 Madrid (Spain)], E-mail: marta.castillejo@iqfr.csic.es

    2007-02-15

    Laser-induced breakdown spectroscopy (LIBS) has been used to determine the lead content of different types of lead silicate glasses commercially designed as sonorous glass (which contain {approx} 10 wt.% PbO); crystal glass (with at least 24 wt.% PbO) and superior crystal glass (with at least 30 wt.% PbO). Seven different types of glass samples were selected, including historic-original, model and commercially available. The selected samples were artificially weathered under neutral, acid and alkaline attack. Analysis by LIBS was carried out in vacuum under excitation at 266 nm and results were compared with those obtained by conventional techniques used for glass characterization. Composition of the bulk glasses was analyzed by XRF (X-ray fluorescence) and the corroded surfaces were characterized by SEM/EDX (scanning electron microscopy/energy dispersive X-ray microanalysis). A linear correlation was obtained between the intensity of selected Pb lines in the LIB spectra and the PbO content. The effect of corrosion could be characterized by comparing successive LIB spectra recorded on the same area; acid attack resulted in a decrease of PbO, CaO and Na{sub 2}O content in the surface with respect to the bulk of the sample, while minor changes in the composition were noticed under alkaline attack. These results show LIBS as a useful technique to classify the different types of lead glasses by their lead content and to determine and asses the degree and type of corrosion.

  1. Microwave assisted laser-induced breakdown spectroscopy at ambient conditions

    Science.gov (United States)

    Viljanen, Jan; Sun, Zhiwei; Alwahabi, Zeyad T.

    2016-04-01

    Signal enhancements in laser-induced breakdown spectroscopy (LIBS) using external microwave power are demonstrated in ambient air. Pulsed microwave at 2.45 GHz and of 1 millisecond duration was delivered via a simple near field applicator (NFA), with which an external electric field is generated and coupled into laser induced plasma. The external microwave power can significantly increase the signal lifetime from a few microseconds to hundreds of microseconds, resulting in a great enhancement on LIBS signals with the use of a long integration time. The dependence of signal enhancement on laser energy and microwave power is experimentally assessed. With the assistance of microwave source, a significant enhancement of ~ 100 was achieved at relatively low laser energy that is only slightly above the ablation threshold. A limit of detection (LOD) of 8.1 ppm was estimated for copper detection in Cu/Al2O3 solid samples. This LOD corresponds to a 93-fold improvement compared with conventional single-pulse LIBS. Additionally, in the microwave assisted LIBS, the self-reversal effect was greatly reduced, which is beneficial in measuring elements of high concentration. Temporal measurements have been performed and the results revealed the evolution of the emission process in microwave-enhanced LIBS. The optimal position of the NFA related to the ablation point has also been investigated.

  2. Study of Bacterial Samples Using Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    W, A. Farooq; M, Atif; W, Tawfik; M, S. Alsalhi; Z, A. Alahmed; M, Sarfraz; J, P. Singh

    2014-12-01

    Laser-induced breakdown spectroscopy (LIBS) technique has been applied to investigate two different types of bacteria, Escherichia coli (B1) and Micrococcus luteus (B2) deposited on glass slides using Spectrolaser 7000. LIBS spectra were analyzed using spectrolaser software. LIBS spectrum of glass substrate was compared with bacteria spectra. Ca, Mg, Na, K, P, S, Cl, Fe, Al, Mn, Cu, C, H and CN-band appeared in bacterial samples in air. Two carbon lines at 193.02 nm, 247.88 nm and one hydrogen line at 656.28 nm with intensity ratios of 1.9, 1.83 and 1.53 appeared in bacterial samples B1 and B2 respectively. Carbon and hydrogen are the important components of the bio-samples like bacteria and other cancer cells. Investigation on LIBS spectra of the samples in He and Ar atmospheres is also presented. Ni lines appeared only in B2 sample in Ar atmosphere. From the present experimental results we are able to show that LIBS technique has a potential in the identification and discrimination of different types of bacteria.

  3. Mid-infrared emission from laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Yang, Clayton S-C; Brown, Ei E; Hommerich, Uwe H; Trivedi, Sudhir B; Samuels, Alan C; Snyder, A Peter

    2007-03-01

    Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique for detecting and identifying trace elemental contaminants by monitoring the visible atomic emission from small plasmas. However, mid-infrared (MIR), generally referring to the wavelength range between 2.5 to 25 microm, molecular vibrational and rotational emissions generated by a sample during a LIBS event has not been reported. The LIBS investigations reported in the literature largely involve spectral analysis in the ultraviolet-visible-near-infrared (UV-VIS-NIR) region (less than 1 microm) to probe elemental composition and profiles. Measurements were made to probe the MIR emission from a LIBS event between 3 and 5.75 microm. Oxidation of the sputtered carbon atoms and/or carbon-containing fragments from the sample and atmospheric oxygen produced CO(2) and CO vibrational emission features from 4.2 to 4.8 microm. The LIBS MIR emission has the potential to augment the conventional UV-VIS electronic emission information with that in the MIR region. PMID:17389073

  4. Nanoparticle detection in aqueous solutions using Raman and Laser Induced Breakdown Spectroscopy

    NARCIS (Netherlands)

    Sovago, M.; Buis, E.-J.; Sandtke, M.

    2013-01-01

    We show the chemical identification and quantification of the concentration and size of nanoparticle (NP) dispersions in aqueous solutions by using a combination of Raman Spectroscopy and Laser Induced Breakdown Spectroscopy (LIBS). The two spectroscopic techniques are applied to demonstrate the NP

  5. Identification of British one pound counterfeit coins using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Appleby, Andrew; Thevar, Thangavel

    2016-04-01

    The use of laser-induced breakdown spectroscopy (LIBS) as a low-cost, nondestructive method for detecting counterfeit coins was examined. A pulsed laser was used to evaporate a minute amount of coin surface, and the emanating plasma was interrogated with an entry-level spectrometer. The spectra produced showed evidence of lead content in six of the eight counterfeits examined. Thus, LIBS could offer a viable low-cost technique for identifying a significant number of fake coins.

  6. Laser-induced breakdown spectroscopy for real time and online elemental analysis

    OpenAIRE

    Rai, V. N.; Rai, Awadhesh K.; Yueh, Fang-Yu; Singh, J P

    2014-01-01

    Laser-induced breakdown spectroscopy (LIBS) is a laser based diagnostics used to study atomic emission from the expanding plasma plume formed during the laser-matter interaction. It provides valuable information about the composition of the target material. LIBS has proved its potential application in the analysis of impurities, pollutants and toxic elements in various types of matrices of different samples (solid, liquid and gases), even those present under difficult and harsh environmental ...

  7. Stoichiometric analysis of compositionally graded combinatorial amorphous thin film oxides using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) is a recently developed locally destructive elemental analysis technique that can be used to analyze solid, liquid, and gaseous samples. In the system explored here, a neodymium-doped yttrium aluminum garnet laser ablates a small amount of the sample and spectral emission from the plume is analyzed using a set of synchronized spectrometers. We explore the use of LIBS to map the stoichiometry of compositionally graded amorphous indium zinc oxide thin-film libraries. After optimization of the experimental parameters (distance between lens and samples, spot size on the samples, etc.), the LIBS system was calibrated against inductively coupled plasma atomic emission spectroscopy which resulted in a very consistent LIBS-based elemental analysis. Various parameters that need to be watched closely in order to produce consistent results are discussed. We also compare LIBS and x-ray fluorescence as techniques for the compositional mapping of libraries.

  8. Laser Induced Breakdown Spectroscopy, advances in resolution and portability

    International Nuclear Information System (INIS)

    Laser Induced Breakdown Spectroscopy (LIBS), can be considered as one of the most dynamic and promising technique in the field of analytical spectroscopy. LIBS has turned into a powerful alternative for a wide front of applications, from the geological exploration to the industrial inspection, including the environmental monitoring, the biomedical analysis, the study of patrimonial works, the safety and defense. The advances in LIBS instrumentation have allowed improving gradually the analysis services and quality, on the basis of a better knowledge of the technology principles. Recently, systems of double pulse have facilitated a better dosing of energy, the improvement of the signal-noise relation and the study of the different process stages. Femtosecond lasers offers the possibility of study in detail the ablation and atomic emission processes. New advances like multi-pulse or multi-wavelength systems -in fact stilling without exploring, must offer new information to advance in this knowledge. Finally, which it does to this technology really attractive, is the aptitude to be employed in field conditions, or for the detection of the elementary composition at long distances. In this presentation there are discussed the designs of portable instrumentation, compact and low cost, which can improve substantially the LIBS possibilities. (Author)

  9. Towards a two-dimensional laser induced breakdown spectroscopy mapping of liquefied petroleum gas and electrolytic oxy-hydrogen flames

    International Nuclear Information System (INIS)

    Two-dimensional mapping of the laser-induced breakdown spectroscopy (LIBS) signal of chemical species information in liquefied petroleum gas (LPG) and electrolytic oxy-hydrogen (EOH) flames was performed with in situ flame diagnostics. Base LIBS signals averaged from measurements at wavelengths of 320 nm to 350 nm describe the density information of a flame. The CN LIBS signal provides the concentration of fuel, while the H/O signal represents the fuel/air equivalence ratio. Here, we demonstrate the meaningful use of two-dimensional LIBS mappings to provide key combustion information, such as density, fuel concentration, and fuel/air equivalence ratio. - Highlights: • 2-dimensional mapping of chemical species information is achieved by LIBS in flames. • We consider LPG–EOH (electrolytic oxy-hydrogen) flame for its chemical analysis. • The optical emission spectroscopy (OES) is used for validation of the LIBS results. • LIBS signal provides additional chemical information not attainable via OES

  10. Multivariate classification of pigments and inks using combined Raman spectroscopy and LIBS.

    Science.gov (United States)

    Hoehse, Marek; Paul, Andrea; Gornushkin, Igor; Panne, Ulrich

    2012-02-01

    The authenticity of objects and artifacts is often the focus of forensic analytic chemistry. In document fraud cases, the most important objective is to determine the origin of a particular ink. Here, we introduce a new approach which utilizes the combination of two analytical methods, namely Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS). The methods provide complementary information on both molecular and elemental composition of samples. The potential of this hyphenation of spectroscopic methods is demonstrated for ten blue and black ink samples on white paper. LIBS and Raman spectra from different inks were fused into a single data matrix, and the number of different groups of inks was determined through multivariate analysis, i.e., principal component analysis, soft independent modelling of class analogy, partial least-squares discriminant analysis, and support vector machine. In all cases, the results obtained with the combined LIBS and Raman spectra were found to be superior to those obtained with the individual Raman or LIBS data sets. PMID:21845528

  11. Laser-induced breakdown spectroscopy determination of toxic metals in fresh fish.

    Science.gov (United States)

    Ponce, L V; Flores, T; Sosa-Saldaña, M; Alvira, F C; Bilmes, G M

    2016-01-10

    A method based on laser induced breakdown spectroscopy (LIBS) for monitoring lead and copper accumulation in edible fish, particularly "tilapia del Nilo" (Oreochromis niloticus) is presented. The capability of this analytical method is compared with results obtained by atomic absorption spectrometry. Detection limits by LIBS are 25 parts per million (ppm) for Pb and 100 ppm for Cu, values that are below the maximum permissible levels of some international standards. Application of LIBS detection allows the development of portable instruments for contamination control of edible fish. PMID:26835760

  12. Laser-induced breakdown spectroscopy analysis of energetic materials

    Science.gov (United States)

    de Lucia, Frank C.; Harmon, Russell S.; McNesby, Kevin L.; Winkel, Raymond J.; Miziolek, Andrzej W.

    2003-10-01

    A number of energetic materials and explosives have been studied by laser-induced breakdown spectroscopy (LIBS). They include black powder, neat explosives such as TNT, PETN, HMX, and RDX (in various forms), propellants such as M43 and JA2, and military explosives such as C4 and LX-14. Each of these materials gives a unique spectrum, and generally the spectra are reproducible shot to shot. We observed that the laser-produced microplasma did not initiate any of the energetic materials studied. Extensive studies of black powder and its ingredients by use of a reference spectral library have demonstrated excellent accuracy for unknown identification. Finally, we observed that these nitrogen- and oxygen-rich materials yield LIBS spectra in air that have correspondingly different O:N peak ratios compared with air. This difference can help in the detection and identification of such energetic materials.

  13. Independent component analysis classification of laser induced breakdown spectroscopy spectra

    Science.gov (United States)

    Forni, Olivier; Maurice, Sylvestre; Gasnault, Olivier; Wiens, Roger C.; Cousin, Agnès; Clegg, Samuel M.; Sirven, Jean-Baptiste; Lasue, Jérémie

    2013-08-01

    The ChemCam instrument on board Mars Science Laboratory (MSL) rover uses the laser-induced breakdown spectroscopy (LIBS) technique to remotely analyze Martian rocks. It retrieves spectra up to a distance of seven meters to quantify and to quantitatively analyze the sampled rocks. Like any field application, on-site measurements by LIBS are altered by diverse matrix effects which induce signal variations that are specific to the nature of the sample. Qualitative aspects remain to be studied, particularly LIBS sample identification to determine which samples are of interest for further analysis by ChemCam and other rover instruments. This can be performed with the help of different chemometric methods that model the spectra variance in order to identify a the rock from its spectrum. In this paper we test independent components analysis (ICA) rock classification by remote LIBS. We show that using measures of distance in ICA space, namely the Manhattan and the Mahalanobis distance, we can efficiently classify spectra of an unknown rock. The Mahalanobis distance gives overall better performances and is easier to manage than the Manhattan distance for which the determination of the cut-off distance is not easy. However these two techniques are complementary and their analytical performances will improve with time during MSL operations as the quantity of available Martian spectra will grow. The analysis accuracy and performances will benefit from a combination of the two approaches.

  14. Forensic comparative glass analysis by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Glass samples of four types commonly encountered in forensic examinations have been analyzed by laser-induced breakdown spectroscopy (LIBS) for the purpose of discriminating between samples originating from different sources. Some of the glass sets were also examined by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Refractive index (RI) measurements were also made on all glass samples and the refractive index data was combined with the LIBS and with the LA-ICP-MS data to enhance discrimination. The glass types examined included float glass taken from front and side automobile windows (examined on the non-float side), automobile headlamp glass, automobile side-mirror glass and brown beverage container glass. The largest overall discrimination was obtained by employing RI data in combination with LA-ICP-MS (98.8% discrimination of 666 pairwise comparisons at 95% confidence), while LIBS in combination with RI provided a somewhat lower discrimination (87.2% discrimination of 1122 pairwise comparisons at 95% confidence). Samples of side-mirror glass were less discriminated by LIBS due to a larger variance in emission intensities, while discrimination of side-mirror glass by LA-ICP-MS remained high

  15. Detection of explosives with laser-induced breakdown spectroscopy

    Science.gov (United States)

    Wang, Qian-Qian; Liu, Kai; Zhao, Hua; Ge, Cong-Hui; Huang, Zhi-Wen

    2012-12-01

    Our recent work on the detection of explosives by laser-induced breakdown spectroscopy (LIBS) is reviewed in this paper. We have studied the physical mechanism of laser-induced plasma of an organic explosive, TNT. The LIBS spectra of TNT under single-photon excitation are simulated using MATLAB. The variations of the atomic emission lines intensities of carbon, hydrogen, oxygen, and nitrogen versus the plasma temperature are simulated too. We also investigate the time-resolved LIBS spectra of a common inorganic explosive, black powder, in two kinds of surrounding atmospheres, air and argon, and find that the maximum value of the O atomic emission line SBR of black powder occurs at a gate delay of 596 ns. Another focus of our work is on using chemometic methods such as principle component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) to distinguish the organic explosives from organic materials such as plastics. A PLS-DA model for classification is built. TNT and seven types of plastics are chosen as samples to test the model. The experimental results demonstrate that LIBS coupled with the chemometric techniques has the capacity to discriminate organic explosive from plastics.

  16. Laser-induced breakdown spectroscopy: A versatile technique of elemental analysis and its applications

    CERN Document Server

    Rai, V N

    2014-01-01

    This paper reviews the state of art technology of laser induced breakdown spectroscopy (LIBS). Research on LIBS is gaining momentum in the field of instrumentation and data analysis technique due to its wide application in various field particularly in environmental monitoring and in industry. The main focus is on its miniaturization for field application and on increasing its sensitivity. The sensitivity of LIBS has been increased by confining the laser produced plasma using external magnetic field as well as using two successive laser pulse excitation of plasma. LIBS has capability for simultaneous multi element determination, localized microanalysis, surface analysis and has been used successfully for determination and identification of hazardous explosive and biological samples. Experimental findings of LIBS study in different applications have been discussed.

  17. Comparative study of laser-induced breakdown spectroscopy measurement using two slurry circulation systems

    International Nuclear Information System (INIS)

    The experimental conditions associated with slurry measurements to achieve good precision by using laser-induced breakdown spectroscopy (LIBS) are examined. LIBS analysis was applied to a special waste slurry sample that contains 85.4% water, 2.5% ferric oxide Fe2O3, 1.7% alumina Al2O3, and small quantities of oxides of boron and chromium. While liquids add challenge to LIBS measurements, the analysis was successfully performed on iron and aluminum. Two slurry circulation systems were devised to overcome the major technical problems associated with LIBS measurements of slurry samples, namely, sedimentation and change in the lens-to-sample distance during measurement. LIBS slurry measurements using both circulation systems are compared. The results show that the experimental configuration plays a crucial role for online slurry analysis

  18. Evaluation of femtosecond laser-induced breakdown spectroscopy for explosive residue detection.

    Science.gov (United States)

    De Lucia, Frank C; Gottfried, Jennifer L; Miziolek, Andrzej W

    2009-01-19

    Recently laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential technique for trace explosive detection. Typically LIBS is performed using nanosecond laser pulses. For this work, we have investigated the use of femtosecond laser pulses for explosive residue detection at two different fluences. Femtosecond laser pulses have previously been shown to provide several advantages for laser ablation and other LIBS applications. We have collected LIBS spectra of several bulk explosives and explosive residues at different pulse durations and energies. In contrast to previous femtosecond LIBS spectra of explosives, we have observed atomic emission peaks for the constituent elements of explosives - carbon, hydrogen, nitrogen, and oxygen. Preliminary results indicate that several advantages attributed to femtosecond pulses are not realized at higher laser fluences. PMID:19158854

  19. Analysis of allyl diglycol carbonate by laser induced-breakdown spectroscopy

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) has been used to identify the impurities in the allyl diglycol carbonate, which is used as a charged particle track recording material in solid-state nuclear track detectors. Impurities of magnesium, calcium, sodium and silicon are detected. Plasma parameters such as temperature and electron density are also calculated at optimized conditions in air and argon atmosphere using the silicon lines. The temperature of the LIBS plasma produced in argon atmosphere was higher than the temperature of the LIBS plasma produced in air. Variation in the emission intensity of the carbon I line (247.8561 nm) with respect to acquisition delay and laser power is also studied. It is found that the intensities of Ca and Na lines from LIBS spectra were enhanced 30–40 times in an argon atmosphere as compared to air. Hence LIBS in an argon atmosphere can be used for better identification of impurities in plastics. (paper)

  20. Application of Laser Induced Breakdown Spectroscopy under Polar Conditions

    Science.gov (United States)

    Clausen, J. L.; Hark, R.; Bol'shakov, A.; Plumer, J.

    2015-12-01

    Over the past decade our research team has evaluated the use of commercial-off-the-shelf laser-induced breakdown spectroscopy (LIBS) for chemical analysis of snow and ice samples under polar conditions. One avenue of research explored LIBS suitability as a detector of paleo-climate proxy indicators (Ca, K, Mg, and Na) in ice as it relates to atmospheric circulation. LIBS results revealed detection of peaks for C and N, consistent with the presence of organic material, as well as major ions (Ca, K, Mg, and Na) and trace metals (Al, Cu, Fe, Mn, Ti). The detection of Ca, K, Mg, and Na confirmed that LIBS has sufficient sensitivity to be used as a tool for characterization of paleo-climate proxy indicators in ice-core samples. Techniques were developed for direct analysis of ice as well as indirect measurements of ice via melting and filtering. Pitfalls and issues of direct ice analysis using several cooling techniques to maintain ice integrity will be discussed. In addition, a new technique, laser ablation molecular isotopic spectroscopy (LAMIS) was applied to detection of hydrogen and oxygen isotopes in ice as isotopic analysis of ice is the main tool in paleoclimatology and glaciology studies. Our results demonstrated that spectra of hydroxyl isotopologues 16OH, 18OH, and 16OD can be recorded with a compact spectrograph to determine hydrogen and oxygen isotopes simultaneously. Quantitative isotopic calibration for ice analysis can be accomplished using multivariate chemometric regression as previously realized for water vapor. Analysis with LIBS and LAMIS required no special sample preparation and was about ten times faster than analysis using ICP-MS. Combination of the two techniques in one portable instrument for in-field analysis appears possible and would eliminate the logistical and cost issues associated with ice core management.

  1. A review of the development of portable laser induced breakdown spectroscopy and its applications

    International Nuclear Information System (INIS)

    In this review, we present person-transportable laser induced breakdown spectroscopy (LIBS) devices that have previously been developed and reported in the literature as well as their applications. They are compared with X-ray fluorescent (XRF) devices, which represent their strongest competition. Although LIBS devices have advantages over XRF devices, such as sensitivity to the light elements, high spatial resolution and the possibility to distinguish between different layers of the sample, there are also disadvantages and both are discussed here. Furthermore, the essential portable LIBS instrumentation (laser, spectrograph and detector) is presented, and published results related to new laser sources (diode-pumped solid-state, microchip and fiber lasers) used in LIBS are overviewed. Compared to conventional compact flashlamp pumped solid-state lasers, the new laser sources provide higher repetition rates, higher efficiency (less power consumption) and higher beam quality, resulting in higher fluences, even for lower energies, and could potentially increase the figure of merit of portable LIBS instruments. Compact spectrometers used in portable LIBS devices and their parts (spectrograph, detector) are also discussed. - Highlights: • Overview of portable LIBS devices transportable by a person • Discussion and new trends about portable LIBS instrumentation: laser, spectrograph and detector • Overview of applications of DPSS, microchip and fiber lasers in LIBS

  2. A review of the development of portable laser induced breakdown spectroscopy and its applications

    Czech Academy of Sciences Publication Activity Database

    Rakovský, Jozef; Čermák, P.; Musset, O.; Veis, P.

    2014-01-01

    Roč. 101, NOV 2014 (2014), s. 269-287. ISSN 0584-8547 R&D Projects: GA ČR GA13-11635S Institutional support: RVO:61388955 Keywords : Fiber laser * Fieldable LIBS * Laser-induced breakdown spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.176, year: 2014

  3. Independent component analysis classification of laser induced breakdown spectroscopy spectra

    International Nuclear Information System (INIS)

    The ChemCam instrument on board Mars Science Laboratory (MSL) rover uses the laser-induced breakdown spectroscopy (LIBS) technique to remotely analyze Martian rocks. It retrieves spectra up to a distance of seven meters to quantify and to quantitatively analyze the sampled rocks. Like any field application, on-site measurements by LIBS are altered by diverse matrix effects which induce signal variations that are specific to the nature of the sample. Qualitative aspects remain to be studied, particularly LIBS sample identification to determine which samples are of interest for further analysis by ChemCam and other rover instruments. This can be performed with the help of different chemometric methods that model the spectra variance in order to identify a the rock from its spectrum. In this paper we test independent components analysis (ICA) rock classification by remote LIBS. We show that using measures of distance in ICA space, namely the Manhattan and the Mahalanobis distance, we can efficiently classify spectra of an unknown rock. The Mahalanobis distance gives overall better performances and is easier to manage than the Manhattan distance for which the determination of the cut-off distance is not easy. However these two techniques are complementary and their analytical performances will improve with time during MSL operations as the quantity of available Martian spectra will grow. The analysis accuracy and performances will benefit from a combination of the two approaches. - Highlights: • We use a novel independent component analysis method to classify LIBS spectra. • We demonstrate the usefulness of ICA. • We report the performances of the ICA classification. • We compare it to other classical classification schemes

  4. Detection of uranium using laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Chinni, Rosemarie C; Cremers, David A; Radziemski, Leon J; Bostian, Melissa; Navarro-Northrup, Claudia

    2009-11-01

    The goal of this work is a detailed study of uranium detection by laser-induced breakdown spectroscopy (LIBS) for application to activities associated with environmental surveillance and detecting weapons of mass destruction (WMD). The study was used to assist development of LIBS instruments for standoff detection of bulk radiological and nuclear materials and these materials distributed as contaminants on surfaces. Uranium spectra were analyzed under a variety of different conditions at room pressure, reduced pressures, and in an argon atmosphere. All spectra displayed a high apparent background due to the high density of uranium lines. Time decay curves of selected uranium lines were monitored and compared to other elements in an attempt to maximize detection capabilities for each species in the complicated uranium spectrum. A survey of the LIBS uranium spectra was conducted and relative emission line strengths were determined over the range of 260 to 800 nm. These spectra provide a guide for selection of the strongest LIBS analytical lines for uranium detection in different spectral regions. A detection limit for uranium in soil of 0.26% w/w was obtained at close range and 0.5% w/w was achieved at a distance of 30 m. Surface detection limits were substrate dependent and ranged from 13 to 150 microg/cm2. Double-pulse experiments (both collinear and orthogonal arrangements) were shown to enhance the uranium signal in some cases. Based on the results of this work, a short critique is given of the applicability of LIBS for the detection of uranium residues on surfaces for environmental monitoring and WMD surveillance. PMID:19891832

  5. Independent component analysis classification of laser induced breakdown spectroscopy spectra

    Energy Technology Data Exchange (ETDEWEB)

    Forni, Olivier, E-mail: olivier.forni@irap.omp.eu [Université de Toulouse, UPS-OMP, Institut de Recherche en Astrophysiqe et Planétologie, Toulouse (France); CNRS, IRAP, 9, av. Colonel Roche, BP 44346, F-31028 Cedex 4, Toulouse (France); Maurice, Sylvestre, E-mail: sylvestre.maurice@irap.omp.eu [Université de Toulouse, UPS-OMP, Institut de Recherche en Astrophysiqe et Planétologie, Toulouse (France); CNRS, IRAP, 9, av. Colonel Roche, BP 44346, F-31028 Cedex 4, Toulouse (France); Gasnault, Olivier, E-mail: olivier.gasnault@irap.omp.eu [Université de Toulouse, UPS-OMP, Institut de Recherche en Astrophysiqe et Planétologie, Toulouse (France); CNRS, IRAP, 9, av. Colonel Roche, BP 44346, F-31028 Cedex 4, Toulouse (France); Wiens, Roger C., E-mail: rwiens@lanl.gov [Space Remote Sensing, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Cousin, Agnès, E-mail: acousin@lanl.gov [Université de Toulouse, UPS-OMP, Institut de Recherche en Astrophysiqe et Planétologie, Toulouse (France); CNRS, IRAP, 9, av. Colonel Roche, BP 44346, F-31028 Cedex 4, Toulouse (France); Chemical Division, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Clegg, Samuel M., E-mail: sclegg@lanl.gov [Chemical Division, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Sirven, Jean-Baptiste, E-mail: jean-baptiste.sirven@cea.f [CEA Saclay, DEN/DPC/SCP, 91191 Cedex, Gif sur Yvette (France); Lasue, Jérémie, E-mail: jeremie.lasue@irap.omp.eu [Université de Toulouse, UPS-OMP, Institut de Recherche en Astrophysiqe et Planétologie, Toulouse (France); CNRS, IRAP, 9, av. Colonel Roche, BP 44346, F-31028 Cedex 4, Toulouse (France)

    2013-08-01

    The ChemCam instrument on board Mars Science Laboratory (MSL) rover uses the laser-induced breakdown spectroscopy (LIBS) technique to remotely analyze Martian rocks. It retrieves spectra up to a distance of seven meters to quantify and to quantitatively analyze the sampled rocks. Like any field application, on-site measurements by LIBS are altered by diverse matrix effects which induce signal variations that are specific to the nature of the sample. Qualitative aspects remain to be studied, particularly LIBS sample identification to determine which samples are of interest for further analysis by ChemCam and other rover instruments. This can be performed with the help of different chemometric methods that model the spectra variance in order to identify a the rock from its spectrum. In this paper we test independent components analysis (ICA) rock classification by remote LIBS. We show that using measures of distance in ICA space, namely the Manhattan and the Mahalanobis distance, we can efficiently classify spectra of an unknown rock. The Mahalanobis distance gives overall better performances and is easier to manage than the Manhattan distance for which the determination of the cut-off distance is not easy. However these two techniques are complementary and their analytical performances will improve with time during MSL operations as the quantity of available Martian spectra will grow. The analysis accuracy and performances will benefit from a combination of the two approaches. - Highlights: • We use a novel independent component analysis method to classify LIBS spectra. • We demonstrate the usefulness of ICA. • We report the performances of the ICA classification. • We compare it to other classical classification schemes.

  6. Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

    International Nuclear Information System (INIS)

    We report on the application of laser-induced breakdown spectroscopy (LIBS) to the determination of elements distinctive in terms of their biological significance (such as potassium, magnesium, calcium, and sodium) and to the monitoring of accumulation of potentially toxic heavy metal ions in living microorganisms (algae), in order to trace e.g. the influence of environmental exposure and other cultivation and biological factors having an impact on them. Algae cells were suspended in liquid media or presented in a form of adherent cell mass on a surface (biofilm) and, consequently, characterized using their spectra. In our feasibility study we used three different experimental arrangements employing double-pulse LIBS technique in order to improve on analytical selectivity and sensitivity for potential industrial biotechnology applications, e.g. for monitoring of mass production of commercial biofuels, utilization in the food industry and control of the removal of heavy metal ions from industrial waste waters. - Highlights: ► We realized laser-induced breakdown spectroscopy (LIBS) analysis of algal biomass. ► We used water jet setup, bulk liquid arrangement and algal biofilms. ► LIBS analysis of macro- and micro-element concentrations in algae was shown. ► LIBS can be of assistance in research of sustainable biofuel generation. ► LIBS can be used in research of algal food applications and bioremediation.

  7. Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Porizka, P.; Prochazka, D. [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, 616 00 Brno (Czech Republic); Pilat, Z. [Institute of Scientific Instruments of the ASCR v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, Brno 61669 (Czech Republic); Krajcarova, L. [Department of Chemistry, Faculty of Sciences, Masaryk University, Kotlarska 2, Brno 611 37 (Czech Republic); Kaiser, J., E-mail: kaiser@fme.vutbr.cz [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, 616 00 Brno (Czech Republic); Malina, R.; Novotny, J. [X-ray micro CT and nano CT research group, CEITEC-Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, 616 00 Brno (Czech Republic); Zemanek, P.; Jezek, J.; Sery, M.; Bernatova, S.; Krzyzanek, V.; Dobranska, K. [Institute of Scientific Instruments of the ASCR v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, Brno 61669 (Czech Republic); Novotny, K. [Department of Chemistry, Faculty of Sciences, Masaryk University, Kotlarska 2, Brno 611 37 (Czech Republic); Trtilek, M. [Photon Systems Instruments, Drasov 470, 664 24 Drasov (Czech Republic); Samek, O. [Institute of Scientific Instruments of the ASCR v.v.i., Academy of Sciences of the Czech Republic, Kralovopolska 147, Brno 61669 (Czech Republic)

    2012-08-15

    We report on the application of laser-induced breakdown spectroscopy (LIBS) to the determination of elements distinctive in terms of their biological significance (such as potassium, magnesium, calcium, and sodium) and to the monitoring of accumulation of potentially toxic heavy metal ions in living microorganisms (algae), in order to trace e.g. the influence of environmental exposure and other cultivation and biological factors having an impact on them. Algae cells were suspended in liquid media or presented in a form of adherent cell mass on a surface (biofilm) and, consequently, characterized using their spectra. In our feasibility study we used three different experimental arrangements employing double-pulse LIBS technique in order to improve on analytical selectivity and sensitivity for potential industrial biotechnology applications, e.g. for monitoring of mass production of commercial biofuels, utilization in the food industry and control of the removal of heavy metal ions from industrial waste waters. - Highlights: Black-Right-Pointing-Pointer We realized laser-induced breakdown spectroscopy (LIBS) analysis of algal biomass. Black-Right-Pointing-Pointer We used water jet setup, bulk liquid arrangement and algal biofilms. Black-Right-Pointing-Pointer LIBS analysis of macro- and micro-element concentrations in algae was shown. Black-Right-Pointing-Pointer LIBS can be of assistance in research of sustainable biofuel generation. Black-Right-Pointing-Pointer LIBS can be used in research of algal food applications and bioremediation.

  8. Geographical analysis of “conflict minerals” utilizing laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) offers a means of rapidly distinguishing different geographic sources for a mineral because the LIBS plasma emission spectrum provides information on the chemical composition (i.e. geochemical fingerprint) of a geomaterial. An application of this approach with potentially significant commercial and political importance is the spectral fingerprinting of “conflict minerals” such as columbite–tantalite (“coltan”). Following a successful pilot study of a columbite–tantalite suite from North America, a more geographically diverse set of 57 samples from 37 locations around the world was analyzed using a commercially available LIBS system. The LIBS spectra were analyzed using advanced multivariate statistical signal processing techniques. Partial least squares discriminant analysis (PLSDA) resulted in a correct place-level geographic classification at success rates above 90%. The possible role of rare-earth elements (REEs) as a factor contributing to the high levels of sample discrimination was explored. These results provide additional evidence that LIBS has the potential to be utilized in the field as a real-time screening tool to discriminate between columbite–tantalite ores of different provenance. - Highlights: ► Analysis of columbite–tantalite using laser-induced breakdown spectroscopy (LIBS) ► Chemometric analysis (PLSDA) affords 90–100% correct sample classification. ► Possible role of rare-earth elements in the high level of sample discrimination

  9. Comparing predictive ability of Laser-Induced Breakdown Spectroscopy to Near Infrared Spectroscopy for soil texture and organic carbon determination

    DEFF Research Database (Denmark)

    Knadel, Maria; Peng, Yi; Gislum, René; Greve, Mogens Humlekrog

    Soil organic carbon (SOC) and texture have a practical value for agronomy and the environment. Thus, alternative techniques to supplement or substitute for the expensive conventional analysis of soil are developed. Here the feasibility of laser-induced breakdown spectroscopy (LIBS) to determine SOC...... and texture was tested and compared with near infrared spectroscopy (NIRS) technique and traditional laboratory analysis. Calibration models were developed on 50 topsoil samples. For all properties except silt, higher predictive ability of LIBS than NIRS models was obtained. Successful calibrations...

  10. Spectroscopy of laser-produced plasmas: Setting up of high-performance laser-induced breakdown spectroscopy system

    Indian Academy of Sciences (India)

    V K Unnikrishnan; Kamlesh Alti; Rajesh Nayak; Rodney Bernard; V B Kartha; C Santhosh; G P Gupta; B M Suri

    2010-12-01

    It is a well-known fact that laser-induced breakdown spectroscopy (LIBS) has emerged as one of the best analytical techniques for multi-elemental compositional analysis of samples. We report assembling and optimization of LIBS set up using high resolution and broad-range echelle spectrograph coupled to an intensified charge coupled device (ICCD) to detect and quantify trace elements in environmental and clinical samples. Effects of variations of experimental parameters on spectroscopy signals of copper and brass are reported. Preliminary results of some plasma diagnostic calculations using recorded time-resolved optical emission signals are also reported for brass samples.

  11. Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages

    International Nuclear Information System (INIS)

    The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown in recent years its great potential for rapid qualitative analysis of materials. Thanks to the possibility to implement a portable instrument that perform LIBS analysis, this technique is revealed to be particularly useful for in situ analysis in the field of cultural heritages. The purpose of this work is to evaluate the potentiality of LIBS technique in the field of cultural heritages, with respect to the chemical characterization of complex matrix as calcareous and refractory materials for further quantitative analyses on cultural heritages. X-Ray Fluorescence (XRF) analyses were used as reference. Calibration curves of certified materials used as standards were obtained by XRF analyses. The LIBS measurements were performed with a new mobile instrument called Modi (Mobile Double pulse Instrument for LIBS Analysis). The XRF analyses were performed with a portable instrument ArtTAX. LIBS and XRF measurement were performed on both reference materials and samples (bricks and mortars) sampled in the ancient Greek-Roman Theatre of Taormina. Although LIBS measurements performed on reference materials have shown non linear response to concentrations, and so we were not able to obtain quantitative results, an integrated study of XRF and LIBS signals permitted us to distinguish among chemical features and degradation state of measured building materials.

  12. Preliminary Experiments to Develop a He-W Calibration Standard Using Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Shaw, Guinevere; Andre, Nicolas; Bannister, Mark; Biewer, Theodore; Martin, Madhavi; Meyer, Fred; Wirth, Brian

    2015-11-01

    To address the needs of future fusion reactors, laser based diagnostic techniques for plasma-material interactions (PMI) are being developed at ORNL. Laser-induced breakdown spectroscopy (LIBS) is a technique for measuring elemental surface composition, and is a possible diagnostic for characterizing elemental concentrations in plasma-facing materials. The purpose of the LIBS system described here is to quantify helium (He) concentration in exposed tungsten (W) targets. To accurately quantify He concentration in situ a calibration stranded must be developed, including extensive calibration of the entire LIBS system. To accomplish this, two LIBS setups were explored: ex-situ LIBS and in-situ LIBS. Ex-situ LIBS experiments used W targets exposed to a He + ion beam to determine laser parameters and calibration settings for in-situ experiments. Results will be discussed. In-situ LIBS analysis will be assessed for W targets exposed to He plasma. Preliminary results will be discussed. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy.

  13. Double pulse laser induced breakdown spectroscopy applied to natural and artificial materials from cultural heritages

    Energy Technology Data Exchange (ETDEWEB)

    Brai, Maria; Gennaro, Gaetano [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze Ed.18, 90128 Palermo (Italy); Schillaci, Tiziano, E-mail: tschillaci@unipa.i [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze Ed.18, 90128 Palermo (Italy); Tranchina, Luigi [Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze Ed.18, 90128 Palermo (Italy)

    2009-10-15

    The laser-induced breakdown spectroscopy (LIBS) is an applied physical technique that has shown in recent years its great potential for rapid qualitative analysis of materials. Thanks to the possibility to implement a portable instrument that perform LIBS analysis, this technique is revealed to be particularly useful for in situ analysis in the field of cultural heritages. The purpose of this work is to evaluate the potentiality of LIBS technique in the field of cultural heritages, with respect to the chemical characterization of complex matrix as calcareous and refractory materials for further quantitative analyses on cultural heritages. X-Ray Fluorescence (XRF) analyses were used as reference. Calibration curves of certified materials used as standards were obtained by XRF analyses. The LIBS measurements were performed with a new mobile instrument called Modi (Mobile Double pulse Instrument for LIBS Analysis). The XRF analyses were performed with a portable instrument ArtTAX. LIBS and XRF measurement were performed on both reference materials and samples (bricks and mortars) sampled in the ancient Greek-Roman Theatre of Taormina. Although LIBS measurements performed on reference materials have shown non linear response to concentrations, and so we were not able to obtain quantitative results, an integrated study of XRF and LIBS signals permitted us to distinguish among chemical features and degradation state of measured building materials.

  14. Laser-induced breakdown spectroscopy of tantalum plasma

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Sidra; Bashir, Shazia; Hayat, Asma; Khaleeq-ur-Rahman, M.; Faizan–ul-Haq [Centre for Advanced Studies in Physics, GC University, Lahore (Pakistan)

    2013-07-15

    Laser Induced Breakdown spectroscopy (LIBS) of Tantalum (Ta) plasma has been investigated. For this purpose Q-switched Nd: YAG laser pulses (λ∼ 1064 nm, τ∼ 10 ns) of maximum pulse energy of 100 mJ have been employed as an ablation source. Ta targets were exposed under the ambient environment of various gases of Ar, mixture (CO{sub 2}: N{sub 2}: He), O{sub 2}, N{sub 2}, and He under various filling pressure. The emission spectrum of Ta is observed by using LIBS spectrometer. The emission intensity, excitation temperature, and electron number density of Ta plasma have been evaluated as a function of pressure for various gases. Our experimental results reveal that the optical emission intensity, the electron temperature and density are strongly dependent upon the nature and pressure of ambient environment. The SEM analysis of the ablated Ta target has also been carried out to explore the effect of ambient environment on the laser induced grown structures. The growth of grain like structures in case of molecular gases and cone-formation in case of inert gases is observed. The evaluated plasma parameters by LIBS analysis such as electron temperature and the electron density are well correlated with the surface modification of laser irradiated Ta revealed by SEM analysis.

  15. Laser-induced breakdown spectroscopy of tantalum plasma

    International Nuclear Information System (INIS)

    Laser Induced Breakdown spectroscopy (LIBS) of Tantalum (Ta) plasma has been investigated. For this purpose Q-switched Nd: YAG laser pulses (λ∼ 1064 nm, τ∼ 10 ns) of maximum pulse energy of 100 mJ have been employed as an ablation source. Ta targets were exposed under the ambient environment of various gases of Ar, mixture (CO2: N2: He), O2, N2, and He under various filling pressure. The emission spectrum of Ta is observed by using LIBS spectrometer. The emission intensity, excitation temperature, and electron number density of Ta plasma have been evaluated as a function of pressure for various gases. Our experimental results reveal that the optical emission intensity, the electron temperature and density are strongly dependent upon the nature and pressure of ambient environment. The SEM analysis of the ablated Ta target has also been carried out to explore the effect of ambient environment on the laser induced grown structures. The growth of grain like structures in case of molecular gases and cone-formation in case of inert gases is observed. The evaluated plasma parameters by LIBS analysis such as electron temperature and the electron density are well correlated with the surface modification of laser irradiated Ta revealed by SEM analysis

  16. Laser Induced Breakdown Spectroscopy in archeometry: A review of its application and future perspectives

    International Nuclear Information System (INIS)

    Laser Induced Breakdown Spectroscopy (LIBS) in the last decades has been more and more applied to the field of Cultural Heritage with great results obtained either alone or in combination with complementary laser techniques. Its ability to analyze, with a minimal loss, different kinds of materials in laboratory, in situ and even in hostile environments has been highly appreciated. The main aim of this paper is to present a review of LIBS applications in the interdisciplinary field of archeometry. The LIBS technique is shortly described both from a theoretical and practical point of view, discussing the instrumental setup, also in comparison with typical features of laser induced fluorescence (LIF) and Raman spectroscopy apparata. The complementary with multivariate analysis, a method that can help in reducing data set dimensions and in pulling out effective information, is stressed. In particular the role of LIBS in Cultural Heritage material characterization, recognition of fakes and indirect dating is described, reporting general considerations and case studies on metal alloys, mural paintings, decorated ceramics, glasses, stones and gems. - Highlights: • Applications of LIBS to archeometry are reviewed. • Complementary among LIBS, LIF, Raman and multivariate analysis is highlighted. • Three major areas of successful LIBS application in archeometry are identified. • Significant results have been presented for several different materials

  17. Signal enhancement in collinear double-pulse laser-induced breakdown spectroscopy applied to different soils

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) is a well-known consolidated analytical technique employed successfully for the qualitative and quantitative analysis of solid, liquid, gaseous and aerosol samples of very different nature and origin. Several techniques, such as dual-pulse excitation setup, have been used in order to improve LIBS's sensitivity. The purpose of this paper was to optimize the key parameters as excitation wavelength, delay time and interpulse, that influence the double pulse (DP) LIBS technique in the collinear beam geometry when applied to the analysis at atmospheric air pressure of soil samples of different origin and texture from extreme regions of Brazil. Additionally, a comparative study between conventional single pulse (SP) LIBS and DP LIBS was performed. An optimization of DP LIBS system, choosing the correct delay time between the two pulses, was performed allowing its use for different soil types and the use of different emission lines. In general, the collinear DP LIBS system improved the analytical performances of the technique by enhancing the intensity of emission lines of some elements up to about 5 times, when compared with conventional SP-LIBS, and reduced the continuum emission. Further, the IR laser provided the best performance in re-heating the plasma. - Highlights: • The correct choice of the delay time between the two pulses is crucial for the DP system. • An optimization of DP LIBS system was performed allowing its use for different soil and the use of different emission lines. • The DP LIBS system improved the analytical performances of the technique up to about 5 times, when compared with SP LIBS. • The IR laser provided the best performance in re-heating the plasma

  18. Micro spatial analysis of seashell surface using laser-induced breakdown spectroscopy and Raman spectroscopy

    International Nuclear Information System (INIS)

    The seashell has been studied as a proxy for the marine researches since it is the biomineralization product recording the growth development and the ocean ecosystem evolution. In this work a hybrid of Laser Induced Breakdown Spectroscopy (LIBS) and Raman spectroscopy was introduced to the composition analysis of seashell (scallop, bivalve, Zhikong). Without any sample treatment, the compositional distribution of the shell was obtained using LIBS for the element detection and Raman for the molecule recognition respectively. The elements Ca, K, Li, Mg, Mn and Sr were recognized by LIBS; the molecule carotene and carbonate were identified with Raman. It was found that the LIBS detection result was more related to the shell growth than the detection result of Raman. The obtained result suggested the shell growth might be developing in both horizontal and vertical directions. It was indicated that the LIBS–Raman combination could be an alternative way for the shell researches. - Highlights: • A LIBS–Raman hybrid system was developed. • A seashell has been analyzed for the elementary and molecular distribution with a system. • The shell growth development was studied on the surface and in the depth

  19. Micro spatial analysis of seashell surface using laser-induced breakdown spectroscopy and Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yuan; Li, Yuandong; Li, Ying [Optics and Optoelectronics Lab, Ocean University of China, Qingdao 266100 (China); Wang, Yangfan; Wang, Shi; Bao, Zhenmin [Life Science College, Ocean University of China, Qingdao 266003 (China); Zheng, Ronger, E-mail: rzheng@ouc.edu.cn [Optics and Optoelectronics Lab, Ocean University of China, Qingdao 266100 (China)

    2015-08-01

    The seashell has been studied as a proxy for the marine researches since it is the biomineralization product recording the growth development and the ocean ecosystem evolution. In this work a hybrid of Laser Induced Breakdown Spectroscopy (LIBS) and Raman spectroscopy was introduced to the composition analysis of seashell (scallop, bivalve, Zhikong). Without any sample treatment, the compositional distribution of the shell was obtained using LIBS for the element detection and Raman for the molecule recognition respectively. The elements Ca, K, Li, Mg, Mn and Sr were recognized by LIBS; the molecule carotene and carbonate were identified with Raman. It was found that the LIBS detection result was more related to the shell growth than the detection result of Raman. The obtained result suggested the shell growth might be developing in both horizontal and vertical directions. It was indicated that the LIBS–Raman combination could be an alternative way for the shell researches. - Highlights: • A LIBS–Raman hybrid system was developed. • A seashell has been analyzed for the elementary and molecular distribution with a system. • The shell growth development was studied on the surface and in the depth.

  20. Laser-induced breakdown spectroscopy measurement in methane and biodiesel flames using an ungated detector

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) has been applied to measure the equivalence ratio of CH4/air flames using gated detection. In this work, we have developed an ungated, miniature LIBS-based sensor for studying CH4/air and biodiesel flames. We have used this sensor to characterize the biodiesel flame. LIBS spectra of biodiesel flames were recorded with different ethanol concentrations in the biodiesel and also at different axial locations within the flame. The sensor performance was evaluated with a CH4/air flame. LIBS signals of N, O, and H from a CH4/air flame were used to determine the equivalence ratio. A linear relationship between the intensity ratio of H and O lines and the calculated equivalence ratio were obtained with this sensor

  1. Laser-induced breakdown spectroscopy measurement in methane and biodiesel flames using an ungated detector.

    Science.gov (United States)

    Eseller, Kemal E; Yueh, Fang Y; Singh, Jagdish P

    2008-11-01

    Laser-induced breakdown spectroscopy (LIBS) has been applied to measure the equivalence ratio of CH(4)/air flames using gated detection. In this work, we have developed an ungated, miniature LIBS-based sensor for studying CH(4)/air and biodiesel flames. We have used this sensor to characterize the biodiesel flame. LIBS spectra of biodiesel flames were recorded with different ethanol concentrations in the biodiesel and also at different axial locations within the flame. The sensor performance was evaluated with a CH(4)/air flame. LIBS signals of N, O, and H from a CH(4)/air flame were used to determine the equivalence ratio. A linear relationship between the intensity ratio of H and O lines and the calculated equivalence ratio were obtained with this sensor. PMID:19122695

  2. Real-time fingerprinting of structural isomers using laser induced breakdown spectroscopy.

    Science.gov (United States)

    Myakalwar, Ashwin Kumar; Anubham, Siva Kumar; Paidi, Santosh Kumar; Barman, Ishan; Gundawar, Manoj Kumar

    2016-05-10

    Laser induced breakdown spectroscopy (LIBS) has surfaced as an attractive alternative to mass spectrometry and wet chemistry methods for chemical identification, driven by its real-time, label-free nature. Rapid analysis needs, especially in high-energy materials and pharmaceutical compounds, have further fueled an increasing number of refinements in LIBS. Yet, isomers are seldom identifiable by LIBS as they generate nearly identical spectra. Here we employ a suite of chemometric approaches to exploit the subtle, but reproducible, differences in LIBS spectra acquired from structural isomers, a set of pyrazoles, to develop a sensitive and reliable segmentation method. We also investigate the possible mechanistic principles (causation) behind such spectral variations and confirm their statistically significant nature that empowers the excellent classification performance. PMID:27090343

  3. A Hydrogel's Formation Device for Quick Analysis of Liquid Samples Using Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Guo, Guangmeng; Wang, Jie; Bian, Fang; Tian, Di; Fan, Qingwen

    2016-06-01

    The laser-induced breakdown spectroscopy technique has irreplaceable advantages in the field of detection due to its multi-phase specimen detection ability. The development of the LIBS technique for liquid analysis is obstructed by its inherent drawbacks like the surface ripples and extinction of emitted intensity, which make it unpractical. In this work, an in-situ hydrogel formation sampling device was designed and used the hydrogel as the detection phase of LIBS for Cu, Cr and Al in an aqueous solution. With the measured amount of resin placed in the device, the formed hydrogel could be obtained within 20 s after putting the device into water solution. The formed hydrogel could be directly analyzed by LIBS and reflect the elemental information of the water sample. The prominent performance made this hydrogel's formation device especially suitable for quick in-situ environmental liquid analysis using LIBS.

  4. Real-time control of ultrafast laser micromachining by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Ultrafast laser micromachining provides many advantages for precision micromachining. One challenging problem, however, particularly for multilayer and heterogeneous materials, is how to prevent a given material from being ablated, as ultrafast laser micromachining is generally material insensitive. We present a real-time feedback control system for an ultrafast laser micromachining system based on laser-induced breakdown spectroscopy (LIBS). The characteristics of ultrafast LIBS are reviewed and discussed so as to demonstrate the feasibility of the technique. Comparison methods to identify the material emission patterns are developed, and several of the resulting algorithms were implemented into a real-time computer control system. LIBS-controlled micromachining is demonstrated for the fabrication of microheater structures on thermal sprayed materials. Compared with a strictly passive machining process without any such feedback control, the LIBS-based system provides several advantages including less damage to the substrate layer, reduced machining time, and more-uniform machining features

  5. Real-time control of ultrafast laser micromachining by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Tong, Tao; Li, Jinggao; Longtin, Jon P

    2004-03-20

    Ultrafast laser micromachining provides many advantages for precision micromachining. One challenging problem, however, particularly for multilayer and heterogeneous materials, is how to prevent a given material from being ablated, as ultrafast laser micromachining is generally material insensitive. We present a real-time feedback control system for an ultrafast laser micromachining system based on laser-induced breakdown spectroscopy (LIBS). The characteristics of ultrafast LIBS are reviewed and discussed so as to demonstrate the feasibility of the technique. Comparison methods to identify the material emission patterns are developed, and several of the resulting algorithms were implemented into a real-time computer control system. LIBS-controlled micromachining is demonstrated for the fabrication of microheater structures on thermal sprayed materials. Compared with a strictly passive machining process without any such feedback control, the LIBS-based system provides several advantages including less damage to the substrate layer, reduced machining time, and more-uniform machining features. PMID:15065729

  6. Laser-induced breakdown spectroscopy as a diagnostic tool for thin films elemental composition

    International Nuclear Information System (INIS)

    The use of laser induced breakdown spectroscopy (LIBS) as a possible diagnostic tool for thin films elemental composition has been investigated. For this kind of application, LIBS can be advantageous with respect to other conventional techniques of analysis routinely used to determine thin films stoichiometry. LIBS was applied to ferromagnetic thin films of FeHfO in which the electric and magnetic properties are strictly correlated to the stoichiometry. The influence of the laser parameters on the ablation process of a thin film on a substrate has been investigated, together with a study of different substrates in order to identify the film-substrate coupling that would make the LIBS technique applicable also to films whose thickness is less than the laser ablation depth. Finally, the possibility of obtaining semi-quantitative data from the analysis of FeHfO thin films using the evaluated Fe/Hf atomic ratio was investigated

  7. Titanium monoxide spectroscopy following laser-induced optical breakdown

    International Nuclear Information System (INIS)

    This work investigates Titanium Monoxide (TiO) in ablation-plasma by employing laser-induced breakdown spectroscopy (LIBS) with 1 to 10 TW/cm2 irradiance, pulsed, 13 nanosecond, Q-switched Nd:YAG laser radiation at the fundamental wavelength of 1064 nm. The analysis of TiO is based on our first accurate determination of transition line strengths for selected TiO A-X, B-X, and E-X transitions, particularly TiO A-X γ and B-X γ′ bands. Electric dipole line strengths for the A3Φ-X3δ and B3Π-X3δ bands of TiO are computed. The molecular TiO spectra are observed subsequent to laser-induced breakdown (LIB). We discuss analysis of diatomic molecular spectra that may occur simultaneously with spectra originating from atomic species. Gated detection is applied to investigate the development in time of the emission spectra following LIB. Collected emission spectra allow one to infer micro-plasma parameters such as temperature and electron density. Insight into the state of the micro-plasma is gained by comparing measurements with predictions of atomic and molecular spectra. Nonlinear fitting of recorded and computed diatomic spectra provides the basis for molecular diagnostics, while atomic species may overlap and are simultaneously identified. Molecular diagnostic approaches similar to TiO have been performed for diatomic molecules such as AlO, C2, CN, CH, N2, NH, NO and OH.

  8. Analysis of slags using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Sanghapi, Hervé K.; Ayyalasomayajula, Krishna K.; Yueh, Fang Y.; Singh, Jagdish P.; McIntyre, Dustin L.; Jain, Jinesh C.; Nakano, Jinichiro

    2016-01-01

    The feasibility of laser-induced breakdown spectroscopy (LIBS) for the analysis of gasification slags was investigated by comparing LIBS results to the results of an ICP-OES analyzer. A small amount of slag sample was placed on a piece of double sided adhesive tape attached to a glass microscope slide and analyzed for Al, Ca, Fe, Si, and V which are major elements found in slags. The partial least squares regression (PLS-R) and univariate simple linear regression (SLR) calibration methods indicated that apart from V (accuracy up to + 20%) the accuracy of analysis varies within 0.35-6.5% for SLR and 0.06-10% for PLS-R. A paired-sample t-test within the 95% confidence level yielded p-values greater than 0.05, meaning no appreciable statistical difference was observed between the univariate SLR with internal standardization and the multivariate PLS-R for most of the analytes. From the results obtained in this work, LIBS response varies depending on the element and the technique used for quantitative analysis. Simultaneous use of the univariate calibration curves with internal standard (intensity ratio) and PLS regression in multi-elemental analysis can help reduce the matrix effect of slags associated to their high variation in concentration. Overall, these results demonstrate the capability of LIBS as an alternative technique for analyzing gasification slags. Estimated limits of detection for Al, Ca, Fe, Si and V were 0.167, 0.78, 0.171, 0.243 and 0.01 wt.%, respectively.

  9. Signal enhancement in femtosecond laser induced breakdown spectroscopy with a double-pulse configuration composed of two polarizers

    Science.gov (United States)

    Somekawa, Toshihiro; Otsuka, Masataka; Maeda, Yoshinobu; Fujita, Masayuki

    2016-05-01

    Femtosecond double-pulse laser induced breakdown spectroscopy (LIBS) has been performed with a double-pulse configuration composed of two polarizers. The effect of interpulse separation on the Cu I line at 510.55, 515.32, and 521.82 nm showed an optimum enhancement at 50–150 ps delays, which is more than 3–5 times greater compared with the single-pulse excitation case. This enhanced emission may open new possibilities for remote LIBS detection.

  10. Impurity detection in solid and molten silicon by laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Darwiche, Sarah, E-mail: sarah-darwiche@chimie-paristech.fr [Laboratoire de Genie des Procedes Plasmas et Traitement de Surfaces (LGPPTS)-EA3492, 11, rue Pierre et Marie Curie 75005 Paris (France); UPMC Universite Pierre et Marie Curie (France); Benrabbah, Rafik [Laboratoire de Genie des Procedes Plasmas et Traitement de Surfaces (LGPPTS)-EA3492, 11, rue Pierre et Marie Curie 75005 Paris (France); UPMC Universite Pierre et Marie Curie (France); Benmansour, Malek [CEA-DRT-LITEN-DTS-LMPS, Savoie Technolac, BP332 - 73377 Le Bourget Du Lac (France); Morvan, Daniel [Laboratoire de Genie des Procedes Plasmas et Traitement de Surfaces (LGPPTS)-EA3492, 11, rue Pierre et Marie Curie 75005 Paris (France); ENSCP, Chimie ParisTech (France)

    2012-08-15

    The application of Laser Induced Breakdown Spectroscopy (LIBS) for the analysis of both solid and molten silicon has been developed. This technique provides fast and reliable chemical characterization of silicon. This work will present the investigation of experimental parameters such as buffering gas nature and pressure in order to find the most suitable conditions to quantify boron in solid silicon. These results show that the signal to background ratio (SBR) is improved by both the use of helium and argon instead of air and by reducing the pressure to 500 mbar. Using calibrated samples, calibration curves were prepared for boron and limits of detection of the order of 0.2 ppm were obtained working at a distance of 50 cm from the sample. Additionally, the capabilities of LIBS to analyze molten silicon (1410 Degree-Sign C) was demonstrated, opening the way for LIBS to be used as a process analytical technique. - Highlights: Black-Right-Pointing-Pointer Laser Induced Breakdown spectroscopy (LIBS) used for chemical analysis of silicon. Black-Right-Pointing-Pointer Boron and aluminum measured in both solid and molten silicon. Black-Right-Pointing-Pointer Boron is a very important component for the performance of photovoltaic cells. Black-Right-Pointing-Pointer LIBS on molten silicon for process control of industrial silicon production.

  11. Impurity detection in solid and molten silicon by laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The application of Laser Induced Breakdown Spectroscopy (LIBS) for the analysis of both solid and molten silicon has been developed. This technique provides fast and reliable chemical characterization of silicon. This work will present the investigation of experimental parameters such as buffering gas nature and pressure in order to find the most suitable conditions to quantify boron in solid silicon. These results show that the signal to background ratio (SBR) is improved by both the use of helium and argon instead of air and by reducing the pressure to 500 mbar. Using calibrated samples, calibration curves were prepared for boron and limits of detection of the order of 0.2 ppm were obtained working at a distance of 50 cm from the sample. Additionally, the capabilities of LIBS to analyze molten silicon (1410 °C) was demonstrated, opening the way for LIBS to be used as a process analytical technique. - Highlights: ► Laser Induced Breakdown spectroscopy (LIBS) used for chemical analysis of silicon. ► Boron and aluminum measured in both solid and molten silicon. ► Boron is a very important component for the performance of photovoltaic cells. ► LIBS on molten silicon for process control of industrial silicon production.

  12. Movable fiber probe for gas-phase laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    A movable probe that fiber couples both the beam delivery and the signal collection functions of gas-phase laser-induced breakdown spectroscopy (LIBS) measurements was evaluated. The adjustable probe was used to investigate the effect of delivery fiber curvature on plasma characteristics and the associated effect on LIBS spectra and to further identify issues remaining to facilitate fully fiber-coupled gas-phase LIBS measurements. LIBS data were collected from lean methane-air mixtures of various equivalence ratios and spectroscopically analyzed to establish the ability to determine relative fuel-air ratio. Measurements with straight delivery fiber were compared to those with the fiber curved at specific radii. Decreasing fiber radius of curvature decreased fiber transmission efficiency and reduced the spark formation probability by almost a factor of 2. For constant fiber input energy, this decreased transmission increased the percentage of failed spark formations and influenced the LIBS elemental ratio calculations. However, minimal difference was found between LIBS measurements with straight or curved fiber as long as the output energy and a constant laser beam spot diameter were maintained on the exit beam focusing lens. A significant reduction in data scatter and improved linearity were achieved by using the Balmer series Hα and Hβ hydrogen emission line ratio as a data selection criterion. Observed linear variation of H/N elemental ratio with equivalence ratio confirmed the possibility of a flexible, light-contained, fully fiber-coupled probe for remote gas-phase LIBS analysis

  13. Application of Laser Induced Breakdown Spectroscopy to the identification of emeralds from different synthetic processes

    Science.gov (United States)

    Agrosì, G.; Tempesta, G.; Scandale, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Palleschi, V.; Mangone, A.; Lezzerini, M.

    2014-12-01

    Laser Induced Breakdown Spectroscopy can provide a useful contribution in mineralogical field in which the quantitative chemical analyses (including the evaluation of light elements) can play a key role in the studies on the origin of the emeralds. In particular, the chemical analyses permit to determine those trace elements, known as fingerprints, that can be useful to study their provenance. This technique, not requiring sample preparation results particularly suitable for gemstones, that obviously must be studied in a non-destructive way. In this paper, the LIBS technique was applied to distinguish synthetic emeralds grown by Biron hydrothermal method from those grown by Chatham flux method. The analyses performed by collinear double-pulse LIBS give a signal enhancement useful for the quantitative chemical analyses while guaranteeing a minimal sample damage. In this way it was obtained a considerable improvement on the detection limit of the trace elements, whose determination is essential for determining the origin of emerald gemstone. The trace elements V, Cr, and Fe and their relative amounts allowed the correct attribution of the manufacturer. Two different methods for quantitative analyses were used for this study: the standard Calibration-Free LIBS (CF-LIBS) method and its recent evolution, the One Point Calibration LIBS (OPC-LIBS). This is the first approach to the evaluation of the emerald origin by means of the LIBS technique.

  14. Laser-induced breakdown spectroscopy analysis of minerals: Carbonates and silicates

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) provides an alternative chemical analytical technique that obviates the issues of sample preparation and sample destruction common to most laboratory-based analytical methods. This contribution explores the capability of LIBS analysis to identify carbonate and silicate minerals rapidly and accurately. Fifty-two mineral samples (18 carbonates, 9 pyroxenes and pyroxenoids, 6 amphiboles, 8 phyllosilicates, and 11 feldspars) were analyzed by LIBS. Two composite broadband spectra (averages of 10 shots each) were calculated for each sample to produce two databases each containing the composite LIBS spectra for the same 52 mineral samples. By using correlation coefficients resulting from the regression of the intensities of pairs of LIBS spectra, all 52 minerals were correctly identified in the database. If the LIBS spectra of each sample were compared to a database containing the other 51 minerals, 65% were identified as a mineral of similar composition from the same mineral family. The remaining minerals were misidentified for two reasons: 1) the mineral had high concentrations of an element not present in the database; and 2) the mineral was identified as a mineral with similar elemental composition from a different family. For instance, the Ca-Mg carbonate dolomite was misidentified as the Ca-Mg silicate diopside. This pilot study suggests that LIBS has promise in mineral identification and in situ analysis of minerals that record geological processes

  15. An artificial neural network approach to laser-induced breakdown spectroscopy quantitative analysis

    International Nuclear Information System (INIS)

    The usual approach to laser-induced breakdown spectroscopy (LIBS) quantitative analysis is based on the use of calibration curves, suitably built using appropriate reference standards. More recently, statistical methods relying on the principles of artificial neural networks (ANN) are increasingly used. However, ANN analysis is often used as a ‘black box’ system and the peculiarities of the LIBS spectra are not exploited fully. An a priori exploration of the raw data contained in the LIBS spectra, carried out by a neural network to learn what are the significant areas of the spectrum to be used for a subsequent neural network delegated to the calibration, is able to throw light upon important information initially unknown, although already contained within the spectrum. This communication will demonstrate that an approach based on neural networks specially taylored for dealing with LIBS spectra would provide a viable, fast and robust method for LIBS quantitative analysis. This would allow the use of a relatively limited number of reference samples for the training of the network, with respect to the current approaches, and provide a fully automatizable approach for the analysis of a large number of samples. - Highlights: • A methodological approach to neural network analysis of LIBS spectra is proposed. • The architecture of the network and the number of inputs are optimized. • The method is tested on bronze samples already analyzed using a calibration-free LIBS approach. • The results are validated, compared and discussed

  16. Diagnostics of First Wall Materials in a Magnetically Confined Fusion Device by Polarization-Resolved Laser-Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical tool for real-time diagnostics and detection of multiple elements deposited at the first wall of magnetically confined plasma fusion devices. Recently, we have tested LIBS in our laboratory for application to in situ real-time diagnostics in the fusion device EAST. In this study, we applied polarization-resolved LIBS (PR-LIBS) to reduce the background continuum and enhance the resolution and sensitivity of LIBS. We used aluminium (Al) (as a substitute for Be) and the first wall materials tungsten (W) and molybdenum (Mo) to investigate polarized continuum emission and signal-to-background ratio (SBR). A Nd:YAG laser with first, second and third harmonics was used to produce plasma. The effects of the laser polarization plane, environmental pressure and polarizer detection angle were investigated. The spectra obtained without using a polarizer (i.e. LIBS) were compared with those obtained with a polarizer (PR-LIBS). Distribution of emission spectral intensity was observed to follow Malus' law with respect to variation in the angle of detection of the polarizer. The spectra obtained by PR-LIBS had a higher SBR and greater stability than those obtained by LIBS, thereby enhancing the reliability of LIBS for quantitative analyses. A comparison of Al, Mo and W showed that W exhibited a higher continuum with stronger polarization than the low-Z elements. (plasma technology)

  17. Application of Laser Induced Breakdown Spectroscopy to Electrochemical Process Monitoring of Molten Chloride Salts

    International Nuclear Information System (INIS)

    Techniques for in situ, near real-time analysis of molten salt chlorides used in electro- chemical fuel treatment processes face several challenges including atmospheric isolation, high radiation fields, corrosive environments and high temperatures. Therefore, techniques that can operate in a stand-off manner will have a definitive advantage for implementation in a fuel treatment facility. Laser induced breakdown spectroscopy (LIBS), an elemental analysis technique, is being pursued as a near real-time process monitor of various process streams. LIBS can operate at stand-off distances and has been used in other industries as a process monitoring technique. (author)

  18. Optical-fiber-based laser-induced breakdown spectroscopy for detection of early caries

    Science.gov (United States)

    Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

    2015-06-01

    A laser-induced breakdown spectroscopy (LIBS) system targeting for the in vivo analysis of tooth enamel is described. The system is planned to enable real-time analysis of teeth during laser dental treatment by utilizing a hollow optical fiber that transmits both Q-switched Nd:YAG laser light for LIBS and infrared Er:YAG laser light for tooth ablation. The sensitivity of caries detection was substantially improved by expanding the spectral region under analysis to ultraviolet (UV) light and by focusing on emission peaks of Zn in the UV region. Subsequently, early caries were distinguished from healthy teeth with accuracy rates above 80% in vitro.

  19. Laser-induced breakdown spectroscopy for real time and online elemental analysis

    CERN Document Server

    Rai, V N; Yueh, Fang-Yu; Singh, J P

    2014-01-01

    Laser-induced breakdown spectroscopy (LIBS) is a laser based diagnostics used to study atomic emission from the expanding plasma plume formed during the laser-matter interaction. It provides valuable information about the composition of the target material. LIBS has proved its potential application in the analysis of impurities, pollutants and toxic elements in various types of matrices of different samples (solid, liquid and gases), even those present under difficult and harsh environmental conditions. This article reviews some recent developments in the field, and its wide application in various fields of research and analysis.

  20. Double-pulse standoff laser-induced breakdown spectroscopy for versatile hazardous materials detection

    International Nuclear Information System (INIS)

    We have developed a double-pulse standoff laser-induced breakdown spectroscopy (ST-LIBS) system capable of detecting a variety of hazardous materials at tens of meters. The use of a double-pulse laser improves the sensitivity and selectivity of ST-LIBS, especially for the detection of energetic materials. In addition to various metallic and plastic materials, the system has been used to detect bulk explosives RDX and Composition-B, explosive residues, biological species such as the anthrax surrogate Bacillus subtilis, and chemical warfare simulants at 20 m. We have also demonstrated the discrimination of explosive residues from various interferents on an aluminum substrate

  1. Double-pulse standoff laser-induced breakdown spectroscopy for versatile hazardous materials detection

    Science.gov (United States)

    Gottfried, Jennifer L.; De Lucia, Frank C.; Munson, Chase A.; Miziolek, Andrzej W.

    2007-12-01

    We have developed a double-pulse standoff laser-induced breakdown spectroscopy (ST-LIBS) system capable of detecting a variety of hazardous materials at tens of meters. The use of a double-pulse laser improves the sensitivity and selectivity of ST-LIBS, especially for the detection of energetic materials. In addition to various metallic and plastic materials, the system has been used to detect bulk explosives RDX and Composition-B, explosive residues, biological species such as the anthrax surrogate Bacillus subtilis, and chemical warfare simulants at 20 m. We have also demonstrated the discrimination of explosive residues from various interferents on an aluminum substrate.

  2. Determination of As in Industrial Wastewater by Laser-Induced Breakdown Spectroscopy

    OpenAIRE

    Lin, Zhaoxiang; Chang, Liang; Li, Jie; Liu, Linmei

    2009-01-01

    The wastewater from industrial smelting process contains heavy metals such as arsenic(As)that produce serious environmental pollution and cause actual harm to the health of people. It is necessary to control the pollution at the source and achieve a real-time and online monitoring.The 1aser-induced breakdown spectroscopy(LIBS)iS a new elemental analysis technique,and has the advantage of rapid detection.An LIBs setup has been established.The Nd:YAG Iaser beam is focused onto the sample,then t...

  3. Laser-induced breakdown spectroscopy for the classification of unknown powders

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) was used to discern between two biological agent surrogates (Bacillus atrophaeus and ovalbumin) and potential interferent compounds (mold spores, humic acid, house dust, and Arizona road dust). Multiple linear regression and neural network analysis models were constructed by using B. atrophaeus and ovalbumin spectra, and limits of detection were calculated. Classification of the agent surrogates' LIBS spectra was attempted by using a neural network model. False negative rates of 0% were observed for B. atrophaeus (100 colony forming units) spore spectra with the neural network model used for classification

  4. Laser-induced breakdown spectroscopy at high temperatures in industrial boilers and furnaces

    Science.gov (United States)

    Blevins, Linda G.; Shaddix, Christopher R.; Sickafoose, Shane M.; Walsh, Peter M.

    2003-10-01

    Laser-induced breakdown spectroscopy (LIBS) was applied (1) near the superheater of an electric power generation boiler burning biomass, coal, or both; (2) at the exit of a glass-melting furnace burning natural gas and oxygen; and (3) near the nose arches of two paper mill recovery boilers burning black liquor. Difficulties associated with the high temperatures and high particle loadings in these environments were surmounted by use of novel LIBS probes. Echelle and linear spectrometers coupled to intensified CCD cameras were used individually and sometimes simultaneously. Elements detected include Na, K, Ca, Mg, C, B, Si, Mn, Al, Fe, Rb, Cl, and Ti.

  5. Correlation between laser-induced breakdown spectroscopy signal and moisture content

    Science.gov (United States)

    Liu, Yuan; Gigant, Lionel; Baudelet, Matthieu; Richardson, Martin

    2012-07-01

    The possibility of using Laser-Induced Breakdown Spectroscopy (LIBS) for measuring the moisture content of fresh food samples is studied. The normalized line emission of oxygen is highly correlated with the moisture content of the sample, cheese in our case, and can be used as a moisture marker in situations where oxygen interference from the matrix is not a critical issue. The linear correlation between the oxygen signal and the moisture content in the sample shows great potential for using LIBS as an alternative spectroscopic method for moisture monitoring.

  6. Elemental content of enamel and dentin after bleaching of teeth (a comparative study between laser-induced breakdown spectroscopy and x-ray photoelectron spectroscopy)

    International Nuclear Information System (INIS)

    The elemental content of the superficial and inner enamel as well as that of dentin was analyzed using laser-induced breakdown spectroscopy (LIBS) and x-ray photoelectron spectroscopy (XPS) of bleached and unbleached tooth specimens. It is thus clear from the spectral analysis using both the LIBS and XPS technique that elemental changes (though insignificant within the scopes of this study) of variable intensities do occur on the surface of the enamel and extend deeper to reach dentin. The results of the LIBS revealed a slight reduction in the calcium levels in the bleached compared to the control specimens in all the different bleaching groups and in both enamel and dentin. The good correlation found between the LIBS and XPS results demonstrates the possibility of LIBS technique for detection of minor loss in calcium and phosphorus in enamel and dentin.

  7. Elemental content of enamel and dentin after bleaching of teeth (a comparative study between laser-induced breakdown spectroscopy and x-ray photoelectron spectroscopy)

    Energy Technology Data Exchange (ETDEWEB)

    Imam, H. [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt); Ahmed, Doaa [Department of Restorative Sciences, Faculty of Dentistry, Alexandria University, Alexandria (Egypt); Eldakrouri, Ashraf [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt); Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh (Saudi Arabia)

    2013-06-21

    The elemental content of the superficial and inner enamel as well as that of dentin was analyzed using laser-induced breakdown spectroscopy (LIBS) and x-ray photoelectron spectroscopy (XPS) of bleached and unbleached tooth specimens. It is thus clear from the spectral analysis using both the LIBS and XPS technique that elemental changes (though insignificant within the scopes of this study) of variable intensities do occur on the surface of the enamel and extend deeper to reach dentin. The results of the LIBS revealed a slight reduction in the calcium levels in the bleached compared to the control specimens in all the different bleaching groups and in both enamel and dentin. The good correlation found between the LIBS and XPS results demonstrates the possibility of LIBS technique for detection of minor loss in calcium and phosphorus in enamel and dentin.

  8. Elemental content of enamel and dentin after bleaching of teeth (a comparative study between laser-induced breakdown spectroscopy and x-ray photoelectron spectroscopy)

    Science.gov (United States)

    Imam, H.; Ahmed, Doaa; Eldakrouri, Ashraf

    2013-06-01

    The elemental content of the superficial and inner enamel as well as that of dentin was analyzed using laser-induced breakdown spectroscopy (LIBS) and x-ray photoelectron spectroscopy (XPS) of bleached and unbleached tooth specimens. It is thus clear from the spectral analysis using both the LIBS and XPS technique that elemental changes (though insignificant within the scopes of this study) of variable intensities do occur on the surface of the enamel and extend deeper to reach dentin. The results of the LIBS revealed a slight reduction in the calcium levels in the bleached compared to the control specimens in all the different bleaching groups and in both enamel and dentin. The good correlation found between the LIBS and XPS results demonstrates the possibility of LIBS technique for detection of minor loss in calcium and phosphorus in enamel and dentin.

  9. Nanoparticle detection in aqueous solutions using Raman and Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    We show the chemical identification and quantification of the concentration and size of nanoparticle (NP) dispersions in aqueous solutions by using a combination of Raman Spectroscopy and Laser Induced Breakdown Spectroscopy (LIBS). The two spectroscopic techniques are applied to demonstrate the NP detection for off-line configuration. The implementation of the techniques for further in-line and on-line NP monitoring will allow for the optimization of the synthesis process, reduction of the failure rate and improvement of NP quality. We demonstrate the implementation of the Raman–LIBS technique on two metaloxide nanoparticles: titanium dioxide (TiO2) and a rare earth sesquioxide nanoparticle, holmium oxide (Ho2O3). The determination of the elemental (LIBS) and molecular (Raman) compositions, as well as the determination of the particle size down to 5 nm is demonstrated. The LIBS spectra of NP dispersions reveal the absorption of the continuum emission by the electrons present in the plasma via the inverse Bremsstrahlung effect. This effect manifests as the appearance of dips in the LIBS spectrum, rather than the conventional emission peaks. An interpretation of these spectra that incorporates this absorption effect is presented, enabling new opportunities for understanding the LIBS spectra of liquids

  10. Detection of early caries by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

    2015-07-01

    To improve sensitivity of dental caries detection by laser-induced breakdown spectroscopy (LIBS) analysis, it is proposed to utilize emission peaks in the ultraviolet. We newly focused on zinc whose emission peaks exist in ultraviolet because zinc exists at high concentration in the outer layer of enamel. It was shown that by using ratios between heights of an emission peak of Zn and that of Ca, the detection sensitivity and stability are largely improved. It was also shown that early caries are differentiated from healthy part by properly setting a threshold in the detected ratios. The proposed caries detection system can be applied to dental laser systems such as ones based on Er:YAG-lasers. When ablating early caries part by laser light, the system notices the dentist that the ablation of caries part is finished. We also show the intensity of emission peaks of zinc decreased with ablation with Er:YAG laser light.

  11. Note: A portable laser induced breakdown spectroscopy instrument for rapid sampling and analysis of silicon-containing aerosols

    Science.gov (United States)

    McLaughlin, R. P.; Mason, G. S.; Miller, A. L.; Stipe, C. B.; Kearns, J. D.; Prier, M. W.; Rarick, J. D.

    2016-05-01

    A portable instrument has been developed for measuring silicon-containing aerosols in near real-time using laser-induced breakdown spectroscopy (LIBS). The instrument uses a vacuum system to collect and deposit airborne particulate matter onto a translatable reel of filter tape. LIBS is used to analyze the deposited material, determining the amount of silicon-containing compounds present. In laboratory testing with pure silica (SiO2), the correlation between LIBS intensity for a characteristic silicon emission and the concentration of silica in a model aerosol was determined for a range of concentrations, demonstrating the instrument's plausibility for identifying hazardous levels of silicon-containing compounds.

  12. A highly-sensitive automatic transient laser-induced breakdown spectroscopy system with high temporal and spatial resolution

    Institute of Scientific and Technical Information of China (English)

    Liu Qiao-Jun; S.K.Fong; Andrew Y.S.Cheng; Luo Shi-Rong; K.S.Tam; Zhu Jian-Hua; A.Viseu

    2012-01-01

    A highly-sensitive automatic transient laser-induced breakdown spectroscopy (LIBS) system is designed and integrated.It successfully avoids the delay time selecting problem in the conventional LIBS system,and realizes the LIBS data acquisition with high spatiotemporal resolution automatically.Multiple transient spectra can be obtained in each measurement,which will provide more information for spectral research.The water-vapour and liquid-water Raman scattering spectra are captured by this system,and the comparison of experimental water-vapour Raman scattering spectrum with theoretical data verifies the reliability of the LIBS system.Based on this system,the air laser induced air breakdown spectra are captured and analysed.The system is also useful for the research on water-vapour Raman Lidar remote sensing.

  13. Laboratory feasibility study of fusion vessel inner wall chemical analysis by Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Graphical abstract: Laser-Induced-Breakdown-Spectroscopy was used for the determination of the atomic composition of multilayered samples simulating the tiles of plasma facing components in the next generation fusion machines. Highlights: ► Description and characterization of an LIBS set-up for diagnostics in fusion machines. ► Identification of atomic composition of multilayered tiles simulating plasma facing components. ► Qualitative applicability of the Calibration Free method for quantitative analysis. ► Feasibility of large scale application in the processes of control during the tiles fabrication. ► Feasibility of erosion monitoring during operation of fusion machines. - Abstract: Laser Induced Breakdown Spectroscopy (LIBS) is nowadays a well established tool for qualitative, semi-quantitative and quantitative analyses of surfaces, with micro-destructive characteristics and capabilities for stratigraphy. LIBS is an appealing technique compared with many other types of elemental analysis thanks to the set up versatility facilitating non-invasive and remote analyses, as well as suitability to diagnostics in harsh environments. In this work, LIBS capabilities were used for the determination of the atomic composition of multilayered samples simulating the tiles of plasma facing components in the next generation fusion machines such as ITER. A new experimental setup was designed and realized in order to optimize the characteristics of an LIBS system working at low pressure and remotely, as it should be for an in situ system to be applied in monitoring the erosion and redeposition phenomena occurring on the inner walls of a fusion device. The effects of time delay and laser fluence on LIBS sensitivity at reduced pressure were examined, looking for operational conditions suitable to analytical applications. The quantitative analysis of some atomic species in the superficial layer has been carried out using a Calibration Free (CF) approach in the time

  14. Optimal conditions for taking spectra of coffee beans plasma spectroscopy induced by laser (LIBS)

    International Nuclear Information System (INIS)

    Coffee beans, arabica and robusta, from Mexico (Chiapas and Veracruz), Colombia, Kenya and Sumatra were analyzed by Laser-induced breakdown spectroscopy (LIBS). The time delay and pulse energy were varied in order to find the optimal conditions for taking spectra in coffee beans; finding that the increased visibility of the peaks and the lowest electronic background is observed with 1 s and 450 mJ. Spectra were taken in different regions of grain area to confirm its homogeneous composition. It was found that the intensity of the signal Ca is much higher than that of K in African coffee, lower in the coffee of America, and much lower in the coffee from Asia. (Author)

  15. Quantitative analysis of oxide materials by laser-induced breakdown spectroscopy with argon as an internal standard

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) is demonstrated as a quantitative technique for geochemical analysis. This study demonstrates the applicability of LIBS to multielemental analysis of minerals using argon as an internal standard. Laser-induced breakdown spectroscopy has been applied to measure elements in oxide form. In the present study, the contents of several oxides, such as Fe2O3, CaO and MgO, in geological samples from the Tierga Mine (Zaragoza, Spain) were analyzed by LIBS. An argon environment was used to eliminate interference from air at atmospheric pressure. Furthermore, argon was used as an internal standard. The result was enhanced signal and enhanced linearity of the calibration curves. The Fe2O3, CaO and MgO concentrations determined by LIBS were compared with the results obtained using another analytical technique, inductively coupled plasma optical emission spectrometry (ICP-OES). The concentrations found using LIBS were in good agreement with the values obtained by ICP-OES. - Highlights: ► Multi-elemental quantitative analysis of oxide material using LIBS was developed. ► A buffer gas was used to minimize the matrix effect and as an internal standard. ► The LIBS results were compared with ICP, successfully

  16. A versatile interaction chamber for laser-based spectroscopic applications, with the emphasis on Laser-Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    The technical note describes the interaction chamber developed particularly for the laser spectroscopy technique applications, such as Laser-Induced Breakdown Spectroscopy (LIBS), Raman Spectroscopy and Laser-Induced Fluorescence. The chamber was designed in order to provide advanced possibilities for the research in mentioned fields and to facilitate routine research procedures. Parameters and the main benefits of the chamber are described, such as the built-in module for automatic 2D chemical mapping and the possibility to set different ambient gas conditions (pressure value and gas type). Together with the chamber description, selected LIBS application examples benefiting from chamber properties are described. - Highlights: • Development of the interaction chamber for LIBS applications • Example of automated chemical mapping of lead in a chalcopyrite sample • Example of LIBS measurement of fluorine in underpressure • Overview of chamber benefits

  17. Assessment of statistical uncertainty in the quantitative analysis of solid samples in motion using laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Cabalin, L.M.; Gonzalez, A. [Department of Analytical Chemistry, University of Malaga, E-29071 Malaga (Spain); Ruiz, J. [Department of Applied Physics I, University of Malaga, E-29071 Malaga (Spain); Laserna, J.J., E-mail: laserna@uma.e [Department of Analytical Chemistry, University of Malaga, E-29071 Malaga (Spain)

    2010-08-15

    Statistical uncertainty in the quantitative analysis of solid samples in motion by laser-induced breakdown spectroscopy (LIBS) has been assessed. For this purpose, a LIBS demonstrator was designed and constructed in our laboratory. The LIBS system consisted of a laboratory-scale conveyor belt, a compact optical module and a Nd:YAG laser operating at 532 nm. The speed of the conveyor belt was variable and could be adjusted up to a maximum speed of 2 m s{sup -1}. Statistical uncertainty in the analytical measurements was estimated in terms of precision (reproducibility and repeatability) and accuracy. The results obtained by LIBS on shredded scrap samples under real conditions have demonstrated that the analytical precision and accuracy of LIBS is dependent on the sample geometry, position on the conveyor belt and surface cleanliness. Flat, relatively clean scrap samples exhibited acceptable reproducibility and repeatability; by contrast, samples with an irregular shape or a dirty surface exhibited a poor relative standard deviation.

  18. Detection and Classification of Live and Dead Escherichia coli by Laser-Induced Breakdown Spectroscopy

    OpenAIRE

    P. Sivakumar; Fernández-Bravo, A.; Taleh, L.; J. F. Biddle; Melikechi, N.

    2015-01-01

    A common goal for astrobiology is to detect organic materials that may indicate the presence of life. However, organic materials alone may not be representative of currently living systems. Thus, it would be valuable to have a method with which to determine the health of living materials. Here, we present progress toward this goal by reporting on the application of laser-induced breakdown spectroscopy (LIBS) to study characteristics of live and dead cells using Escherichia coli (E. coli) stra...

  19. Analysis of geological samples by laser-induced breakdown spectroscopy at low atmospheric pressures

    OpenAIRE

    Pavlov, S.G.; Schröder, Susanne; Jessberger, E.K.; Hübers, H.-W.

    2011-01-01

    Several future space missions to planets, moons and asteroids in the solar system consider landers equip-ped with a laser-induced breakdown spectroscopy (LIBS) instrument. This technique provides an in-situ elemental analysis of all major and many trace elements on surfaces of the solar system bodies by identification of particular atomic transitions in emission spectra of laser-induced plasmas. Excitation and evolution of the plasma depends strongly on the environmental pressure. Therefore, ...

  20. Qualitative Analysis of Teeth and Evaluation of Amalgam Elements Penetration into Dental Matrix Using Laser Induced Breakdown Spectroscopy

    OpenAIRE

    Gazmeh, Meisam; Bahreini, Maryam; Tavassoli, Seyed Hassan; Asnaashari, Mohammad

    2015-01-01

    Introduction: In this study, laser induced breakdown spectroscopy (LIBS) is used for qualitative analysis of healthy and carious teeth. The technique of laser ablation is receiving increasing attention for applications in dentistry, specifically for the treatment of teeth such as drilling of micro-holes and plaque removal.

  1. Discriminating crude oil grades using laser-induced breakdown spectroscopy

    Science.gov (United States)

    El-Hussein, A.; Marzouk, A.; Harith, M. A.

    2015-11-01

    The analysis of crude oil using laser-based analytical techniques such as laser-induced breakdown spectroscopy (LIBS) has become of great interest to various specialists in different fields such as geology, petro-chemistry and environmental science. In this work, a detailed study is presented wherein the implementation of an efficient and simple LIBS technique to identify the elemental constituents of crude oil and to distinguish between different grades of petroleum crude oil is discussed. Laser-induced plasma (LIP) technique has been used in this work for direct measurements of atomic, ionic and molecular species in dry crude oil samples with API gravities ranging between 18 and 36. The technique was implemented using the first harmonic of a pulsed Nd-YAG laser source. Atomic and molecular emission bands were observed, consisting of characteristic spectral lines of atoms and diatomic molecular bands, namely from C, H, Si, Na, Ca, Mg, AL, Fe, Ti, Mo, C2 and CN. The intensities of high-resolution spectral lines for some atoms and molecules of elements such as Ca, Na, Fe, Mo, C2 and CN were evaluated at different wavelengths along the obtained spectra. The molecular bands and the elemental spectral lines were used to assess the possibility of adopting the LIBS technique in differentiating between crude oil samples with different American Petroleum Institute (API) gravity values. The results indicate the presence of a distinct correlation between the API gravity values of the various oil samples and the spectral line intensities of the elements and some molecular radical constituents. In addition, the possibility of identifying the API gravity values of unknown oil samples is also indicated.

  2. Laser-induced breakdown spectroscopy measurements of uranium and thorium powders and uranium ore

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze depleted uranium and thorium oxide powders and uranium ore as a potential rapid in situ analysis technique in nuclear production facilities, environmental sampling, and in-field forensic applications. Material such as pressed pellets and metals, has been extensively studied using LIBS due to the high density of the material and more stable laser-induced plasma formation. Powders, on the other hand, are difficult to analyze using LIBS since ejection and removal of the powder occur in the laser interaction region. The capability of analyzing powders is important in allowing for rapid analysis of suspicious materials, environmental samples, or trace contamination on surfaces since it most closely represents field samples (soil, small particles, debris etc.). The rapid, in situ analysis of samples, including nuclear materials, also reduces costs in sample collection, transportation, sample preparation, and analysis time. Here we demonstrate the detection of actinides in oxide powders and within a uranium ore sample as both pressed pellets and powders on carbon adhesive discs for spectral comparison. The acquired LIBS spectra for both forms of the samples differ in overall intensity but yield a similar distribution of atomic emission spectral lines. - Highlights: • LIBS analysis of mixed actinide samples: depleted uranium oxide and thorium oxide • LIBS analysis of actinide samples in powder form on carbon adhesive discs • Detection of uranium in a complex matrix (uranium ore) as a precursor to analyzing uranium in environmental samples

  3. Artificial neural network for on-site quantitative analysis of soils using laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Nowadays, due to environmental concerns, fast on-site quantitative analyses of soils are required. Laser induced breakdown spectroscopy is a serious candidate to address this challenge and is especially well suited for multi-elemental analysis of heavy metals. However, saturation and matrix effects prevent from a simple treatment of the LIBS data, namely through a regular calibration curve. This paper details the limits of this approach and consequently emphasizes the advantage of using artificial neural networks well suited for non-linear and multi-variate calibration. This advanced method of data analysis is evaluated in the case of real soil samples and on-site LIBS measurements. The selection of the LIBS data as input data of the network is particularly detailed and finally, resulting errors of prediction lower than 20% for aluminum, calcium, copper and iron demonstrate the good efficiency of the artificial neural networks for on-site quantitative LIBS of soils. - Highlights: ► We perform on-site quantitative LIBS analysis of soil samples. ► We demonstrate that univariate analysis is not convenient. ► We exploit artificial neural networks for LIBS analysis. ► Spectral lines other than the ones from the analyte must be introduced

  4. Establishment of the laser induced breakdown spectroscopy in a vacuum atmosphere for a accuracy improvement

    International Nuclear Information System (INIS)

    This report describes the fundamentals of the Laser Induced Breakdown Spectroscopy(LIBS), and it describes the quantitative analysis method in the vacuum condition to obtain a high measurement accuracy. The LIBS system employs the following major components: a pulsed laser, a gas chamber, an emission spectrometer, a detector, and a computer. When the output from a pulsed laser is focused onto a small spot on a sample, an optically induced plasma, called a laser-induced plasma (LIP) is formed at the surface. The LIBS is a laser-based sensitive optical technique used to detect certain atomic and molecular species by monitoring the emission signals from a LIP. This report was described a fundamentals of the LIBS and current states of research. And, It was described a optimization of measurement condition and characteristic analysis of a LIP by measurement of the fundamental metals. The LIBS system shows about a 0.63 ∼ 5.82% measurement errors and calibration curve for the 'Cu, Cr and Ni'. It also shows about a 5% less of a measurement errors and calibration curve for a Nd and Sm. As a result, the LIBS accuracy for a part was little improved than preexistence by the optimized condition

  5. Calibration-free laser-induced breakdown spectroscopy for quantitative elemental analysis of materials

    Indian Academy of Sciences (India)

    V K Unnikrishnan; K Mridul; R Nayak; K Alti; V B Kartha; C Santhosh; G Gupta; B M Suri

    2012-08-01

    The application of calibration-free laser-induced breakdown spectroscopy (CF-LIBS) for quantitative analysis of materials, illustrated by CF-LIBS applied to a brass sample of known composition, is presented in this paper. The LIBS plasma is produced by a 355 nm pulsed Nd:YAG laser with a pulse duration of 6 ns focussed onto a brass sample in air at atmospheric pressure. The time-resolved atomic and ionic emission lines of Cu and Zn from the LIBS spectra recorded by an Echelle spectrograph coupled with a gated intensified charge coupled detector are used for the plasma characterization and the quantitative analysis of the sample. The time delay where the plasma is optically thin and is also in local thermodynamic equilibrium (LTE), necessary for the elemental analysis of samples from the LIBS spectra, is deduced. An algorithm relating the experimentally measured spectral intensity values with the basic physics of the plasma is developed. Using the algorithm, the Zn and Cu concentratioins in the brass sample are determined. The analytical result obtained from the CF-LIBS technique agree well with the certified valued of the elements in the sample, with an accuracy error < 1%

  6. Identification of quantum dots labeled metallothionein by fast scanning laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The technique described in this paper allows detection of quantum dots (QDs) specifically deposited on the polystyrene surface by laser-induced breakdown spectroscopy (LIBS). Using LIBS, the distribution of QDs or their conjugates with biomolecules deposited on the surface can be observed, regardless of the fact if they exhibit fluorescence or not. QDs deposited on the specific surface of polystyrene microplate in the form of spots are detected by determination of the metal included in the QDs structure. Cd-containing QDs (CdS, CdTe) stabilized with mercaptopropionic (MPA) or mercaptosuccinic (MSA) acid, respectively, alone or in the form of conjugates with metallothionein (MT) biomolecule are determined by using the 508.58 nm Cd emission line. The observed absolute detection limit for Cd in CdTe QDs conjugates with MT in one spot was 3 ng Cd. Due to the high sensitivity of this technique, the immunoanalysis in combination with LIBS was also investigated. Cd spatial distribution in sandwich immunoassay was detected. - Highlights: • We describe determination of biomolecules labeled with quantum dots by LIBS. • LIBS and immunoassay are applied for the determination of metallothionein. • Metallothionein amount detected by LIBS is 10-times lower compared to ELISA

  7. Laser-Induced Breakdown Spectroscopy Coupled with Multivariate Chemometrics for Variety Discrimination of Soil

    Science.gov (United States)

    Yu, Ke-Qiang; Zhao, Yan-Ru; Liu, Fei; He, Yong

    2016-06-01

    The aim of this work was to analyze the variety of soil by laser-induced breakdown spectroscopy (LIBS) coupled with chemometrics methods. 6 certified reference materials (CRMs) of soil samples were selected and their LIBS spectra were captured. Characteristic emission lines of main elements were identified based on the LIBS curves and corresponding contents. From the identified emission lines, LIBS spectra in 7 lines with high signal-to-noise ratio (SNR) were chosen for further analysis. Principal component analysis (PCA) was carried out using the LIBS spectra at 7 selected lines and an obvious cluster of 6 soils was observed. Soft independent modeling of class analogy (SIMCA) and least-squares support vector machine (LS-SVM) were introduced to establish discriminant models for classifying the 6 types of soils, and they offered the correct discrimination rates of 90% and 100%, respectively. Receiver operating characteristic (ROC) curve was used to evaluate the performance of models and the results demonstrated that the LS-SVM model was promising. Lastly, 8 types of soils from different places were gathered to conduct the same experiments for verifying the selected 7 emission lines and LS-SVM model. The research revealed that LIBS technology coupled with chemometrics could conduct the variety discrimination of soil.

  8. Determination of poisonous metals in wastewater collected from paint manufacturing plant using laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Gondal, M A; Hussain, T

    2007-01-15

    Laser-induced breakdown spectroscopy (LIBS) system was developed for determination of toxic metals in wastewater collected from local paint manufacturing plant. The plasma was generated by focusing a pulsed Nd:YAG laser at 1064nm on the solid residue from wastewater collected from paint industry. The concentration of different elements of environmental significance like, lead, copper, chromium, calcium, sulphur, magnesium, zinc, titanium, strontium, nickel, silicone, iron, aluminum, barium, sodium, potassium and zirconium, in paint wastewater were 6, 3, 4, 301, 72, 200, 20, 42, 4, 1, 35, 120, 133, 119, 173, 28 and 12mg kg(-1), respectively. The evaluation of potential and capabilities of LIBS as a rapid tool for paint industry effluent characterization is discussed in detail. Optimal experimental conditions were evaluated for improving the sensitivity of our LIBS system through parametric dependence study. The laser-induced breakdown spectroscopy (LIBS) results were compared with the results obtained using standard analytical technique such as inductively coupled plasma emission spectroscopy (ICP). The relative accuracy of our LIBS system for various elements as compared with ICP method is in the range of 0.03-0.6 at 2.5% error confidence. Limits of detection (LOD) of our LIBS system were also estimated for the above mentioned elements. PMID:19071270

  9. Application of laser-induced breakdown spectroscopy method for elements analysis of metal ions in an aqueous solution in nuclear reprocessing process control

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) is an attractive technique for determining elemental composition in real time, in-situ, and remotely without any sample preparation. The LIBS analysis of metal ions in an aqueous solution is available in process control and environmental monitoring. In the present paper, we reviewed LIBS methods for a liquid phase to improve detection sensitivity. We performed LIBS measurements with the sheet flow for the simultaneous determination of elements in simulated high-level radioactive waste liquid and discussed the application potential as a tool for online process monitoring. (author)

  10. Use of laser induced breakdown spectroscopy in the determination of gem provenance: beryls.

    Science.gov (United States)

    McManus, Catherine E; McMillan, Nancy J; Harmon, Russell S; Whitmore, Robert C; De Lucia, Frank C; Miziolek, Andrzej W

    2008-11-01

    The provenance of gem stones has been of interest to geologists, gemologists, archeologists, and historians for centuries. Laser induced breakdown spectroscopy (LIBS) provides a minimally destructive tool for recording the rich chemical signatures of gem beryls (aquamarine, goshenite, heliodor, and morganite). Broadband LIBS spectra of 39 beryl (Be(3)Al(2)Si(6)O(18)) specimens from 11 pegmatite mines in New Hampshire, Connecticut, and Maine (USA) are used to assess the potential of using principal component analysis of LIBS spectra to determine specimen provenance. Using this technique, beryls from the three beryl-bearing zones in the Palermo #1 pegmatite (New Hampshire) can be recognized. However, the compositional variation within this single mine is comparable to that in beryls from all three states. Thus, a very large database with detailed location metadata will be required to routinely determine gem beryl provenance. PMID:19122706

  11. An overview of some influential factors in laser-induced breakdown spectroscopy

    CERN Document Server

    Rai, V N

    2014-01-01

    This paper presents the process of plasma formation during laser induced breakdown spectroscopy (LIBS) along with analysis of emission from double pulse LIBS to better understand the processes and the factors involved in enhancement of plasma emission. In this analysis plasma emission has been considered directly proportional to the square of plasma density, its volume, and the fraction of absorption of second laser pulse in the plasma plume produced by the first laser through inverse Bremsstrahlung absorption process. The electron ion collision frequency, which is dependent on the density and temperature of the plasma, has been found playing important role in the enhancement of emission as well as in the saturation of emission during LIBS. The effect of material ablation, delay between lasers, plasma confinement and shielding effect has also been discussed.

  12. Laser-induced breakdown spectroscopy of whole blood and other liquid organic compounds

    Science.gov (United States)

    Melikechi, N.; Ding, H.; Rock, S.; Marcano O., A.; Connolly, D.

    2008-02-01

    We report on laser-induced breakdown spectroscopy (LIBS) of whole blood and other organic fluids. LIBS spectra, in the region 200-970 nm, are measured by recording the radiation emitted by the samples following their ablation in a helium environment. We show that these spectra, although very complex, reveal the presence of elements such as nitrogen, hydrogen, oxygen and carbon and that of important metallic elements such as iron, magnesium, calcium, potassium, and sodium. We compare the measured LIBS spectra of whole blood to that of pure carbon and pure iron and find that in the 200-300 nm region. Nearly 90% of the peaks can be assigned to only these two elements. We also report on similar studies of methanol, ethanol, isopropanol and water solutions of protein molecules of interest to cancer research. We show that using simple numerical algorithms, it is possible to distinguish between complex organic compounds that have nearly the same chemical composition.

  13. Correlation between laser-induced breakdown spectroscopy signal and moisture content

    International Nuclear Information System (INIS)

    The possibility of using Laser-Induced Breakdown Spectroscopy (LIBS) for measuring the moisture content of fresh food samples is studied. The normalized line emission of oxygen is highly correlated with the moisture content of the sample, cheese in our case, and can be used as a moisture marker in situations where oxygen interference from the matrix is not a critical issue. The linear correlation between the oxygen signal and the moisture content in the sample shows great potential for using LIBS as an alternative spectroscopic method for moisture monitoring. - Highlights: ► Quantitative moisture measurement by LIBS. ► Use of matrix effects and normalization for physical information on the sample. ► Use of signal from oxygen and CN radical in air background for moisture measurement.

  14. Correlation between laser-induced breakdown spectroscopy signal and moisture content

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuan [Townes Laser Institute, CREOL - The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816 (United States); Gigant, Lionel [Townes Laser Institute, CREOL - The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816 (United States); Universite Bordeaux 1, 351 cours de la Liberation 33405 Talence Cedex (France); Baudelet, Matthieu, E-mail: baudelet@creol.ucf.edu [Townes Laser Institute, CREOL - The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816 (United States); Richardson, Martin [Townes Laser Institute, CREOL - The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816 (United States)

    2012-07-15

    The possibility of using Laser-Induced Breakdown Spectroscopy (LIBS) for measuring the moisture content of fresh food samples is studied. The normalized line emission of oxygen is highly correlated with the moisture content of the sample, cheese in our case, and can be used as a moisture marker in situations where oxygen interference from the matrix is not a critical issue. The linear correlation between the oxygen signal and the moisture content in the sample shows great potential for using LIBS as an alternative spectroscopic method for moisture monitoring. - Highlights: Black-Right-Pointing-Pointer Quantitative moisture measurement by LIBS. Black-Right-Pointing-Pointer Use of matrix effects and normalization for physical information on the sample. Black-Right-Pointing-Pointer Use of signal from oxygen and CN radical in air background for moisture measurement.

  15. Discrimination of human bodies from bones and teeth remains by Laser Induced Breakdown Spectroscopy and Neural Networks

    Energy Technology Data Exchange (ETDEWEB)

    Moncayo, S.; Manzoor, S.; Ugidos, T.; Navarro-Villoslada, F.; Caceres, J.O., E-mail: jcaceres@ucm.es

    2014-11-01

    A fast and minimally destructive method based on Laser Induced Breakdown Spectroscopy (LIBS) and Neural Networks (NN) has been developed and applied to the classification and discrimination of human bones and teeth fragments. The methodology can be useful in Disaster Victim Identification (DVI) tasks. The elemental compositions of bone and teeth samples provided enough information to achieve a correct discrimination and reassembling of different human remains. Individuals were classified with spectral correlation higher than 95%, regardless of the type of bone or tooth sample analyzed. No false positive or false negative was observed, demonstrating the high robustness and accuracy of the proposed methodology. - Highlights: • Classification and discrimination of human remains have been studied. • Remains were analyzed by Laser Induced Breakdown Spectroscopy (LIBS). • Neural Networks models (NN) were used. • Individuals were classified with spectral correlation higher than 95 %. • LIBS-NN showed the potential for rapid and cost-effective analysis.

  16. Discrimination of human bodies from bones and teeth remains by Laser Induced Breakdown Spectroscopy and Neural Networks

    International Nuclear Information System (INIS)

    A fast and minimally destructive method based on Laser Induced Breakdown Spectroscopy (LIBS) and Neural Networks (NN) has been developed and applied to the classification and discrimination of human bones and teeth fragments. The methodology can be useful in Disaster Victim Identification (DVI) tasks. The elemental compositions of bone and teeth samples provided enough information to achieve a correct discrimination and reassembling of different human remains. Individuals were classified with spectral correlation higher than 95%, regardless of the type of bone or tooth sample analyzed. No false positive or false negative was observed, demonstrating the high robustness and accuracy of the proposed methodology. - Highlights: • Classification and discrimination of human remains have been studied. • Remains were analyzed by Laser Induced Breakdown Spectroscopy (LIBS). • Neural Networks models (NN) were used. • Individuals were classified with spectral correlation higher than 95 %. • LIBS-NN showed the potential for rapid and cost-effective analysis

  17. Double-pulse laser ablation coupled to laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Laser ablation coupled to laser-induced breakdown spectroscopy (LA-LIBS) is an analytical method, which minimizes sample matrix effects typically found in quantitative LIBS-based direct solid analyses. This paper reports the application of double-pulse laser ablation (DP-LA) to improve the analyte response and the achievable precisions of LA-LIBS. Two coaxial laser beams were applied at the ablation site and the analytical signals were then collected from a second free-standing LIBS plasma downstream of the ablation site. Signal improvements of up to one order of magnitude were observed compared to single-pulse LA-LIBS. The effect of the interpulse delay on the observed signal-to-noise ratios was studied and the quantification capabilities of the optimized DP-LA-LIBS setup were investigated for manganese and iron in a broad range of different alloy types. A linear response was observed for manganese across the different matrices, allowing for nonmatrix-matched calibrations. Matrix effects were observed when analyzing aluminum samples, which, however, could be compensated for by applying iron as internal standard. Size distributions of the ablated material and electron density measurements provide additional insight into the double-pulse process, with additional future work suggested. - Highlights: • Double-pulse laser ablation was coupled to laser-induced breakdown spectroscopy. • Nonmatrix-matched calibration of manganese in various alloys was performed. • Improved sensitivities and precisions compared to single-pulse LA were demonstrated. • Remaining matrix effects and internal standardization are discussed

  18. Application of Laser Induced Breakdown Spectroscopy to the identification of emeralds from different synthetic processes

    Energy Technology Data Exchange (ETDEWEB)

    Agrosì, G. [Department of Scienze della Terra e Geoambientali, University of Bari, Bari (Italy); Tempesta, G., E-mail: gioacchino.tempesta@uniba.it [Department of Scienze della Terra e Geoambientali, University of Bari, Bari (Italy); Scandale, E. [Department of Scienze della Terra e Geoambientali, University of Bari, Bari (Italy); Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Palleschi, V. [Institute of Chemistry of Organometallic Compounds, CNR, Pisa (Italy); Mangone, A. [Department of Chemistry, University of Bari, Bari (Italy); Lezzerini, M. [Department of Earth Sciences, University of Pisa, Pisa (Italy)

    2014-12-01

    Laser Induced Breakdown Spectroscopy can provide a useful contribution in mineralogical field in which the quantitative chemical analyses (including the evaluation of light elements) can play a key role in the studies on the origin of the emeralds. In particular, the chemical analyses permit to determine those trace elements, known as fingerprints, that can be useful to study their provenance. This technique, not requiring sample preparation results particularly suitable for gemstones, that obviously must be studied in a non-destructive way. In this paper, the LIBS technique was applied to distinguish synthetic emeralds grown by Biron hydrothermal method from those grown by Chatham flux method. The analyses performed by collinear double-pulse LIBS give a signal enhancement useful for the quantitative chemical analyses while guaranteeing a minimal sample damage. In this way it was obtained a considerable improvement on the detection limit of the trace elements, whose determination is essential for determining the origin of emerald gemstone. The trace elements V, Cr, and Fe and their relative amounts allowed the correct attribution of the manufacturer. Two different methods for quantitative analyses were used for this study: the standard Calibration-Free LIBS (CF-LIBS) method and its recent evolution, the One Point Calibration LIBS (OPC-LIBS). This is the first approach to the evaluation of the emerald origin by means of the LIBS technique. - Highlights: • A LIBS method for discrimination between synthetic emeralds is presented. • Only one standard of known composition is needed for the analysis. • A set of two kind of synthetic emeralds has been analyzed. • The cromophoric elements Cr, V and Fe amounts have been used to determine the origin of emerald gemstone.

  19. Application of Laser Induced Breakdown Spectroscopy to the identification of emeralds from different synthetic processes

    International Nuclear Information System (INIS)

    Laser Induced Breakdown Spectroscopy can provide a useful contribution in mineralogical field in which the quantitative chemical analyses (including the evaluation of light elements) can play a key role in the studies on the origin of the emeralds. In particular, the chemical analyses permit to determine those trace elements, known as fingerprints, that can be useful to study their provenance. This technique, not requiring sample preparation results particularly suitable for gemstones, that obviously must be studied in a non-destructive way. In this paper, the LIBS technique was applied to distinguish synthetic emeralds grown by Biron hydrothermal method from those grown by Chatham flux method. The analyses performed by collinear double-pulse LIBS give a signal enhancement useful for the quantitative chemical analyses while guaranteeing a minimal sample damage. In this way it was obtained a considerable improvement on the detection limit of the trace elements, whose determination is essential for determining the origin of emerald gemstone. The trace elements V, Cr, and Fe and their relative amounts allowed the correct attribution of the manufacturer. Two different methods for quantitative analyses were used for this study: the standard Calibration-Free LIBS (CF-LIBS) method and its recent evolution, the One Point Calibration LIBS (OPC-LIBS). This is the first approach to the evaluation of the emerald origin by means of the LIBS technique. - Highlights: • A LIBS method for discrimination between synthetic emeralds is presented. • Only one standard of known composition is needed for the analysis. • A set of two kind of synthetic emeralds has been analyzed. • The cromophoric elements Cr, V and Fe amounts have been used to determine the origin of emerald gemstone

  20. Determination of Cd, Cr and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    A validated method for quantitative determination of Cd, Cr, and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy (LIBS) is presented. Laboratory samples were comminuted and homogenized by cryogenic or planetary ball milling, pressed into pellets and analyzed by LIBS. The experimental setup was designed by using a Q-switched Nd:YAG at 1064 nm with 10 Hz repetition rate, and the intensity signals from Cd II 214.441 nm, Cr II 267.716 nm and Pb II 220.353 nm emission lines were measured by using a spectrometer furnished with an intensified charge-coupled device. LIBS parameters (laser fluence, lens-to-sample distance, delay time, integration time gate, number of sites and number of laser pulses per site) were chosen after univariate experiments with a pellet of NIST SRM 695 (Trace Elements in Multi-Nutrient Fertilizer). Calibration and validation were carried out with 30 fertilizer samples from single superphosphate, triple superphosphate, monoammonium phosphate, and NPK mixtures. Good results were obtained by using 30 pulses of 50 J cm−2 (750 μm spot size), 2.0 μs delay time and 5.0 μs integration time gate. No significant differences between Cd, Cr, and Pb mass fractions determined by the proposed LIBS method and by ICP OES after microwave-assisted acid digestion (AOAC 2006.03 Official Method) were found at 95% confidence level. The limits of detection of 1 mg kg−1 Cd, 2 mg kg−1 Cr and 15 mg kg−1 Pb and the precision (coefficients of variation of results ranging from 2% to 15%) indicate that the proposed LIBS method can be recommended for the determination of these analytes in phosphate fertilizers. - Highlights: • First LIBS application for quantitative Cd, Cr and Pb determination in fertilizers. • LIBS method was validated for analysis of phosphate fertilizers pressed pellets. • LIBS sample throughput is remarkably better than already existing methods

  1. Improving sensitivity of laser-induced breakdown spectroscopy using laser plasmas interaction

    Science.gov (United States)

    Il'in, Alexey A.; Golik, Sergey S.; Nagorny, Ivan G.; Bulanov, Alexey V.

    2006-11-01

    Laser plasmas interaction and spectral characteristics of plasma were investigated at a laser breakdown in a normal atmosphere with the purpose of improving laser-induced breakdown spectroscopy sensitivity. Colliding plasmas interaction was investigated depending on mechanism of absorption wave of laser radiation and distance between foci. Laser supported detonation wave, breakdown wave and fast wave of ionization are absorption wave observed in experiment. It was shown that seed electrons for cascade breakdown in front of fast wave of ionization is occurred due to oxygen molecules photoionization. Molecular emission and collapse of intensity of plasma continuum during the initial moments of laser plasma expansion were registered. The line/continuum ratio was essentially increased in case of laser plasmas interaction. Thus laser plasmas interaction improves sensitivity of LIBS.

  2. A method for improving wavelet threshold denoising in laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bo, E-mail: zhangbo@sia.cn [Lab. of Networked Control Systems, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); University of the Chinese Academy of Sciences, Beijing 100039 (China); Sun, Lanxiang, E-mail: sunlanxiang@sia.cn [Lab. of Networked Control Systems, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China); Yu, Haibin; Xin, Yong; Cong, Zhibo [Lab. of Networked Control Systems, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang 110016 (China)

    2015-05-01

    The wavelet threshold denoising method is an effective noise suppression approach for noisy laser-induced breakdown spectroscopy signal. In this paper, firstly, the noise sources of LIBS system are summarized. Secondly, wavelet multi-resolution analysis and wavelet threshold denoising method are introduced briefly. As one of the major factors influencing the denoising results in the process of wavelet threshold denoising, the optimal decomposition level selection is studied. Based on the entropy analysis of noisy LIBS signal and noise, a method of choosing optimal decomposition level is presented. Thirdly, the performance of the proposed method is verified by analyzing some synthetic signals. Not only the denoising results of the synthetic signals are analyzed, but also the ultimate denoising capacity of the wavelet threshold denoising method with the optimal decomposition level is explored. Finally, the experimental data analysis implies that the fluctuation of the noisy LIBS signals can be decreased and the weak LIBS signals can be recovered. The optimal decomposition level is able to improve the performance of the denoising results obtained by wavelet threshold denoising with non-optimal wavelet functions. The signal to noise ratios of the elements are improved and the limit of detection values are reduced by more than 50% by using the proposed method. - Highlights: • The noise sources of LIBS system are summarized. • The optimal decomposition level selection method in wavelet threshold denoising is obtained by entropy analysis.

  3. Determination of a brass alloy concentration composition using calibration-free laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) is a technique that can provide qualitative and quantitative measurements of the characteristics of irradiated metals. In the present work, we have calculated the parameters of the plasma produced from a brass alloy sample under the action of a pulsed Nd: YAG laser operating at 1064 nm. The emission lines of copper atoms (Cu I), zinc atoms (Zn I), and lead atoms (Pb I), which are elements of a brass alloy composition, were used to investigate the parameters of the brass plasma. The spectral profiles of Cu, Zn, and Pb lines have been used to extract the electron temperature and density of the brass alloy plasma. The characteristics of Cu, Zn, and Pb were determined quantatively by the calibration-free LIBS (CF-LIBS) method considering for accurate analysis that the laser-induced ablated plasma is optically thin in local thermodynamic equilibrium conditions and the plasma ablation is stoichiometric. The Boltzmann plot method was used to evaluate the plasma temperature, and the Stark broadened profiles were used to determine the electron density. An algorithm based on the experimentally measured values of the intensity of spectral lines and the basic laws of plasma physics was developed for the determination of Cu, Zn, and Pb concentrations in the brass sample. The concentrations CCF-LIBS calculated by CF-LIBS and the certified concentrations Ccertified were very close

  4. Determination of a brass alloy concentration composition using calibration-free laser-induced breakdown spectroscopy

    Science.gov (United States)

    Achouri, M.; Baba-Hamed, T.; Beldjilali, S. A.; Belasri, A.

    2015-09-01

    Laser-induced breakdown spectroscopy (LIBS) is a technique that can provide qualitative and quantitative measurements of the characteristics of irradiated metals. In the present work, we have calculated the parameters of the plasma produced from a brass alloy sample under the action of a pulsed Nd: YAG laser operating at 1064 nm. The emission lines of copper atoms (Cu I), zinc atoms (Zn I), and lead atoms (Pb I), which are elements of a brass alloy composition, were used to investigate the parameters of the brass plasma. The spectral profiles of Cu, Zn, and Pb lines have been used to extract the electron temperature and density of the brass alloy plasma. The characteristics of Cu, Zn, and Pb were determined quantatively by the calibration-free LIBS (CF-LIBS) method considering for accurate analysis that the laser-induced ablated plasma is optically thin in local thermodynamic equilibrium conditions and the plasma ablation is stoichiometric. The Boltzmann plot method was used to evaluate the plasma temperature, and the Stark broadened profiles were used to determine the electron density. An algorithm based on the experimentally measured values of the intensity of spectral lines and the basic laws of plasma physics was developed for the determination of Cu, Zn, and Pb concentrations in the brass sample. The concentrations C CF-LIBS calculated by CF-LIBS and the certified concentrations C certified were very close.

  5. Spectroscopic detection of health hazardous contaminants in lipstick using Laser Induced Breakdown Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gondal, M.A., E-mail: magondal@kfupm.edu.sa [Physics Department and Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Seddigi, Z.S. [Chemistry Department, Umm Al-Qura University, Makkah (Saudi Arabia); Nasr, M.M. [Natural Science Departments, Riyadh College of Dentistry and Pharmacy, P.O. Box 321815, Riyadh 11343 (Saudi Arabia); Gondal, B. [Plastic and Reconstructive Aesthetic Surgery, Whitfield Hospital, Waterford (Ireland)

    2010-03-15

    Laser Induced Breakdown Spectroscopy (LIBS) technique was applied to determine the concentrations of different toxic elements like lead, chromium, cadmium and zinc in four different lipstick brands sold at local markets in Saudi Arabia. These samples contain toxic elements like lead, cadmium and chromium which are carcinogen dermatitis, allergic and eczematous. Their extraction from human body takes over 40 years and accumulation in the body cause problems like disruption of nervous systems and kidney damage. They could trigger to systemic lupus erythematosus (SLE). In order to test the validity of our LIBS results, standard technique like (ICP-AES) was also applied. To the best of our knowledge, this is the first study where LIBS technique was applied for the measurement of toxic substances in lipsticks. The maximum concentration detected in four lipstick brands was much higher than the permissible safe limits for human use and could lead to serious health problems. It is worth mentioning that the lipstick is not a solid rather is in fluid state which is not trivial to analyze using LIBS technique. For this purpose, special treatment of the lipstick samples was necessary to analyze with our LIBS method.

  6. High-Resolution Laser-Induced Breakdown Spectroscopy used in Homeland Security and Forensic Applications

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Madhavi Z [ORNL; Wullschleger, Stan D [ORNL; Vass, Arpad Alexander [ORNL; Martin, Rodger Carl [ORNL; Grissino-Mayer, Henri [ORNL

    2006-01-01

    The technique of laser-induced breakdown spectroscopy (LIBS) to detect elements for a variety of homeland security applications such as nuclear materials identification and inventory,and forensic applications has been demonstrated. For nuclear materials applications, we detected and profiled metals in coatings that were used to encapsulate nuclear fuel. Multivariate analysis has been successfully employed in the quantification of elements present in treated wood and engineered wood composites. These examples demonstrate that LIBS-based techniques are inherently well suited for diverse environmental applications related to homeland security. Three key advantages are evident: (1) small samples (mg) are sufficient; (2) samples can be analyzed by LIBS very rapidly, and (3) biological materials such as human and animal bones and wood can be analyzed with minimal sample preparation. For forensic applications they have used LIBS to determine differences in animal and human bones. They have also applied this technique in the determination of counterfeit and non-counterfeit currency. They recently applied LIBS in helping to solve a murder case.

  7. High resolution applications of laser-induced breakdown spectroscopy for environmental and forensic applications

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) has been used in the elemental analysis for a variety of environmental samples and as a proof of concept for a host of forensic applications. In the first application, LIBS was used for the rapid detection of carbon from a number of different soil types. In this application, a major breakthrough was achieved by using a multivariate analytical approach that has brought us closer towards a 'universal calibration curve'. In a second application, it has been demonstrated that LIBS in combination with multivariate analysis can be employed to analyze the chemical composition of annual tree growth rings and correlate them to external parameters such as changes in climate, forest fires, and disturbances involving human activity. The objectives of using this technology in fire scar determinations are: 1) To determine the characteristic spectra of wood exposed to forest fires and 2) To examine the viability of this technique for detecting fire occurrences in stems that did not develop fire scars. These examples demonstrate that LIBS-based techniques are inherently well suited for diverse environmental applications. LIBS was also applied to a variety of proof of concept forensic applications such as the analysis of cremains (human cremation remains) and elemental composition analysis of prosthetic implants

  8. Laser induced breakdown spectroscopy for analysis and characterization of degradation pathologies of Roman glasses

    Energy Technology Data Exchange (ETDEWEB)

    Palomar, T. [Instituto de Historia, Centro de Ciencias Humanas y Sociales, CSIC, C/Albasanz 26-28, 28037 Madrid (Spain); Oujja, M., E-mail: m.oujja@iqfr.csic.es [Instituto de Química Física Rocasolano, CSIC, C/Serrano 119, 28006 Madrid (Spain); García-Heras, M.; Villegas, M.A. [Instituto de Historia, Centro de Ciencias Humanas y Sociales, CSIC, C/Albasanz 26-28, 28037 Madrid (Spain); Castillejo, M. [Instituto de Química Física Rocasolano, CSIC, C/Serrano 119, 28006 Madrid (Spain)

    2013-09-01

    The feasibility and possibilities of laser induced breakdown spectroscopy (LIBS) in the full study of non-destructible historic glasses have been explored in the present work. Thirteen Roman glass samples, including seven entire glass beads, from the ancient town of Augusta Emerita (SW Spain) were characterized by LIBS in combination with other conventional techniques, such as scanning electron microscopy/energy dispersive X-ray spectrometry, X-ray fluorescence and ultraviolet–visible spectrophotometry. LIBS stratigraphic analysis, carried out by the application of successive laser pulses on the same spot, has been mainly targeted at characterizing particular features of non-destructible historic glasses, such as bulk chemical composition, surface degradation pathologies (dealkalinization layers and deposits), chromophores, and opacifying elements. The obtained data demonstrate that LIBS can be a useful and alternative technique for spectroscopic studies of historical glasses, especially for those conserved under burial conditions and when it deals with studying non-destructible samples. - Highlights: • Determination of chromophores and opacifiers in non-destructible glass by LIBS • Manganese is determined as principal component of dark deposits. • Antimony appears in all decorations while lead is only present in yellow ones. • Stratigraphic analysis enables the identification of dealkalinization layers.

  9. Determination of a brass alloy concentration composition using calibration-free laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Achouri, M.; Baba-Hamed, T.; Beldjilali, S. A., E-mail: sidahmed.beldjilali@univ-usto.dz; Belasri, A. [Université des Sciences et de la Technologie d’Oran Mohamed Boudiaf USTO-MB, LPPMCA (Algeria)

    2015-09-15

    Laser-induced breakdown spectroscopy (LIBS) is a technique that can provide qualitative and quantitative measurements of the characteristics of irradiated metals. In the present work, we have calculated the parameters of the plasma produced from a brass alloy sample under the action of a pulsed Nd: YAG laser operating at 1064 nm. The emission lines of copper atoms (Cu I), zinc atoms (Zn I), and lead atoms (Pb I), which are elements of a brass alloy composition, were used to investigate the parameters of the brass plasma. The spectral profiles of Cu, Zn, and Pb lines have been used to extract the electron temperature and density of the brass alloy plasma. The characteristics of Cu, Zn, and Pb were determined quantatively by the calibration-free LIBS (CF-LIBS) method considering for accurate analysis that the laser-induced ablated plasma is optically thin in local thermodynamic equilibrium conditions and the plasma ablation is stoichiometric. The Boltzmann plot method was used to evaluate the plasma temperature, and the Stark broadened profiles were used to determine the electron density. An algorithm based on the experimentally measured values of the intensity of spectral lines and the basic laws of plasma physics was developed for the determination of Cu, Zn, and Pb concentrations in the brass sample. The concentrations C{sub CF-LIBS} calculated by CF-LIBS and the certified concentrations C{sub certified} were very close.

  10. A method for improving wavelet threshold denoising in laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The wavelet threshold denoising method is an effective noise suppression approach for noisy laser-induced breakdown spectroscopy signal. In this paper, firstly, the noise sources of LIBS system are summarized. Secondly, wavelet multi-resolution analysis and wavelet threshold denoising method are introduced briefly. As one of the major factors influencing the denoising results in the process of wavelet threshold denoising, the optimal decomposition level selection is studied. Based on the entropy analysis of noisy LIBS signal and noise, a method of choosing optimal decomposition level is presented. Thirdly, the performance of the proposed method is verified by analyzing some synthetic signals. Not only the denoising results of the synthetic signals are analyzed, but also the ultimate denoising capacity of the wavelet threshold denoising method with the optimal decomposition level is explored. Finally, the experimental data analysis implies that the fluctuation of the noisy LIBS signals can be decreased and the weak LIBS signals can be recovered. The optimal decomposition level is able to improve the performance of the denoising results obtained by wavelet threshold denoising with non-optimal wavelet functions. The signal to noise ratios of the elements are improved and the limit of detection values are reduced by more than 50% by using the proposed method. - Highlights: • The noise sources of LIBS system are summarized. • The optimal decomposition level selection method in wavelet threshold denoising is obtained by entropy analysis

  11. Laser induced breakdown spectroscopy for analysis and characterization of degradation pathologies of Roman glasses

    International Nuclear Information System (INIS)

    The feasibility and possibilities of laser induced breakdown spectroscopy (LIBS) in the full study of non-destructible historic glasses have been explored in the present work. Thirteen Roman glass samples, including seven entire glass beads, from the ancient town of Augusta Emerita (SW Spain) were characterized by LIBS in combination with other conventional techniques, such as scanning electron microscopy/energy dispersive X-ray spectrometry, X-ray fluorescence and ultraviolet–visible spectrophotometry. LIBS stratigraphic analysis, carried out by the application of successive laser pulses on the same spot, has been mainly targeted at characterizing particular features of non-destructible historic glasses, such as bulk chemical composition, surface degradation pathologies (dealkalinization layers and deposits), chromophores, and opacifying elements. The obtained data demonstrate that LIBS can be a useful and alternative technique for spectroscopic studies of historical glasses, especially for those conserved under burial conditions and when it deals with studying non-destructible samples. - Highlights: • Determination of chromophores and opacifiers in non-destructible glass by LIBS • Manganese is determined as principal component of dark deposits. • Antimony appears in all decorations while lead is only present in yellow ones. • Stratigraphic analysis enables the identification of dealkalinization layers

  12. Spectroscopic detection of health hazardous contaminants in lipstick using Laser Induced Breakdown Spectroscopy.

    Science.gov (United States)

    Gondal, M A; Seddigi, Z S; Nasr, M M; Gondal, B

    2010-03-15

    Laser Induced Breakdown Spectroscopy (LIBS) technique was applied to determine the concentrations of different toxic elements like lead, chromium, cadmium and zinc in four different lipstick brands sold at local markets in Saudi Arabia. These samples contain toxic elements like lead, cadmium and chromium which are carcinogen dermatitis, allergic and eczematous. Their extraction from human body takes over 40 years and accumulation in the body cause problems like disruption of nervous systems and kidney damage. They could trigger to systemic lupus erythematosus (SLE). In order to test the validity of our LIBS results, standard technique like (ICP-AES) was also applied. To the best of our knowledge, this is the first study where LIBS technique was applied for the measurement of toxic substances in lipsticks. The maximum concentration detected in four lipstick brands was much higher than the permissible safe limits for human use and could lead to serious health problems. It is worth mentioning that the lipstick is not a solid rather is in fluid state which is not trivial to analyze using LIBS technique. For this purpose, special treatment of the lipstick samples was necessary to analyze with our LIBS method. PMID:19926220

  13. Laser-induced breakdown spectroscopy for lambda quantification in a direct-injection engine

    International Nuclear Information System (INIS)

    We apply laser-induced breakdown spectroscopy (LIBS) to determine local lambda values (i.e. the normalized air-fuel mass ratio) at the ignition location λip in a direct-injection single-cylinder optical research engine. The technique enables us to determine variations of λip for different fuel injection strategies, as well as correlations between variations in λip and the combustion dynamics. In particular we observe, that fluctuations in λip are not the major cause of cycle-to-cycle variations in the combustion process. Moreover, our experiments identify insufficient lean λip values as a source of misfires in lean combustions. In a combination of LIBS with laser-induced fluorescence (LIF), we obtain additionally information about the two-dimensional λ distribution. These results demonstrate the potential of LIBS to monitor λ values during mixture formation in gasoline engines. - Highlights: ► Determination of λ values by means of LIBS in an optical gasoline engine. ► Evaluation of λ fluctuations for different fuel injection strategies. ► Investigation of the effect of λ upon combustion dynamics. ► Combination of LIBS and LIF to obtain two-dimensional λ distributions.

  14. Element analysis of complex materials by calibration-free laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Full text: Laser-induced breakdown spectroscopy (LIBS) is a promising method for fast and quantitative element analysis of complex materials. We report on LIBS measurements of multi-component oxide materials and the compositional analysis of materials by a calibration-free (CF) method. This CF-LIBS method relies on modeling of the optical emission of laser-induced plasma assuming local thermodynamic equilibrium. Materials containing up to eight different oxides are investigated and for all samples the calculated concentration values (CCF) are in good agreement with nominal concentration values (CN) from reference analysis. The relative error in oxide concentration, er = | CCF - CN | / CN , decreases with increasing concentration. The quantitation is limited to major oxides (CN ≥ 1 wt %). Slag materials from industrial steel production are analyzed on-site by means of a mobile measurement system. LIBS measurements are performed at different sample temperature. The results obtained show that CF-LIBS is applicable to fast compositional analysis of complex materials in harsh environment. (author)

  15. Spectroscopic detection of health hazardous contaminants in lipstick using Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Laser Induced Breakdown Spectroscopy (LIBS) technique was applied to determine the concentrations of different toxic elements like lead, chromium, cadmium and zinc in four different lipstick brands sold at local markets in Saudi Arabia. These samples contain toxic elements like lead, cadmium and chromium which are carcinogen dermatitis, allergic and eczematous. Their extraction from human body takes over 40 years and accumulation in the body cause problems like disruption of nervous systems and kidney damage. They could trigger to systemic lupus erythematosus (SLE). In order to test the validity of our LIBS results, standard technique like (ICP-AES) was also applied. To the best of our knowledge, this is the first study where LIBS technique was applied for the measurement of toxic substances in lipsticks. The maximum concentration detected in four lipstick brands was much higher than the permissible safe limits for human use and could lead to serious health problems. It is worth mentioning that the lipstick is not a solid rather is in fluid state which is not trivial to analyze using LIBS technique. For this purpose, special treatment of the lipstick samples was necessary to analyze with our LIBS method.

  16. One-point calibration for calibration-free laser-induced breakdown spectroscopy quantitative analysis

    International Nuclear Information System (INIS)

    We present a new method for improving the reliability of quantitative analysis by laser-induced breakdown spectroscopy (LIBS). The method can be considered as a variation of the calibration-free LIBS approach; although not completely standard-less, only one standard of known composition and similar matrix to the one to be analyzed is needed. On the other hand, the one-point calibration approach allows the empirical determination of essential experimental and spectroscopic parameters, whose knowledge is often imprecise or lacking; the result is a definite improvement of the trueness of LIBS analysis with respect to the traditional calibration-free approach. The characteristics and advantages of the proposed one-point calibration LIBS approach will be demonstrated on a set of copper-based samples of known composition. - Highlights: • A new method for improving the quantitative analysis by LIBS is presented. • Only one standard of known composition is needed for the analysis. • A set of copper-based samples of known composition is analyzed. • The concentrations calculated result remarkably close to the nominal concentrations

  17. Multielemental analysis of prehistoric animal teeth by laser-induced breakdown spectroscopy and laser ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Galiova, Michaela; Kaiser, Jozef; Fortes, Francisco J.; Novotny, Karel; Malina, Radomir; Prokes, Lubomir; Hrdlicka, Ales; Vaculovic, Tomas; Nyvltova Fisakova, Miriam; Svoboda, Jiri; Kanicky, Viktor; Laserna, Javier J.

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) and laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry (MS) were utilized for microspatial analyses of a prehistoric bear (Ursus arctos) tooth dentine. The distribution of selected trace elements (Sr, Ba, Fe) was measured on a 26 mmx15 mm large and 3 mm thick transverse cross section of a canine tooth. The Na and Mg content together with the distribution of matrix elements (Ca, P) was also monitored within this area. The depth of the LIBS craters was measured with an optical profilometer. As shown, both LIBS and LA-ICP-MS can be successfully used for the fast, spatially resolved analysis of prehistoric teeth samples. In addition to microchemical analysis, the sample hardness was calculated using LIBS plasma ionic-to-atomic line intensity ratios of Mg (or Ca). To validate the sample hardness calculations, the hardness was also measured with a Vickers microhardness tester.

  18. Multielemental analysis of prehistoric animal teeth by laser-induced breakdown spectroscopy and laser ablation inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) and laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry (MS) were utilized for microspatial analyses of a prehistoric bear (Ursus arctos) tooth dentine. The distribution of selected trace elements (Sr, Ba, Fe) was measured on a 26 mmx15 mm large and 3 mm thick transverse cross section of a canine tooth. The Na and Mg content together with the distribution of matrix elements (Ca, P) was also monitored within this area. The depth of the LIBS craters was measured with an optical profilometer. As shown, both LIBS and LA-ICP-MS can be successfully used for the fast, spatially resolved analysis of prehistoric teeth samples. In addition to microchemical analysis, the sample hardness was calculated using LIBS plasma ionic-to-atomic line intensity ratios of Mg (or Ca). To validate the sample hardness calculations, the hardness was also measured with a Vickers microhardness tester.

  19. Trace element quantification of lead based roof sheets of historical monuments by Laser Induced Breakdown Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Syvilay, D., E-mail: delphine.syvilay@culture.gouv.fr [LRMH USR 3224, 29 rue de Paris, 77420 Champs-sur-Marne (France); Texier, A. [LRMH USR 3224, 29 rue de Paris, 77420 Champs-sur-Marne (France); Arles, A.; Gratuze, B. [IRAMAT, 3D, rue de la Férollerie, 45071 Orléans Cedex 2 (France); Wilkie-Chancellier, N.; Martinez, L.; Serfaty, S. [SATIE, UMR CNRS 8029, Université de Cergy-Pontoise, ENS Cachan, 95000 Cergy-Pontoise Cedex (France); Detalle, V. [LRMH USR 3224, 29 rue de Paris, 77420 Champs-sur-Marne (France)

    2015-01-01

    The aim of this paper is to identify the different periods of construction or restoration of the lead roof of a historic monument. Trace elements in a lead matrix can be a signature of the metallurgical processes, allowing identification of a specific time period for the production of the lead used to build the roof. The ability of LIBS (Laser Induced Breakdown Spectroscopy) to detect such trace elements in a lead matrix is therefore explored and checked by comparing its results with LA-ICP-MS as a reference method (Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry). Concentrations of 263 samples were compared between LIBS and LA-ICP-MS data and their correlation was evaluated. Another way to compare their results is also suggested by combining PCA (Principal Component Analysis) and GIS (Geographic Information System). As a result statistical mappings were created, highlighting metallurgical groups of samples across the roof of the building. This innovative approach links concentration and spatial location resulting in an easily interpretable graphical presentation of the data. The results of both spectrometry methods lead to similar conclusions with distinctive areas of different lead compositions and by extension different lead dating across the roof. But since LIBS is portable we can conclude that it is a suitable and reliable instrument for in-situ applications on historic monuments. - Highlights: • Quantification of trace elements (Ag, Bi, Cu and Sn) in a lead matrix by LIBS and LA-ICP-MS • Low limit of detection for Ag, Bi, Cu and Sn by using LIBS portable instrumentation • Set up a specific data processing combining PCA and GIS for cultural heritage application • Comparison of LIBS and LA-ICP-MS results with 263 samples • 488 samples analyzed by LIBS.

  20. Surface element-mapping of three dimensional structures by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    During lateral mapping with laser-induced breakdown spectroscopy (LIBS) the focal position of the plasma-generating laser needs to be kept stable on the sample surface area to be probed. Therefore, three-dimensional structures like edged surfaces require a permanent re-focusing. We describe a new auto-focusing technique to perform surface elemental mapping with LIBS by correcting the focusing lens-to-sample distance using a direct monitoring of the LIBS signal intensity. This method allows the scanning of surfaces with strong height fluctuations of several millimeters without the need of any additional devices. The auto-focusing method is valuable for LIBS applications made on complex-shaped samples or simply to improve the measurement reproducibility. Applications are LIBS analyses of samples exhibiting drill holes or steep edges. Our procedure does not need a constant focal plane and follows the topographic profile of the sample surface. Impurities and material inclusions are well detected. From the topographic information additionally obtained, a three-dimensional image of the sample can be deduced. Depth resolution is limited by the Rayleigh range of the LIBS laser light. The method is best suited for low energy laser pulses with high repetition rate and infrared emission. - Highlights: • We describe an automatically focusing technique for lateral LIBS mapping of uneven samples. • No additional devices are required for focusing. • No vignetting occurs since the focusing information is derived directly from the plasma spectrum itself. • Improved accuracy and reproducibility of elemental analysis • We present several examples with complex-shaped, sharply edged surfaces

  1. Evaluation of laser-induced breakdown spectroscopy analysis potential for addressing radiological threats from a distance

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, I.; Serrano, J.; Moros, J.; Laserna, J.J., E-mail: laserna@uma.es

    2014-06-01

    Although radioactive materials are nowadays valuable tools in nearly all fields of modern science and technology, the dangers stemming from the uncontrolled use of ionizing radiation are more than evident. Since preparedness is a key issue to face the risks of a radiation dispersal event, development of rapid and efficient monitoring technologies to control the contamination caused by radioactive materials is of crucial interest. Laser-induced breakdown spectroscopy (LIBS) exhibits appealing features for this application. This research focuses on the assessment of LIBS potential for the in-situ fingerprinting and identification of radioactive material surrogates from a safe distance. LIBS selectivity and sensitivity to detect a variety of radioactive surrogates, namely {sup 59}Co, {sup 88}Sr, {sup 130}Ba, {sup 133}Cs, {sup 193}Ir and {sup 238}U, on the surface of common urban materials at a distance of 30 m have been evaluated. The performance of the technique for nuclear forensics has been also studied on different model scenarios. Findings have revealed the difficulties to detect and to identify the analytes depending on the surface being interrogated. However, as demonstrated, LIBS shows potential enough for prompt and accurate gathering of essential evidence at a number of sites after the release, either accidental or intentional, of radioactive material. The capability of standoff analysis confers to LIBS unique advantages in terms of fast and safe inspection of forensic scenarios. The identity of the radioactive surrogates is easily assigned from a distance and the sensitivity to their detection is in the range of a few hundreds of ng per square centimeter. - Highlights: • Distant identification of radioactive surrogates on urban surfaces has been proved. • LIBS sensitivity to distant detection of radioactive surrogates has been checked. • Influences of the atmosphere on emission signals have been ascertained. • Usage of standoff LIBS for identifying

  2. Trace element quantification of lead based roof sheets of historical monuments by Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    The aim of this paper is to identify the different periods of construction or restoration of the lead roof of a historic monument. Trace elements in a lead matrix can be a signature of the metallurgical processes, allowing identification of a specific time period for the production of the lead used to build the roof. The ability of LIBS (Laser Induced Breakdown Spectroscopy) to detect such trace elements in a lead matrix is therefore explored and checked by comparing its results with LA-ICP-MS as a reference method (Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry). Concentrations of 263 samples were compared between LIBS and LA-ICP-MS data and their correlation was evaluated. Another way to compare their results is also suggested by combining PCA (Principal Component Analysis) and GIS (Geographic Information System). As a result statistical mappings were created, highlighting metallurgical groups of samples across the roof of the building. This innovative approach links concentration and spatial location resulting in an easily interpretable graphical presentation of the data. The results of both spectrometry methods lead to similar conclusions with distinctive areas of different lead compositions and by extension different lead dating across the roof. But since LIBS is portable we can conclude that it is a suitable and reliable instrument for in-situ applications on historic monuments. - Highlights: • Quantification of trace elements (Ag, Bi, Cu and Sn) in a lead matrix by LIBS and LA-ICP-MS • Low limit of detection for Ag, Bi, Cu and Sn by using LIBS portable instrumentation • Set up a specific data processing combining PCA and GIS for cultural heritage application • Comparison of LIBS and LA-ICP-MS results with 263 samples • 488 samples analyzed by LIBS

  3. Laser-induced breakdown spectroscopy for in situ qualitative and quantitative analysis of mineral ores

    International Nuclear Information System (INIS)

    In this work, the potential of laser-induced breakdown spectroscopy (LIBS) for discrimination and analysis of geological materials was examined. The research was focused on classification of mineral ores using their LIBS spectra prior to quantitative determination of copper. Quantitative analysis is not a trivial task in LIBS measurement because intensities of emission lines in laser-induced plasmas (LIP) are strongly affected by the sample matrix (matrix effect). To circumvent this effect, typically matrix-matched standards are used to obtain matrix-dependent calibration curves. If the sample set consists of a mixture of different matrices, even in this approach, the corresponding matrix has to be known prior to the downstream data analysis. For this categorization, the multielemental character of LIBS spectra can be of help. In this contribution, a principal component analysis (PCA) was employed on the measured data set to discriminate individual rocks as individual matrices against each other according to their overall elemental composition. Twenty-seven igneous rock samples were analyzed in the form of fine dust, classified and subsequently quantitatively analyzed. Two different LIBS setups in two laboratories were used to prove the reproducibility of classification and quantification. A superposition of partial calibration plots constructed from the individual clustered data displayed a large improvement in precision and accuracy compared to the calibration plot constructed from all ore samples. The classification of mineral samples with complex matrices can thus be recommended prior to LIBS system calibration and quantitative analysis. - Highlights: • Twenty seven igneous rocks were measured on different LIBS systems. • Principal component analysis (PCA) was employed for classification. • The necessity of the classification of the rock (ore) samples prior to the quantification analysis is stressed. • Classification based on the whole LIP spectra and

  4. Quantitative analyses of glass via laser-induced breakdown spectroscopy in argon

    International Nuclear Information System (INIS)

    We demonstrate that elemental analysis of glass with a measurement precision of about 10% can be performed via calibration-free laser-induced breakdown spectroscopy. Therefore, plasma emission spectra recorded during ultraviolet laser ablation of different glasses are compared to the spectral radiance computed for a plasma in local thermodynamic equilibrium. Using an iterative calculation algorithm, we deduce the relative elemental fractions and the plasma properties from the best agreement between measured and computed spectra. The measurement method is validated in two ways. First, the LIBS measurements are performed on fused silica composed of more than 99.9% of SiO2. Second, the oxygen fractions measured for heavy flint and barite crown glasses are compared to the values expected from the glass composing oxides. The measured compositions are furthermore compared with those obtained by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy. It is shown that accurate LIBS analyses require spectra recording with short enough delays between laser pulse and detector gate, when the electron density is larger than 1017 cm−3. The results show that laser-induced breakdown spectroscopy based on accurate plasma modeling is suitable for elemental analysis of complex materials such as glasses, with an analytical performance comparable or even better than that obtained with standard techniques. - Highlights: • Plasma modeling including the calculation of the plasma pressure • Calibration-free LIBS based on accurate modeling of the plasma emission spectrum • Quantitative LIBS analysis of multicomponent optical glasses including oxygen • Good measurement accuracy obtained only for small delays between laser pulse and detector gate

  5. Quantitative analyses of glass via laser-induced breakdown spectroscopy in argon

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard, C. [Laboratory of Laser and Plasma Technologies, University of Applied Sciences and Arts, Von-Ossietzky-Straße 99, 37085 Göttingen (Germany); Hermann, J., E-mail: Hermann@lp3.univ-mrs.fr [LP3, CNRS – Aix–Marseille University, 163 Av. de Luminy, 13288 Marseille (France); Mercadier, L. [LP3, CNRS – Aix–Marseille University, 163 Av. de Luminy, 13288 Marseille (France); Loewenthal, L. [Laboratory of Laser and Plasma Technologies, University of Applied Sciences and Arts, Von-Ossietzky-Straße 99, 37085 Göttingen (Germany); Axente, E.; Luculescu, C.R. [Laser–Surface–Plasma Interactions Laboratory, Lasers Department, National Institute for Lasers, Plasma and Radiation Physics, Măgurele (Romania); Sarnet, T.; Sentis, M. [LP3, CNRS – Aix–Marseille University, 163 Av. de Luminy, 13288 Marseille (France); Viöl, W. [Laboratory of Laser and Plasma Technologies, University of Applied Sciences and Arts, Von-Ossietzky-Straße 99, 37085 Göttingen (Germany)

    2014-11-01

    We demonstrate that elemental analysis of glass with a measurement precision of about 10% can be performed via calibration-free laser-induced breakdown spectroscopy. Therefore, plasma emission spectra recorded during ultraviolet laser ablation of different glasses are compared to the spectral radiance computed for a plasma in local thermodynamic equilibrium. Using an iterative calculation algorithm, we deduce the relative elemental fractions and the plasma properties from the best agreement between measured and computed spectra. The measurement method is validated in two ways. First, the LIBS measurements are performed on fused silica composed of more than 99.9% of SiO{sub 2}. Second, the oxygen fractions measured for heavy flint and barite crown glasses are compared to the values expected from the glass composing oxides. The measured compositions are furthermore compared with those obtained by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy. It is shown that accurate LIBS analyses require spectra recording with short enough delays between laser pulse and detector gate, when the electron density is larger than 10{sup 17} cm{sup −3}. The results show that laser-induced breakdown spectroscopy based on accurate plasma modeling is suitable for elemental analysis of complex materials such as glasses, with an analytical performance comparable or even better than that obtained with standard techniques. - Highlights: • Plasma modeling including the calculation of the plasma pressure • Calibration-free LIBS based on accurate modeling of the plasma emission spectrum • Quantitative LIBS analysis of multicomponent optical glasses including oxygen • Good measurement accuracy obtained only for small delays between laser pulse and detector gate.

  6. Spectral analysis of rare earth elements using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Martin, Madhavi Z.; Fox, Robert V.; Miziolek, Andrzej W.; DeLucia, Frank C.; André, Nicolas

    2015-06-01

    There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to be able to quantify the concentrations of various REEs in realworld complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.

  7. Spectral Analysis of Rare Earth Elements using Laser-Induced Breakdown Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Madhavi Z. Martin; Robert V. Fox; Andrzej W. Miziolek; Frank C. DeLucia, Jr.; Nicolas Andre

    2001-05-01

    There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to be able to quantify the concentrations of various REEs in realworld complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.

  8. Spectral Analysis of Rare Earth Elements using Laser-Induced Breakdown Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Madhavi Z [ORNL; Fox, Dr. Richard V [Idaho National Laboratory (INL); Miziolek, Andrzej W [United States Army Research Laboratory; DeLucia, Frank C [United States Army Research Laboratory; Andre, Nicolas O [ORNL

    2015-01-01

    There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to be able to quantify the concentrations of various REEs in real-world complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.

  9. Spectral Analysis of Rare Earth Elements using Laser-Induced Breakdown Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Madhavi Z [ORNL; Fox, Dr. Richard V [Idaho National Laboratory (INL); Miziolek, Andrzej W [United States Army Research Laboratory; DeLucia, Frank C [United States Army Research Laboratory; Andre, Nicolas O [ORNL

    2015-01-01

    There is growing interest in rapid analysis of rare earth elements (REEs) both due to the need to find new natural sources to satisfy increased demand in their use in various electronic devices, as well as the fact that they are used to estimate actinide masses for nuclear safeguards and nonproliferation. Laser-Induced Breakdown Spectroscopy (LIBS) appears to be a particularly well-suited spectroscopy-based technology to rapidly and accurately analyze the REEs in various matrices at low concentration levels (parts-per-million). Although LIBS spectra of REEs have been reported for a number of years, further work is still necessary in order to be able to quantify the concentrations of various REEs in realworld complex samples. LIBS offers advantages over conventional solution-based radiochemistry in terms of cost, analytical turnaround, waste generation, personnel dose, and contamination risk. Rare earth elements of commercial interest are found in the following three matrix groups: 1) raw ores and unrefined materials, 2) as components in refined products such as magnets, lighting phosphors, consumer electronics (which are mostly magnets and phosphors), catalysts, batteries, etc., and 3) waste/recyclable materials (aka e-waste). LIBS spectra for REEs such as Gd, Nd, and Sm found in rare earth magnets are presented.

  10. X-ray photoelectron spectroscopy of nonlinear LiB3O5 crystal

    International Nuclear Information System (INIS)

    Electronic structure of LiB3O5 crystals has been studied by the method of X-ray electron spectroscopy. The results presented show that electronic structure of the perfect LBO is determined mainly by B3O5 boron-oxygen skeleton. The crystals of LiB3O5 possess very low chemical activity. An alkali component of lithium triborate is found not to reach the crystal surface. 9 refs., 2 figs

  11. Elemental analysis of tissue pellets for the differentiation of epidermal lesion and normal skin by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Moon, Youngmin; Han, Jung Hyun; Shin, Sungho; Kim, Yong-Chul; Jeong, Sungho

    2016-05-01

    By laser induced breakdown spectroscopy (LIBS) analysis of epidermal lesion and dermis tissue pellets of hairless mouse, it is shown that Ca intensity in the epidermal lesion is higher than that in dermis, whereas Na and K intensities have an opposite tendency. It is demonstrated that epidermal lesion and normal dermis can be differentiated with high selectivity either by univariate or multivariate analysis of LIBS spectra with an intensity ratio difference by factor of 8 or classification accuracy over 0.995, respectively. PMID:27231610

  12. Spatial and Temporal Dependence of Interspark Interactions in Femtosecond-Nanosecond Dual-Pulse Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Scaffidi, Jon; Pearman, William; Lawrence, Marion; Chance Carter, J.; Colston, Bill W., Jr.; Angel, S. Michael

    2004-09-01

    A femtosecond air spark has recently been combined with a nanosecond ablative pulse in order to map the spatial and temporal interactions of the two plasmas in femtosecond-nanosecond orthogonal preablation spark dual-pulse laser-induced breakdown spectroscopy (LIBS). Good spatial and temporal correlation was found for reduced atomic emission from atmospheric species (nitrogen and oxygen) and increased atomic emission from ablated species (copper and aluminum) in the femtosecond-nanosecond plasma, suggesting a potential role for atmospheric pressure or nitrogen/oxygen concentration reduction following air spark formation in generating atomic emission enhancements in dual-pulse LIBS.

  13. Nanoparticle Enhanced Laser Induced Breakdown Spectroscopy: Effect of nanoparticles deposited on sample surface on laser ablation and plasma emission

    International Nuclear Information System (INIS)

    In this paper the use of metallic nanoparticles (NPs) for improving Laser Induced Breakdown Spectroscopy (LIBS) is discussed. In the case of conductors an emission signal enhancement up to 1–2 orders of magnitude was obtained depositing NPs on the sample surface by drying a micro-drop of colloidal solution. The basic mechanisms of Nanoparticle Enhanced LIBS (NELIBS) were studied and the main causes of this significantly large enhancement were found to be related to the effect of NPs on the laser ablation process, in terms of a faster and more efficient production of seed electrons with respect to conventional LIBS. The characteristics of NELIBS-produced plasma were investigated by emission spectroscopy and spectrally resolved images. In spite of similar plasma parameters, the NELIBS plasma was found to have larger emission volume and longer persistence than the LIBS one. A method to determine NP concentration and size was also proposed, which involved depositing NPs on non-interacting substrates, and proved the feasibility of LIBS as a fast detection tool for a preliminary characterization of NPs. - Highlights: • Effect of NPs on sample surface enables instantaneous field emission. • More efficient ablation • LIBS emission enhancement up to 1–2 orders of magnitude • Possibility of NP characterization in terms of concentration and size

  14. Fusion related research with laser-induced-breakdown-spectroscopy on metallic samples at the ENEA-Frascati laboratory.

    Science.gov (United States)

    Almaviva, S.; Caneve, L.; Colao, F.; Maddaluno, G.

    2016-04-01

    The study of plasma-wall interactions is of paramount importance for continuous and fault free operations in thermonuclear fusion research to monitor the damages of plasma facing components (PFCs), plasma pollution from impurities and wall retention of hydrogen isotopes, like tritium. These needs make laser-induced-breakdown-spectroscopy (LIBS) a suitable candidate for a real time monitoring of PFCs in the current and next generation fusion devices, like ITER. It is also worthwhile for the quantitative analysis of surfaces, with micro-destructivity of the sample and depth profiling capabilities with sub-micrometric sensitivity. In this paper LIBS spectroscopy is exploited as a valid diagnostic tool for PFCs at the ENEA Research Center in Frascati (Italy) and at the Institute of Plasma Physics and Laser Microfusion (IPPLM) of Warsaw (Poland). The activities have been focused on LIBS characterization of samples simulating PFCs surfaces eroded/redeposited or contaminated from nuclear fuel after or during the normal operation of the reactor.

  15. Variational study of the constituents of cholesterol stones by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Singh, Vivek K; Rai, Vinita; Rai, A K

    2009-01-01

    The major and minor constituents of cholesterol gallstones were investigated by Laser-induced breakdown spectroscopy. The elements detected in the center and in the shell part were calcium (Ca), carbon (C), copper (Cu), hydrogen (H), magnesium (Mg), nitrogen (N), sodium (Na), oxygen (O) and potassium (K), but Cu was absent from the surface of the cholesterol gallstones. Our experimental results revealed that calcium was a major constituent of cholesterol gallstones. Our results also showed that the concentration of Ca, Cu and Mg were large in the center in comparison with the shell. Laser-induced breakdown (LIB) spectra of both portions of the surface (colored part and discolored part) of the cholesterol gallstones were recorded. The concentrations of sodium and potassium were higher in the non-pigmented (colored) part than in the pigmented part (discolored/pigment), which showed that the deficiency of sodium and potassium was playing a key role in the formation of discoloration at the different locations on the outer surfaces of the cholesterol gallstones. Thus, laser-induced breakdown spectroscopy (LIBS) is a suitable technique for the analysis of cholesterol gallstones without any sample preparation. PMID:18043957

  16. Quantitative analyses of glass via laser-induced breakdown spectroscopy in argon

    Science.gov (United States)

    Gerhard, C.; Hermann, J.; Mercadier, L.; Loewenthal, L.; Axente, E.; Luculescu, C. R.; Sarnet, T.; Sentis, M.; Viöl, W.

    2014-11-01

    We demonstrate that elemental analysis of glass with a measurement precision of about 10% can be performed via calibration-free laser-induced breakdown spectroscopy. Therefore, plasma emission spectra recorded during ultraviolet laser ablation of different glasses are compared to the spectral radiance computed for a plasma in local thermodynamic equilibrium. Using an iterative calculation algorithm, we deduce the relative elemental fractions and the plasma properties from the best agreement between measured and computed spectra. The measurement method is validated in two ways. First, the LIBS measurements are performed on fused silica composed of more than 99.9% of SiO2. Second, the oxygen fractions measured for heavy flint and barite crown glasses are compared to the values expected from the glass composing oxides. The measured compositions are furthermore compared with those obtained by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy. It is shown that accurate LIBS analyses require spectra recording with short enough delays between laser pulse and detector gate, when the electron density is larger than 1017 cm- 3. The results show that laser-induced breakdown spectroscopy based on accurate plasma modeling is suitable for elemental analysis of complex materials such as glasses, with an analytical performance comparable or even better than that obtained with standard techniques.

  17. Laser induced incandescence and laser induced breakdown spectroscopy based sensor development

    Science.gov (United States)

    Eseller, Kemal Efe

    In this doctoral dissertation, two laser-based sensors were evaluated for different applications. Laser Induced Incandescence (LII) is a technique which can provide non-intrusive quantitative measurement of soot and it provides a unique diagnostic tool to characterize engine performance. Since LII is linearly proportional to the soot volume fraction, it can provide in situ, real time measurement of soot volume fraction with high temporal and spatial resolution. LII has the capability to characterize soot formation during combustion. The soot volume fraction from both flames and a soot generator was investigated with LII. The effects of experimental parameters, such as laser fluence, gate delay, gate width and various laser beam focusing, on LII signal was studied. Laser Induced Breakdown Spectroscopy (LIBS), a diagnostic tool for in situ elemental analysis, has been evaluated for on-line, simultaneous, multi-species impurity monitoring in hydrogen. LIBS spectra with different impurity levels of nitrogen, argon, and oxygen were recorded and the intensity of the spectral lines of Ar, O, N, and H observed were used to form calibration plots for impurities in hydrogen measurements. An ungated detection method for LIBS has been developed and applied to equivalence ratio measurements of CH4/air and biofuel/air. LIBS has also been used to quantitatively analyze the composition of a slurry sample. The quenching effect of water in slurry samples causes low LIBS signal quality with poor sensitivity. Univariate and multivariate calibration was performed on LIBS spectra of dried slurry samples for elemental analysis of Mg, Si and Fe. Calibration results show that the dried slurry samples give good correlation between spectral intensity and elemental concentration.

  18. 3D Imaging of Nanoparticle Distribution in Biological Tissue by Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Gimenez, Y.; Busser, B.; Trichard, F.; Kulesza, A.; Laurent, J. M.; Zaun, V.; Lux, F.; Benoit, J. M.; Panczer, G.; Dugourd, P.; Tillement, O.; Pelascini, F.; Sancey, L.; Motto-Ros, V.

    2016-07-01

    Nanomaterials represent a rapidly expanding area of research with huge potential for future medical applications. Nanotechnology indeed promises to revolutionize diagnostics, drug delivery, gene therapy, and many other areas of research. For any biological investigation involving nanomaterials, it is crucial to study the behavior of such nano-objects within tissues to evaluate both their efficacy and their toxicity. Here, we provide the first account of 3D label-free nanoparticle imaging at the entire-organ scale. The technology used is known as laser-induced breakdown spectroscopy (LIBS) and possesses several advantages such as speed of operation, ease of use and full compatibility with optical microscopy. We then used two different but complementary approaches to achieve 3D elemental imaging with LIBS: a volume reconstruction of a sliced organ and in-depth analysis. This proof-of-concept study demonstrates the quantitative imaging of both endogenous and exogenous elements within entire organs and paves the way for innumerable applications.

  19. Quantitative mixture fraction measurements in combustion system via laser induced breakdown spectroscopy

    KAUST Repository

    Mansour, Mohy S.

    2015-01-01

    Laser induced breakdown spectroscopy (LIBS) technique has been applied to quantitative mixture fraction measurements in flames. The measured spectra of different mixtures of natural gas and air are used to obtain the calibration parameters for local elemental mass fraction measurements and hence calculate the mixture fraction. The results are compared with the mixture fraction calculations based on the ratios of the spectral lines of H/N elements, H/O elements and C/(N+O) and they show good agreement within the reaction zone of the flames. Some deviations are observed outside the reaction zone. The ability of LIBS technique as a tool for quantitative mixture fraction as well as elemental fraction measurements in reacting and non-reacting of turbulent flames is feasible. © 2014 Elsevier Ltd. All rights reserved.

  20. Parametric Study of Pellets for Elemental Analysis with Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Lal, Bansi; Zheng, Hongbo; Yueh, Fang-Yu; Singh, Jagdish P.

    2004-05-01

    The effect of various parameters on the accuracy of the laser-induced breakdown spectroscopy (LIBS) data taken from pellet samples has been investigated. The dependence of the standard deviation of the LIBS data on the amount and nature of the binder used, pressure used to press the powder into a pellet, and the position of the focal spot on the pellet has been investigated. Pellets made from industrially important materials such as silica, alumina, and lime with polyvinyl alcohol, sucrose, and starch as binders have been studied. The results thus obtained are tested by preparation of the calibration curves for Si, Fe, and B in the pellets made from the powder glass batch used as a surrogate for the batch employed for the vitrification of radioactive waste.

  1. Validation of the solidifying soil process using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Lin, Zhao-Xiang; Liu, Lin-Mei; Liu, Lu-Wen

    2016-09-01

    Although an Ionic Soil Stabilizer (ISS) has been widely used in landslide control, it is desirable to effectively monitor the stabilization process. With the application of laser-induced breakdown spectroscopy (LIBS), the ion contents of K, Ca, Na, Mg, Al, and Si in the permeable fluid are detected after the solidified soil samples have been permeated. The processes of the Ca ion exchange are analyzed at pressures of 2 and 3 atm, and it was determined that the cation exchanged faster as the pressure increased. The Ca ion exchanges were monitored for different stabilizer mixtures, and it was found that a ratio of 1:200 of ISS to soil is most effective. The investigated plasticity and liquidity indexes also showed that the 1:200 ratio delivers the best performance. The research work indicates that it is possible to evaluate the engineering performances of soil solidified by ISS in real time and online by LIBS.

  2. Quantitative analysis of impurities in aluminum alloys by laser-induced breakdown spectroscopy without internal calibration

    Institute of Scientific and Technical Information of China (English)

    LI Hong-kun; LIU Ming; CHEN Zhi-jiang; LI Run-hua

    2008-01-01

    To develop a fast and sensitive alloy elemental analysis method, a laser-induced breakdown spectroscopy(LIBS) system was established and used to carry out quantitative analysis of impurities in aluminum alloys in air at atmospheric pressure. A digital storage oscilloscope was used as signal recording instrument, instead of traditional gate integrator or Boxcar averager, to reduce the cost of the whole system. Linear calibration curves in the concentration range of 4×10-5-10-2 are built for Mg, Cr, Mn, Cu and Zn using absolute line intensity without internal calibrations. Limits of detection for these five elements in aluminum alloy are determined to be (2-90)×10-6. It is demonstrated that LIBS can provide quantitative trace elemental analysis in alloys even without internal calibration. This approach is easy to use in metallurgy industries and relative research fields.

  3. Application of laser-induced breakdown spectroscopy to the analysis of algal biomass for industrial biotechnology

    Science.gov (United States)

    Pořízka, P.; Prochazka, D.; Pilát, Z.; Krajcarová, L.; Kaiser, J.; Malina, R.; Novotný, J.; Zemánek, P.; Ježek, J.; Šerý, M.; Bernatová, S.; Krzyžánek, V.; Dobranská, K.; Novotný, K.; Trtílek, M.; Samek, O.

    2012-08-01

    We report on the application of laser-induced breakdown spectroscopy (LIBS) to the determination of elements distinctive in terms of their biological significance (such as potassium, magnesium, calcium, and sodium) and to the monitoring of accumulation of potentially toxic heavy metal ions in living microorganisms (algae), in order to trace e.g. the influence of environmental exposure and other cultivation and biological factors having an impact on them. Algae cells were suspended in liquid media or presented in a form of adherent cell mass on a surface (biofilm) and, consequently, characterized using their spectra. In our feasibility study we used three different experimental arrangements employing double-pulse LIBS technique in order to improve on analytical selectivity and sensitivity for potential industrial biotechnology applications, e.g. for monitoring of mass production of commercial biofuels, utilization in the food industry and control of the removal of heavy metal ions from industrial waste waters.

  4. Qualitative and quantitative laser-induced breakdown spectroscopy of bronze objects

    Science.gov (United States)

    Tankova, V.; Blagoev, K.; Grozeva, M.; Malcheva, G.; Penkova, P.

    2016-03-01

    Laser-induced breakdown spectroscopy (LIBS) is an analytical technique for qualitative and quantitative elemental analysis of solids, liquids and gases. In this work, the method was applied for investigation of archaeological bronze objects. The analytical information obtained by LIBS was used for qualitative determination of the elements in the material used for manufacturing of the objects under study. Quantitative chemical analysis was also performed after generating calibration curves with standard samples of similar matrix composition. Quantitative estimation of the elemental concentration of the bulk of the samples was performed, together with investigation of the surface layer of the objects. The results of the quantitative analyses gave indications about the manufacturing process of the investigated objects.

  5. Detection sensitivity of laser-induced breakdown spectroscopy for Cr II in liquid samples

    International Nuclear Information System (INIS)

    The performance of laser-induced breakdown spectroscopy (LIBS) has been evaluated for detection of toxic metals such as Cr in water. Pure aqueous solutions (unitary matrix) with variable Cr concentration were used to construct calibration curves and to estimate the LIBS limit of detection (LOD). The calibration curves for Cr in a binary matrix (Cr plus Cd) and a tertiary matrix (Cr plus Cd and Co) were used to evaluate the matrix effect on the LOD. The LOD for Cr was found to be 1.1, 1.5, and 2.0 ppm (parts in 106) in a unitary, binary, and tertiary matrix, respectively. Once calibrated, the system was utilized for the detection and quantification of the Cr in tannery wastewater collected from different locations in the industrial area of Kanpur, India, where Cr concentrations were determined to be far higher than the U.S. Environmental Protection Agency safe drinking water limit of 0.05 ppm

  6. Determination of Different Metals in Steel Waste Samples Using laser Induced Breakdown Spectroscopy

    Directory of Open Access Journals (Sweden)

    A. H. Bakry

    2007-12-01

    Full Text Available Elemental analysis of waste samples collected from steel products manufacturing plant (SPS located at industrial city of Jeddah, Saudi-Arabia has been carried out using Laser Induced Breakdown Spectroscopy (LIBS. The 1064 nm laser radiations from a Nd:YAG laser at an irradiance of 7.6  1010 W cm –2 were used. Atomic emission spectra of the elements present in the waste samples were recorded in the 200 – 620 nm region. Elements such as Fe, W, Ti, Al, Mg, Ca, S, Mn, and Na were detected in these samples. Quantitative determination of the elemental concentration was obtained for these metals against certified standard samples. Parametric dependences of LIBS signal intensity on incident laser energy and time delay between the laser pulse and data acquisition system were also carried out.

  7. Fiber optic laser-induced breakdown spectroscopy sensor for molten material analysis

    Science.gov (United States)

    Zhang, Hansheng; Rai, Awadesh K.; Singh, Jagdish P.; Yueh, Fang-Yu

    2004-07-13

    A fiber optic laser-induced breakdown spectroscopy (LIBS) sensor, including a laser light source, a harmonic separator for directing the laser light, a dichroic mirror for reflecting the laser light, a coupling lens for coupling the laser light at an input of a multimode optical fiber, a connector for coupling the laser light from an output of the multimode optical fiber to an input of a high temperature holder, such as a holder made of stainless steel, and a detector portion for receiving emission signal and analyzing LIBS intensities. In one variation, the multimode optical fiber has silica core and silica cladding. The holder includes optical lenses for collimating and focusing the laser light in a molten alloy to produce a plasma, and for collecting and transmitting an emission signal to the multimode optical fiber.

  8. In situ chemical imaging of lithiated tungsten using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Li, Cong; Wu, Xingwei; Zhang, Chenfei; Ding, Hongbin; Hu, Jiansheng; Luo, Guang-Nan

    2014-09-01

    Lithium conditioning can significantly improve the plasma confinement of EAST tokamak by reducing the amount of hydrogen and impurities recycled from the wall, but the details of this mechanism and approaches that reduce the concentrations of hydrogen and impurities recycle still remain unclear. In this paper, we studied lithiated tungsten via a cascaded-arc plasma simulator. An in situ laser-induced breakdown spectroscopy (LIBS) diagnostic system has been developed to chemically image the three-dimensional distribution of lithium and impurities on the surface of lithiated tungsten co-deposition layer for the first time. The results indicate that lithium has a strong ability to draw hydrogen and oxygen. The impurity components from the co-deposition processes present more intensity on the surface of co-deposition layer. This work improves the understanding of lithiated tungsten mechanism and is useful for using LIBS as a wall-diagnostic technique for EAST.

  9. In situ chemical imaging of lithiated tungsten using laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Cong; Wu, Xingwei; Zhang, Chenfei [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Chinese Ministry of Education, School of Physics and Optical Electronic Technology, Dalian University of Technology, Dalian 116024 (China); Ding, Hongbin, E-mail: hding@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Chinese Ministry of Education, School of Physics and Optical Electronic Technology, Dalian University of Technology, Dalian 116024 (China); Hu, Jiansheng; Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei 230031 (China)

    2014-09-15

    Lithium conditioning can significantly improve the plasma confinement of EAST tokamak by reducing the amount of hydrogen and impurities recycled from the wall, but the details of this mechanism and approaches that reduce the concentrations of hydrogen and impurities recycle still remain unclear. In this paper, we studied lithiated tungsten via a cascaded-arc plasma simulator. An in situ laser-induced breakdown spectroscopy (LIBS) diagnostic system has been developed to chemically image the three-dimensional distribution of lithium and impurities on the surface of lithiated tungsten co-deposition layer for the first time. The results indicate that lithium has a strong ability to draw hydrogen and oxygen. The impurity components from the co-deposition processes present more intensity on the surface of co-deposition layer. This work improves the understanding of lithiated tungsten mechanism and is useful for using LIBS as a wall-diagnostic technique for EAST.

  10. Suitability of laser-induced breakdown spectroscopy in screening potential additives to mitigate fouling deposits

    Science.gov (United States)

    Balakrishnan, S.; Midhun Reddy, V.; Mehta, A.; Vasa, N. J.; Nagarajan, R.

    2016-04-01

    Alkali vapors present in the flue gas generated during coal-based combustion form fouling deposits as they condense. An additive added to coal can trap alkali elements in ash, therefore suppress the growth rate of fouling deposits, and increase thermal efficiency of a coal-fired thermal power plant. Laser-induced breakdown spectroscopy (LIBS) technique is proposed and demonstrated to screen potential additives to trap alkali elements in ash. Five additives—namely, kaolinite, alumina, silica, magnesia, and pumice—were analyzed for their effectiveness on four Indian coals for retaining/confining alkali elements in ash during coal combustion. Ratio analysis based on LIBS emission intensity values clearly shows that kaolinite and pumice are promising additives to trap sodium. Similarly, kaolinite, pumice, and silica exhibited good potassium retention.

  11. Identification of inks and structural characterization of contemporary artistic prints by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Identification of the inks used in artistic prints and the order in which different ink layers have been applied on a paper substrate are important factors to complement the classical stylistic aspects for the authentication of this type of objects. Laser-induced breakdown spectroscopy (LIBS) is investigated to determine the chemical composition and structural distribution of the constituent materials of model prints made by applying one or two layers of several blue and black inks on an Arches paper substrate. By using suitable laser excitation conditions, identification of the inks was possible by virtue of emissions from key elements present in their composition. Analysis of successive spectra on the same spot allowed the identification of the order in which the inks were applied on the paper. The results show the potential of laser-induced breakdown spectroscopy for the chemical and structural characterization of artistic prints

  12. Identification of inks and structural characterization of contemporary artistic prints by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oujja, M. [Instituto de Quimica Fisica Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Vila, A. [Departament de Pintura, Conservacio-Restauracio, Facultat de Belles Arts, Universitat de Barcelona, Pau Gargallo 4, 08028 Barcelona (Spain); Rebollar, E. [Instituto de Quimica Fisica Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain); Garcia, J.F. [Departament de Pintura, Conservacio-Restauracio, Facultat de Belles Arts, Universitat de Barcelona, Pau Gargallo 4, 08028 Barcelona (Spain); Castillejo, M. [Instituto de Quimica Fisica Rocasolano, CSIC, Serrano 119, 28006 Madrid (Spain)]. E-mail: marta.castillejo@iqfr.csic.es

    2005-08-31

    Identification of the inks used in artistic prints and the order in which different ink layers have been applied on a paper substrate are important factors to complement the classical stylistic aspects for the authentication of this type of objects. Laser-induced breakdown spectroscopy (LIBS) is investigated to determine the chemical composition and structural distribution of the constituent materials of model prints made by applying one or two layers of several blue and black inks on an Arches paper substrate. By using suitable laser excitation conditions, identification of the inks was possible by virtue of emissions from key elements present in their composition. Analysis of successive spectra on the same spot allowed the identification of the order in which the inks were applied on the paper. The results show the potential of laser-induced breakdown spectroscopy for the chemical and structural characterization of artistic prints.

  13. Chemical and explosive detection with long-wave infrared laser induced breakdown spectroscopy

    Science.gov (United States)

    Jin, Feng; Trivedi, Sudhir B.; Yang, Clayton S.; Brown, Ei E.; Kumi-Barimah, Eric; Hommerich, Uwe H.; Samuels, Alan C.

    2016-05-01

    Conventional laser induced breakdown spectroscopy (LIBS) mostly uses silicon-based detectors and measures the atomic emission in the UV-Vis-NIR (UVN) region of the spectrum. It can be used to detect the elements in the sample under test, such as the presence of lead in the solder for electronics during RoHS compliance verification. This wavelength region, however, does not provide sufficient information on the bonding between the elements, because the molecular vibration modes emit at longer wavelength region. Measuring long-wave infrared spectrum (LWIR) in a LIBS setup can instead reveal molecular composition of the sample, which is the information sought in applications including chemical and explosive detection and identification. This paper will present the work and results from the collaboration of several institutions to develop the methods of LWIR LIBS for chemical/explosive/pharmaceutical material detection/identification, such as DMMP and RDX, as fast as using a single excitation laser pulse. In our latest LIBS setup, both UVN and LWIR spectra can be collected at the same time, allowing more accurate detection and identification of materials.

  14. Laser-induced breakdown spectroscopy measurements of uranium and thorium powders and uranium ore

    Science.gov (United States)

    Judge, Elizabeth J.; Barefield, James E., II; Berg, John M.; Clegg, Samuel M.; Havrilla, George J.; Montoya, Velma M.; Le, Loan A.; Lopez, Leon N.

    2013-05-01

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze depleted uranium and thorium oxide powders and uranium ore as a potential rapid in situ analysis technique in nuclear production facilities, environmental sampling, and in-field forensic applications. Material such as pressed pellets and metals, has been extensively studied using LIBS due to the high density of the material and more stable laser-induced plasma formation. Powders, on the other hand, are difficult to analyze using LIBS since ejection and removal of the powder occur in the laser interaction region. The capability of analyzing powders is important in allowing for rapid analysis of suspicious materials, environmental samples, or trace contamination on surfaces since it most closely represents field samples (soil, small particles, debris etc.). The rapid, in situ analysis of samples, including nuclear materials, also reduces costs in sample collection, transportation, sample preparation, and analysis time. Here we demonstrate the detection of actinides in oxide powders and within a uranium ore sample as both pressed pellets and powders on carbon adhesive discs for spectral comparison. The acquired LIBS spectra for both forms of the samples differ in overall intensity but yield a similar distribution of atomic emission spectral lines.

  15. Laser induced breakdown spectroscopy of pure aluminum with high temporal resolution.

    Science.gov (United States)

    Li, Yu-Tai; Liu, Tze-An; Chen, Chen-Wei; Lee, Yu-Hsien; Yabushita, Atsushi

    2013-09-01

    We report on a Laser Induced Breakdown Spectroscopy (LIBS) system with a very high temporal resolution, using femtosecond and picosecond pulse laser excitation of pure aluminum (Al). By using a 140 fs Ti:Sapphire laser in an ultrafast optical Kerr gate (OKG), we demonstrate LIBS sampling with a sub-ps time resolution (0.8 ± 0.08 ps) in a 14 ns window. The width of the gating window in this system was as narrow as 0.8 ps, owing to the inclusion of a carbon disulfide (CS(2)) cell, which has a fast response and a large nonlinear coefficient. Furthermore, when using a 100 ps pulsed Nd:YAG laser and a fast photomultiplier tube (PMT) we demonstrate a LIBS system with a nanosecond time resolution (2.20 ± 0.08 ns) in a microsecond window. With this sort of temporal resolution, a non-continuous decay in the Al signal could be observed. After 50 ns decay of the first peak, the second peak at 230 ns is started to perform. Experimental results with such short temporal windows in LIBS, in both nanosecond and microsecond ranges, are important for fast temporal evolution measurements and observations of early continuum emission in materials. PMID:24104032

  16. Optimization of liquid jet system for laser-induced breakdown spectroscopy analysis

    Science.gov (United States)

    Skočovská, Katarína; Novotný, Jan; Prochazka, David; Pořízka, Pavel; Novotný, Karel; Kaiser, Jozef

    2016-04-01

    A complex optimization of geometrical and temporal parameters of a jet system (developed in Laser-induced breakdown spectroscopy (LIBS) laboratory of Brno University of Technology) for direct elemental analysis of samples in a liquid state of matter using LIBS was carried out. First, the peristaltic pump was synchronized with the flashlamp of the ablation laser, which reduced variation of the ablated sample amount. Also, the fluctuation of the laser ray angle incident on the jet surface was diminished. Such synchronization reduced signal standard deviations and thus increased repeatability of the measurements. Then, laser energy and distance of the focusing lens from the sample were optimized. The gate delay time and the gate width were optimized for single pulse (SP) experiments; the gate delay time and the inter-pulse delay were optimized for the use of double pulse (DP) variant. Results were assessed according to the highest signal to noise ratios and the lowest relative standard deviations of the signal. The sensitivity of the single pulse and the double pulse LIBS for the detection of heavy metals traces, copper (Cu i at 324.754 nm) and lead (Pb i at 405.781 nm), in aqueous solution of copper (ii) sulfate and lead (ii) acetate, was estimated in terms of limits of detection (LODs). As a result, sensitivity improvement of DP LIBS system was observed, the LOD of Cu obtained with DP was calculated 40% lower than LOD gained from SP technique.

  17. Laser Induced Breakdown Spectroscopy machine for online ash analyses in coal

    International Nuclear Information System (INIS)

    Presently, online coal ash content monitoring is performed by PGNAA (Prompt Gamma Neutron Activation Analyses) machines. Laser Detect Systems has developed an online mineral analysis system using Laser Induced Breakdown Spectroscopy (LIBS). The main advantages of the system are that it is without a radioactive source, compact (1.5 m x 0.8 m x 1.3 m), comparatively light (250 kg) and easy to install. The main disadvantage is that a LIBS system analyzes surface chemistry of the mineral exclusively and not the volume. To prove the LIBS machine analytical ability for coal ash content evaluation, a trial was arranged at Optimum Colliery (South Africa). The LIBS machine was installed in line with a PGNAA machine and laboratory data served as a referee in the final assessment for analytical accuracy. The trial was carried out over a four month period. This paper presents the successful trial results achieved for accurate (at least +/- 0.5% mean absolute error) online coal ash content monitoring

  18. Studying the enhanced phytoremediation of lead contaminated soils via laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Phytoremediation popularly known as 'green clean technology' is a new promising technology used for toxic contaminants removal from the environment such as heavy metals (HMs), adopting suitable plants. This concept is increasingly being adopted as it is a cost effective and environmentally friendly alternative to traditional methods of treatment. This study was focused on using scented geranium, Pelargonium zonale, as accumulator or hyperaccumulator plant for natural lead extraction from artificially contaminated soil with different Pb concentrations (0, 2000, 5000, 7000 ppm). Utilization of EDTA as a chelator, that would permit higher metal availability and uptake by the tested plants roots, was also tested. Laser Induced Breakdown Spectroscopy (LIBS) was used to follow up Pb concentrations in both soil and plant green harvestable parts known as shoots, before, during and after lead addition in soil. LIBS measurements were conducted in a microdestructive way by focusing a high energy Nd:YAG laser, emitting at 1064 nm, on plant and soil samples previously dried, homogenized and pressed in pellets. The emitted LIBS spectra were acquired by a gated CCD after dispersion on a monochromator and analyzed to retrieve relative concentrations of the selected HM both in the soil and on plants as a function of the time after doping and eventual chelator addition. EDTA was found to enhance Pb uptake from the soil which increased with time, good correlation was found between LIBS and ICP-OES results of plant tissues spectrochemical analysis

  19. Quantitative estimation of carbonation and chloride penetration in reinforced concrete by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Eto, Shuzo; Matsuo, Toyofumi; Matsumura, Takuro; Fujii, Takashi; Tanaka, Masayoshi Y.

    2014-11-01

    The penetration profile of chlorine in a reinforced concrete (RC) specimen was determined by laser-induced breakdown spectroscopy (LIBS). The concrete core was prepared from RC beams with cracking damage induced by bending load and salt water spraying. LIBS was performed using a specimen that was obtained by splitting the concrete core, and the line scan of laser pulses gave the two-dimensional emission intensity profiles of 100 × 80 mm2 within one hour. The two-dimensional profile of the emission intensity suggests that the presence of the crack had less effect on the emission intensity when the measurement interval was larger than the crack width. The chlorine emission spectrum was measured without using the buffer gas, which is usually used for chlorine measurement, by collinear double-pulse LIBS. The apparent diffusion coefficient, which is one of the most important parameters for chloride penetration in concrete, was estimated using the depth profile of chlorine emission intensity and Fick's law. The carbonation depth was estimated on the basis of the relationship between carbon and calcium emission intensities. When the carbon emission intensity was statistically higher than the calcium emission intensity at the measurement point, we determined that the point was carbonated. The estimation results were consistent with the spraying test results using phenolphthalein solution. These results suggest that the quantitative estimation by LIBS of carbonation depth and chloride penetration can be performed simultaneously.

  20. Identification of meat species by using laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Bilge, Gonca; Velioglu, Hasan Murat; Sezer, Banu; Eseller, Kemal Efe; Boyaci, Ismail Hakki

    2016-09-01

    The aim of the present study is to identify meat species by using laser-induced breakdown spectroscopy (LIBS). Elemental composition differences between meat species were used for meat identification. For this purpose, certain amounts of pork, beef and chicken were collected from different sources and prepared as pellet form for LIBS measurements. The obtained LIBS spectra were evaluated with some chemometric methods, and meat species were qualitatively discriminated with principal component analysis (PCA) method with 83.37% ratio. Pork-beef and chicken-beef meat mixtures were also analyzed with partial least square (PLS) method quantitatively. Determination coefficient (R(2)) and limit of detection (LOD) values were found as 0.994 and 4.4% for pork adulterated beef, and 0.999 and 2.0% for chicken adulterated beef, respectively. In the light of the findings, it was seen that LIBS can be a valuable tool for quality control measurements of meat as a routine method. PMID:27179147

  1. Multivariate calibration of spectra obtained by Laser Induced Breakdown Spectroscopy of plutonium oxide surrogate residues

    International Nuclear Information System (INIS)

    Laser Induced Breakdown Spectroscopy (LIBS) was used to determine elemental concentration of plutonium oxide surrogate (cerium oxide) residue for monitoring the fabrication of lanthanide borosilicate glass. Quantitative analysis by LIBS is affected by the severe limitation of variation in the induced plasma due to changes in the matrix. Multivariate calibration was applied to LIBS data to predict the concentrations of Ce, Cr, Fe, Mo, and Ni. A total of 18 different samples were prepared to compare calibration from univariate data analysis and from multivariate data analysis. Multivariate calibration was obtained using Principal Component Regression (PCR) and Partial Least Squares (PLS). Univariate calibration was obtained from background-corrected atomic emission lines. Calibration results show improvement in the coefficient of determination from 0.87 to 0.97 for Ce compared to univariate calibration. The root mean square error also reduced from 7.46 to 2.93%. A similar trend was obtained for Cr, Fe, Mo, and Ni also. These results clearly demonstrate the feasibility of using LIBS for online process monitoring in a hazardous waste management environment.

  2. Stoichiometric Analysis of Inorganic Compounds Using Laser-Induced Breakdown Spectroscopy with Gated and Nongated Spectrometers

    OpenAIRE

    Sreedhar Sunku; Ashwin Kumar Myakalwar; Manoj Kumar Gundawar; Prem Kiran Paturi; Surya Praksh Tewari; Venugopal Rao Soma

    2012-01-01

    We describe our results obtained from stoichiometric ratio studies of three different energetic, inorganic samples (ammonium perchlorate (AP), boron potassium nitrate (BPN), and ammonium nitrate (AN)) using the technique of laser-induced breakdown spectroscopy (LIBS) with nanosecond pulses. Signal collection was independently executed using both gated and nongated spectrometers. The oxygen peak at 777.31 nm (O) and nitrogen peaks at 742.50 nm (N1), 744.34 nm (N2), and 746.91 nm (N3) were used...

  3. Laser-induced breakdown spectroscopy application to control of the process of precious metal recovery and recycling

    International Nuclear Information System (INIS)

    In this paper, we discuss the application of laser-induced breakdown spectroscopy to precious metal alloys used for the control of the process of recovery and recycling of scraps and waste of industrial processes. In particular, the possibility to obtain sensitivity and trueness comparable to the current systems used in industrial environment in the quantitative determination of the elements of interest was explored. The present study demonstrates that laser-induced breakdown spectroscopy can be considered as a viable alternative to inductively coupled plasma optical emission spectrometry and X-ray fluorescence spectroscopy for the determination of recovered precious metals. The limits of detection obtained are of the order of 0.2 mg/g for all the elements considered. The maximum deviation with respect to the nominal concentrations is around 1 mg/g at concentrations around 20 mg/g (gold) corresponding to a relative error slightly higher than ± 5%. - Highlights: ► We discuss application of LIBS for the analysis of recovered precious metals. ► The advantages and drawbacks of LIBS vs. XRF are evidenced. ► A strategy is devised for obtaining by LIBS limits of detection comparable to XRF. ► The same strategy would provide trueness in analytical results comparable to XRF. ► The time needed and the complexity of LIBS analysis would not exceed the XRF ones.

  4. Laser-induced breakdown spectroscopy-based investigation and classification of pharmaceutical tablets using multivariate chemometric analysis

    OpenAIRE

    Myakalwar, Ashwin Kumar; Sreedhar, S.; Barman, Ishan; Dingari, Narahara Chari; Rao, S. Venugopal; Kiran, P. Prem; Tewari, Surya P.; Kumar, G. Manoj

    2011-01-01

    We report the effectiveness of laser-induced breakdown spectroscopy (LIBS) in probing the content of pharmaceutical tablets and also investigate its feasibility for routine classification. This method is particularly beneficial in applications where its exquisite chemical specificity and suitability for remote and on site characterization significantly improves the speed and accuracy of quality control and assurance process. Our experiments reveal that in addition to the presence of carbon, h...

  5. Double pulse laser induced breakdown spectroscopy: A potential tool for the analysis of contaminants and macro/micronutrients in organic mineral fertilizers.

    Science.gov (United States)

    Nicolodelli, Gustavo; Senesi, Giorgio Saverio; de Oliveira Perazzoli, Ivan Luiz; Marangoni, Bruno Spolon; De Melo Benites, Vinícius; Milori, Débora Marcondes Bastos Pereira

    2016-09-15

    Organic fertilizers are obtained from waste of plant or animal origin. One of the advantages of organic fertilizers is that, from the composting, it recycles waste-organic of urban and agriculture origin, whose disposal would cause environmental impacts. Fast and accurate analysis of both major and minor/trace elements contained in organic mineral and inorganic fertilizers of new generation have promoted the application of modern analytical techniques. In particular, laser induced breakdown spectroscopy (LIBS) is showing to be a very promising, quick and practical technique to detect and measure contaminants and nutrients in fertilizers. Although, this technique presents some limitations, such as a low sensitivity, if compared to other spectroscopic techniques, the use of double pulse (DP) LIBS is an alternative to the conventional LIBS in single pulse (SP). The macronutrients (Ca, Mg, K, P), micronutrients (Cu, Fe, Na, Mn, Zn) and contaminant (Cr) in fertilizer using LIBS in SP and DP configurations were evaluated. A comparative study for both configurations was performed using optimized key parameters for improving LIBS performance. The limit of detection (LOD) values obtained by DP LIBS increased up to seven times as compared to SP LIBS. In general, the marked improvement obtained when using DP system in the simultaneous LIBS quantitative determination for fertilizers analysis could be ascribed to the larger ablated mass of the sample. The results presented in this study show the promising potential of the DP LIBS technique for a qualitative analysis in fertilizers, without requiring sample preparation with chemical reagents. PMID:27261426

  6. In situ Laser Induced Breakdown Spectroscopy as a tool to discriminate volcanic rocks and magmatic series, Iceland

    Energy Technology Data Exchange (ETDEWEB)

    Roux, C.P.M., E-mail: clement.roux@u-bourgogne.fr [Laboratoire interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, BP 47 870, F-21078 Dijon Cedex (France); Rakovský, J.; Musset, O. [Laboratoire interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, BP 47 870, F-21078 Dijon Cedex (France); Monna, F. [Laboratoire ARTéHIS, UMR 6298 CNRS-Université de Bourgogne, 6 Boulevard Gabriel, F-21000 Dijon (France); Buoncristiani, J.-F.; Pellenard, P.; Thomazo, C. [Laboratoire Biogéosciences, UMR 6282 CNRS-Université de Bourgogne, 6 Boulevard Gabriel, F-21000 Dijon (France)

    2015-01-01

    This study evaluates the potentialities of a lab-made pLIBS (portable Laser-Induced Breakdown Spectroscopy) to sort volcanic rocks belonging to various magmatic series. An in-situ chemical analysis of 19 atomic lines, including Al, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Na, Si, Sr and Ti, from 21 sampled rocks was performed during a field exploration in Iceland. Iceland was chosen both for the various typologies of volcanic rocks and the rugged conditions in the field in order to test the sturdiness of the pLIPS. Elemental compositions were also measured using laboratory ICP-AES measurements on the same samples. Based on these latter results, which can be used to identify three different groups of volcanic rocks, a classification model was built in order to sort pLIBS data and to categorize unknown samples. Using a reliable statistical scheme applied to LIBS compositional data, the classification capability of the pLIBS system is clearly demonstrated (90–100% success rate). Although this prototype does not provide quantitative measurements, its use should be of particular interest for future geological field investigations. - Highlights: • Portable LIBS applied to field geology • Fast semi-quantitative geochemical analysis of volcanic rocks and magmatic series • Discriminant analysis and statistical treatments for LIBS compositional data.

  7. In situ Laser Induced Breakdown Spectroscopy as a tool to discriminate volcanic rocks and magmatic series, Iceland

    International Nuclear Information System (INIS)

    This study evaluates the potentialities of a lab-made pLIBS (portable Laser-Induced Breakdown Spectroscopy) to sort volcanic rocks belonging to various magmatic series. An in-situ chemical analysis of 19 atomic lines, including Al, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Na, Si, Sr and Ti, from 21 sampled rocks was performed during a field exploration in Iceland. Iceland was chosen both for the various typologies of volcanic rocks and the rugged conditions in the field in order to test the sturdiness of the pLIPS. Elemental compositions were also measured using laboratory ICP-AES measurements on the same samples. Based on these latter results, which can be used to identify three different groups of volcanic rocks, a classification model was built in order to sort pLIBS data and to categorize unknown samples. Using a reliable statistical scheme applied to LIBS compositional data, the classification capability of the pLIBS system is clearly demonstrated (90–100% success rate). Although this prototype does not provide quantitative measurements, its use should be of particular interest for future geological field investigations. - Highlights: • Portable LIBS applied to field geology • Fast semi-quantitative geochemical analysis of volcanic rocks and magmatic series • Discriminant analysis and statistical treatments for LIBS compositional data

  8. In-line measurements of chlorine containing polymers in an industrial waste sorting plant by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Full text: Laser-induced breakdown spectroscopy (LIBS) is applied to the identification of chlorine containing waste polymers in-line of an industrial waste sorting plant. Material from municipal waste plastic collection is transported on a conveyor belt (forward speed 2 m/s). Waste pieces are measured without any pre-treatment using an encapsulated LIBS system mounted to the conveyor belt. LIBS spectra are evaluated in real-time and approx. 800000 spectra are collected during the in-line measurement series. The emission of Cl I at 837.6 nm is used to identify polyvinylchloride (PVC) waste employing a linear correlation algorithm. The LIBS signals and the signals of a commercial sensor based on near-infrared (NIR) optical reflection show good correlation for many pieces as well as deviations for some other pieces. Off-line analysis of LIBS spectra and comparison with x-ray fluorescence reference analysis enables to estimate the Cl content in the waste pieces. Our results show that LIBS in-line sensing of chemically and environmentally hazardous elements under industrial conditions is feasible. (author)

  9. Depth-resolved chemical mapping of rock coatings using Laser-Induced Breakdown Spectroscopy: Implications for geochemical investigations on Mars

    Science.gov (United States)

    Lefebvre, C.; Catalá-Espí, A.; Sobron, P.; Koujelev, A.; Léveillé, R.

    2016-07-01

    We demonstrate that Laser-Induced Breakdown Spectroscopy (LIBS) is capable of identifying the presence of natural rock coatings, and we define LIBS signatures of complex multi-layered coatings. This is illustrated by detailed LIBS analysis, in Mars-simulated conditions, of a rock collected in the Svalbard Islands, and which is analogous to some altered Martian rocks. The sample is a basaltic rock with sub-mm Ca-Mg-Fe-Si rich mineral coatings. LIBS elemental analysis of several distinct regions on the surface of the rock demonstrates the variability of chemical compositions of the various coatings, which is confirmed by complementary scanning electron microscope (SEM) analysis. Furthermore, the LIBS analysis as a function of the depth at different locations shows chemical variability, indicative of penetration through thin coatings of varying composition. Fine-scale, three-dimensional LIBS analysis is of interest for identifying and characterizing coatings on martian rocks, likely originating from aqueous processes, providing a rapid chemical composition as a function of the layers and further understanding of the formation of the deposits and on planetary evolution.

  10. Compositional Analysis of Aerosols Using Calibration-Free Laser-Induced Breakdown Spectroscopy.

    Science.gov (United States)

    Boudhib, Mohamed; Hermann, Jörg; Dutouquet, Christophe

    2016-04-01

    We demonstrate that the elemental composition of aerosols can be measured using laser-induced breakdown spectroscopy (LIBS) without any preliminary calibration with standard samples. Therefore, a nanosecond Nd:YAG laser beam was focused into a flux of helium charged with alumina aerosols of a few micrometers diameter. The emission spectrum of the laser-generated breakdown plasma was recorded with an echelle spectrometer coupled to a gated detector. The spectral features including emission from both the helium carrier gas and the Al2O3 aerosols were analyzed on the base of a partial local thermodynamic equilibrium. Thus, Boltzmann equilibrium distributions of population number densities were assumed for all plasma species except of helium atoms and ions. By analyzing spectra recorded for different delays between the laser pulse and the detector gate, it is shown that accurate composition measurements are only possible for delays ≤1 μs, when the electron density is large enough to ensure collisional equilibrium for the aerosol vapor species. The results are consistent with previous studies of calibration-free LIBS measurements of solid alumina and glass and promote compositional analysis of aerosols via laser-induced breakdown in helium. PMID:26974717

  11. Trace metal detection in E. crassipes (water hyacinth) from the Pasig River via laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Detection of trace metals in organic samples was performed using laser-induced breakdown spectroscopy (LIBS). A pulsed 1064-nm Nd:YAG laser was used to excite E. crassipes (water hyacinth) plant samples obtained from three areas in the Pasig River. Preliminary results from the analysis of obtained spectra show five distinct emission peaks in the 350-450 nm and around the 520-600 nm regions that could be attributed to the presence of iron, chromium, sodium and possibly aluminum, calcium and/or magnesium. Several methods for improving the LIBS emission signal detected from the set-up are enumerated. LIBS was presented as a possible alternative elemental analysis technique for organic and environmental detection applications. (author)

  12. Recent progress on laser-induced breakdown spectroscopy for the monitoring of coal quality and unburned carbon in fly ash

    Science.gov (United States)

    Zhang, Lei; Hu, Zhi-Yu; Yin, Wang-Bao; Huang, Dan; Ma, Wei-Guang; Dong, Lei; Wu, Hong-Peng; Li, Zhi-Xin; Xiao, Lian-Tuan; Jia, Suo-Tang

    2012-12-01

    Our recent progress on developments of laser-induced breakdown spectroscopy (LIBS) based equipments for on-line monitoring of pulverized coal and unburned carbon (UC) level of fly ash are reviewed. A fully software-controlled LIBS equipment comprising a self-cleaning device for on-line coal quality monitoring in power plants is developed. The system features an automated sampling device, which is capable of elemental (C, Ca, Mg, Ti, Si, H, Al, Fe, S, and organic oxygen) and proximate analysis ( Q ad and A ad) through optimal data processing methods. An automated prototype LIBS apparatus has been developed for possible application to power plants for on-line analysis of UC level in fly ash. New data processing methods are proposed to correct spectral interference and matrix effects, with the accuracy for UC level analysis estimated to be 0.26%.

  13. Determination of Cd, Cr and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Lidiane Cristina; Gustinelli Arantes de Carvalho, Gabriel [NAPTISA Research Support Center “Technology and Innovation for a Sustainable Agriculture”, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário 303, 13416-000, Piracicaba SP (Brazil); Santos, Dario [Federal University of São Paulo, R. Prof. Artur Riedel 275, 09972-270, Diadema SP (Brazil); Krug, Francisco José, E-mail: fjkrug@cena.usp.br [NAPTISA Research Support Center “Technology and Innovation for a Sustainable Agriculture”, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário 303, 13416-000, Piracicaba SP (Brazil)

    2014-07-01

    A validated method for quantitative determination of Cd, Cr, and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy (LIBS) is presented. Laboratory samples were comminuted and homogenized by cryogenic or planetary ball milling, pressed into pellets and analyzed by LIBS. The experimental setup was designed by using a Q-switched Nd:YAG at 1064 nm with 10 Hz repetition rate, and the intensity signals from Cd II 214.441 nm, Cr II 267.716 nm and Pb II 220.353 nm emission lines were measured by using a spectrometer furnished with an intensified charge-coupled device. LIBS parameters (laser fluence, lens-to-sample distance, delay time, integration time gate, number of sites and number of laser pulses per site) were chosen after univariate experiments with a pellet of NIST SRM 695 (Trace Elements in Multi-Nutrient Fertilizer). Calibration and validation were carried out with 30 fertilizer samples from single superphosphate, triple superphosphate, monoammonium phosphate, and NPK mixtures. Good results were obtained by using 30 pulses of 50 J cm{sup −2} (750 μm spot size), 2.0 μs delay time and 5.0 μs integration time gate. No significant differences between Cd, Cr, and Pb mass fractions determined by the proposed LIBS method and by ICP OES after microwave-assisted acid digestion (AOAC 2006.03 Official Method) were found at 95% confidence level. The limits of detection of 1 mg kg{sup −1} Cd, 2 mg kg{sup −1} Cr and 15 mg kg{sup −1} Pb and the precision (coefficients of variation of results ranging from 2% to 15%) indicate that the proposed LIBS method can be recommended for the determination of these analytes in phosphate fertilizers. - Highlights: • First LIBS application for quantitative Cd, Cr and Pb determination in fertilizers. • LIBS method was validated for analysis of phosphate fertilizers pressed pellets. • LIBS sample throughput is remarkably better than already existing methods.

  14. Laser-induced breakdown spectroscopy: Extending its application to soil pH measurements

    International Nuclear Information System (INIS)

    Acid–base equilibria are involved in almost all the processes that occur in soil. The bioavailability of nutrients for plants, for instance, depends on the solubilization of mineral nutrients in the soil solution, which is a pH-dependent process. The determination of pH in soil solutions is usually carried out by potentiometry using a glass membrane electrode, after extracting some of the soil components with water or CaCl2 solution. The present work describes a simple method for determining the pH of soil, using laser-induced breakdown spectroscopy (LIBS). Sixty samples presenting different textural composition and pH (previously determined by potentiometry) were employed. The samples were divided into a calibration set with fifty samples and a validation set with ten samples. LIBS spectra were recorded for each pelleted sample using laser pulse energy of 115 mJ. The intensities of thirty-two emission lines for Al, Ca, H, and O were used to fit a partial least squares (PLS) model. The model was validated by prediction of the pH of the validation set samples, which showed good agreement with the reference values. The prediction mean absolute error was 0.3 pH units and the root mean square error of the prediction was 0.4. These results highlight the potential of LIBS for use in other applications beyond elemental composition determinations. For soil analysis, the proposed method offers the possibility of determining pH, in addition to nutrients and contaminants, using a single LIBS measurement. - Highlights: • Physical, chemical, and biological properties of soil are influenced by pH. • The pH of mineral soils is normally determined in slurries of water and soil sample by potentiometric measurements. • The association of LIBS elemental emissions with multivariate strategies of analysis has become LIBS a powerful technique. • LIBS was unprecedentedly applied for direct pH determination in different kinds of soil sample. • The clean and fast proposed

  15. Laser-induced breakdown spectroscopy: Extending its application to soil pH measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Edilene Cristina, E-mail: edilene@iq.unesp.br [São Paulo State University – UNESP, Analytical Chemistry Department, Rua Prof. Francisco Degni 55, CEP 14800-060, Araraquara, SP (Brazil); Gomes Neto, José A. [São Paulo State University – UNESP, Analytical Chemistry Department, Rua Prof. Francisco Degni 55, CEP 14800-060, Araraquara, SP (Brazil); Milori, Débora M.B.P.; Ferreira, Ednaldo José [Embrapa Agricultural Instrumentation, Rua XV de Novembro 1452, CEP 13560-970, São Carlos, SP (Brazil); Anzano, Jesús Manuel [Laser Laboratory & Environment, Faculty of Sciences, University of Zaragoza, C/. Pedro Cerbuna 12, 50009, Zaragoza (Spain)

    2015-08-01

    Acid–base equilibria are involved in almost all the processes that occur in soil. The bioavailability of nutrients for plants, for instance, depends on the solubilization of mineral nutrients in the soil solution, which is a pH-dependent process. The determination of pH in soil solutions is usually carried out by potentiometry using a glass membrane electrode, after extracting some of the soil components with water or CaCl{sub 2} solution. The present work describes a simple method for determining the pH of soil, using laser-induced breakdown spectroscopy (LIBS). Sixty samples presenting different textural composition and pH (previously determined by potentiometry) were employed. The samples were divided into a calibration set with fifty samples and a validation set with ten samples. LIBS spectra were recorded for each pelleted sample using laser pulse energy of 115 mJ. The intensities of thirty-two emission lines for Al, Ca, H, and O were used to fit a partial least squares (PLS) model. The model was validated by prediction of the pH of the validation set samples, which showed good agreement with the reference values. The prediction mean absolute error was 0.3 pH units and the root mean square error of the prediction was 0.4. These results highlight the potential of LIBS for use in other applications beyond elemental composition determinations. For soil analysis, the proposed method offers the possibility of determining pH, in addition to nutrients and contaminants, using a single LIBS measurement. - Highlights: • Physical, chemical, and biological properties of soil are influenced by pH. • The pH of mineral soils is normally determined in slurries of water and soil sample by potentiometric measurements. • The association of LIBS elemental emissions with multivariate strategies of analysis has become LIBS a powerful technique. • LIBS was unprecedentedly applied for direct pH determination in different kinds of soil sample. • The clean and fast proposed

  16. Elemental analyses and determination of lead content in kohl (stone) by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Haider, Abul Fazal Mohammed Yusuf; Lubna, Rebeka Sultana; Abedin, Kazi Monowar

    2012-04-01

    Elemental analyses of kohl (stone) samples collected from three different parts of the world were performed using laser-induced breakdown spectroscopy (LIBS). The analyses indicated that lead (Pb), copper (Cu), silver (Ag), iron (Fe), calcium (Ca), aluminum (Al), silicon (Si), and sodium (Na) were present in all the kohl samples. In addition to these elements, the sample from Madina, Kingdom of Saudi Arabia (KSA), contained the elements tin (Sn), zirconium (Zr), and antimony (Sb). The sample from Mount Toor, Egypt, also contained Sn. Also, quantitative analysis for lead was carried out by the standard addition method using the LIBS technique. The result showed the presence of 14.12 ± 0.28% by weight of Pb in the sample from Madina, which compares well with the measurement done using atomic absorption spectroscopy (AAS) (13.31 ± 0.46%). The standard addition method used three calibration curves drawn for three emission lines of the LIBS spectra of Pb. The limits of detection (LoD) for these calibration curves varied from 0.27% to 1.16% by weight. The lead contents of the samples from Mount Toor and the local market of Bangladesh were also measured by the AAS technique, and the results were 14.61 ± 0.48% and 8.98 ± 0.35% by weight, respectively. The reason for determining only the lead content in kohl, which may be used as an eye cosmetic, is the adverse effect that lead has on health. PMID:22449323

  17. Analysis of the Composition of Titanium Oxide Coating by Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Estupiñán, Hugo; Peña, Dario Y.; Cabanzo, Rafael; Mejía-Ospino, Enrique

    2008-04-01

    Laser Induced Plasma Spectroscopy (LIPS or LIBS) is an alternative elemental analysis technology based on the optical emission spectra of the plasma produced by the interaction of high-power laser with gas, solid and liquid. The increasing popularity of this technique is due to the ease of the experimental set-up and to the wide fiexibility in the investigated material that does not need any pre-treatment of the sample before the analysis. In this work, Laser Induced Breakdown Spectroscopy (LIBS) is used to determine the composition of titanium oxide film produced by anodized of Ti6Al4V alloy. We have used Ti lines in the spectral region between 470-520 nm to determine temperature of the plasma generated on anodized surface of Ti6Al4V alloy for temperature determination by Boltzmann plot method. In order to measure the content of oxygen and titanium ratio on the surface the alloy, we have used the oxygen lines 777.194, 777.417 and 777.539 nm, and titanium lines 780.597 and 782.491 nm observed in an ambient of argon. We have determined the best conditions of electro-deposition, observing the intensity of the oxygen lines. Finally, we report the possibilities for the determination of the coating chemical composition using LIBS.

  18. Development of a fiber-coupled laser-induced breakdown spectroscopy instrument for analysis of underwater debris in a nuclear reactor core

    International Nuclear Information System (INIS)

    To inspect the post-accident nuclear core reactor of the TEPCO Fukushima Daiichi nuclear power plant (F1-NPP), a transportable fiber-coupled laser-induced breakdown spectroscopy (LIBS) instrument has been developed. The developed LIBS instrument was designed to analyze underwater samples in a high-radiation field by single-pulse breakdown with gas flow or double-pulse breakdown. To check the feasibility of the assembled fiber-coupled LIBS instrument for the analysis of debris material (mixture of the fuel core, fuel cladding, construction material and so on) in the F1-NPP, we investigated the influence of the radiation dose on the optical transmittance of the laser delivery fiber, compared data quality among various LIBS techniques for an underwater sample and studied the feasibility of the fiber-coupled LIBS system in an analysis of the underwater sample of the simulated debris in F1-NPP. In a feasible study conducted by using simulated debris, which was a mixture of CeO2 (surrogate of UO2), ZrO2 and Fe, we selected atomic lines suitable for the analysis of materials, and prepared calibration curves for the component elements. The feasible study has guaranteed that the developed fiber-coupled LIBS system is applicable for analyzing the debris materials in the F1-NPP. (author)

  19. Chemical characterization of single micro- and nano-particles by optical catapulting–optical trapping–laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Spectral identification of individual micro- and nano-sized particles by the sequential intervention of optical catapulting, optical trapping and laser-induced breakdown spectroscopy is presented. The three techniques are used for different purposes. Optical catapulting (OC) serves to put the particulate material under inspection in aerosol form. Optical trapping (OT) permits the isolation and manipulation of individual particles from the aerosol, which are subsequently analyzed by laser-induced breakdown spectroscopy (LIBS). Once catapulted, the dynamics of particle trapping depends both on the laser beam characteristics (power and intensity gradient) and on the particle properties (size, mass and shape). Particles are stably trapped in air at atmospheric pressure and can be conveniently manipulated for a precise positioning for LIBS analysis. The spectra acquired from the individually trapped particles permit a straightforward identification of the material inspected. Variability of LIBS signal for the inspection of Ni microspheres was 30% relative standard deviation. OC–OT–LIBS permits the separation of particles in a heterogeneous mixture and the subsequent analysis of the isolated particle of interest. In order to evaluate the sensitivity of the approach, the number of absolute photons emitted by a single trapped particle was calculated. The limit of detection (LOD) for Al2O3 particles was calculated to be 200 attograms aluminium. - Highlights: • Detection of single nanoparticles by OC–OT–LIBS has been described for the first time. • An absolute mass quantity of 17 fg (single particle 100-nm sized Al2O3) was detected. • Results confirm the extreme sensitivity of LIBS for single nanoparticle analysis. • The LOD for Al2O3 particles was calculated to be 200 attograms aluminium. • A photon budget was performed in order to evaluate the sensitivity of the approach

  20. Chemical characterization of single micro- and nano-particles by optical catapulting–optical trapping–laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fortes, Francisco J.; Fernández-Bravo, Angel; Javier Laserna, J., E-mail: laserna@uma.es

    2014-10-01

    Spectral identification of individual micro- and nano-sized particles by the sequential intervention of optical catapulting, optical trapping and laser-induced breakdown spectroscopy is presented. The three techniques are used for different purposes. Optical catapulting (OC) serves to put the particulate material under inspection in aerosol form. Optical trapping (OT) permits the isolation and manipulation of individual particles from the aerosol, which are subsequently analyzed by laser-induced breakdown spectroscopy (LIBS). Once catapulted, the dynamics of particle trapping depends both on the laser beam characteristics (power and intensity gradient) and on the particle properties (size, mass and shape). Particles are stably trapped in air at atmospheric pressure and can be conveniently manipulated for a precise positioning for LIBS analysis. The spectra acquired from the individually trapped particles permit a straightforward identification of the material inspected. Variability of LIBS signal for the inspection of Ni microspheres was 30% relative standard deviation. OC–OT–LIBS permits the separation of particles in a heterogeneous mixture and the subsequent analysis of the isolated particle of interest. In order to evaluate the sensitivity of the approach, the number of absolute photons emitted by a single trapped particle was calculated. The limit of detection (LOD) for Al{sub 2}O{sub 3} particles was calculated to be 200 attograms aluminium. - Highlights: • Detection of single nanoparticles by OC–OT–LIBS has been described for the first time. • An absolute mass quantity of 17 fg (single particle 100-nm sized Al{sub 2}O{sub 3}) was detected. • Results confirm the extreme sensitivity of LIBS for single nanoparticle analysis. • The LOD for Al{sub 2}O{sub 3} particles was calculated to be 200 attograms aluminium. • A photon budget was performed in order to evaluate the sensitivity of the approach.

  1. 2-D analysis of Ge implanted SiO2 surfaces by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    2-D elemental distribution of Ge in silicon oxide substrates with differing implantation doses of between 3 x 1016 cm-2 and 1.5 x 1017 cm-2 has been investigated by Laser-Induced Breakdown Spectroscopy (LIBS). Spectral emission intensity has been optimized with respect to time, crater size, ablation depth and laser energy. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) coupled with Energy-Dispersive X-Ray Spectroscopy (EDX) have been utilized to obtain crater depth, morphology and elemental composition of the sample material, respectively. LIBS spectral data revealed the possibility of performing 2-D distribution analysis of Ge atoms in silicon oxide substrate. EDX analysis results confirmed that LIBS is capable to detect Ge atoms at concentrations lower than 0.2% (atomic). LIBS as a fast semi-quantitative analysis method with 50 μm lateral and 800 nm depth resolution has been evaluated. Results illustrate the potential use of LIBS for rapid, on-line assessment of the quality of advanced technology materials during the manufacturing process

  2. Determination of Cd, Cr and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Nunes, Lidiane Cristina; de Carvalho, Gabriel Gustinelli Arantes; Santos, Dario; Krug, Francisco José

    2014-07-01

    A validated method for quantitative determination of Cd, Cr, and Pb in phosphate fertilizers by laser-induced breakdown spectroscopy (LIBS) is presented. Laboratory samples were comminuted and homogenized by cryogenic or planetary ball milling, pressed into pellets and analyzed by LIBS. The experimental setup was designed by using a Q-switched Nd:YAG at 1064 nm with 10 Hz repetition rate, and the intensity signals from Cd II 214.441 nm, Cr II 267.716 nm and Pb II 220.353 nm emission lines were measured by using a spectrometer furnished with an intensified charge-coupled device. LIBS parameters (laser fluence, lens-to-sample distance, delay time, integration time gate, number of sites and number of laser pulses per site) were chosen after univariate experiments with a pellet of NIST SRM 695 (Trace Elements in Multi-Nutrient Fertilizer). Calibration and validation were carried out with 30 fertilizer samples from single superphosphate, triple superphosphate, monoammonium phosphate, and NPK mixtures. Good results were obtained by using 30 pulses of 50 J cm- 2 (750 μm spot size), 2.0 μs delay time and 5.0 μs integration time gate. No significant differences between Cd, Cr, and Pb mass fractions determined by the proposed LIBS method and by ICP OES after microwave-assisted acid digestion (AOAC 2006.03 Official Method) were found at 95% confidence level. The limits of detection of 1 mg kg- 1 Cd, 2 mg kg- 1 Cr and 15 mg kg- 1 Pb and the precision (coefficients of variation of results ranging from 2% to 15%) indicate that the proposed LIBS method can be recommended for the determination of these analytes in phosphate fertilizers.

  3. Quantitative analysis by laser-induced breakdown spectroscopy based on generalized curves of growth

    International Nuclear Information System (INIS)

    A method for quantitative elemental analysis by laser-induced breakdown spectroscopy (LIBS) is proposed. The method (Cσ-LIBS) is based on Cσ graphs, generalized curves of growth which allow including several lines of various elements at different concentrations. A so-called homogeneous double (HD) model of the laser-induced plasma is used, defined by an integration over a single-region of the radiative transfer equation, combined with a separated treatment for neutral atoms (z = 0) and singly-charged ions (z = 1) in Cσ graphs and characteristic parameters. The procedure includes a criterion, based on a model limit, for eliminating data which, due to a high line intensity or concentration, are not well described by the HD model. An initial procedure provides a set of parameters (βA)z, (ηNl)z, Tz and Nez (z = 0, 1) which characterize the plasma and the LIBS system. After characterization, two different analytical procedures, resulting in relative and absolute concentrations, may be applied. To test the method, fused glass samples prepared from certified slags and pure compounds are analyzed. We determine concentrations of Ca, Mn, Mg, V, Ti, Si and Al relative to Fe in three samples prepared from slags, and absolute concentrations of Fe, Ca and Mn in three samples prepared from Fe2O3, CaCO3 and Mn2O3. The accuracy obtained is 3.2% on the average for relative concentrations and 9.2% for absolute concentrations. - Highlights: • Method for quantitative analysis by LIBS, based on Csigma graphs • Conventional calibration is replaced with characterization of the LIBS system. • All elements are determined from measurement of one or two Csigma graphs. • The method is tested with fused glass disks prepared from slags and pure compounds. • Accurate results for relative (3.2%) and absolute concentrations (9.2%)

  4. [The auto-focusing remote laser-induced breakdown spectroscopy system].

    Science.gov (United States)

    Han, Zhen-yu; Pan, Cong-yuan; An, Ning; Du, Xue-wei; Yu, Yun-si; Du, Liang-liang; Wang, Sheng-bo; Wang, Qiu-ping

    2015-02-01

    The present paper presents an auto-focus laser-induced breakdown spectroscopy (LIBS) remote measuring system. This system contains a Schwarzschild telescope, which consists of a convex mirror and a concave mirror. The two spherical mirrors are coaxially placed. The convex mirror is mounted on a motorized linear translation stage. With this motorized linear translation stage, the convex mirror can move along the optical axis to change the spacing between the convex mirror and the concave mirror. Therefore the focal length can be adjusted to focus the laser on samples at different distances and collect the plasma spectra. The advantages of the telescope system include, firstly, the light path of laser focusing and spectra signal collection is the same, which make it easier for mounting and collimation; secondly, the light path of the telescope uses total reflection type, which is fit for the detection in ultra-violate region; finally, the telescope consists of only two spherical mirrors which are relatively easier to manufacture. Within the translation range of the motorized linear translation stage, the focal length of the telescope in this paper can be adjusted from 1.5 to 3.6 m. The diameter of the focusing spot varies from 0.5 to 1.0 mm. Utilizing this telescope system, LIBS experiments were conducted using copper sample. And the characteristic lines of Cu element (Cu I 223.01 nm, Cu I 224.43 nm) obtained are used for the auto focusing. By investigating the relation of the area of spectral lines covered and the spacing between the mirrors, the optimal laser focusing location was obtained. The LIBS experiment results show that the system functions well, fulfilling the demand of remote ablation of sample and LIBS spectral measuring, and the telescope is able to auto-focus the laser on samples at different position to perform remote LIBS experiment. PMID:25970882

  5. Forensic application of laser-induced breakdown spectroscopy for the discrimination of questioned documents.

    Science.gov (United States)

    Lennard, Chris; El-Deftar, Moteaa M; Robertson, James

    2015-09-01

    Document examination is an important forensic discipline and the legal system regularly needs the knowledge and skills of the scientific expert when questioned documents are involved in criminal or civil matters. Amongst the many aspects of the scientific examination of documents, elemental analysis can provide useful results. In this study, the evaluation of the analytical performance of a commercially available laser-induced breakdown spectroscopy (LIBS) instrument was conducted on office papers, writing inks, inkjet inks and laser printer toners. The paper sample set analysed consisted of 33 Australian paper specimens originating from the same production plant but representing different brands and/or batches. In addition, a total of 131 ink or toner samples were examined that included black and blue ballpoint inks, black inkjet inks, and black laser printer toners originating from several manufacturing sources, models and/or batches. Results from the LIBS method were compared against those obtained using more established elemental profiling method such as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). LIBS demonstrated detectable and significant differences between different batches of the same brand as well as between different brands of paper, ink and toner samples. The LIBS method provided comparable discrimination powers for the selected sample sets when compared to those obtained using LA-ICP-MS (discrimination from 99.8 and 100% of the sample pairs, depending on the sample subset under examination). LIBS is a suitable technique for the determination of elemental composition as part of a protocol for the examination of questioned documents. PMID:26188700

  6. Nondestructive Determination of Cu Residue in Orange Peel by Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Hu, Huiqin; Huang, Lin; Liu, Muhua; Chen, Tianbing; Yang, Ping; Yao, Mingyin

    2015-08-01

    Laser induced breakdown spectroscopy (LIBS) is an emerging tool with rapid, nondestructive, green characteristics in qualitative or quantitative analyses of composition in materials. But LIBS has its shortcomings in detect limit and sensitivity. In this work, heavy metal Cu in Gannan Navel Orange, which is one of famous fruits from Jiangxi of China, was analyzed. In view of LIBS's limit, it is difficult to determinate heavy metals in natural fruits. In this work, nine orange samples were pretreated in 50-500 μg/mL Cu solution, respectively. Another one orange sample was chosen as a control group without any pollution treatment. Previous researchers observed that the content of heavy metals is much higher in peel than in pulp. So, the content in pulp can be reflected by detecting peel. The real concentrations of Cu in peels were acquired by atomic absorption spectrophotometer (AAS). A calibration model of Cu I 324.7 and Cu I 327.4 was constructed between LIBS intensity and AAS concentration by six samples. The correlation coefficient of the two models is also 0.95. All of the samples were used to verify the accuracy of the model. The results show that the relative error (RE) between predicted and real concentration is less than 6.5%, and Cu I 324.7 line has smaller RE than Cu I 327.4. The analysis demonstrated that different characteristic lines decided different accuracy. The results prove the feasibility of detecting heavy metals in fruits by LIBS. But the results are limited in treated samples. The next work will focus on direct analysis of heavy metals in natural fruits without any pretreatment. This work is helpful to explore the distribution of heavy metals between pulp and peel. supported by National Natural Science Foundation of China (No. 31460419) and Major Project of Science and Technology of Jiangxi, China (No. 20143ACB21013)

  7. Fused glass sample preparation for quantitative laser-induced breakdown spectroscopy of geologic materials

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy is a powerful analytical method, but LIBS is subject to a matrix effect which can limit its ability to produce quantitative results in complex materials such as geologic samples. Various methods of sample preparation, calibration, and data processing have been attempted to compensate for the matrix effect and improve LIBS precision. This study focuses on sample preparation by comparing fused glass as a preparation for powdered material to the more commonly used method of pressing powder into pellets for LIBS analysis of major elements in complex geologic materials. Pelletizing powdered material is a common and convenient method for preparing samples but problems with the physical matrix brought on by inconsistencies in the homogeneity, density, and laser absorption, coupled with the chemical matrix problem lead to spectral peak responses that are not always consistent with the absolute concentration of representative elements. Twenty-two mineral and rock samples were analyzed for eight major oxide elements. Samples were prepared under both glass and pellet methods and compared for internal precision and overall accuracy. Fused glass provided a more consistent physical matrix and yielded more reliable peak responses in the LIBS analysis than did the pressed pellet preparation. Statistical comparisons demonstrated that the glass samples expressed stronger separability between different mineral species based on the eight elements than for the pressed pellets and showed better spot-to-spot repeatability. Regression models showed substantially better correlations and predictive ability among the elements for the glass preparation than did those for the pressed pellets. - Highlights: • Glass improves analytical results in LIBS analysis compared to pressed pellets. • Glass yields higher precision and better calibration models than do pressed pellets. • Low concentrations and trace elements remained detectable in fused glass

  8. Optimization of laser-induced breakdown spectroscopy for coal powder analysis with different particle flow diameters

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Shunchun, E-mail: epscyao@scut.edu.cn [School of Electric Power, South China University of Technology, Guangzhou, Guangdong 510640 (China); State Key Laboratory of Pulsed Power Laser Technology, Electronic Engineering Institute, Hefei 230037 (China); Xu, Jialong; Dong, Xuan; Zhang, Bo; Zheng, Jianping [School of Electric Power, South China University of Technology, Guangzhou, Guangdong 510640 (China); Lu, Jidong, E-mail: jdlu@scut.edu.cn [School of Electric Power, South China University of Technology, Guangzhou, Guangdong 510640 (China)

    2015-08-01

    The on-line measurement of coal is extremely useful for emission control and combustion process optimization in coal-fired plant. Laser-induced breakdown spectroscopy was employed to directly analyze coal particle flow. A set of tapered tubes were proposed for beam-focusing the coal particle flow to different diameters. For optimizing the measurement of coal particle flow, the characteristics of laser-induced plasma, including optical breakdown, the relative standard deviation of repeated measurement, partial breakdown spectra ratio and line intensity, were carefully analyzed. The comparison of the plasma characteristics among coal particle flow with different diameters showed that air breakdown and the random change in plasma position relative to the collection optics could significantly influence on the line intensity and the reproducibility of measurement. It is demonstrated that the tapered tube with a diameter of 5.5 mm was particularly useful to enrich the coal particles in laser focus spot as well as to reduce the influence of air breakdown and random changes of plasma in the experiment. - Highlights: • Tapered tube was designed for beam-focusing the coal particle flow as well as enriching the particles in laser focus spot. • The characteristics of laser-induced plasma of coal particle flow were investigated carefully. • An appropriate diameter of coal particle flow was proven to benefit for improving the performance of LIBS measurement.

  9. Optimization of laser-induced breakdown spectroscopy for coal powder analysis with different particle flow diameters

    International Nuclear Information System (INIS)

    The on-line measurement of coal is extremely useful for emission control and combustion process optimization in coal-fired plant. Laser-induced breakdown spectroscopy was employed to directly analyze coal particle flow. A set of tapered tubes were proposed for beam-focusing the coal particle flow to different diameters. For optimizing the measurement of coal particle flow, the characteristics of laser-induced plasma, including optical breakdown, the relative standard deviation of repeated measurement, partial breakdown spectra ratio and line intensity, were carefully analyzed. The comparison of the plasma characteristics among coal particle flow with different diameters showed that air breakdown and the random change in plasma position relative to the collection optics could significantly influence on the line intensity and the reproducibility of measurement. It is demonstrated that the tapered tube with a diameter of 5.5 mm was particularly useful to enrich the coal particles in laser focus spot as well as to reduce the influence of air breakdown and random changes of plasma in the experiment. - Highlights: • Tapered tube was designed for beam-focusing the coal particle flow as well as enriching the particles in laser focus spot. • The characteristics of laser-induced plasma of coal particle flow were investigated carefully. • An appropriate diameter of coal particle flow was proven to benefit for improving the performance of LIBS measurement

  10. Comparison of the Detection Characteristics of Trace Species Using Laser-Induced Breakdown Spectroscopy and Laser Breakdown Time-of-Flight Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Zhenzhen Wang

    2015-03-01

    Full Text Available The rapid and precise element measurement of trace species, such as mercury, iodine, strontium, cesium, etc. is imperative for various applications, especially for industrial needs. The elements mercury and iodine were measured by two detection methods for comparison of the corresponding detection features. A laser beam was focused to induce plasma. Emission and ion signals were detected using laser-induced breakdown spectroscopy (LIBS and laser breakdown time-of-flight mass spectrometry (LB-TOFMS. Multi-photon ionization and electron impact ionization in the plasma generation process can be controlled by the pressure and pulse width. The effect of electron impact ionization on continuum emission, coexisting molecular and atomic emissions became weakened in low pressure condition. When the pressure was less than 1 Pa, the plasma was induced by laser dissociation and multi-photon ionization in LB-TOFMS. According to the experimental results, the detection limits of mercury and iodine in N2 were 3.5 ppb and 60 ppb using low pressure LIBS. The mercury and iodine detection limits using LB-TOFMS were 1.2 ppb and 9.0 ppb, which were enhanced due to different detection features. The detection systems of LIBS and LB-TOFMS can be selected depending on the condition of each application.

  11. Chemical analysis of archeological materials in submarine environments using laser-induced breakdown spectroscopy. On-site trials in the Mediterranean Sea

    Energy Technology Data Exchange (ETDEWEB)

    Guirado, S.; Fortes, F.J. [Department of Analytical Chemistry, Faculty of Sciences, University of Malaga, Campus de Teatinos s/n, 29071 Malaga (Spain); Lazic, V. [ENEA - Italian Agency for New Technologies, Energy and the Environment, Via E. Fermi 45, 00044 Frascati (RM) (Italy); Laserna, J.J., E-mail: laserna@uma.es [Department of Analytical Chemistry, Faculty of Sciences, University of Malaga, Campus de Teatinos s/n, 29071 Malaga (Spain)

    2012-08-15

    The main aim of this work is to demonstrate the capability of laser-induced breakdown spectroscopy (LIBS) for the recognition and identification of archeological materials submerged in sea water at depths up to 30 m. For this purpose, a remote LIBS instrument based on a fiber optic cable to deliver the laser beam energy has been evaluated. An air flux was applied to create a sample-air interface prior to laser ablation. This flux prevents the contact of sea water with the sample surface during the analysis. In this way, good quality LIBS spectra were obtained. Parametric studies in the laboratory such as gas flow pressure, beam focal conditions and angle of incidence, among others, were performed to optimize the best conditions for field analysis. Finally, real samples such as different bronzes containing a high oxidation degree were analyzed underwater in the Mediterranean Sea. The dependence of LIBS signal with the analysis depth was also studied. Results obtained in these field trials confirmed the capability of remote LIBS for in-situ analysis of underwater archeological samples. - Highlights: Black-Right-Pointing-Pointer We used a remote LIBS instrument based on a 45 m long optical fiber. Black-Right-Pointing-Pointer Archeological material was analyzed underwater in the Mediterranean Sea. Black-Right-Pointing-Pointer We examine the influence of the immersion depth on the LIBS signal. Black-Right-Pointing-Pointer The novelty of this application opens a new horizon to the LIBS technique.

  12. Chemical analysis of archeological materials in submarine environments using laser-induced breakdown spectroscopy. On-site trials in the Mediterranean Sea

    International Nuclear Information System (INIS)

    The main aim of this work is to demonstrate the capability of laser-induced breakdown spectroscopy (LIBS) for the recognition and identification of archeological materials submerged in sea water at depths up to 30 m. For this purpose, a remote LIBS instrument based on a fiber optic cable to deliver the laser beam energy has been evaluated. An air flux was applied to create a sample–air interface prior to laser ablation. This flux prevents the contact of sea water with the sample surface during the analysis. In this way, good quality LIBS spectra were obtained. Parametric studies in the laboratory such as gas flow pressure, beam focal conditions and angle of incidence, among others, were performed to optimize the best conditions for field analysis. Finally, real samples such as different bronzes containing a high oxidation degree were analyzed underwater in the Mediterranean Sea. The dependence of LIBS signal with the analysis depth was also studied. Results obtained in these field trials confirmed the capability of remote LIBS for in-situ analysis of underwater archeological samples. - Highlights: ► We used a remote LIBS instrument based on a 45 m long optical fiber. ► Archeological material was analyzed underwater in the Mediterranean Sea. ► We examine the influence of the immersion depth on the LIBS signal. ► The novelty of this application opens a new horizon to the LIBS technique.

  13. Effect of particle size on laser-induced breakdown spectroscopy analysis of alumina suspension in liquids

    International Nuclear Information System (INIS)

    The analysis by Laser Induced Breakdown Spectroscopy (LIBS) was proposed for the detection and the quantification of different elements in water even when the analyte is composed of particles in suspension. We have studied the effect of particle size on the LIBS signal during liquid analysis. In our study we used different particle sizes (from 2 μm to 90 μm) of Al2O3 in suspension in water. The results were compared to the signal obtained in the case of dissolved aluminum. In the case of particles, a linear correlation between the LIBS signal versus concentration was found but a significant decrease in the slope of the calibration curve was found when the particle size increased. Several hypotheses have been tested and only a partial ablation of the particles might explain this decrease in signal intensity. This effect probably does not occur at smaller particle size. We estimated 860 nm/pulse as ablated thickness from the top of the particle. A statistical analysis over all data obtained allowed us to calculate 100 μm as ablated water column depth. - Highlights: ► We have identified a decrease of calibration curve when particle size increases. ► Partial particle ablation has been identified as the origin of this effect. ► The ablation rate on Al2O3 particles in suspension in water has been estimated. ► We can determine the deepness of the interaction volume into the liquid.

  14. Local equivalence ratio measurements in turbulent partially premixed flames using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    One of the most recently applied laser-based techniques in combustion environment is the laser-induced breakdown spectroscopy (LIBS). The technique has been extensively and successfully applied to elemental concentration measurements in solids and liquids. The LIBS signal is much weaker in gases and hence more work is required for quantitative measurements in flames. In the present work we used two orthogonal Nd:YAG lasers that operate at the fundamental wavelength with laser pulse energy of about 100 mJ/pulse. A Princeton-Instruments IMAX ICCD camera attached to a PI-Echelle spectrometer was used for signal detection. The lasers are focused using two 5-cm lenses. Several calibration points have been collected in well defined and homogeneous mixtures of air and fuel in order to be used as references for the measurements in turbulent partially premixed flames. This work shows that the application of the LIBS technique in a turbulent combustion environment is feasible and signal is enhanced by applying an orthogonal dual-pulse arrangement for air-fuel.

  15. Detection of tire tread particles using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Prochazka, David; Bilík, Martin; Prochazková, Petra; Klus, Jakub; Pořízka, Pavel; Novotný, Jan; Novotný, Karel; Ticová, Barbora; Bradáč, Albert; Semela, Marek; Kaiser, Jozef

    2015-06-01

    The objective of this paper is a study of the potential of laser induced breakdown spectroscopy (LIBS) for detection of tire tread particles. Tire tread particles may represent pollutants; simultaneously, it is potentially possible to exploit detection of tire tread particles for identification of optically imperceptible braking tracks at locations of road accidents. The paper describes the general composition of tire treads and selection of an element suitable for detection using the LIBS method. Subsequently, the applicable spectral line is selected considering interferences with lines of elements that might be present together with the detected particles, and optimization of measurement parameters such as incident laser energy, gate delay and gate width is performed. In order to eliminate the matrix effect, measurements were performed using 4 types of tires manufactured by 3 different producers. An adhesive tape was used as a sample carrier. The most suitable adhesive tape was selected from 5 commonly available tapes, on the basis of their respective LIBS spectra. Calibration standards, i.e. an adhesive tape with different area content of tire tread particles, were prepared for the selected tire. A calibration line was created on the basis of the aforementioned calibration standards. The linear section of this line was used for determination of the detection limit value applicable to the selected tire. Considering the insignificant influence of matrix of various types of tires, it is possible to make a simple recalculation of the detection limit value on the basis of zinc content in a specific tire.

  16. High repetition rate laser-induced breakdown spectroscopy using acousto-optically gated detection

    Science.gov (United States)

    Pořízka, Pavel; Klessen, Benjamin; Kaiser, Jozef; Gornushkin, Igor; Panne, Ulrich; Riedel, Jens

    2014-07-01

    This contribution introduces a new type of setup for fast sample analysis using laser-induced breakdown spectroscopy (LIBS). The novel design combines a high repetition rate laser (up to 50 kHz) as excitation source and an acousto-optical modulator (AOM) as a fast switch for temporally gating the detection of the emitted light. The plasma radiation is led through the active medium of the AOM where it is diffracted on the transient ultrasonic Bragg grid. The diffracted radiation is detected by a compact Czerny-Turner spectrometer equipped with a CCD line detector. Utilizing the new combination of high repetition rate lasers and AOM gated detection, rapid measurements with total integration times of only 10 ms resulted in a limit of detection (LOD) of 0.13 wt.% for magnesium in aluminum alloys. This short integration time corresponds to 100 analyses/s. Temporal gating of LIP radiation results in improved LODs and consecutively higher sensitivity of the LIBS setup. Therefore, an AOM could be beneficially utilized to temporally detect plasmas induced by high repetition rate lasers. The AOM in combination with miniaturized Czerny-Turner spectrometers equipped with CCD line detectors and small footprint diode pumped solid state lasers results in temporally gateable compact LIBS setups.

  17. Study on Cluster Analysis Used with Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    He, Li'ao; Wang, Qianqian; Zhao, Yu; Liu, Li; Peng, Zhong

    2016-06-01

    Supervised learning methods (eg. PLS-DA, SVM, etc.) have been widely used with laser-induced breakdown spectroscopy (LIBS) to classify materials; however, it may induce a low correct classification rate if a test sample type is not included in the training dataset. Unsupervised cluster analysis methods (hierarchical clustering analysis, K-means clustering analysis, and iterative self-organizing data analysis technique) are investigated in plastics classification based on the line intensities of LIBS emission in this paper. The results of hierarchical clustering analysis using four different similarity measuring methods (single linkage, complete linkage, unweighted pair-group average, and weighted pair-group average) are compared. In K-means clustering analysis, four kinds of choosing initial centers methods are applied in our case and their results are compared. The classification results of hierarchical clustering analysis, K-means clustering analysis, and ISODATA are analyzed. The experiment results demonstrated cluster analysis methods can be applied to plastics discrimination with LIBS. supported by Beijing Natural Science Foundation of China (No. 4132063)

  18. A Novel and Effective Multivariate Method for Compositional Analysis using Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Wang, W.; Ayhan, B.; Kwan, C.; Qi, H.; Vance, S.

    2014-03-01

    Compositional analysis is important to interrogate spectral samples for direct analysis of materials in agriculture, environment and archaeology, etc. In this paper, multi-variate analysis (MVA) techniques are coupled with laser induced breakdown spectroscopy (LIBS) to estimate quantitative elemental compositions and determine the type of the sample. In particular, we present a new multivariate analysis method for composition analysis, referred to as "spectral unmixing". The LIBS spectrum of a testing sample is considered as a linear mixture with more than one constituent signatures that correspond to various chemical elements. The signature library is derived from regression analysis using training samples or is manually set up with the information from an elemental LIBS spectral database. A calibration step is used to make all the signatures in library to be homogeneous with the testing sample so as to avoid inhomogeneous signatures that might be caused by different sampling conditions. To demonstrate the feasibility of the proposed method, we compare it with the traditional partial least squares (PLS) method and the univariate method using a standard soil data set with elemental concentration measured a priori. The experimental results show that the proposed method holds great potential for reliable and effective elemental concentration estimation.

  19. Time-resolved ultraviolet laser-induced breakdown spectroscopy for organic material analysis

    International Nuclear Information System (INIS)

    Ultraviolet pulses (266 nm) delivered by a quadrupled Nd:YAG laser were used to analyze organic samples with laser-induced breakdown spectroscopy (LIBS). We present characteristics of the spectra obtained from organic samples with special attentions on the emissions of organic elements, O and N, and molecular bonds CN. The choice of these atomic or molecular species is justified on one hand, by the importance of these species to specify organic or biological materials; and on the other hand by the possible interferences with ambient air when laser ablation takes place in the atmosphere. Time-resolved LIBS was used to determine the time-evolution of line intensity emitted from these species. We demonstrate different kinetic behaviors corresponding to different origins of emitters: native atomic or molecular species directly vaporized from the sample or those generated through dissociation or recombination due to interaction between laser-induced plasma and air molecules. Our results show the ability of time-resolved UV-LIBS for detection and identification of native atomic or molecular species from an organic sample

  20. Application of laser-induced breakdown spectroscopy in carbon sequestration research and development

    Indian Academy of Sciences (India)

    Jinesh Jain; Dustin Mcintyre; Krishna Ayyalasomayajula; Vivek Dikshit; Christian Goueguel; F Yu-Yueh; Jagdish Singh

    2014-08-01

    The success of carbon capture and storage (CCS) programme relies on the long-term isolation of CO2 from the atmosphere. Therefore, technologies concomitant to physical storage of CO2 such as reliable measurement, monitoring, and verification (MMV) techniques are needed to ensure that the integrity of the storage site is maintained. We propose the use of laser-induced breakdown spectroscopy (LIBS) analytical technique to detect carbon dioxide leaks to aid in the successful application of CCS. LIBS has a real-time monitoring capability and can be reliably used for the elemental and isotopic analysis of solid, liquid, and gas samples. The flexibility of probe design and use of fibre optics make it a suitable technique for real-time measurements in harsh conditions and at hard-to-reach places. Proposed monitoring with LIBS includes terrestrial soil samples, water samples from monitoring wells or from different formations, air samples from monitoring wells or suspected leakage areas. This work details the laboratory scale experiments to measure carbon contents in soil, aqueous, and air samples. The potential of the technology for measurements in high-pressure, high-temperature conditions has been discussed.

  1. [Determination of Acid-Insoluble Aluminum Content in Steel by Laser-Induced Breakdown Spectroscopy].

    Science.gov (United States)

    Yang, Chun; Jia, Yun-hai; Zhang, Yong

    2015-03-01

    Laser-induced breakdown spectroscopy (LIBS) has become a very attractive and popular chemical analysis technique in material science for its advantage of rapid analysis, non-contact measurement, micro surface analysis and online analysis. In this paper, LIBS were used to determine insoluble aluminum content by analyzing the scanning data on massive steel samples. Abnormal data were discarded by Nalimov criterion, and the remaining data was used to calculate the average and the standard deviation. The threshold to distinguish acid-insoluble aluminum and soluble aluminum was identified as the average value plus triple standard deviation. Two different mathematical models were proposed to calculate insoluble aluminum content, respectively according to the ratio of the total acid-insoluble aluminium signal strength to total aluminum signal strength and acid-insoluble signal number to total aluminum signal number. The total aluminum content was determined by the calibration curve. Insoluble aluminum content of certified reference materials and plate blank samples obtained by mathematical model is coincident to chemical wet method results. The result according to total acid-insoluble aluminium signal strength is much better. LIBS can be used as a rapid analysis method to characterize insoluble aluminum content in steel samples. PMID:26117896

  2. A Novel and Effective Multivariate Method for Compositional Analysis using Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Compositional analysis is important to interrogate spectral samples for direct analysis of materials in agriculture, environment and archaeology, etc. In this paper, multi-variate analysis (MVA) techniques are coupled with laser induced breakdown spectroscopy (LIBS) to estimate quantitative elemental compositions and determine the type of the sample. In particular, we present a new multivariate analysis method for composition analysis, referred to as spectral unmixing. The LIBS spectrum of a testing sample is considered as a linear mixture with more than one constituent signatures that correspond to various chemical elements. The signature library is derived from regression analysis using training samples or is manually set up with the information from an elemental LIBS spectral database. A calibration step is used to make all the signatures in library to be homogeneous with the testing sample so as to avoid inhomogeneous signatures that might be caused by different sampling conditions. To demonstrate the feasibility of the proposed method, we compare it with the traditional partial least squares (PLS) method and the univariate method using a standard soil data set with elemental concentration measured a priori. The experimental results show that the proposed method holds great potential for reliable and effective elemental concentration estimation

  3. Laser Induced Breakdown Spectroscopy of meteorites as a probe of the early solar system

    International Nuclear Information System (INIS)

    This paper presents an evaluation of Laser Induced Breakdown Spectroscopy (LIBS) as a technique for gathering data relevant to Solar System geophysics. Two test cases were demonstrated: elemental analysis of chondrules in a chondrite meteorite, and space- resolved analysis of the interface between kamacite and taenite crystals in an octahedrite iron meteorite. In particular most major and minor elements (Fe, Mg, Si, Ti, Al, Cr, Mn, Ca, Fe, Ni, Co) in Sahara 98222 (chondrite) and its chondrules, as well as the profile of Ni content in Toluca (iron meteorite), were determined with the Calibration Free (CF) method. A special attention was devoted to exploring the possibilities offered by variants of the basic technique, such as the use of Fe I Boltzmann distribution as an intensity calibration method of the spectroscopic system, and the use of spatially resolved analysis. - Highlights: • LIBS of meteorites can supply data relevant to the early evolution of solar system. • CF-LIBS was applied to two different test cases. • Chemical identification of chondrules embedded in a chondrite meteorite • Experimental and theoretical profiles of Ni content in an iron meteorite

  4. Femtosecond laser induced breakdown spectroscopy of silver within surrogate high temperature gas reactor fuel coated particles

    International Nuclear Information System (INIS)

    The detection of metallic silver on Chemical Vapour Deposited (CVD) grown silicon carbide and in Pebble Bed Modular Reactor (PBMR) supplied tri-structural isotropic (TRISO) coated particles (with 500 μm diameter zirconium oxide surrogate kernel) has been studied with femtosecond Laser Induced Breakdown Spectroscopy (femto-LIBS). The SiC layer of the TRISO coated particle is the main barrier to metallic and gaseous fission products of which 110mAg is of particular interest for direct cycle high temperature reactors. This work is a feasibility study for diagnosing and profiling silver transport through the silicon carbide layer of fuel particles for a high temperature gas reactor in out-of-reactor experimentation. The zirconium oxide is a surrogate for the enriched uranium oxide fuel. The conclusion reached in this study was that femto-LIBS can achieve good surface spatial resolution and good depth resolution for studies of silver in experimental coated particles. The LIBS technique also offers a good alternative for a remote analytical technique.

  5. Laser Induced Breakdown Spectroscopy of meteorites as a probe of the early solar system

    Energy Technology Data Exchange (ETDEWEB)

    Dell' Aglio, M., E-mail: marcella.dellaglio@ba.imip.cnr.it [CNR-IMIP, Via Amendola 122/D, 70126 Bari (Italy); De Giacomo, A. [CNR-IMIP, Via Amendola 122/D, 70126 Bari (Italy); Chemistry Department, University of Bari, Via Orabona 4, 70126 Bari (Italy); Gaudiuso, R.; De Pascale, O. [CNR-IMIP, Via Amendola 122/D, 70126 Bari (Italy); Longo, S. [Chemistry Department, University of Bari, Via Orabona 4, 70126 Bari (Italy); INAF-Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, Firenze (Italy)

    2014-11-01

    This paper presents an evaluation of Laser Induced Breakdown Spectroscopy (LIBS) as a technique for gathering data relevant to Solar System geophysics. Two test cases were demonstrated: elemental analysis of chondrules in a chondrite meteorite, and space- resolved analysis of the interface between kamacite and taenite crystals in an octahedrite iron meteorite. In particular most major and minor elements (Fe, Mg, Si, Ti, Al, Cr, Mn, Ca, Fe, Ni, Co) in Sahara 98222 (chondrite) and its chondrules, as well as the profile of Ni content in Toluca (iron meteorite), were determined with the Calibration Free (CF) method. A special attention was devoted to exploring the possibilities offered by variants of the basic technique, such as the use of Fe I Boltzmann distribution as an intensity calibration method of the spectroscopic system, and the use of spatially resolved analysis. - Highlights: • LIBS of meteorites can supply data relevant to the early evolution of solar system. • CF-LIBS was applied to two different test cases. • Chemical identification of chondrules embedded in a chondrite meteorite • Experimental and theoretical profiles of Ni content in an iron meteorite.

  6. Stoichiometric analysis of ammonium nitrate and ammonium perchlorate with nanosecond laser induced breakdown spectroscopy

    Science.gov (United States)

    Sreedhar, S.; Rao, S. Venugopal; Kiran, P. Prem; Tewari, Surya P.; Kumar, G. Manoj

    2010-04-01

    We present our results on the stoichiometric analysis of ammonium nitrate (AN) and ammonium Perchlorate (AP) studied using laser induced breakdown spectroscopy (LIBS) with nanosecond pulses. The LIBS spectra collected for AP and AN, without any gating and using a high resolution spectrometer, exhibited characteristic lines corresponding to O, N, H, C, and K. The Oxygen line at 777.38 nm and three Nitrogen lines (N1, N2, N3) at 742.54 nm, 744.64 nm, 747.12 nm were used for evaluating the Oxygen/Nitrogen ratios. The intensities were calculated using area under the peaks and normalized to their respective transition probabilities and statistical weights. The O/N1 ratios estimated from the LIBS spectra were ~4.94 and ~5.11 for AP and O/N3 ratios were ~1.64 and ~1.47 for AN obtained from two independent measurements. The intensity ratios show good agreement with the actual stoichiometric ratios - four for AP and one for AN.

  7. Femtosecond laser induced breakdown spectroscopy of silver within surrogate high temperature gas reactor fuel coated particles

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, D.E., E-mail: troberts@csir.co.za [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Plessis, A. du [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Laser Research Institute, Physics Department, University of Stellenbosch, Private Bag X1, Matieland 7602 (South Africa); Steyn, J. [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Botha, L.R. [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Laser Research Institute, Physics Department, University of Stellenbosch, Private Bag X1, Matieland 7602 (South Africa); Strydom, C.A. [Chemical Resource Beneficiation, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Rooyen, I.J. van [PBMR, Fuel Design, 1279 Mike Crawford Avenue, Centurion, 0046 (South Africa)

    2010-11-15

    The detection of metallic silver on Chemical Vapour Deposited (CVD) grown silicon carbide and in Pebble Bed Modular Reactor (PBMR) supplied tri-structural isotropic (TRISO) coated particles (with 500 {mu}m diameter zirconium oxide surrogate kernel) has been studied with femtosecond Laser Induced Breakdown Spectroscopy (femto-LIBS). The SiC layer of the TRISO coated particle is the main barrier to metallic and gaseous fission products of which {sup 110m}Ag is of particular interest for direct cycle high temperature reactors. This work is a feasibility study for diagnosing and profiling silver transport through the silicon carbide layer of fuel particles for a high temperature gas reactor in out-of-reactor experimentation. The zirconium oxide is a surrogate for the enriched uranium oxide fuel. The conclusion reached in this study was that femto-LIBS can achieve good surface spatial resolution and good depth resolution for studies of silver in experimental coated particles. The LIBS technique also offers a good alternative for a remote analytical technique.

  8. Pathogenic Escherichia coli strain discrimination using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Diedrich, Jonathan; Rehse, Steven J.; Palchaudhuri, Sunil

    2007-07-01

    A pathogenic strain of bacteria, Escherichia coli O157:H7 (enterohemorrhagic E. coli or EHEC), has been analyzed by laser-induced breakdown spectroscopy (LIBS) with nanosecond pulses and compared to three nonpathogenic E. coli strains: a laboratory strain of K-12 (AB), a derivative of the same strain termed HF4714, and an environmental strain, E. coli C (Nino C). A discriminant function analysis (DFA) was performed on the LIBS spectra obtained from live colonies of all four strains. Utilizing the emission intensity of 19 atomic and ionic transitions from trace inorganic elements, the DFA revealed significant differences between EHEC and the Nino C strain, suggesting the possibility of identifying and discriminating the pathogenic strain from commonly occurring environmental strains. EHEC strongly resembled the two K-12 strains, in particular, HF4714, making discrimination between these strains difficult. DFA was also used to analyze spectra from two of the nonpathogenic strains cultured in different media: on a trypticase soy (TS) agar plate and in a liquid TS broth. Strains cultured in different media were identified and effectively discriminated, being more similar than different strains cultured in identical media. All bacteria spectra were completely distinct from spectra obtained from the nutrient medium or ablation substrate alone. The ability to differentiate strains prepared and tested in different environments indicates that matrix effects and background contaminations do not necessarily preclude the use of LIBS to identify bacteria found in a variety of environments or grown under different conditions.

  9. Laser-induced breakdown spectroscopy: A versatile tool for monitoring traces in materials

    Indian Academy of Sciences (India)

    Shiwani Pandhija; A K Rai

    2008-03-01

    Laser-induced breakdown spectroscopy (LIBS) is an emerging technique for simultaneous multi-elemental analysis of solids, liquids and gases with minute or no sample preparation and thus revolutionized the area of on-line analysis technologies. The foundation for LIBS is a solid state, short-pulsed laser that is focused on a sample to generate a high-temperature plasma, and the emitted radiation from the excited atomic and ionic fragments produced within the plasma is characteristic of the elemental composition of the sample that can be detected and analyzed using a suitable optical spectrograph. In the present paper, the applicability of LIBS for different solid samples having homogeneous (silver ornament, aluminum plate) or heterogeneous composition (soil) using nanosecond laser pulses is discussed. Nanosecond pulse laser makes plasma at the sample surface even at very low pulse energies and also allows for precise ablation of the substrate material with little damage to the surrounding area. We have also studied the penetration of different heavy metals inside the soil surface.

  10. Calibration-free analysis of immersed brass alloys using long-ns-duration pulse laser-induced breakdown spectroscopy with and without correction for nonstoichiometric ablation

    International Nuclear Information System (INIS)

    Long-ns-duration, single pulse laser-induced breakdown spectroscopy (LIBS) is known to be an effective method to observe well resolved spectra from samples immersed in water at high hydrostatic pressures. The aim of this study is to investigate whether the signals obtained using this method are suitable for quantitative analysis of chemical composition. Six certified brass alloys consisting of copper (Cu), zinc (Zn) and lead (Pb) were measured underwater using a laser pulse of duration 250 ns, and their compositions were determined using calibration-free LIBS (CF-LIBS) and corrected CF-LIBS (CCF-LIBS) methods. The mass fractions of Cu and Zn calculated using CF-LIBS showed better agreement with the certified values than those determined using CCF-LIBS, with relative errors of Cu 4.2 ± 3.3 % and Zn 7.2 ± 6.4 %. From the results, it can be said that the difference of preferential evaporation and ablation among elements does not need to be considered for underwater measurements with the long-pulse LIBS setup used in this work. While the results indicate that the CF-LIBS method can be applied for in situ quantitative analysis of major elements with concentrations > ~ 10 %, the mass fractions determined for Pb, with concentrations < 5 % had large relative errors, suggesting that an alternative method is required to quantify minor elements. - Highlights: • The spectra of submerged metal alloys obtained using a long pulse is suitable for CF-LIBS. • CF-LIBS determines the mass fractions of major elements of submerged brass targets in water. • The compositions of Cu and Zn are determined within 10 % relative error. • The preferential evaporation and ablation among elements do not have a significant influence on the quantitative analysis of brass samples submerged in water using a long-ns-duration laser pulse

  11. Calibration-free analysis of immersed brass alloys using long-ns-duration pulse laser-induced breakdown spectroscopy with and without correction for nonstoichiometric ablation

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Tomoko, E-mail: takahas@iis.u-tokyo.ac.jp [Institute of Industrial Science, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Thornton, Blair [Institute of Industrial Science, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Ohki, Koichi [OK Lab. Co., Ltd. 8-7-3 Shimorenjyaku, Mitaka, Tokyo 181-0013 (Japan); Sakka, Tetsuo [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan)

    2015-09-01

    Long-ns-duration, single pulse laser-induced breakdown spectroscopy (LIBS) is known to be an effective method to observe well resolved spectra from samples immersed in water at high hydrostatic pressures. The aim of this study is to investigate whether the signals obtained using this method are suitable for quantitative analysis of chemical composition. Six certified brass alloys consisting of copper (Cu), zinc (Zn) and lead (Pb) were measured underwater using a laser pulse of duration 250 ns, and their compositions were determined using calibration-free LIBS (CF-LIBS) and corrected CF-LIBS (CCF-LIBS) methods. The mass fractions of Cu and Zn calculated using CF-LIBS showed better agreement with the certified values than those determined using CCF-LIBS, with relative errors of Cu 4.2 ± 3.3 % and Zn 7.2 ± 6.4 %. From the results, it can be said that the difference of preferential evaporation and ablation among elements does not need to be considered for underwater measurements with the long-pulse LIBS setup used in this work. While the results indicate that the CF-LIBS method can be applied for in situ quantitative analysis of major elements with concentrations > ~ 10 %, the mass fractions determined for Pb, with concentrations < 5 % had large relative errors, suggesting that an alternative method is required to quantify minor elements. - Highlights: • The spectra of submerged metal alloys obtained using a long pulse is suitable for CF-LIBS. • CF-LIBS determines the mass fractions of major elements of submerged brass targets in water. • The compositions of Cu and Zn are determined within 10 % relative error. • The preferential evaporation and ablation among elements do not have a significant influence on the quantitative analysis of brass samples submerged in water using a long-ns-duration laser pulse.

  12. Application of Laser Induced Breakdown Spectroscopy in Early Detection of Red Palm Weevil: (Rhynchophorus ferrugineus) Infestation in Date Palm

    Science.gov (United States)

    A. Farooq, W.; G. Rasool, K.; Walid, Tawfik; S. Aldawood, A.

    2015-11-01

    The Kingdom of Saudi Arabia is one of the leading date producing countries. Unfortunately, this important fruit crop is under great threat from the red palm weevil (RPW) (Rhynchophorus ferrugineus), which is a highly invasive pest. Several techniques, including visual inspection, acoustic sensors, sniffer dogs, and pheromone traps have been tried to detect the early stages of a RPW infestation; however, each method has suffered certain logistical and implementation issues. We have applied laser induced breakdown spectroscopy (LIBS) for the early detection of RPW infestation. Through the analysis of the observed LIBS spectra of different infested and healthy samples, we have found presence of Ca, Mg, Na, C, K elements and OH, CN molecules. The spectra also reveal that with the population growth of the pest, the intensity of Mg and Ca atomic lines in LIBS spectra increases rapidly. Similar behavior is observed in the molecular lines of LIBS spectra. The obtained results indicate that the LIBS technique can be used for the early detection of RPW infestation without damaging the date palms.

  13. Detection of zinc and lead in water using evaporative preconcentration and single-particle laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    A novel laser-induced breakdown spectroscopy (LIBS)-based measurement method for metals in water is demonstrated. In the presented technology a small amount of sodium chloride is dissolved in the sample solution before spraying the sample into a tubular oven. After water removal monodisperse dry NaCl aerosol particles are formed where trace metals are present as additives. A single-particle LIBS analysis is then triggered with a scattering based particle detection system. Benefits are the highly increased metal concentration in the LIBS focal volume and the static NaCl-matrix which can be exploited in the signal processing procedure. Emitted light from the emerged plasma plume is collected with wide angle optics and dispersed with a grating spectrometer. In an aqueous solution, the respective limits of detection for zinc and lead were 0.3 ppm and 0.1 ppm using a relatively low 14 mJ laser pulse energy. Zn/Na peak intensity ratio calibration curve for zinc concentration was also determined and LIBS signal dependence on laser pulse energy was investigated. - Highlights: • Metals in a water sample are preconcentrated inside drying salt water droplets. • LIBS measurement from a single 5 μm dry salt particle using low laser pulse energy. • Stable sodium matrix can be utilized in the signal processing. • 0.3 ppm and 0.1 ppm detection limits in water obtained for Zn and Pb respectively

  14. Laser-induced breakdown spectroscopy of major and minor oxides in steel slags: Influence of detection geometry and signal normalization

    Science.gov (United States)

    Ahamer, C. M.; Eschlböck-Fuchs, S.; Kolmhofer, P. J.; Rössler, R.; Huber, N.; Pedarnig, J. D.

    2016-08-01

    Slag from secondary metallurgy in industrial steel production is analyzed by laser-induced breakdown spectroscopy (LIBS). The major oxides CaO, Al2O3, MgO, SiO2, FeO, MnO, and TiO2 are determined by calibration-free LIBS (CF-LIBS) method. For the minor oxide P2O5 calibration curves are established and the limits of detection (LOD) and the root-mean squared errors of prediction (RMSEP) are determined. The optical emission of the laser-induced plasma is measured for different detection geometries and varying sample position relative to the focal plane of the laser beam. LIBS spectra, plasma parameters, and analytical results are very similar for light collection with optical fibres close to the plasma ("direct detection") and at remote position ("collinear detection"). With collinear detection, the CF-LIBS calculated oxide concentrations are insensitive to sample position along the optical axis over wide range. The detection limits and the prediction errors of minor P2O5 depend on the major slag element used for signal normalization. With Mg and Si as internal reference elements the LOD values are 0.31 wt% and 0.07 wt%, respectively. The RMSEP values are lowest for signal normalization to Si. Calculations of the optical emission of ideal plasma support the experimental preference for Si as reference element in the phosphorous calibration.

  15. Matrix effect on emission/current correlated analysis in laser-induced breakdown spectroscopy of liquid droplets

    International Nuclear Information System (INIS)

    We have investigated influence of matrix salts on the liquid droplets by laser-induced breakdown spectroscopy (LIBS). An electrospray ionization technique coupled with LIBS is employed to generate the microdroplets of the Na sample solution with various matrix salts added. A sequence of single-shot time-resolved LIB emission signals is detected. The LIB signal intensity integrated within a gate linearly correlates with the plasma-induced current response obtained simultaneously on a single-shot basis. The slopes thus obtained increase with the sample concentration, but appear to be irrespective of different matrix salts, added up to a 2000 mg/l concentration. The matrix salts involved have the same K+ cation but different anions. Given a laser radiation emitting at 355 nm with the energy fixed at 23±1 mJ, a limit of detection (LOD) of 1.0 mg/l may be achieved for the Na analysis. The current normalization might have probably taken into account the ablated amount of the sample and the plasma temperature. Accordingly, the LIB/current correlated analysis becomes efficient to suppress the signal fluctuation, improve the LOD determination, and concurrently correct the matrix effect

  16. Simultaneous laser induced breakdown spectroscopy and Pd-assisted methane decomposition at different pressures

    International Nuclear Information System (INIS)

    Methane decomposition is investigated during Pd-assisted laser induced plasma in the controlled chamber at various pressures using Q-switched Nd:YAG laser. Real time LIBS monitoring is applied to reveal the involved mechanisms during methane decomposition by inspecting the plasma parameters at mano-metric pressures of 1 to 10 mbar. The dependence of electron density and plasma temperature with pressure is also studied. It is shown that the plasma recreates higher hydrocarbons during the decomposition of methane. In addition, Fourier transform infrared spectroscopy, gas chromatography, scanning electron microscopy and transmission electron microscopy are applied to support the findings. - Highlights: ► Simultaneous laser induced breakdown spectroscopy ► Pd-assisted methane decomposition ► Nanosecond pulsed laser decomposition of methane ► Generation of higher hydrocarbon ► Dependence of electron density and temperature of induced plasma with pressure

  17. Laser-induced breakdown spectroscopy and spectral analysis of improvised explosive materials

    Science.gov (United States)

    Bauer, Amy J. R.; Farrington, Michael P.; Sorauf, Kellen; Miziolek, Andrzej W.

    2014-05-01

    There exists an unmet need in the discovery and identification of certain improvised explosive (IE) materials. IE contain a wide range of materials, many of which are not well classified by available hand-held tools, especially metal powders and food products. Available measurement approaches are based in the identification of specific subgroups such as nitro/nitrate and chlorate/perchlorate, normally with Raman spectroscopy. The presence of metal powders is not detected by these approaches, and further the powders themselves scatter the laser radiation used in the excitation of the spectra, making other components more difficult to discern. Preliminary work with laserinduced breakdown spectroscopy (LIBS) shows that metal powders are easily detected and identified, and that fuel compounds in flash powder mixtures are easily classified with principal component analysis into those containing oxygen and chlorine or those containing oxygen and nitrogen. Alkali and alkali metal signals are readily used to determine the cation of any salt submitted to analysis.

  18. Remote quantitative analysis of cerium through a shielding window by stand-off laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Highlights: • Remote LIBS analysis of cerium in the samples located behind a shielding window. • Effects of a shielding window on the remote LIBS analysis were investigated. • Multivariate analysis improves the calibration quality. - Abstract: Laser-Induced Breakdown Spectroscopy (LIBS) has been considered in many applications in nuclear industry. LIBS can be an ideal technique for analyzing the inaccessible nuclear materials typically located behind a shielding window. We report the effect of optical transmittance of the shielding window on the analytical performances of stand-off LIBS for the preliminary surrogate sample of demonstration pyrochemical process, a mixture of cerium oxide (CeO2) and potassium chloride (KCl). A pulsed laser beam was focused on the surface of the sample located 1.45 m away from the stand-off LIBS device. The laser-induced plasma emission was collected through a Schmidt–Cassegrain telescope. LIBS spectra were obtained in an open path and through the shielding window. Univariate calibration curves were obtained using the integrated area of partially resolved Ce I and II lines. The limits of detection (LOD) for Ce were estimated to be 0.046 and 0.061 wt.% for the open-path and through-window analysis, respectively. We found that the through-window LOD is mainly influenced by the optical transmittance of the shielding window and therefore, the through-window LOD can be predicted from the open-path LOD and the optical transmittance of the shielding window. Also, multivariate calibration using partial least squares regression was successfully applied. The quality of calibration could be improved by the multivariate analysis

  19. Remote quantitative analysis of cerium through a shielding window by stand-off laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yongdeuk [Department of Chemistry, Mokpo National University, Jeonnam 534-729 (Korea, Republic of); Choi, Daewoong [Department of Chemistry, Mokpo National University, Jeonnam 534-729 (Korea, Republic of); Korea Atomic Energy Research Institute, P.O. Box 255, Yuseong, Daejeon 305-353 (Korea, Republic of); Han, Bo-Young, E-mail: byhan@kaeri.re.kr [Korea Atomic Energy Research Institute, P.O. Box 255, Yuseong, Daejeon 305-353 (Korea, Republic of); Yoo, Jonghyun [Applied Spectra, 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Han, Song-Hee [Division of Maritime Transportation System, Mokpo National Maritime University, Jeonnam 530-729 (Korea, Republic of); Lee, Yonghoon, E-mail: yhlee@mokpo.ac.kr [Department of Chemistry, Mokpo National University, Jeonnam 534-729 (Korea, Republic of)

    2014-10-15

    Highlights: • Remote LIBS analysis of cerium in the samples located behind a shielding window. • Effects of a shielding window on the remote LIBS analysis were investigated. • Multivariate analysis improves the calibration quality. - Abstract: Laser-Induced Breakdown Spectroscopy (LIBS) has been considered in many applications in nuclear industry. LIBS can be an ideal technique for analyzing the inaccessible nuclear materials typically located behind a shielding window. We report the effect of optical transmittance of the shielding window on the analytical performances of stand-off LIBS for the preliminary surrogate sample of demonstration pyrochemical process, a mixture of cerium oxide (CeO{sub 2}) and potassium chloride (KCl). A pulsed laser beam was focused on the surface of the sample located 1.45 m away from the stand-off LIBS device. The laser-induced plasma emission was collected through a Schmidt–Cassegrain telescope. LIBS spectra were obtained in an open path and through the shielding window. Univariate calibration curves were obtained using the integrated area of partially resolved Ce I and II lines. The limits of detection (LOD) for Ce were estimated to be 0.046 and 0.061 wt.% for the open-path and through-window analysis, respectively. We found that the through-window LOD is mainly influenced by the optical transmittance of the shielding window and therefore, the through-window LOD can be predicted from the open-path LOD and the optical transmittance of the shielding window. Also, multivariate calibration using partial least squares regression was successfully applied. The quality of calibration could be improved by the multivariate analysis.

  20. Detection of Ni, Pb and Zn in water using electrodynamic single-particle levitation and laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Järvinen, Samu T., E-mail: samu.jarvinen@tut.fi; Saari, Sampo; Keskinen, Jorma; Toivonen, Juha

    2014-09-01

    We report the development of a unique laser-induced breakdown spectroscopy (LIBS) based method for the trace metal analysis of water. The method is further applied to the analysis of aqueous samples containing known concentrations of nickel, lead and zinc. Effects that reduce the sensitivity of the LIBS analysis of aqueous samples were avoided in the presented technology by performing the LIBS analysis from a single dried salt particle which was levitated in an electric field. The salt is added to the water sample prior to analysis. A single-droplet generator injects a droplet of the solution to the measurement chamber. The droplet is trapped using electrodynamic balance technology and metals are highly concentrated as the water from the droplet rapidly evaporates without a need for additional heating. The resultant solid 7 μm particle is levitated with a high spatial stability in the LIBS focal volume. The constant mass and position of the particle enable the high reproducibility of the LIBS signal. The limits of detection in the original solution were recorded low 60 ppb, 60 ppb, and 50 ppb for nickel, lead, and zinc, respectively using low, 14 mJ excitation pulse energy. The methodology is applicable to the online monitoring of industrial waters due to the achieved sensitivity and robust instrumentation. - Highlights: • A single droplet of the water sample is trapped electrodynamically. • Metals in the droplet are rapidly preconcentrated as the water evaporates. • LIBS measurement from a single 7 μm dry salt particle using low laser pulse energy • Repeatable LIBS signal due to constant sample position and mass • Obtained detection limits for Ni, Pb and Zn were 60 ppb, 60 ppb and 50 ppb, respectively.

  1. Detection of Ni, Pb and Zn in water using electrodynamic single-particle levitation and laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    We report the development of a unique laser-induced breakdown spectroscopy (LIBS) based method for the trace metal analysis of water. The method is further applied to the analysis of aqueous samples containing known concentrations of nickel, lead and zinc. Effects that reduce the sensitivity of the LIBS analysis of aqueous samples were avoided in the presented technology by performing the LIBS analysis from a single dried salt particle which was levitated in an electric field. The salt is added to the water sample prior to analysis. A single-droplet generator injects a droplet of the solution to the measurement chamber. The droplet is trapped using electrodynamic balance technology and metals are highly concentrated as the water from the droplet rapidly evaporates without a need for additional heating. The resultant solid 7 μm particle is levitated with a high spatial stability in the LIBS focal volume. The constant mass and position of the particle enable the high reproducibility of the LIBS signal. The limits of detection in the original solution were recorded low 60 ppb, 60 ppb, and 50 ppb for nickel, lead, and zinc, respectively using low, 14 mJ excitation pulse energy. The methodology is applicable to the online monitoring of industrial waters due to the achieved sensitivity and robust instrumentation. - Highlights: • A single droplet of the water sample is trapped electrodynamically. • Metals in the droplet are rapidly preconcentrated as the water evaporates. • LIBS measurement from a single 7 μm dry salt particle using low laser pulse energy • Repeatable LIBS signal due to constant sample position and mass • Obtained detection limits for Ni, Pb and Zn were 60 ppb, 60 ppb and 50 ppb, respectively

  2. Temperature effect on laser-induced breakdown spectroscopy spectra of molten and solid salts

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Cynthia, E-mail: chanson@vandals.uidaho.edu [Department of Chemical and Materials Engineering, Nuclear Engineering Program, University of Idaho, Idaho Falls, ID 83401 (United States); Chemical and Radiation Measurement, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Phongikaroon, Supathorn, E-mail: sphongikaroon@vcu.edu [Department of Chemical and Materials Engineering, Nuclear Engineering Program, University of Idaho, Idaho Falls, ID 83401 (United States); Scott, Jill R., E-mail: jill.scott@inl.gov [Chemical and Radiation Measurement, Idaho National Laboratory, Idaho Falls, ID 83415 (United States)

    2014-07-01

    Laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential analytical tool to improve operations and safeguards for electrorefiners, such as those used in processing spent nuclear fuel. This study set out to better understand the effect of sample temperature and physical state on LIBS spectra of molten and solid salts by building calibration curves of cerium and assessing self-absorption, plasma temperature, electron density, and local thermal equilibrium (LTE). Samples were composed of a LiCl–KCl eutectic salt, an internal standard of MnCl{sub 2}, and varying concentrations of CeCl{sub 3} (0.1, 0.3, 0.5, 0.8, and 1.0 wt.% Ce) under different temperatures (773, 723, 673, 623, and 573 K). Analysis of salts in their molten form is preferred as plasma plumes from molten samples experienced less self-absorption, less variability in plasma temperature, and higher clearance of the minimum electron density required for local thermal equilibrium. These differences are attributed to plasma dynamics as a result of phase changes. Spectral reproducibility was also better in the molten state due to sample homogeneity. - Highlights: • Effect of temperature on LIBS spectra and conditions is presented for molten salt samples. • Signal intensity varied with physical state in the order transition > solid > molten state. • Temperature changes within the molten state also affected signal intensity. • For the given experimental parameters, self-absorption is least for the molten state. • Samples in the molten state gave the most homogeneous LIBS spectra.

  3. Temperature effect on laser-induced breakdown spectroscopy spectra of molten and solid salts

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential analytical tool to improve operations and safeguards for electrorefiners, such as those used in processing spent nuclear fuel. This study set out to better understand the effect of sample temperature and physical state on LIBS spectra of molten and solid salts by building calibration curves of cerium and assessing self-absorption, plasma temperature, electron density, and local thermal equilibrium (LTE). Samples were composed of a LiCl–KCl eutectic salt, an internal standard of MnCl2, and varying concentrations of CeCl3 (0.1, 0.3, 0.5, 0.8, and 1.0 wt.% Ce) under different temperatures (773, 723, 673, 623, and 573 K). Analysis of salts in their molten form is preferred as plasma plumes from molten samples experienced less self-absorption, less variability in plasma temperature, and higher clearance of the minimum electron density required for local thermal equilibrium. These differences are attributed to plasma dynamics as a result of phase changes. Spectral reproducibility was also better in the molten state due to sample homogeneity. - Highlights: • Effect of temperature on LIBS spectra and conditions is presented for molten salt samples. • Signal intensity varied with physical state in the order transition > solid > molten state. • Temperature changes within the molten state also affected signal intensity. • For the given experimental parameters, self-absorption is least for the molten state. • Samples in the molten state gave the most homogeneous LIBS spectra

  4. Optimal emission enhancement in orthogonal double-pulse laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sanginés, R. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México (CCADET-UNAM), Apartado Postal 70-186, México, DF 04510 (Mexico); Cátedra CONACyT, Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apartado Postal 14, Ensenada, BC 22800 (Mexico); Contreras, V. [Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere (Finland); Sobral, H., E-mail: martin.sobral@ccadet.unam.mx [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México (CCADET-UNAM), Apartado Postal 70-186, México, DF 04510 (Mexico); Robledo-Martinez, A. [Universidad Autónoma Metropolitana-Unidad Azcapotzalco, Av. San Pablo 180, Azcapotzalco, México, DF 02200 (Mexico)

    2015-08-01

    Orthogonal double-pulse (DP) laser-induced breakdown spectroscopy (LIBS) was performed using reheating and pre-ablative configurations. The ablation pulse power density was varied by two orders of magnitude and the DP experiments were carried out for a wide range of interpulse delays. For both DP-LIBS schemes, the signal enhancement was evaluated with respect to the corresponding single-pulse (SP) LIBS as a function of the interpulse delay. The reheating scheme shows a sharp maximum signal enhancement of up to 200-fold for low ablative power densities (0.4 GW cm{sup −2}); however, for power densities larger than 10 GW cm{sup −2} this configuration did not improve the SP outcome. On the other hand, a more uniform signal enhancement of about 4–6 was obtained for the pre-ablative scheme nearly independently of the used ablative power density. In terms of the signal-to-noise ratio (SNR) the pre-ablative scheme shows a monotonic increment with the ablative power density. Whereas the reheating configuration reaches a maximum at 2.2 GW cm{sup −2}, its enhancement effect collapses markedly for fluencies above 10 GW cm{sup −2}. - Highlights: • Comparison of reheating and pre-ablative double-pulse LIBS was done using a wide range of ablation power densities. • Experimental parameters that could achieve optimal signal-to-noise ratio were investigated. • A reheating scheme is better for low-ablation power densities. • A pre-ablative configuration is better for high-ablation power densities.

  5. Detection of tire tread particles using laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prochazka, David, E-mail: prochazka.d@fme.vutbr.cz [Brno University of Technology, Institute of Physical Engineering, Technická 2, 616 00 Brno (Czech Republic); Brno University of Technology, Central European Institute of Technology, Technická 3058/10, CZ-616 00 Brno (Czech Republic); Bilík, Martin [Brno University of Technology, Institute of Forensic Engineering, Údolní 244/53, 602 00 Brno (Czech Republic); Prochazková, Petra [Masaryk University, Faculty of Science, Department of Chemistry, Kamenice 735/5, 625 00 Brno (Czech Republic); Klus, Jakub; Pořízka, Pavel; Novotný, Jan [Brno University of Technology, Central European Institute of Technology, Technická 3058/10, CZ-616 00 Brno (Czech Republic); Novotný, Karel [Masaryk University, Faculty of Science, Department of Chemistry, Kamenice 735/5, 625 00 Brno (Czech Republic); Brno University of Technology, Central European Institute of Technology, Technická 3058/10, CZ-616 00 Brno (Czech Republic); Ticová, Barbora [Masaryk University, Faculty of Science, Department of Chemistry, Kamenice 735/5, 625 00 Brno (Czech Republic); Bradáč, Albert; Semela, Marek [Brno University of Technology, Institute of Forensic Engineering, Údolní 244/53, 602 00 Brno (Czech Republic); and others

    2015-06-01

    The objective of this paper is a study of the potential of laser induced breakdown spectroscopy (LIBS) for detection of tire tread particles. Tire tread particles may represent pollutants; simultaneously, it is potentially possible to exploit detection of tire tread particles for identification of optically imperceptible braking tracks at locations of road accidents. The paper describes the general composition of tire treads and selection of an element suitable for detection using the LIBS method. Subsequently, the applicable spectral line is selected considering interferences with lines of elements that might be present together with the detected particles, and optimization of measurement parameters such as incident laser energy, gate delay and gate width is performed. In order to eliminate the matrix effect, measurements were performed using 4 types of tires manufactured by 3 different producers. An adhesive tape was used as a sample carrier. The most suitable adhesive tape was selected from 5 commonly available tapes, on the basis of their respective LIBS spectra. Calibration standards, i.e. an adhesive tape with different area content of tire tread particles, were prepared for the selected tire. A calibration line was created on the basis of the aforementioned calibration standards. The linear section of this line was used for determination of the detection limit value applicable to the selected tire. Considering the insignificant influence of matrix of various types of tires, it is possible to make a simple recalculation of the detection limit value on the basis of zinc content in a specific tire. - Highlights: • LIBS experimental measurement parameters for tire tread particles were optimize. • Calibration curve was prepared. • Limit of detection was determined.

  6. Detection of tire tread particles using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The objective of this paper is a study of the potential of laser induced breakdown spectroscopy (LIBS) for detection of tire tread particles. Tire tread particles may represent pollutants; simultaneously, it is potentially possible to exploit detection of tire tread particles for identification of optically imperceptible braking tracks at locations of road accidents. The paper describes the general composition of tire treads and selection of an element suitable for detection using the LIBS method. Subsequently, the applicable spectral line is selected considering interferences with lines of elements that might be present together with the detected particles, and optimization of measurement parameters such as incident laser energy, gate delay and gate width is performed. In order to eliminate the matrix effect, measurements were performed using 4 types of tires manufactured by 3 different producers. An adhesive tape was used as a sample carrier. The most suitable adhesive tape was selected from 5 commonly available tapes, on the basis of their respective LIBS spectra. Calibration standards, i.e. an adhesive tape with different area content of tire tread particles, were prepared for the selected tire. A calibration line was created on the basis of the aforementioned calibration standards. The linear section of this line was used for determination of the detection limit value applicable to the selected tire. Considering the insignificant influence of matrix of various types of tires, it is possible to make a simple recalculation of the detection limit value on the basis of zinc content in a specific tire. - Highlights: • LIBS experimental measurement parameters for tire tread particles were optimize. • Calibration curve was prepared. • Limit of detection was determined

  7. Optimal emission enhancement in orthogonal double-pulse laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Orthogonal double-pulse (DP) laser-induced breakdown spectroscopy (LIBS) was performed using reheating and pre-ablative configurations. The ablation pulse power density was varied by two orders of magnitude and the DP experiments were carried out for a wide range of interpulse delays. For both DP-LIBS schemes, the signal enhancement was evaluated with respect to the corresponding single-pulse (SP) LIBS as a function of the interpulse delay. The reheating scheme shows a sharp maximum signal enhancement of up to 200-fold for low ablative power densities (0.4 GW cm−2); however, for power densities larger than 10 GW cm−2 this configuration did not improve the SP outcome. On the other hand, a more uniform signal enhancement of about 4–6 was obtained for the pre-ablative scheme nearly independently of the used ablative power density. In terms of the signal-to-noise ratio (SNR) the pre-ablative scheme shows a monotonic increment with the ablative power density. Whereas the reheating configuration reaches a maximum at 2.2 GW cm−2, its enhancement effect collapses markedly for fluencies above 10 GW cm−2. - Highlights: • Comparison of reheating and pre-ablative double-pulse LIBS was done using a wide range of ablation power densities. • Experimental parameters that could achieve optimal signal-to-noise ratio were investigated. • A reheating scheme is better for low-ablation power densities. • A pre-ablative configuration is better for high-ablation power densities

  8. Laser-induced breakdown spectroscopy analysis of asbestos

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy was applied to test the possibility of detecting and identifying asbestos in different samples in view of the perspective at field operation without sample preparation which is peculiar to this technique. Several like-resin materials were first investigated by laser-induced breakdown spectroscopy, in order to find an asbestos container assuring safe laboratory operation during the material characterization aimed to identify indicators suitable for a quick identification on field. Successively, spectra of asbestos samples of both in serpentine and amphibole forms were measured and the variability in elemental composition was calculated from the emission spectra. Ratios of intensities of characteristic elements were tested as indicators for asbestos recognition. Laser-induced breakdown spectroscopy results were compared with those obtained by analyzing the same asbestos samples with a scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy, a good correlation was found for Mg/Si and Fe/Si, thus showing the capability of laser-induced breakdown spectroscopy as a diagnostic tool for this category of materials. In particular, it was demonstrated that the method based on two indicators derived from laser-induced breakdown spectroscopy intensity ratios allows to discriminate between asbestos and cements in single shot measurements suitable to field operation

  9. Quantification of total carbon in soil using laser-induced breakdown spectroscopy: a method to correct interference lines.

    Science.gov (United States)

    Nicolodelli, Gustavo; Marangoni, Bruno S; Cabral, Jader S; Villas-Boas, Paulino R; Senesi, Giorgio S; Dos Santos, Cléber Hilario; Romano, Renan A; Segnini, Aline; Lucas, Yves; Montes, Célia R; Milori, Débora M B P

    2014-04-01

    The C cycle in the Brazilian forests is very important, mainly for issues addressed to climate changes and soil management. Assessing and understanding C dynamics in Amazonian soils can help scientists to improve models and anticipate scenarios. New methods that allow soil C measurements in situ are a crucial approach for this kind of region, due to the costs for collecting and sending soil samples from the rainforest to the laboratory. Laser-induced breakdown spectroscopy (LIBS) is a multielemental atomic emission spectroscopy technique that employs a highly energetic laser pulse for plasma production and requires neither sample preparation nor the use of reagents. As LIBS takes less than 10 s per sample measurement, it is considered a promising technique for in situ soil analyses. One of the limitations of portable LIBS systems, however, is the common overlap of the emission lines that cannot be spectrally resolved. In this study a method was developed capable of separating the Al interference from the C emission line in LIBS measurements. Two typical forest Brazilian soils rich in Al were investigated: a spodosol (Amazon Forest) and an oxisol (Atlantic Forest). Fifty-three samples were collected and analyzed using a low-resolution LIBS apparatus to measure the intensities of C lines. In particular, two C lines were evaluated, at 193.03 and 247.86 nm. The line at 247.86 nm showed very strong interference with Fe and Si lines, which made quantitative analysis difficult. The line at 193.03 nm showed interference with atomic and ionic Al emission lines, but this problem could be solved by applying a correction method that was proposed and tested in this work. The line at 247.86 was used to assess the proposed model. The strong correlation (Pearson's coefficient R=0.91) found between the LIBS values and those obtained by a reference technique (dry combustion by an elemental analyzer) supported the validity of the proposed method. PMID:24787177

  10. X-Ray Fluorescence and Laser-Induced Breakdown Spectroscopy analysis of Roman silver denarii

    Energy Technology Data Exchange (ETDEWEB)

    Pardini, L. [Istituto di Chimica dei Composti Organometallici del CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); El Hassan, A. [National Institute for Laser- Enhanced Sciences (NILES), Cairo University Giza (Egypt); Ferretti, M. [Istituto per le Tecnologie Applicate ai Beni Culturali, Area della Ricerca del CNR di Montelibretti Roma (Italy); Foresta, A.; Legnaioli, S.; Lorenzetti, G. [Istituto di Chimica dei Composti Organometallici del CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); Nebbia, E. [Universita degli Studi di Torino (Italy); Catalli, F. [Monetiere di Firenze, Museo Archeologico Nazionale Firenze (Italy); Harith, M.A. [National Institute for Laser- Enhanced Sciences (NILES), Cairo University Giza (Egypt); Diaz Pace, D. [Institute of Physics ' Arroyo Seco' , Faculty of Science, Tandil (Argentina); Anabitarte Garcia, F. [Photonics Engineering Group, University of Cantabria, Santander (Spain); Scuotto, M. [Dipartimento di Scienze Archeologiche, Via Galvani 1, 56126 Pisa (Italy); Palleschi, V., E-mail: vincenzo.palleschi@cnr.it [Istituto di Chimica dei Composti Organometallici del CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); Dipartimento di Scienze Archeologiche, Via Galvani 1, 56126 Pisa (Italy)

    2012-08-15

    In this paper we present the results of a study performed on a large collection of silver Roman republican denarii, encompassing about two centuries of history. The joint use of Laser-Induced Breakdown Spectroscopy (LIBS) and X-Ray Fluorescence (XRF) spectroscopy allowed for an accurate determination of the coins' elemental composition; the measurements, performed mostly in situ at the 'Monetiere' in Florence, revealed a striking connection between the 'quality' of the silver alloy and some crucial contemporary events. This finding was used to classify a group of denarii whose dating was otherwise impossible. The comparison with other contemporary denarii disproves a recent theory on the origin of the so called 'serrated' denarii (denarii showing notched chisel marks on the edge of the coin). - Highlights: Black-Right-Pointing-Pointer We studied a large collection of Roman republican silver denarii. Black-Right-Pointing-Pointer XRF and LIBS allowed to determine the precious metal content of the coins. Black-Right-Pointing-Pointer A correlation of the 'quality' of the alloy with some contemporary events was found. Black-Right-Pointing-Pointer The study allowed to controvert a recent theory on the so called 'serrated' denarii.

  11. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, J. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic)], E-mail: kaiser@fme.vutbr.cz; Galiova, M.; Novotny, K.; Cervenka, R. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Reale, L. [Faculty of Sciences, University of L' Aquila, Via Vetoio (Coppito 1), 67010 L' Aquila (Italy); Novotny, J.; Liska, M.; Samek, O. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic); Kanicky, V.; Hrdlicka, A. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Stejskal, K.; Adam, V.; Kizek, R. [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemedelska 1, 613 00 Brno (Czech Republic)

    2009-01-15

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 {mu}m in a up to cm x cm area of sunflower (Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  12. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Kaiser, J.; Galiová, M.; Novotný, K.; Červenka, R.; Reale, L.; Novotný, J.; Liška, M.; Samek, O.; Kanický, V.; Hrdlička, A.; Stejskal, K.; Adam, V.; Kizek, R.

    2009-01-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 μm in a up to cm × cm area of sunflower ( Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  13. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 μm in a up to cm x cm area of sunflower (Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed

  14. New ways for the quantification by the laser-induced plasma spectroscopy; Neue Wege zur Quantifizierung mit der laserinduzierten Plasmaspektroskopie (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Maike

    2010-04-27

    Laser Induced Breakdown Spectroscopy (LIBS) is capable of a fast and multielement analysis of various samples types and matrices which makes the method particularly attractive for industrial process analysis. However, for LIBS to become well accepted as an analytical method some issues in calibration and understanding of the underlying transient plasma processes have to be solved. The objective of this work was to identify influential instrumental parameters and plasma conditions in order to improve the overall quantitative performance of LIBS. As the spectral sensitivity and signal-to-noise ratio of the detector represents a decisive element for the application of LIBS in an industrial environment, two detectors, an ICCD and CCD camera, were compared. In combination with a high-resolution echelle spectrograph, the superior or at least equivalent efficiency of the non-intensified CCD was experimentally demonstrated and supported by corresponding plasma simulations. Further investigations of the plasma expansion under different atmospheric conditions revealed that the geometry of observing the expanding plasma influences the sensitivity and reproducibility of the measurements considerably. The diagnostics of self-absorbed spectral lines and their use for calibration purposes were studied with a mirror-based duplication method and a statistical line shape analysis employing linear correlation. The linear correlation approach displayed good performance for identifying the on-set of self absorption in comparison to the duplication method. As matrixmatched reference materials are essential to validate laser ablation methods, two novel preparations of individual calibration standards based on a copper-and polyacrylamide matrix were tested for their applicability to LIBS. (orig.)

  15. Quantitative Remote Laser-Induced Breakdown Spectroscopy by Multivariate Analysis

    Science.gov (United States)

    Clegg, S. M.; Sklute, E. C.; Dyar, M. D.; Barefield, J. E.; Wiens, R. C.

    2007-12-01

    The ChemCam instrument selected for the Mars Science Laboratory (MSL) rover includes a remote Laser- Induced Breakdown Spectrometer (LIBS) that will quantitatively probe samples up to 9m from the rover mast. LIBS is fundamentally an elemental analysis technique. LIBS involves focusing a Nd:YAG laser operating at 1064 nm onto the surface of the sample. The laser ablates material from the surface, generating an expanding plasma containing electronically excited ions, atoms, and small molecules. As these electronically excited species relax back to the ground state, they emit light at wavelengths characteristic of the species present in the sample. Some of this emission is directed into one of three dispersive spectrometers. In this paper, we studied a suite of 18 igneous and highly-metamorphosed samples from a wide variety of parageneses for which chemical analyses by XRF were already available. Rocks were chosen to represent a range of chemical composition from basalt to rhyolite, thus providing significant variations in all of the major element contents (Si, Fe, Al, Ca, Na, K, O, Ti, Mg, and Mn). These samples were probed at a 9m standoff distance under experimental conditions that are similar to ChemCam. Extracting quantitative elemental concentrations from LIBS spectra is complicated by the chemical matrix effects. Conventional methods for obtaining quantitative chemical data from LIBS analyses are compared with new multivariate analysis (MVA) techniques that appear to compensate for these chemical matrix effects. The traditional analyses use specific elemental peak heights or areas, which compared with calibration curves for each element at one or more emission lines for a series of standard samples. Because of matrix effects, the calibration standards generally must have similar chemistries to the unknown samples, and thus this conventional approach imposes severe limitations on application of the technique to remote analyses. In this suite of samples, the use

  16. Calibration-free analysis of steel slag by laser-induced breakdown spectroscopy with combined UV and VIS spectra

    Energy Technology Data Exchange (ETDEWEB)

    Kolmhofer, P.J.; Eschlböck-Fuchs, S.; Huber, N. [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, Linz A-4040 Austria (Austria); Rössler, R. [voestalpine Stahl GmbH, Linz A-4031 Austria (Austria); Heitz, J., E-mail: johannes.heitz@jku.at [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, Linz A-4040 Austria (Austria); Pedarnig, J.D., E-mail: johannes.pedarnig@jku.at [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, Linz A-4040 Austria (Austria)

    2015-04-01

    Slag from secondary metallurgy in industrial steel production is analyzed by calibration-free laser-induced breakdown spectroscopy (CF-LIBS). The slag pieces are homogenized by ball milling and sintering. LIBS spectra are measured under ambient conditions using nanosecond Nd:YAG laser pulses (1064 nm) for ablation. A fiber-coupled Echelle spectrometer with two separate detection arms in the UV range (190 to 360 nm) and in the VIS range (298 to 864 nm) and one ICCD camera is used for detection. The UV and VIS spectra are measured sequentially and combined to one spectrum to increase the number of highly resolved emission lines for the calculation of oxide concentrations in slags. The combination of spectra requires an adaption procedure including independent radiometric calibration, the de-convolution of spectrometer functions, baseline corrections, and intensity scaling. More than 60 emission lines of elements Ca, Al, Mg, Si, Fe, Mn, and Ti are evaluated. The electron density is derived from Stark broadening of a Mg line, and the plasma temperature is determined from Saha–Boltzmann plots of Ca, Mn, or Ti lines. With the combined LIBS spectra, the CF-LIBS calculated concentrations C{sub CF} are closer to the nominal concentrations C{sub N} determined by x-ray fluorescence spectrometry. Significantly reduced relative errors of concentration e{sub r} = |C{sub CF} − C{sub N}| / C{sub N} are observed for the oxides CaO, Al{sub 2}O{sub 3}, MgO, SiO{sub 2}, and MnO, and no reduction was found for FeO and the minor phase TiO{sub 2}. The improved accuracy of concentrations is attributed to a better detection of the major elements Ca, Al, and Si in the combined LIBS spectra. - Highlights: • Major oxides in steel slag are quantified with improved accuracy by calibration-free laser-induced breakdown spectroscopy. • For CF-LIBS calculations, LIBS spectra measured in VIS und UV ranges are combined by a mathematical adaption procedure. • In combined spectra more

  17. Calibration-free analysis of steel slag by laser-induced breakdown spectroscopy with combined UV and VIS spectra

    International Nuclear Information System (INIS)

    Slag from secondary metallurgy in industrial steel production is analyzed by calibration-free laser-induced breakdown spectroscopy (CF-LIBS). The slag pieces are homogenized by ball milling and sintering. LIBS spectra are measured under ambient conditions using nanosecond Nd:YAG laser pulses (1064 nm) for ablation. A fiber-coupled Echelle spectrometer with two separate detection arms in the UV range (190 to 360 nm) and in the VIS range (298 to 864 nm) and one ICCD camera is used for detection. The UV and VIS spectra are measured sequentially and combined to one spectrum to increase the number of highly resolved emission lines for the calculation of oxide concentrations in slags. The combination of spectra requires an adaption procedure including independent radiometric calibration, the de-convolution of spectrometer functions, baseline corrections, and intensity scaling. More than 60 emission lines of elements Ca, Al, Mg, Si, Fe, Mn, and Ti are evaluated. The electron density is derived from Stark broadening of a Mg line, and the plasma temperature is determined from Saha–Boltzmann plots of Ca, Mn, or Ti lines. With the combined LIBS spectra, the CF-LIBS calculated concentrations CCF are closer to the nominal concentrations CN determined by x-ray fluorescence spectrometry. Significantly reduced relative errors of concentration er = |CCF − CN| / CN are observed for the oxides CaO, Al2O3, MgO, SiO2, and MnO, and no reduction was found for FeO and the minor phase TiO2. The improved accuracy of concentrations is attributed to a better detection of the major elements Ca, Al, and Si in the combined LIBS spectra. - Highlights: • Major oxides in steel slag are quantified with improved accuracy by calibration-free laser-induced breakdown spectroscopy. • For CF-LIBS calculations, LIBS spectra measured in VIS und UV ranges are combined by a mathematical adaption procedure. • In combined spectra more emission lines are available for calculations with some lines

  18. Application of Graph Theory to unsupervised classification of materials by Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Grifoni, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Palleschi, V.

    2016-04-01

    In this paper we present a new approach for unsupervised classification of materials from the spectra obtained using the Laser-Induced Breakdown Spectroscopy technique. The method is based on the calculation of the correlation matrix between the LIBS spectra, which is interpreted as an Adjacency matrix in the framework of Graph theory. A threshold is applied on the edge values, which is determined through maximization of the Modularity of the Graph. The classification of the spectra is done automatically after the calculation of the Modularity parameter. An example of the application of the proposed method is given, based on the study of six bronze standards of known composition. The advantages of the proposed approach with respect to Principal Component Analysis are also discussed.

  19. Influence of Lead on the Interpretation of Bone Samples with Laser-Induced Breakdown Spectroscopy

    Directory of Open Access Journals (Sweden)

    Abdolhamed Shahedi

    2016-01-01

    Full Text Available This study is devoted to tracing and identifying the elements available in bone sample using Laser-Induced Breakdown Spectroscopy (LIBS. The bone samples were prepared from the thigh of laboratory rats, which consumed 325.29 g/mol lead acetate having 4 mM concentration in specified time duration. About 76 atomic lines have been analyzed and we found that the dominant elements are Ca I, Ca II, Mg I, Mg II, Fe I, and Fe II. Temperature curve and bar graph were drawn to compare bone elements of group B which consumed lead with normal group, group A, in the same laboratory conditions. Plasma parameters including plasma temperature and electron density were determined by considering Local Thermodynamic Equilibrium (LTE condition in the plasma. An inverse relationship has been detected between lead absorption and elements like Calcium and Magnesium absorption comparing elemental values for both the groups.

  20. Elemental analysis of metals under water using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Pichahchy, A. E.; Cremers, D. A.; Ferris, M. J.

    1997-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been evaluated for the detection of metals located under water. Repetitive laser sparks were formed on the metals by focused pulses from a Q-switched Nd:YAG laser (1064 nm). Using repetitive single sparks (RSS) at 10 Hz, only weak elemental emission signals were generated from even strongly emitting species at high concentrations (e.g. Al(I) from commercially pure aluminum). The spectrum in these cases was dominated by spectrally broad emissions (continuum radiation) from the plume ( T bubble or vapor cavity (maximum diameter ˜ 8 mm) on the metal surface which is then interrogated by the second pulse. The second pulse then forms a plasma resulting in excitation similar to that produced by a single laser spark formed on metal in air.

  1. Near-crater discoloration of white lead in wall paintings during laser induced breakdown spectroscopy analysis

    Science.gov (United States)

    Bruder, R.; L'Hermite, D.; Semerok, A.; Salmon, L.; Detalle, V.

    2007-12-01

    During Laser-Induced Breakdown Spectroscopy (LIBS) analysis of white lead pigment (basic lead carbonate, 2PbCO 3·Pb(OH) 2), used in wall paintings of historical interest, a yellow-brown discoloration has been observed around the crater. This phenomenon faded after a few days exposure under ambient atmosphere. It was established that the mechanism of this discoloration consists in lead oxides (PbO) formation. It was verified by further experiments under argon atmosphere that recombination of lead with oxygen in the plasma plume produces the oxides, which settle around the crater and induce this discoloration. The impact of discoloration on the artwork's aesthetic aspect and the role of atmosphere on discoloration attenuation are discussed. The mechanism is studied on three other pigments (malachite, Prussian blue and ultramarine blue) and threshold for discoloration occurrence is estimated.

  2. Evaluation of the standard normal variate method for Laser-Induced Breakdown Spectroscopy data treatment applied to the discrimination of painting layers

    Science.gov (United States)

    Syvilay, D.; Wilkie-Chancellier, N.; Trichereau, B.; Texier, A.; Martinez, L.; Serfaty, S.; Detalle, V.

    2015-12-01

    Nowadays, Laser-Induced Breakdown Spectroscopy (LIBS) is frequently used for in situ analyses to identify pigments from mural paintings. Nonetheless, in situ analyses require a robust instrumentation in order to face to hard experimental conditions. This may imply variation of fluencies and thus inducing variation of LIBS signal, which degrades spectra and then results. Usually, to overcome these experimental errors, LIBS signal is processed. Signal processing methods most commonly used are the baseline subtraction and the normalization by using a spectral line. However, the latter suggests that this chosen element is a constant component of the material, which may not be the case in paint layers organized in stratigraphic layers. For this reason, it is sometimes difficult to apply this normalization. In this study, another normalization will be carried out to throw off these signal variations. Standard normal variate (SNV) is a normalization designed for these conditions. It is sometimes implemented in Diffuse Reflectance Infrared Fourier Transform Spectroscopy and in Raman Spectroscopy but rarely in LIBS. The SNV transformation is not newly applied on LIBS data, but for the first time the effect of SNV on LIBS spectra was evaluated in details (energy of laser, shot by shot, quantification). The aim of this paper is the quick visualization of the different layers of a stratigraphic painting sample by simple data representations (3D or 2D) after SNV normalization. In this investigation, we showed the potential power of SNV transformation to overcome undesired LIBS signal variations but also its limit of application. This method appears as a promising way to normalize LIBS data, which may be interesting for in-situ depth analyses.

  3. Time-Resolved Spectroscopy Diagnostic of Laser-Induced Optical Breakdown

    International Nuclear Information System (INIS)

    Transient laser plasma is generated in laser-induced optical breakdown (LIOB). Here we report experiments conducted with 10.6-micron CO2 laser radiation, and with 1.064-micron fundamental, 0.532-micron frequency-doubled, 0.355-micron frequency-tripled Nd:YAG laser radiation. Characterization of laser induced plasma utilizes laser-induced breakdown spectroscopy (LIBS) techniques. Atomic hydrogen Balmer series emissions show electron number density of 1017 cm-3 measured approximately 10μs and 1μs after optical breakdown for CO2 and Nd:YAG laser radiation, respectively. Recorded molecular recombination emission spectra of CN and C2 Swan bands indicate an equilibrium temperature in excess of 7000 Kelvin, inferred for these diatomic molecules. Reported are also graphite ablation experiments where we use unfocused laser radiation that is favorable for observation of neutral C3 emission due to reduced C3 cation formation. Our analysis is based on computation of diatomic molecular spectra that includes accurate determination of rotational line strengths, or Honl-London factors

  4. Time-Resolved Spectroscopy Diagnostic of Laser-Induced Optical Breakdown

    Directory of Open Access Journals (Sweden)

    Christian G. Parigger

    2010-01-01

    Full Text Available Transient laser plasma is generated in laser-induced optical breakdown (LIOB. Here we report experiments conducted with 10.6-micron CO2 laser radiation, and with 1.064-micron fundamental, 0.532-micron frequency-doubled, 0.355-micron frequency-tripled Nd:YAG laser radiation. Characterization of laser induced plasma utilizes laser-induced breakdown spectroscopy (LIBS techniques. Atomic hydrogen Balmer series emissions show electron number density of 1017 cm−3 measured approximately 10 μs and 1 μs after optical breakdown for CO2 and Nd:YAG laser radiation, respectively. Recorded molecular recombination emission spectra of CN and C2 Swan bands indicate an equilibrium temperature in excess of 7000 Kelvin, inferred for these diatomic molecules. Reported are also graphite ablation experiments where we use unfocused laser radiation that is favorable for observation of neutral C3 emission due to reduced C3 cation formation. Our analysis is based on computation of diatomic molecular spectra that includes accurate determination of rotational line strengths, or Hönl-London factors.

  5. Miniaturized Laser-Induced Breakdown Spectroscopy for the in-situ analysis of the Martian surface: Calibration and quantification

    International Nuclear Information System (INIS)

    We report on our ongoing studies to develop Laser-Induced Breakdown Spectroscopy (LIBS) for planetary surface missions to Mars and other planets and moons, like Jupiter's moon Europa or the Earth's moon. Since instruments for space missions are severely mass restricted, we are developing a light-weight miniaturized close-up LIBS instrument to be installed on a lander or rover for the in-situ geochemical analysis of planetary surface rocks and coarse fines. The total mass of the instrument will be ∼ 1 kg in flight configuration. Here we report on a systematic performance study of a LIBS instrument equipped with a prototype laser of 216 g total mass and an energy of 1.8 mJ. The LIBS measurements with the prototype laser and the comparative measurements with a regular 40 mJ laboratory laser were both performed under Martian atmospheric conditions. We calibrated 14 major and minor elements by analyzing 18 natural samples of certified composition. The calibration curves define the limits of detection that are > 5 ppm for the lab laser and > 400 ppm for the prototype laser, reflecting the different analyzed sample masses of ∼ 20 μg and ∼ 2 μg, respectively. To test the accuracy we compared the LIBS compositions, determined with both lasers, of Mars analogue rocks with certified or independently measured compositions and found agreements typically within 10-20%. In addition we verified that dust coverage is effectively removed from rock surfaces by the laser blast. Our study clearly demonstrates that a close-up LIBS instrument (spot size ∼ 50 μm) will decisively enhance the scientific output of planetary lander missions by providing a very large number of microscopic elemental analyses.

  6. Detection of trace concentrations of helium and argon in gas mixtures by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    McNaghten, E.D., E-mail: Edward.McNaghten@awe.co.u [AWE Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom); Parkes, A.M.; Griffiths, B.C. [AWE Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom); Whitehouse, A.I.; Palanco, S. [Applied Photonics Ltd., Skipton, North Yorkshire, BD23 2DE (United Kingdom)

    2009-10-15

    We report what we believe to be the first demonstration of the detection of trace quantities of helium and argon in binary and ternary gas mixtures with nitrogen by laser-induced breakdown spectroscopy (LIBS). Although significant quenching of helium transitions due to collisional deactivation of excited species was observed, it was found that losses in analytical sensitivity could be minimized by increasing the laser irradiance and decreasing the pressure at which the analyses were performed. In consequence, limits of detection of parts-per-million and tens of parts-per-million and linear dynamic ranges of several orders of magnitude in analyte concentration were obtained. The results of this study suggest that LIBS may have potential applications in the detection of other noble gases at trace concentrations.

  7. The application of spectrum standardization method for carbon analysis in coal using laser-induced breakdown spectroscopy

    CERN Document Server

    Li, Xiongwei; Fu, Yangting; Li, Zheng; Liu, Jianming; Ni, Weidou

    2014-01-01

    Measurements of carbon content in coal using laser-induced breakdown spectroscopy (LIBS) is limited by its low measurement precision and accuracy. A spectrum standardization method was proposed to achieve both reproducible and accurate results for the quantitative analysis of carbon content in coal with LIBS. The proposed method utilized the molecular carbon emissions to compensate the diminution of atomic carbon emission caused by matrix effect. The compensated carbon line intensities were further converted into an assumed standard state with fixed plasma temperature, electron density, and total number density of elemental carbon, which is proportional to its concentration in the coal samples. In addition, in order to obtained better compensation for total carbon number density fluctuations, an iterative algorithm was applied, which is different from our previous standardization calculations. The modified spectrum standardization model was applied to the measurement of carbon content in 24 bituminous coal sa...

  8. Laser-induced breakdown spectroscopy used to detect endophyte-mediated accumulation of metals by tall fescue

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Madhavi Z.; Stewart, Arthur J.; Gwinn, Kimberley D.; Waller, John C.

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) was used to determine the impact of endophyte (Neotyphodium sp.) infection on elemental composition of tall fescue (Festuca arundinacea). Leaf material from endophyte-infected (E+) and endophyte-free (E-) tall fescue populations in established plots was examined. Leaf-tissue digestates were also tested for metals, by inductively coupled plasma (ICP) mass spectrometry (MS). Seven of eleven metals (Ca, Mg, Fe, Mn, Cu, Ni, and Zn) were measured by both techniques at concentrations great enough for a reliable comparison. Mg, Zn, and Cd, a toxic metal that can be present in forage, were readily detected by LIBS, even though Cd concentrations in the plants were below levels typically achieved using ICP MS detection. Implications of these results for research on forage analysis and phytoremediation are discussed.

  9. Laser-induced breakdown spectroscopy used to detect endophyte-mediated accumulation of metals by tall fescue

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) was used to determine the impact of endophyte (Neotyphodium sp.) infection on elemental composition of tall fescue (Festuca arundinacea). Leaf material from endophyte-infected (E+) and endophyte-free (E-) tall fescue populations in established plots was examined. Leaf-tissue digestates were also tested for metals, by inductively coupled plasma (ICP) mass spectrometry (MS). Seven of eleven metals (Ca, Mg, Fe, Mn, Cu, Ni, and Zn) were measured by both techniques at concentrations great enough for a reliable comparison. Mg, Zn, and Cd, a toxic metal that can be present in forage, were readily detected by LIBS, even though Cd concentrations in the plants were below levels typically achieved using ICP MS detection. Implications of these results for research on forage analysis and phytoremediation are discussed.

  10. Kinetic model of C/H/N/O emissions in laser-induced breakdown spectroscopy of organic compounds

    International Nuclear Information System (INIS)

    A kinetic model to predict the relative intensities of the atomic C/H/N/O emission lines in laser-induced breakdown spectroscopy (LIBS) has been developed for organic compounds. The model includes a comprehensive set of chemical processes involving both neutral and ionic chemistry and physical excitation and de-excitation of atomic levels affecting the neutral, ionic, and excited-state species concentrations. The relative excited-state atom concentrations predicted by this modeling are compared with those derived from the observed LIBS intensities for 355 nm ns laser irradiation of residues of two organic compounds on aluminum substrate. The model reasonably predicts the relative excited-state concentrations, as well as their time profiles. Comparison of measured and computed concentrations has also allowed an estimation of the degree of air entrainment.

  11. Quantitative Analysis of Carbon Steel with Multi-Line Internal Standard Calibration Method Using Laser-Induced Breakdown Spectroscopy.

    Science.gov (United States)

    Pan, Congyuan; Du, Xuewei; An, Ning; Zeng, Qiang; Wang, Shengbo; Wang, Qiuping

    2016-04-01

    A multi-line internal standard calibration method is proposed for the quantitative analysis of carbon steel using laser-induced breakdown spectroscopy (LIBS). A procedure based on the method was adopted to select the best calibration curves and the corresponding emission lines pairs automatically. Laser-induced breakdown spectroscopy experiments with carbon steel samples were performed, and C, Cr, and Mn were analyzed via the proposed method. Calibration curves of these elements were constructed via a traditional single line internal standard calibration method and a multi-line internal standard calibration method. The calibration curves obtained were evaluated with the determination coefficient, the root mean square error of cross-validation, and the average relative error of cross-validation. All of the parameters were improved significantly with the proposed method. The results show that accurate and stable calibration curves can be obtained efficiently via the multi-line internal standard calibration method. PMID:26872822

  12. Laser-induced breakdown spectroscopy and multivariate statistics for the rapid identification of oxide inclusions in steel products

    Science.gov (United States)

    Boué-Bigne, Fabienne

    2016-05-01

    Laser induced breakdown spectroscopy (LIBS) scanning measurements can generally be used to detect the presence of non-metallic inclusions in steel samples. However, the inexistence of appropriate standards to calibrate the LIBS instrument signal means that its application is limited to identifying simple diatomic inclusions and inclusions that are chemically fully distinct from one another. Oxide inclusions in steel products have varied and complex chemical content, with an approximate size of interest of 1 μm. Several oxide inclusions types have chemical elements in common, but it is the concentration of these elements that makes an inclusion type have little or, on the contrary, deleterious impact on the final steel product quality. During the LIBS measurement of such inclusions, the spectroscopic signal is influenced not only by the inclusions' chemical concentrations but also by their varying size and associated laser ablation matrix effects. To address the complexity of calibrating the LIBS instrument signal for identifying such inclusion species, a new approach was developed where a calibration dataset was created, combining the elemental concentrations of typical oxide inclusions with the associated LIBS signal, in order to define a multivariate discriminant function capable of identifying oxide inclusions from LIBS data obtained from the measurement of unknown samples. The new method was applied to a variety of steel product samples. Inclusions populations consisting of mixtures of several complex oxides, with overlapping chemical content and size ranging typically from 1 to 5 μm, were identified and correlated well with validation data. The ability to identify complex inclusion types from LIBS data could open the way to new applications as, for a given sample area, the LIBS measurement is performed in a fraction of the time required by scanning electron microscopy, which is the conventional technique used for inclusion characterisation in steel

  13. Direct spectral analysis and determination of high content of carcinogenic bromine in bread using UV pulsed laser induced breakdown spectroscopy.

    Science.gov (United States)

    Mehder, A O; Gondal, Mohammed A; Dastageer, Mohamed A; Habibullah, Yusuf B; Iqbal, Mohammed A; Oloore, Luqman E; Gondal, Bilal

    2016-06-01

    Laser induced breakdown spectroscopy (LIBS) was applied for the detection of carcinogenic elements like bromine in four representative brands of loaf bread samples and the measured bromine concentrations were 352, 157, 451, and 311 ppm, using Br I (827.2 nm) atomic transition line as the finger print atomic transition. Our LIBS system is equipped with a pulsed laser of wavelength 266 nm with energy 25 mJ pulse(-1), 8 ns pulse duration, 20 Hz repetition rate, and a gated ICCD camera. The LIBS system was calibrated with the standards of known concentrations in the sample (bread) matrix and such plot is linear in 20-500 ppm range. The capability of our system in terms of limit of detection and relative accuracy with respect to the standard inductively coupled plasma mass spectrometry (ICPMS) technique was evaluated and these values were 5.09 ppm and 0.01-0.05, respectively, which ensures the applicability of our system for Br trace level detection, and LIBS results are in excellent agreement with that of ICPMS results. PMID:26950676

  14. Laser-induced breakdown spectroscopy study of silversmith pieces: the case of a Spanish canopy of the nineteenth century

    Science.gov (United States)

    Gómez-Morón, M. A.; Ortiz, P.; Ortiz, R.; Martín, J. M.; Mateo, M. P.; Nicolás, G.

    2016-05-01

    Canopies of needlework velvet or silversmith pieces placed on twelve or more battens are widely employed in Spanish catholic ceremonies to cover the image of the virgin. In this paper, we focus our interest on those pieces made of silver. These silver crafts suffered a revolution in the nineteenth century with the development of an electrolyte system that can be applied over carved metal pieces, in order to obtain a silver layer by electrodeposition similar in appearance to the original sterling silver and cheaper. The aim of this research was the application of laser-induced breakdown spectroscopy (LIBS) to the study of a canopy of the nineteenth century in order to assess the techniques used for its manufacturing and the identification of replacement and restoration of original pieces. The LIBS depth profiles show the presence of a micron silver layer over an alloy of copper and zinc in most of the surfaces. Corrosion products, alloy missing, and the restoration with copper layers were detected. These results are consistent with those obtained by scanning electron microscopy with energy-dispersive of X-ray with the advantage that LIBS is a methodology that allows analysing metal pieces without sampling or preparation. In summary, LIBS is a technique that allows the study of silversmith pieces with electrochemical preparation according to the Ruolz technique, and it is also possible to detect subsequent restoration or corrosion zones.

  15. Rock and Soil Classification Using PLS-DA and SVM Combined with a Laser-Induced Breakdown Spectroscopy Library

    Science.gov (United States)

    Yang, Guang; Qiao, Shujun; Chen, Pengfei; Ding, Yu; Tian, Di

    2015-08-01

    Laser-induced breakdown spectroscopy (LIBS) has become a powerful technology in geological applications. The correct identification of rocks and soils is critical to many geological projects. In this study, LIBS database software with a user-friendly and intuitive interface is developed based on Windows, consisting of a database module and a sample identification module. The database module includes a basic database containing LIBS persistent lines for elements and a dedicated geological database containing LIBS emission lines for several rock and soil reference standards. The module allows easy use of the data. A sample identification module based on partial least squares discriminant analysis (PLS-DA) or support vector machine (SVM) algorithms enables users to classify groups of unknown spectra. The developed system was used to classify rock and soil data sets in a dedicated database and the results demonstrate that the system is capable of fast and accurate classification of rocks and soils, and is thus useful for the detection of geological materials. supported by National Major Scientific Instruments and Equipment Development Special Funds, China (No. 2011YQ030113)

  16. Artificial neural network for Cu quantitative determination in soil using a portable Laser Induced Breakdown Spectroscopy system

    International Nuclear Information System (INIS)

    Laser Induced Breakdown Spectroscopy (LIBS) is an advanced analytical technique for elemental determination based on direct measurement of optical emission of excited species on a laser induced plasma. In the realm of elemental analysis, LIBS has great potential to accomplish direct analysis independently of physical sample state (solid, liquid or gas). Presently, LIBS has been easily employed for qualitative analysis, nevertheless, in order to perform quantitative analysis, some effort is still required since calibration represents a difficult issue. Artificial neural network (ANN) is a machine learning paradigm inspired on biological nervous systems. Recently, ANNs have been used in many applications and its classification and prediction capabilities are especially useful for spectral analysis. In this paper an ANN was used as calibration strategy for LIBS, aiming Cu determination in soil samples. Spectra of 59 samples from a heterogenic set of reference soil samples and their respective Cu concentration were used for calibration and validation. Simple linear regression (SLR) and wrapper approach were the two strategies employed to select a set of wavelengths for ANN learning. Cross validation was applied, following ANN training, for verification of prediction accuracy. The ANN showed good efficiency for Cu predictions although the features of portable instrumentation employed. The proposed method presented a limit of detection (LOD) of 2.3 mg dm-3 of Cu and a mean squared error (MSE) of 0.5 for the predictions

  17. Location and detection of explosive-contaminated human fingerprints on distant targets using standoff laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Detection of explosive-contaminated human fingerprints constitutes an analytical challenge of high significance in security issues and in forensic sciences. The use of a laser-induced breakdown spectroscopy (LIBS) sensor working at 31 m distance to the target, fitted with 2D scanning capabilities and designed for capturing spectral information from laser-induced plasmas of fingerprints is presented. Distribution chemical maps based on Na and CN emissions are used to locate and detect chloratite, DNT, TNT, RDX and PETN residues that have been deposited on the surface of aluminum and glass substrates. An effectiveness of 100% on fingerprints detection, regardless the substrate scanned, is reached. Environmental factors that affect the prevalence of the fingerprint LIBS response are discussed. - Highlights: • Explosive remnants left behind by fingerprints have been detected from afar. • Operating in scanning mode, LIBS boasts high ability to locate traces over a surface. • Effectiveness in trace detection plainly depends on the scanning spatial resolution. • The detection capability of LIBS shrinks as the fingerprints deteriorate over time

  18. Use of the vacuum ultraviolet spectral region for laser-induced breakdown spectroscopy-based Martian geology and exploration

    International Nuclear Information System (INIS)

    Several elements important to planetary geology (e.g. Br, C, Cl, P, S) and the human exploration of Mars (e.g. toxic elements such as As) have strong emission lines in the purge and vacuum ultraviolet (VUV) spectral region (100-200 nm). This spectral region has not been extensively studied for space applications using geological samples. We studied emissions from the laser-induced breakdown spectroscopy (LIBS) plasma in this region using a sample chamber filled with 7 torr (930 Pa) of CO2 to simulate the Martian atmosphere. Pressures down to 0.02 torr were also used to evaluate the effect of the residual CO2 on the spectra and to begin investigating the use of VUV-LIBS for airless bodies such as asteroids and the Moon. Spectra were recorded using a 0.3-m vacuum spectrometer with an intensified CCD (ICCD) camera. The effects of time delay and laser energy on LIBS detection at reduced pressure were examined. The effect of ambient CO2 on the detection of C in soil was also evaluated. Lines useful for the spectrochemical analysis of As, Br, C, Cl, P, and S were determined and calibration curves were prepared for these elements. Although LIBS is being developed for stand-off analysis at many meters distance, the experiments reported here were aimed at in-situ (close-up) analysis

  19. Determination of plasma temperature and electron density in river sediment plasma using calibration-free laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Calibration-free laser-induced breakdown spectroscopy (CF-LIBS) technique is an approach used to quantitatively measure elemental composition of samples without the use of standard reference materials (SRMs). Due to the unavailability of most SRMs for specific samples, the CF-LIBS approach is steadily becoming more prevalent. CF-LIBS also minimizes interferences from the sample matrix by accounting spectral line intensifies of different elements. The first part of the CF-LIBS algorithm is the calculation of plasma temperature and electron density of the sample while the second part deals with the self-absorption correction and quantitative elemental analysis. In this study, the precursor parameters for the algorithm - plasma temperature and electron density - were measured through the neutral atom and ion line emissions of Fe and Cu in the time window of 0.1 to 10 μs. Plasma from river sediment samples were produced by a 1064 nm nanosecond pulsed Nd:YAG laser at atmospheric pressure. The plasma temperature and electron density were calculated from the Boltzmann plot and Saha-Boltzmann equation methods, respectively. These precursor parameters can be used in calculating the time window wherein the plasma is optically thin at local thermodynamic equilibrium (LTE) and for quantitative multi-elemental analysis. (author)

  20. [Research on accurate measurement of oxygen content in coal using laser-induced breakdown spectroscopy in air environment].

    Science.gov (United States)

    Yin, Wang-bao; Zhang, Lei; Wang, Le; Dong, Lei; Ma, Wei-guang; Jia, Suo-tang

    2012-01-01

    A technique about accurate measurement of oxygen content in coal in air environment using laser-induced breakdown spectroscopy (LIBS) is introduced in the present paper. Coal samples were excited by the laser, and plasma spectra were obtained. Combining internal standard method, temperature correction method and multi-line methods, the oxygen content of coal samples was precisely measured. The measurement precision is not less than 1.37% for oxygen content in coal analysis, so is satisfied for the requirement of coal-fired power plants in coal analysis. This method can be used in surveying, environmental protection, medicine, materials, archaeological and food safety, biochemical and metallurgy application. PMID:22497159

  1. Standoff Sensing Technology Based on Laser-Induced Breakdown Spectroscopy: Advanced Targeting, Surveillance and Reconnaissance in Security and Architectural Heritage Applications

    OpenAIRE

    Gaona Fernández, María Inmaculada

    2014-01-01

    Due to the ability to perform simultaneous, multi-element and real-time analysis without pretreatment and doing from a distance, laser induced breakdown spectroscopy (LIBS) in standoff mode is now considered a cutting-edge analytical technology. All these features have allowed its application in various fields such as security, environment, cultural heritage protection and space exploration, among the more outstanding. Nonetheless, the fact of working to long distances involves greater dif...

  2. Wheat tissue hardness. Application of laser-induced breakdown spectroscopy and chemometrics

    International Nuclear Information System (INIS)

    Complete text of publication follows. Wheat grain is a complex structure made of the germ and starchy endosperm surrounded by several peripheral tissues differing in their structure and chemical compositions. In traditional wheat milling processes, this part of the grain is discarded as the bran, mostly used in animal feed. Bran could be however used for food ingredient preparation if it is fractionated to remove unwanted parts and increase bioactive compounds accessibility. Wheat outer layers mechanical properties are key properties to explain differences observed for bran fractionation. Up to now, these properties are deduced by tensile tests of hand-isolated tissues after wheat humidification, a procedure that could induce artefacts. Pulsed laser ablation have demonstrated a potential technique to reveal wheat tissue properties (Martelli et al., J Cereal Sci, in press.). Ablation rate was deduced from microscopic observations which are time consuming. Taking advantage of compositional heterogeneity within the peripheral tissues, laser-induced breakdown spectroscopy (LIBS) could be a powerful tool to follow wheat tissue ablation. With this aim, native grains of a soft common wheat (Crousty) were gradually ablated with a pulsed excimer laser ArF (193 nm, 15 ns, 1 Hz, 2 J · cm-2) coupled to a miniature optical fibre spectrometer. Spectra were acquired from each pulse. Chemometrics were successfully applied to exploit the complex LIBS spectral data. The bran tissues (pericarp, seed coat, aleurone layer) and the endosperm were successfully predicted by a partial least square discriminant analysis (PLS-DA) model. These results were validated by microscopic observations Tissue hardness was deduced from the ablation rate but also directly from LIBS spectra, by exploring the ionic to atomic magnesium line ratio (Mg II 279.55 nm/Mg I 285.22 nm). Tissue ablation rate were indirectly related to Mg II/Mg I, suggesting the LIBS potential to estimate tissue hardness. Even

  3. Improvement of Soil Carbon Determination using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Moon, S. J.

    2014-12-01

    The increase of atmospheric greenhouse gases such as CO2 has caused noticeable climate change. Since increased CO2 may contribute to carbon storage in terrestrial ecosystems through the CO2 cycle between the atmosphere and vegetation, it is necessary to improve methods for measuring C in soil. In this study, we determined the total carbon concentrations of soils using a laser-induced breakdown spectroscopy (LIBS). The LIBS is a minimally destructive measurement technique that uses an ultra-short laser pulse to create plasma on the sample surface via the process of laser ablation. Compared with the traditional C measurements methods techniques such as wet oxidation and dry combustion, LIBS is known as a potentially elegant and promising solution for measuring C in soils. Although previous studies suggested the advantages of LIBS for measuring the C in soils, there are still challenging obstacles to be solved in measuring C. Previous studies have shown that the C in soil can be detected at wavelengths of 193.03 and 247.86 nm. The C line at 247.86 nm shows strong interference with Fe lines at 247.86 nm and 247.95 nm due to overlapping or self-absorption. To dismiss the problem of measuring the C line at 247.86 nm, the C line at 193.03 nm has been used to observe C emission. The C line at 193.03 nm can be quantified without interference from other elements, however, the ratio of Al line (198.90 nm) and Si line (212.40 nm) were used as standardizing factors to develop a significant calibration curve for soils. Although the wavelengths of both 193.03 and 247.86 nm presented the potential to measure C in soils, there has still been a lack of studies comparing the accuracy and effectiveness between the 193.03- and 247.8-nm C lines to analyze soil samples with different chemical and textural characteristics. In this study, we conducted extensive measurements of the C lines at 193.03 and 247.86 nm using LIBS to evaluate the C concentrations of Korean soils with different

  4. Quantitative estimation of carbonation and chloride penetration in reinforced concrete by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The penetration profile of chlorine in a reinforced concrete (RC) specimen was determined by laser-induced breakdown spectroscopy (LIBS). The concrete core was prepared from RC beams with cracking damage induced by bending load and salt water spraying. LIBS was performed using a specimen that was obtained by splitting the concrete core, and the line scan of laser pulses gave the two-dimensional emission intensity profiles of 100 × 80 mm2 within one hour. The two-dimensional profile of the emission intensity suggests that the presence of the crack had less effect on the emission intensity when the measurement interval was larger than the crack width. The chlorine emission spectrum was measured without using the buffer gas, which is usually used for chlorine measurement, by collinear double-pulse LIBS. The apparent diffusion coefficient, which is one of the most important parameters for chloride penetration in concrete, was estimated using the depth profile of chlorine emission intensity and Fick's law. The carbonation depth was estimated on the basis of the relationship between carbon and calcium emission intensities. When the carbon emission intensity was statistically higher than the calcium emission intensity at the measurement point, we determined that the point was carbonated. The estimation results were consistent with the spraying test results using phenolphthalein solution. These results suggest that the quantitative estimation by LIBS of carbonation depth and chloride penetration can be performed simultaneously. - Highlights: • We estimated the carbonation depth and the apparent diffusion coefficient of chlorine sodium in the reinforced concrete with cracking damage by LIBS. • Two-dimensional profile measurement of the emission intensity in each element was performed to visualize the chloride penetration and the carbonation in the reinforced concrete. • Apparent diffusion coefficient of chlorine and sodium can be estimated using the Fick’s law

  5. Quantitative estimation of carbonation and chloride penetration in reinforced concrete by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Shuzo, E-mail: eto@criepi.denken.or.jp [Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan); Matsuo, Toyofumi; Matsumura, Takuro; Fujii, Takashi [Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan); Tanaka, Masayoshi Y. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan)

    2014-11-01

    The penetration profile of chlorine in a reinforced concrete (RC) specimen was determined by laser-induced breakdown spectroscopy (LIBS). The concrete core was prepared from RC beams with cracking damage induced by bending load and salt water spraying. LIBS was performed using a specimen that was obtained by splitting the concrete core, and the line scan of laser pulses gave the two-dimensional emission intensity profiles of 100 × 80 mm{sup 2} within one hour. The two-dimensional profile of the emission intensity suggests that the presence of the crack had less effect on the emission intensity when the measurement interval was larger than the crack width. The chlorine emission spectrum was measured without using the buffer gas, which is usually used for chlorine measurement, by collinear double-pulse LIBS. The apparent diffusion coefficient, which is one of the most important parameters for chloride penetration in concrete, was estimated using the depth profile of chlorine emission intensity and Fick's law. The carbonation depth was estimated on the basis of the relationship between carbon and calcium emission intensities. When the carbon emission intensity was statistically higher than the calcium emission intensity at the measurement point, we determined that the point was carbonated. The estimation results were consistent with the spraying test results using phenolphthalein solution. These results suggest that the quantitative estimation by LIBS of carbonation depth and chloride penetration can be performed simultaneously. - Highlights: • We estimated the carbonation depth and the apparent diffusion coefficient of chlorine sodium in the reinforced concrete with cracking damage by LIBS. • Two-dimensional profile measurement of the emission intensity in each element was performed to visualize the chloride penetration and the carbonation in the reinforced concrete. • Apparent diffusion coefficient of chlorine and sodium can be estimated using the Fick

  6. Clustering and training set selection methods for improving the accuracy of quantitative laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    We investigated five clustering and training set selection methods to improve the accuracy of quantitative chemical analysis of geologic samples by laser induced breakdown spectroscopy (LIBS) using partial least squares (PLS) regression. The LIBS spectra were previously acquired for 195 rock slabs and 31 pressed powder geostandards under 7 Torr CO2 at a stand-off distance of 7 m at 17 mJ per pulse to simulate the operational conditions of the ChemCam LIBS instrument on the Mars Science Laboratory Curiosity rover. The clustering and training set selection methods, which do not require prior knowledge of the chemical composition of the test-set samples, are based on grouping similar spectra and selecting appropriate training spectra for the partial least squares (PLS2) model. These methods were: (1) hierarchical clustering of the full set of training spectra and selection of a subset for use in training; (2) k-means clustering of all spectra and generation of PLS2 models based on the training samples within each cluster; (3) iterative use of PLS2 to predict sample composition and k-means clustering of the predicted compositions to subdivide the groups of spectra; (4) soft independent modeling of class analogy (SIMCA) classification of spectra, and generation of PLS2 models based on the training samples within each class; (5) use of Bayesian information criteria (BIC) to determine an optimal number of clusters and generation of PLS2 models based on the training samples within each cluster. The iterative method and the k-means method using 5 clusters showed the best performance, improving the absolute quadrature root mean squared error (RMSE) by ∼ 3 wt.%. The statistical significance of these improvements was ∼ 85%. Our results show that although clustering methods can modestly improve results, a large and diverse training set is the most reliable way to improve the accuracy of quantitative LIBS. In particular, additional sulfate standards and specifically

  7. Temperature effect on laser-induced breakdown spectroscopy spectra of molten and solid salts

    Energy Technology Data Exchange (ETDEWEB)

    Cynthia Hanson; Supathorn Phongikaroon; Jill R. Scott

    2014-07-01

    Laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential analytical tool to improve operations and safeguards for electrorefiners, such as those used in processing spent nuclear fuel. This study set out to better understand the effect of sample temperature and physical state on LIBS spectra of molten and solid salts by building calibration curves of cerium and assessing self-absorption, plasma temperature, electron density, and local thermal equilibrium (LTE). Samples were composed of a LiCl–KCl eutectic salt, an internal standard of MnCl2, and varying concentrations of CeCl3 (0.1, 0.3, 0.5, 0.8, and 1.0 wt.% Ce) under different temperatures (773, 723, 673, 623, and 573 K). Analysis of salts in their molten form is preferred as plasma plumes from molten samples experienced less self-absorption, less variability in plasma temperature, and higher clearance of the minimum electron density required for local thermal equilibrium. These differences are attributed to plasma dynamics as a result of phase changes. Spectral reproducibility was also better in the molten state due to sample homogeneity.

  8. Microanalysis of tool steel and glass with laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Loebe, Klaus; Uhl, Arnold; Lucht, Hartmut

    2003-10-20

    A laser microscope system for the microanalytical characterization of complex materials is described. The universal measuring principle of laser-induced breakdown spectroscopy (LIBS) in combination with echelle optics permits a fast simultaneous multielement analysis with a possible spatial resolution below 10 pm. The developed system features completely UV-transparent optics for the laser-microscope coupling and the emission beam path and enables parallel signal detection within the wavelength range of 200-800 nm with a spectral resolution of a few picometers. Investigations of glass defects and tool steels were performed. The characterization of a glass defect in a tumbler by a micro-LIBS line scan, with use of a 266-nm diode-pumped Nd:YAG laser for excitation, is possible by simple comparison of plasma spectra of the defect and the surrounding area. Variations in the main elemental composition as well as impurities by trace elements are detected at the same time. Through measurement of the calibration samples with the known concentration of the corresponding element, a correlation between the intensity of spectral lines and the element concentration was also achieved. The change of elemental composition at the transient stellite solder of tool steels has been determined by an area scan. The two-dimensional pictures show abrupt changes of the element distribution along the solder edge and allow fundamental researches of dynamic modifications (e.g., diffusion) in steel. PMID:14594080

  9. Determination of the postmortem interval by Laser Induced Breakdown Spectroscopy using swine skeletal muscles

    Energy Technology Data Exchange (ETDEWEB)

    Marín-Roldan, A.; Manzoor, S.; Moncayo, S.; Navarro-Villoslada, F.; Izquierdo-Hornillos, R.C.; Caceres, J.O., E-mail: jcaceres@quim.ucm.es

    2013-10-01

    Skin and muscle samples are useful to discriminate individuals as well as their postmortem interval (PMI) in crime scenes and natural or caused disasters. In this study, a simple and fast method based on Laser Induced Breakdown Spectroscopy (LIBS) has been developed to estimate PMI using swine skeletal muscle samples. Environmental conditions (moisture, temperature, fauna, etc.) having strong influence on the PMI determination were considered. Time-dependent changes in the emission intensity ratio for Mg, Na, Hα and K were observed, as a result of the variations in their concentration due to chemical reactions in tissues and were correlated with PMI. This relationship, which has not been reported previously in the forensic literature, offers a simple and potentially valuable means of estimating the PMI. - Highlights: • LIBS has been applied for Postmortem Interval estimation. • Environmental and sample storage conditions have been considered. • Significant correlation of elemental emission intensity with PMI has been observed. • Pig skeletal muscle samples have been used.

  10. Evaluation of laser induced breakdown spectroscopy for the determination of micronutrients in plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Trevizan, Lilian Cristina [Centro de Energia Nuclear na Agricultura-Universidade de Sao Paulo, Av. Centenario 303, 13416-000, Piracicaba-SP (Brazil); Santos, Dario [Universidade Federal de Sao Paulo - UNIFESP, Rua Prof. Artur Riedel 275, 09972-270, Diadema-SP (Brazil); Elgul Samad, Ricardo; Dias Vieira, Nilson [Centro de Lasers e Aplicacoes, IPEN/CNEN-SP, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo-SP (Brazil); Nunes, Lidiane Cristina [Centro de Energia Nuclear na Agricultura-Universidade de Sao Paulo, Av. Centenario 303, 13416-000, Piracicaba-SP (Brazil); Departamento de Quimica, Universidade Federal de Sao Carlos, Rodovia Washington Luis (SP-310), km 235, 13565-905, Sao Carlos-SP (Brazil); Aparecida Rufini, Iolanda [Centro de Energia Nuclear na Agricultura-Universidade de Sao Paulo, Av. Centenario 303, 13416-000, Piracicaba-SP (Brazil); Krug, Francisco Jose [Centro de Energia Nuclear na Agricultura-Universidade de Sao Paulo, Av. Centenario 303, 13416-000, Piracicaba-SP (Brazil)], E-mail: fjkrug@cena.usp.br

    2009-05-15

    Laser induced breakdown spectroscopy (LIBS) has been evaluated for the determination of micronutrients (B, Cu, Fe, Mn and Zn) in pellets of plant materials, using NIST, BCR and GBW biological certified reference materials for analytical calibration. Pellets of approximately 2 mm thick and 15 mm diameter were prepared by transferring 0.5 g of powdered material to a 15 mm die set and applying 8.0 tons cm{sup -2}. An experimental setup was designed by using a Nd:YAG laser operating at 1064 nm (200 mJ per pulse, 10 Hz) and an Echelle spectrometer with ICCD detector. Repeatability precision varied from 4 to 30% from measurements obtained in 10 different positions (8 laser shots per test portion) in the same sample pellet. Limits of detection were appropriate for routine analysis of plant materials and were 2.2 mg kg{sup -1} B, 3.0 mg kg{sup -1} Cu, 3.6 mg kg{sup -1} Fe, 1.8 mg kg{sup -1} Mn and 1.2 mg kg{sup -1} Zn. Analysis of different plant samples were carried out by LIBS and results were compared with those obtained by ICP OES after wet acid decomposition.

  11. Determination of whey adulteration in milk powder by using laser induced breakdown spectroscopy.

    Science.gov (United States)

    Bilge, Gonca; Sezer, Banu; Eseller, Kemal Efe; Berberoglu, Halil; Topcu, Ali; Boyaci, Ismail Hakki

    2016-12-01

    A rapid and in situ method has been developed to detect and quantify adulterated milk powder through adding whey powder by using laser induced breakdown spectroscopy (LIBS). The methodology is based on elemental composition differences between milk and whey products. Milk powder, sweet and acid whey powders were produced as standard samples, and milk powder was adulterated with whey powders. Based on LIBS spectra of standard samples and commercial products, species was identified using principle component analysis (PCA) method, and discrimination rate of milk and whey powders was found as 80.5%. Calibration curves were obtained with partial least squares regression (PLS). Correlation coefficient (R(2)) and limit of detection (LOD) values were 0.981 and 1.55% for adulteration with sweet whey powder, and 0.985 and 0.55% for adulteration with acid whey powder, respectively. The results were found to be consistent with the data from inductively coupled plasma - mass spectrometer (ICP-MS) method. PMID:27374522

  12. Statistical Classification of Soft Solder Alloys by Laser-Induced Breakdown Spectroscopy: Review of Methods

    Science.gov (United States)

    Zdunek, R.; Nowak, M.; Pliński, E.

    2016-02-01

    This paper reviews machine-learning methods that are nowadays the most frequently used for the supervised classification of spectral signals in laser-induced breakdown spectroscopy (LIBS). We analyze and compare various statistical classification methods, such as linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), partial least-squares discriminant analysis (PLS-DA), soft independent modeling of class analogy (SIMCA), support vector machine (SVM), naive Bayes method, probabilistic neural networks (PNN), and K-nearest neighbor (KNN) method. The theoretical considerations are supported with experiments conducted for real soft-solder-alloy spectra obtained using LIBS. We consider two decision problems: binary and multiclass classification. The former is used to distinguish overheated soft solders from their normal versions. The latter aims to assign a testing sample to a given group of materials. The measurements are obtained for several laser-energy values, projection masks, and numbers of laser shots. Using cross-validation, we evaluate the above classification methods in terms of their usefulness in solving both classification problems.

  13. Methods of Data Processing for Trace Elements Analysis Using Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Wang, Rui; Ma, Xiaohong; Yu, Qi; Song, Yang; Zhao, Huafeng; Zhang, Min; Liao, Yanbiao

    2015-11-01

    With the development of Laser Induced Breakdown Spectroscopy (LIBS), increasing numbers of researchers have begun to focus on problems of the application. We are not just satisfied with analyzing what kinds of elements are in the samples but are also eager to accomplish quantitative detection with LIBS. There are several means to improve the limit of detection and stability, which are important to quantitative detection, especially of trace elements, increasing the laser energy and the resolution of spectrometer, using dual pulse setup, vacuuming the ablation environment etc. All of these methods are about to update the hardware system, which is effective but expensive. So we establish the following spectrum data processing methods to improve the trace elements analysis in this paper: spectrum sifting, noise filtering, and peak fitting. There are small algorithms in these three method groups, which we will introduce in detail. Finally, we discuss how these methods affect the results of trace elements detection in an experiment to analyze the lead content in Chinese cabbage. supported by National High-Tech R&D Program (863 Program), China (No. 2013AA102402)

  14. Spectrochemical Analysis of Soil around Leather Tanning Industry Using Laser Induced Breakdown Spectroscopy

    Directory of Open Access Journals (Sweden)

    Shakeel Ahmad Khan

    2013-01-01

    Full Text Available We report the use of laser induced breakdown spectroscopy (LIBS to determine the chromium contamination of soil due to effluents from leather tanning industry in Kasur District of Punjab (+31∘6′23.21″, +74∘27′16.29″ in Pakistan. Calibration curves were constructed by indigenously prepared standard sample and fitting of curves by linear regression. The limit of detection (LOD was found to be 23.71 mg kg−1. It has been found that the concentration of chromium in the soil is up to 839 mg kg−1 in vicinity of effluent drain and 1829 mg kg−1 in the area of old stagnant pool, which is much higher than the safe limits. Qualitative detection of other elements like Na, Cl, Fe, P, and Si was done from LIBS spectra. The leaching of soil contaminants due to seepage of industrial effluents from deteriorating brick lined drains in horizontal direction has also been observed.

  15. 3D Imaging of Nanoparticle Distribution in Biological Tissue by Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Gimenez, Y.; Busser, B.; Trichard, F.; Kulesza, A.; Laurent, J. M.; Zaun, V.; Lux, F.; Benoit, J. M.; Panczer, G.; Dugourd, P.; Tillement, O.; Pelascini, F.; Sancey, L.; Motto-Ros, V.

    2016-01-01

    Nanomaterials represent a rapidly expanding area of research with huge potential for future medical applications. Nanotechnology indeed promises to revolutionize diagnostics, drug delivery, gene therapy, and many other areas of research. For any biological investigation involving nanomaterials, it is crucial to study the behavior of such nano-objects within tissues to evaluate both their efficacy and their toxicity. Here, we provide the first account of 3D label-free nanoparticle imaging at the entire-organ scale. The technology used is known as laser-induced breakdown spectroscopy (LIBS) and possesses several advantages such as speed of operation, ease of use and full compatibility with optical microscopy. We then used two different but complementary approaches to achieve 3D elemental imaging with LIBS: a volume reconstruction of a sliced organ and in-depth analysis. This proof-of-concept study demonstrates the quantitative imaging of both endogenous and exogenous elements within entire organs and paves the way for innumerable applications. PMID:27435424

  16. Laser-induced breakdown spectroscopy and chemometrics for classification of toys relying on toxic elements

    International Nuclear Information System (INIS)

    Quality control of toys for avoiding children exposure to potentially toxic elements is of utmost relevance and it is a common requirement in national and/or international norms for health and safety reasons. Laser-induced breakdown spectroscopy (LIBS) was recently evaluated at authors' laboratory for direct analysis of plastic toys and one of the main difficulties for the determination of Cd, Cr and Pb was the variety of mixtures and types of polymers. As most norms rely on migration (lixiviation) protocols, chemometric classification models from LIBS spectra were tested for sampling toys that present potential risk of Cd, Cr and Pb contamination. The classification models were generated from the emission spectra of 51 polymeric toys and by using Partial Least Squares - Discriminant Analysis (PLS-DA), Soft Independent Modeling of Class Analogy (SIMCA) and K-Nearest Neighbor (KNN). The classification models and validations were carried out with 40 and 11 test samples, respectively. Best results were obtained when KNN was used, with corrected predictions varying from 95% for Cd to 100% for Cr and Pb.

  17. Observations in collinear femtosecond-nanosecond dual-pulse laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Scaffidi, J; Pearman, W; Carter, J C; Angel, S M

    2006-01-01

    In the work reported herein, we have combined a short-lived femtosecond laser-induced plasma (LIP) and a longer-lived nanosecond LIP in a collinear pulse configuration to examine the source(s) of atomic emission and signal-to-noise enhancement in dual-pulse laser-induced breakdown spectroscopy (LIBS). Initial studies indicate that the primary source of dual-pulse LIBS enhancement in the collinear configuration may in large part be a matter of pulse focus; focusing on the sample surface, for example, yields atomic emission enhancements whose lifetime correlates reasonably well with the femtosecond LIP emissive lifetime, suggesting that plasma-plasma coupling may play an important role at that pulse focus. At a second "optimal" focal position above the sample surface, alternatively, atomic emission and signal-to-noise enhancements correlate quite well with the nitrogen and oxygen atomic emission reductions previously seen following use of a femtosecond air spark and a nanosecond ablative pulse in the orthogonal dual-pulse configuration, suggesting that pressure or number density reductions due to femtosecond LIP formation in air may be significant at that pulse focus. PMID:16454914

  18. Influence of Ambient Gas on Laser-Induced Breakdown Spectroscopy of Uranium Metal

    Science.gov (United States)

    Zhang, Dacheng; Ma, Xinwen; Wang, Shulong; Zhu, Xiaolong

    2015-11-01

    Laser-induced breakdown spectroscopy (LIBS) is regarded as a suitable method for the remote analysis of materials in any phase, even in an environment with high radiation levels. In the present work we used the third harmonic pulse of a Nd:YAG laser for ablation of uranium metal and measured the plasma emission with a fiber-optic spectrometer. The LIBS spectra of uranium metal and their features in different ambient gases (i.e., argon, neon, oxygen, and nitrogen) at atmospheric pressure were studied. Strong continuum spectrum and several hundreds of emission lines from UI and UII were observed. It is found that the continuum spectrum observed in uranium not only comes from bremsstrahlung emission but is also due to the complex spectrum of uranium. The influence of ambient gas and the gas flow rate for ablation of uranium metal was investigated. The experimental results indicate that the intensity of the uranium lines was enhanced in argon and nitrogen. However, the intensity of uranium lines was decreased in oxygen due to the generation of UO and other oxides. The results also showed that the highest intensity of uranium lines were obtained in argon gas with a gas flow rate above 2.5 L/min. The enhanced mechanism in ambient gas and the influence of the gas flow rate were analyzed in this work.

  19. Determination of silicon in plant materials by laser-induced breakdown spectroscopy

    Science.gov (United States)

    de Souza, Paulino Florêncio; Santos, Dário, Júnior; de Carvalho, Gabriel Gustinelli Arantes; Nunes, Lidiane Cristina; da Silva Gomes, Marcos; Guerra, Marcelo Braga Bueno; Krug, Francisco José

    2013-05-01

    In spite of the importance of Si for improving the productivity of many important crops, such as those from the Poaceae family (e.g. sugar cane, maize, wheat, rice), its quantitative determination in plants is seldom carried out and restricted to few laboratories in the world. There is a survey of methods in the literature, but most of them are either laborious or difficult to validate in view of the low availability of reference materials with a certified Si mass fraction. The aim of this study is to propose a method for the direct determination of Si in pellets of plant materials by laser-induced breakdown spectroscopy (LIBS). The experimental setup was designed by using a Q-switched Nd:YAG laser at 1064 nm (5 ns, 10 Hz) and the emission signals were collected by lenses into an optical fiber coupled to an Echelle spectrometer equipped with an intensified charge-coupled device. Experiments were carried out with leaves from 24 sugar cane varieties, with mass fractions varying from ca. 2 to 10 g kg- 1 Si. Pellets prepared from cryogenically ground leaves were used as test samples for both method development and validation of the calibration model. Best results were obtained when the test samples were interrogated with laser fluence of 50 J cm- 2 (750 μm spot size) and measurements carried out at Si I 212.412 nm emission line. The results obtained by LIBS were compared with those from inductively coupled plasma optical emission spectrometry after oven-induced alkaline digestion, and no significant differences were observed after applying the Student's t-test at 95% confidence level. The trueness of the proposed LIBS method was also confirmed from the analysis of CRM GBW 07603 (Bush branches and leaves).

  20. Vibrational emission analysis of the CN molecules in laser-induced breakdown spectroscopy of organic compounds

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) of organic materials is based on the analysis of atomic and ionic emission lines and on a few molecular bands, the most important being the CN violet system and the C2 Swan system. This paper is focused in molecular emission of LIBS plasmas based on the CN (B2Σ–X2Σ) band, one of the strongest emissions appearing in all carbon materials when analyzed in air atmosphere. An analysis of this band with sufficient spectral resolution provides a great deal of information on the molecule, which has revealed that valuable information can be obtained from the plume chemistry and dynamics affecting the excitation mechanisms of the molecules. The vibrational emission of this molecular band has been investigated to establish the dependence of this emission on the molecular structure of the materials. The paper shows that excitation/emission phenomena of molecular species observed in the plume depend strongly on the time interval selected and on the irradiance deposited on the sample surface. Precise time resolved LIBS measurements are needed for the observation of distinctive CN emission. For the organic compounds studied, larger differences in the behavior of the vibrational emission occur at early stages after plasma ignition. Since molecular emission is generally more complex than that involving atomic emission, local plasma conditions as well as plume chemistry may induce changes in vibrational emission of molecules. As a consequence, alterations in the distribution of the emissions occur in terms of relative intensities, being sensitive to the molecular structure of every single material. - Highlights: • Vibrational emission of CN species in laser-induced plasmas has been investigated. • Distribution of vibrational emission of CN has been found to be time dependent. • Laser irradiance affects the vibrational distribution of the CN molecules. • Plume chemistry controls the excitation mechanisms of CN molecules in the

  1. Corrections for variable plasma parameters in laser induced breakdown spectroscopy: Application on archeological samples

    Science.gov (United States)

    Lazic, V.; Trujillo-Vazquez, A.; Sobral, H.; Márquez, C.; Palucci, A.; Ciaffi, M.; Pistilli, M.

    2016-08-01

    The final scope of this work was to determine the elemental composition of different types of decorative layers present on ancient ceramic fragments through depth profiling by laser induced breakdown spectroscopy (LIBS). The measurements were performed by a stand-off LIBS system at distance of 10.5 m, by employing ns laser pulses at 1064 nm and an Echelle spectrometer. The detected plume intensity strongly differs from one sample/coating to another and changes importantly also in repeated measurements on the almost homogeneous bulk materials. Furthermore, the plasma intensity and its parameters widely change during the depth profiling, as evident from the ratio of here monitored Fe I and Fe II spectral lines. Averaging the line intensities over six repeated measurements, also on the bulk material and for a selected consecutive shot number, produces the errors up to 60% around the mean value and this makes impossible to compare composition of the ceramic body with its decorative layers. To overcome this problem, we developed a theoretically supported procedure for the spectral line corrections in presence of variable plasma parameters, which considers the relative changes among a sufficiently large data set. This method allowed improving the measurement precision up to five times, obtaining a flat response during the depth profiling, and measuring composition of the surface layers. The correction factors are specific for one analytical line of the considered element. The proposed procedure could be universally applied for increasing the LIBS precision in repeated samplings or during the depth profiling, without time consuming calculations of the plasma temperature and the electron density, which also suffer from large measurement errors.

  2. Parameters Optimization of Laser-Induced Breakdown Spectroscopy Experimental Setup for the Case with Beam Expander

    Science.gov (United States)

    Wang, Xin; Zhang, Lei; Fan, Juanjuan; Li, Yufang; Gong, Yao; Dong, Lei; Ma, Weiguang; Yin, Wangbao; Jia, Suotang

    2015-11-01

    Improvement of measurement precision and repeatability is one of the issues currently faced by the laser-induced breakdown spectroscopy (LIBS) technique, which is expected to be capable of precise and accurate quantitative analysis. It was found that there was great potential to improve the signal quality and repeatability by reducing the laser beam divergence angle using a suitable beam expander (BE). In the present work, the influences of several experimental parameters for the case with BE are studied in order to optimize the analytical performances: the signal to noise ratio (SNR) and the relative standard deviation (RSD). We demonstrate that by selecting the optimal experimental parameters, the BE-included LIBS setup can give higher SNR and lower RSD values of the line intensity normalized by the whole spectrum area. For validation purposes, support vector machine (SVM) regression combined with principal component analysis (PCA) was used to establish a calibration model to realize the quantitative analysis of the ash content. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The measurement accuracy presented here for ash content analysis is estimated to be 0.31%, while the average relative error is 2.36%. supported by the 973 Program of China (No. 2012CB921603), National Natural Science Foundation of China (Nos. 61475093, 61127017, 61178009, 61108030, 61378047, 61275213, 61475093, and 61205216), the National Key Technology R&D Program of China (No. 2013BAC14B01), the Shanxi Natural Science Foundation (Nos. 2013021004-1 and 2012021022-1), the Shanxi Scholarship Council of China (Nos. 2013-011 and 2013-01), and the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi, China

  3. Quantitative elemental detection of size-segregated particles using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Wang, Zhen Zhen; Deguchi, Yoshihiro; Kuwahara, Masakazu; Taira, Takuya; Zhang, Xiao Bo; Yan, Jun Jie; Liu, Ji Ping; Watanabe, Hiroaki; Kurose, Ryoichi

    2013-09-01

    In order to simulate coal combustion and develop optimal and stable boiler control systems in real power plants, it is imperative to obtain the detailed information in coal combustion processes as well as to measure species contents in fly ash, which should be controlled and analyzed for enhancing boiler efficiency and reducing environmental pollution. The fly ash consists of oxides (SiO2, Al2O3, Fe2O3, CaO, and so on), unburned carbon, and other minor elements. Recently laser-induced breakdown spectroscopy (LIBS) technique has been applied to coal combustion and other industrial fields because of the fast response, high sensitivity, real-time and non-contact features. In these applications it is important to measure controlling factors without any sample preparation to maintain the real-time measurement feature. The relation between particle content and particle diameter is also one of the vital researches, because compositions of particles are dependent on their diameter. In this study, we have detected the contents of size-segregated particles using LIBS. Particles were classified by an Anderson cascade impactor and their contents were measured using the output of 1064 nm YAG laser, a spectrograph and an ICCD camera. The plasma conditions such as plasma temperature are dependent on the size of particles and these effects must be corrected to obtain quantitative information. The plasma temperature was corrected by the emission intensity ratio from the same atom. Using this correction method, the contents of particles can be measured quantitatively in fixed experimental parameters. This method was applied to coal and fly ash from a coal-fired burner to measure unburned carbon and other contents according to the particle diameter. The acquired results demonstrate that the LIBS technique is applicable to measure size-segregated particle contents in real time and this method is useful for the analysis of coal combustion and its control because of its sensitive and

  4. Optical emission enhancement in laser-induced breakdown spectroscopy using micro-torches

    Science.gov (United States)

    Liu, L.; Huang, X.; Li, S.; Lu, Yao; Chen, K.; Lu, Y. F.

    2016-03-01

    A cost effective method for optical emission enhancement in laser-induced breakdown spectroscopy (LIBS) has been proposed in this research. The pulsed Nd:YAG laser with a wavelength of 532 nm was used for sample ablation and plasma generation. A cost effective commercial butane micro-torch was put parallel to the sample surface to generate a small flame above the surface. The laser-induced plasma expanded in the flame environment. The time-resolved optical emission intensity and signal-to-noise ratio (SNR) have been observed with and without micro torch. For laser with pulse energy of 20 mJ, the relationship between optical emission intensity and delay time indicates that signal intensities have been greatly enhanced in the initial several microseconds when using micro torch. The time-resolved study of signal-to-noise ratio shows that the maximum SNR occurs at the delay time of 2 μs. The laser energy effects on the enhancements of optical emission intensity and SNR have also been analyzed, which indicates that the enhancement factors are both delay time and laser energy dependent. The maximum enhancement factors for both optical emission intensity and SNR gradually decreases with the laser energy increase. The limits of detection (LODs) for aluminum (Al) and molybdenum (Mo) in steel have been estimated, which shows that the detection sensitivity has been improved by around 4 times. The LODs of Al and Mo have been reduced from 18 to 6 ppm and from 110 to 36 ppm in LIBS, respectively. The method of LIBS by a micro torch has been demonstrated to be a cost effective method for detection sensitivity improvement, especially in the situation of low laser pulse energy.

  5. Airborne Nanoparticle Detection By Sampling On Filters And Laser-Induced Breakdown Spectroscopy Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dewalle, Pascale; Sirven, Jean-Baptiste [CEA Saclay, DEN, Department of Physical Chemistry, F-91191 Gif-sur-Yvette (France); Roynette, Audrey; Gensdarmes, Francois [IRSN, DSU, Aerosol Physics and Metrology Laboratory, F-91192 Gif-sur-Yvette (France); Golanski, Luana; Motellier, Sylvie, E-mail: jean-baptiste.sirven@cea.fr [CEA Grenoble, DRT, LITEN, Laboratory of Nanomaterial Chemistry and Security, F-38054 Grenoble (France)

    2011-07-06

    Nowadays, due to their unique physical and chemical properties, engineered nanoparticles are increasingly used in a variety of industrial sectors. However, questions are raised about the safety of workers who produce and handle these particles. Therefore it is necessary to assess the potential exposure by inhalation of these workers. There is thereby a need to develop a suitable instrumentation which can detect selectively the presence of engineered nanoparticles in the ambient atmosphere. In this paper Laser-Induced Breakdown Spectroscopy (LIBS) is used to meet this target. LIBS can be implemented on site since it is a fast and direct technique which requires no sample preparation. The approach consisted in sampling Fe{sub 2}O{sub 3} and TiO{sub 2} nanoparticles on a filter, respectively a mixed cellulose ester membrane and a polycarbonate membrane, and to measure the surface concentration of Fe and Ti by LIBS. Then taking into account the sampling parameters (flow, duration, filter surface) we could calculate a detection limit in volume concentration in the atmosphere. With a sampling at 10 L/min on a 10 cm{sup 2} filter during 1 min, we obtained detection limits of 56 {mu}g/m{sup 3} for Fe and 22 {mu}g/m{sup 3} for Ti. These figures, obtained in real time, are significantly below existing workplace exposure recommendations of the EU-OSHA and of the NIOSH. These results are very encouraging and will be completed in a future work on airborne carbon nanotube detection.

  6. Evaluation of a commercially available passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber for laser-induced breakdown spectroscopy

    Science.gov (United States)

    Carson, Cantwell G.; Goueguel, Christian L.; Sanghapi, Hervé; Jain, Jinesh; McIntyre, Dustin

    2016-05-01

    Interest in passively Q-switched microchip lasers as a means for miniaturization of laser-induced breakdown spectroscopy (LIBS) apparatus has rapidly grown in the last years. To explore the possibility of using a comparatively UV-vis transparent absorber, we herein present the first report on the evaluation of a commercially available flash lamp-pumped passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber as an excitation source in LIBS. Quantitative measurements of barium, strontium, rubidium and lithium in granite, rhyolite, basalt and syenite whole-rock glass samples were performed. Using a gated intensified benchtop spectrometer, limits of detection of 0.97, 23, 37, and 144 ppm were obtained for Li, Sr, Rb, and Ba, respectively. Finally, we discuss the advantages of using such a laser unit for LIBS applications in terms of ablation efficiency, analytical performances, output energy, and standoff capabilities.

  7. A Laser Induced Breakdown Spectroscopy application based on Local Thermodynamic Equilibrium assumption for the elemental analysis of alexandrite gemstone and copper-based alloys

    International Nuclear Information System (INIS)

    Graphical abstract: Self-calibrated analytical techniques based on the approximation of Local Thermodynamic Equilibrium (LTE) have been employed for the analysis of gemstones and copper-based alloys by LIBS (Laser Induced Breakdown Spectroscopy), with a special focus on LTE conditions in laser induced plasmas. Highlights: ► Discussion of Local Thermodynamic Equilibrium (LTE) condition in laser-induced plasmas. ► LIBS enables elemental analysis with self-calibrated LTE-based methods. ► Be detection in alexandrite gemstone is made possible by LIBS. - Abstract: Laser Induced Breakdown Spectroscopy (LIBS) is an appealing technique to study laser-induced plasmas (LIPs), both from the basic diagnostics point of view and for analytical applications. LIPs are complex dynamic systems, expanding at supersonic velocities and undergoing a transition between different plasma regimes. If the Local Thermodynamic Equilibrium (LTE) condition is valid for such plasmas, several analytical methods can be employed and fast quantitative analyses can be performed on a variety of samples. In the present paper, a discussion about LTE is carried out and an innovative application to the analysis of the alexandrite gemstone is presented. In addition, a study about the influence of plasma parameters on the performance of LTE-based methods is reported for bronze and brass targets.

  8. A Laser Induced Breakdown Spectroscopy application based on Local Thermodynamic Equilibrium assumption for the elemental analysis of alexandrite gemstone and copper-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    De Giacomo, A. [Department of Chemistry, University of Bari, Via Orabona 4, 70126 Bari (Italy); Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Dell' Aglio, M. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Gaudiuso, R., E-mail: rosalba.gaudiuso@ba.imip.cnr.it [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Santagata, A. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Potenza, Via S. Loja, Zona Ind., 85050 Tito Scalo (PZ) (Italy); Senesi, G.S. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Rossi, M.; Ghiara, M.R. [Department of Earth Sciences, University of Naples ' Federico II' , Via Mezzocannone 8, 80134 Naples (Italy); Capitelli, F. [Institute of Crystallography - CNR, Via Salaria Km 29.300, 00015 Monterotondo (Roma) (Italy); De Pascale, O. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy)

    2012-04-04

    Graphical abstract: Self-calibrated analytical techniques based on the approximation of Local Thermodynamic Equilibrium (LTE) have been employed for the analysis of gemstones and copper-based alloys by LIBS (Laser Induced Breakdown Spectroscopy), with a special focus on LTE conditions in laser induced plasmas. Highlights: Black-Right-Pointing-Pointer Discussion of Local Thermodynamic Equilibrium (LTE) condition in laser-induced plasmas. Black-Right-Pointing-Pointer LIBS enables elemental analysis with self-calibrated LTE-based methods. Black-Right-Pointing-Pointer Be detection in alexandrite gemstone is made possible by LIBS. - Abstract: Laser Induced Breakdown Spectroscopy (LIBS) is an appealing technique to study laser-induced plasmas (LIPs), both from the basic diagnostics point of view and for analytical applications. LIPs are complex dynamic systems, expanding at supersonic velocities and undergoing a transition between different plasma regimes. If the Local Thermodynamic Equilibrium (LTE) condition is valid for such plasmas, several analytical methods can be employed and fast quantitative analyses can be performed on a variety of samples. In the present paper, a discussion about LTE is carried out and an innovative application to the analysis of the alexandrite gemstone is presented. In addition, a study about the influence of plasma parameters on the performance of LTE-based methods is reported for bronze and brass targets.

  9. Laser induced breakdown spectroscopy surface analysis correlated with the process of nanoparticle production by laser ablation in liquids

    International Nuclear Information System (INIS)

    Laser induced ablation of solids situated in liquids (LAL) was used in order to produce nanoparticles. Laser induced breakdown spectroscopy (LIBS) surface analysis correlated with the process of nanoparticle production by LAL was applied to explain the composition of the obtained nanoparticles as determined by Electron Dispersive X-ray Spectroscopy (EDS). In the case of aluminum rods placed in distilled water irradiated with pulsed laser radiation (355 nm wavelength, 6 ns pulse length) we have obtained spheric nanoparticles with dimensions lower than 100 nm. Quantitative EDS analyses on the obtained spheres showed the presence of, Al, O, and Si. This indicates that probably the composition of the nanoparticles is an aluminum silicate. LIBS analysis on the aluminum target have shown the presence of a Si line with low intensity indicating a small quantity of silicon in the first ablated layers. The LIBS spectra for a sequence of pulses evidenced also that the intensity of the aluminum lines after a number of pulses decreases. This means that the quantity of ablated material becomes smaller due to the ablation depth decrease.

  10. Laser induced breakdown spectroscopy surface analysis correlated with the process of nanoparticle production by laser ablation in liquids

    Energy Technology Data Exchange (ETDEWEB)

    Apostol, I., E-mail: ileana.apostol@inflpr.ro; Damian, V. [National Institute for Laser, Plasma and Radiation Physics (Romania); Damian, R.; Nistor, L. C. [National Institute for Materials Physics (Romania); Pascu, A.; Staicu, A.; Udrea, C. [National Institute for Laser, Plasma and Radiation Physics (Romania)

    2013-04-15

    Laser induced ablation of solids situated in liquids (LAL) was used in order to produce nanoparticles. Laser induced breakdown spectroscopy (LIBS) surface analysis correlated with the process of nanoparticle production by LAL was applied to explain the composition of the obtained nanoparticles as determined by Electron Dispersive X-ray Spectroscopy (EDS). In the case of aluminum rods placed in distilled water irradiated with pulsed laser radiation (355 nm wavelength, 6 ns pulse length) we have obtained spheric nanoparticles with dimensions lower than 100 nm. Quantitative EDS analyses on the obtained spheres showed the presence of, Al, O, and Si. This indicates that probably the composition of the nanoparticles is an aluminum silicate. LIBS analysis on the aluminum target have shown the presence of a Si line with low intensity indicating a small quantity of silicon in the first ablated layers. The LIBS spectra for a sequence of pulses evidenced also that the intensity of the aluminum lines after a number of pulses decreases. This means that the quantity of ablated material becomes smaller due to the ablation depth decrease.

  11. Using LIBS Method in Safeguards

    International Nuclear Information System (INIS)

    Laser-Induced Breakdown Spectroscopy (LIBS) is a type of atomic emission spectroscopic technique which is capable to detect almost all the elements from the periodic table in different sample types (solid, liquid or gas). Other advantage of the technique is that a LIBS analysis is much faster than a conventional laboratory technique. Beside the easy usability and fastness of the system the main advantages of the technique is that portable systems are also available. Using a so-called ''backpack'' version in-field analysis can be carried out. Therefore, LIBS is a more and more popular technique also e.g., in the nuclear analytics due to its several advantages. It is also tested for Safeguards purposes as a novel technology. In this work development and test of a portable LIBS system is discussed in detail. Detector system with higher resolution and specific software for evaluation of uranium isotope composition has been developed. Different kind of uranium fuel pellets with various enrichments was analyzed as test samples. Concerning the test measurements the developed LIBS instrument was found well-applicable for analysis of Safeguards samples and determination of higher enrichment of uranium in-field. The method is rapid and simple enough for short in-field sample analysis. (author)

  12. Onboard calibration igneous targets for the Mars Science Laboratory Curiosity rover and the Chemistry Camera laser induced breakdown spectroscopy instrument

    International Nuclear Information System (INIS)

    Accurate characterization of the Chemistry Camera (ChemCam) laser-induced breakdown spectroscopy (LIBS) on-board composition targets is of prime importance for the ChemCam instrument. The Mars Science Laboratory (MSL) science and operations teams expect ChemCam to provide the first compositional results at remote distances (1.5-7 m) during the in situ analyses of the Martian surface starting in 2012. Thus, establishing LIBS reference spectra from appropriate calibration standards must be undertaken diligently. Considering the global mineralogy of the Martian surface, and the possible landing sites, three specific compositions of igneous targets have been determined. Picritic, noritic, and shergottic glasses have been produced, along with a Macusanite natural glass. A sample of each target will fly on the MSL Curiosity rover deck, 1.56 m from the ChemCam instrument, and duplicates are available on the ground. Duplicates are considered to be identical, as the relative standard deviation (RSD) of the composition dispersion is around 8%. Electronic microprobe and laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) analyses give evidence that the chemical composition of the four silicate targets is very homogeneous at microscopic scales larger than the instrument spot size, with RSD 0.1 wt.% using electronic microprobe, and 0.01 wt.% using LA ICP-MS. The LIBS campaign on the igneous targets performed under flight-like Mars conditions establishes reference spectra for the entire mission. The LIBS spectra between 240 and 900 nm are extremely rich, hundreds of lines with high signal-to-noise, and a dynamical range sufficient to identify unambiguously major, minor and trace elements. For instance, a first LIBS calibration curve has been established for strontium from [Sr] = 284 ppm to [Sr] = 1480 ppm, showing the potential for the future calibrations for other major or minor elements.

  13. Onboard calibration igneous targets for the Mars Science Laboratory Curiosity rover and the Chemistry Camera laser induced breakdown spectroscopy instrument

    Energy Technology Data Exchange (ETDEWEB)

    Fabre, C., E-mail: cecile.fabre@g2r.uhp-nancy.fr [G2R, Nancy Universite (France); Maurice, S.; Cousin, A. [IRAP, Toulouse (France); Wiens, R.C. [LANL, Los Alamos, NM (United States); Forni, O. [IRAP, Toulouse (France); Sautter, V. [MNHN, Paris (France); Guillaume, D. [GET, Toulouse (France)

    2011-03-15

    Accurate characterization of the Chemistry Camera (ChemCam) laser-induced breakdown spectroscopy (LIBS) on-board composition targets is of prime importance for the ChemCam instrument. The Mars Science Laboratory (MSL) science and operations teams expect ChemCam to provide the first compositional results at remote distances (1.5-7 m) during the in situ analyses of the Martian surface starting in 2012. Thus, establishing LIBS reference spectra from appropriate calibration standards must be undertaken diligently. Considering the global mineralogy of the Martian surface, and the possible landing sites, three specific compositions of igneous targets have been determined. Picritic, noritic, and shergottic glasses have been produced, along with a Macusanite natural glass. A sample of each target will fly on the MSL Curiosity rover deck, 1.56 m from the ChemCam instrument, and duplicates are available on the ground. Duplicates are considered to be identical, as the relative standard deviation (RSD) of the composition dispersion is around 8%. Electronic microprobe and laser ablation inductively coupled plasma mass spectrometry (LA ICP-MS) analyses give evidence that the chemical composition of the four silicate targets is very homogeneous at microscopic scales larger than the instrument spot size, with RSD < 5% for concentration variations > 0.1 wt.% using electronic microprobe, and < 10% for concentration variations > 0.01 wt.% using LA ICP-MS. The LIBS campaign on the igneous targets performed under flight-like Mars conditions establishes reference spectra for the entire mission. The LIBS spectra between 240 and 900 nm are extremely rich, hundreds of lines with high signal-to-noise, and a dynamical range sufficient to identify unambiguously major, minor and trace elements. For instance, a first LIBS calibration curve has been established for strontium from [Sr] = 284 ppm to [Sr] = 1480 ppm, showing the potential for the future calibrations for other major or minor

  14. Determination of Si/Al molar ratios in microporous zeolites using calibration-free laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    In this paper, the potential application of a calibration-free laser-induced breakdown spectroscopy (CF-LIBS) method for the determination of the silicon-to-aluminum molar ratio in microporous zeolites (with both intermediate and high silica contents) is discussed. Three different zeolite types, i.e., mordenite and zeolites type Y and ZSM-5, were analyzed in this study and were shown to have Si/Al molar ratios in the range between 2.3 and 51.8. Many ionic and neutral atomic spectral lines of silicon and aluminum were detected in the measured LIBS spectra in the spectral range 200–1000 nm, but not all of the observed spectral lines are convenient for a CF-LIBS analysis. To increase the accuracy of the results, only lines with no or low self-absorption probability were selected. A systematic method is proposed to select spectral lines based on three main parameters: the transition probability (Einstein coefficient), the lower level energy of the observed transition and the number density ratio between singly ionized and neutral species (as calculated for Si and Al for the measured electron density and electron temperature). The calculated Si/Al molar ratios were close to that determined by wet chemical analysis with an average relative standard deviation of approximately 5% (maximum less than 15%). Our results point to the possibility of using CF-LIBS for analysis of these types of materials and for determination of Si/Al molar ratios. - Highlights: • CF-LIBS was used for determination of Si/Al molar ratios in three zeolites types. • Zeolites with Si/Al molar ratio in the range of 2.3–51.8 were used. • Si/Al molar ratio was determined with relative errors less than 15%

  15. Qualitative and quantitative spectro-chemical analysis of dates using UV-pulsed laser induced breakdown spectroscopy and inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Mehder, A O; Habibullah, Y B; Gondal, M A; Baig, Umair

    2016-08-01

    Laser Induced Breakdown Spectroscopy (LIBS) is demonstrated for the spectral analysis of nutritional and toxic elements present in several varieties of date fruit samples available in the Saudi Arabia market. The method analyzes the optical emission of a test sample when subjected to pulsed laser ablation. In this demonstration, our primary focus is on calcium (Ca) and magnesium (Mg), as nutritional elements, and on chromium (Cr), as a toxic element. The local thermodynamic equilibrium (LTE) condition was confirmed prior to the elemental characterization of date samples to ensure accuracy of the LIBS analysis. This was achieved by measuring parameters associated with the plasma, such as the electron temperature and the electron number density. These plasma parameters aid interpretation of processes such as ionization, dissociation, and excitation occurring in the plasma plume formed by ablating the date palm sample. The minimum detection limit was established from calibration curves that involved plotting the LIBS signal intensity as a function of standard date samples with known concentrations. The concentration of Ca and Mg detected in different varieties of date samples was between 187 and 515 and 35-196mgL(-1) respectively, while Cr concentration measured between 1.72 and 7.76mgL(-1). In order to optimize our LIBS system, we have studied how the LIBS signal intensity depends on the incident laser energy and the delay time. In order to validate our LIBS analysis results, standard techniques such as inductively coupled plasma mass spectrometry (ICP-MS) were also applied on an identical (duplicate) date samples as those used for the LIBS analysis. The LIBS results exhibit remarkable agreement with those obtained from the ICP-MS analysis. In addition, the finger print wavelengths of other elements present in date samples were also identified and are reported here, which has not been previously reported, to the best of our knowledge. PMID:27216665

  16. Determination of inorganic nutrients in wheat flour by laser-induced breakdown spectroscopy and energy dispersive X-ray fluorescence spectrometry

    Science.gov (United States)

    Peruchi, Lidiane Cristina; Nunes, Lidiane Cristina; de Carvalho, Gabriel Gustinelli Arantes; Guerra, Marcelo Braga Bueno; de Almeida, Eduardo; Rufini, Iolanda Aparecida; Santos, Dário; Krug, Francisco José

    2014-10-01

    Laser-induced breakdown spectroscopy (LIBS) and energy dispersive X-ray fluorescence spectrometry (EDXRF) were evaluated for the determination of P, K, Ca, Mg, S, Fe, Cu, Mn and Zn in pressed pellets of wheat flours. EDXRF and LIBS calibration models were built with analytes mass fractions determined by inductively coupled plasma optical emission spectrometry after microwave-assisted acid digestion in a set of 25 wheat flour laboratory samples. Test samples consisted of pressed pellets prepared from wheat flour mixed with 30% mm- 1 cellulose binder. Experiments were carried out with a LIBS setup consisted of a Q-switched Nd:YAG laser and a spectrometer with Echelle optics and ICCD, and a benchtop EDXRF system fitted with a Rh target X-ray tube and a Si(Li) semiconductor detector. The correlation coefficients from the linear calibration models of P, K, Ca, Mg, S, Fe, Mn and Zn determined by LIBS and/or EDXRF varied from 0.9705 for Zn to 0.9990 for Mg by LIBS, and from 0.9306 for S to 0.9974 for K by EDXRF. The coefficients of variation of measurements varied from 1.2 to 20% for LIBS, and from 0.3 to 24% for EDXRF. The predictive capabilities based on RMSEP (root mean square error of prediction) values were appropriate for the determination of P, Ca, Mg, Fe, Mn and Zn by LIBS, and for P, K, S, Ca, Fe, and Zn by EDXRF. In general, results from the analysis of NIST SRM 1567a Wheat flour by LIBS and EDXRF were in agreement with their certified mass fractions.

  17. Laser-induced breakdown spectroscopy for measurement of fuel/oxygen mixing in combustion

    Science.gov (United States)

    Dackman, Matthew; Lewis, J. W. L.; Chen, Ying-Ling; Shi, Lei

    2007-11-01

    Laser-induced breakdown spectroscopy (LIBS) is applied for measurement of C-O equivalence ratios and mixing in a methane/oxygen flame. A nominal 10-nanosecond Q-switched Nd:YAG laser is used to effect a cascade-type optical breakdown in the flame, which is projected above a pre-mixed McKenna burner. Atomic and ionic carbon and oxygen spectra are used to verify the combustion equivalence ratios in the range of 0.5 to 2.0. Emission spectra are obtained separately from the near ultraviolet (vicinity of 250nm) and from the visible (vicinity of 430nm) using gated array detectors. Emission data are obtained over a range of sub-microsecond delay times following the laser pulse. The ultraviolet lines exhibit significantly larger signal-to-noise/background ratios, but the visible lines possess greater relative intensity. Implications of these results are discussed for local measurements of fuel-oxidizer ratios for both atmospheric pressure and high pressure combustion.

  18. Determination of silicon in plant materials by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Paulino Florêncio de [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil); Centro de Tecnologia Canavieira, PO Box 162, 13400-970 Piracicaba, SP (Brazil); Santos, Dário [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Rua Prof. Artur Riedel, 275, 09972-270, Diadema, SP (Brazil); Gustinelli Arantes de Carvalho, Gabriel; Nunes, Lidiane Cristina [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil); Silva Gomes, Marcos da [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil); Departamento de Química, Universidade Federal de São Carlos, 13565-905 São Carlos, SP (Brazil); Guerra, Marcelo Braga Bueno [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil); Krug, Francisco José, E-mail: fjkrug@cena.usp.br [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000, Piracicaba, SP (Brazil)

    2013-05-01

    In spite of the importance of Si for improving the productivity of many important crops, such as those from the Poaceae family (e.g. sugar cane, maize, wheat, rice), its quantitative determination in plants is seldom carried out and restricted to few laboratories in the world. There is a survey of methods in the literature, but most of them are either laborious or difficult to validate in view of the low availability of reference materials with a certified Si mass fraction. The aim of this study is to propose a method for the direct determination of Si in pellets of plant materials by laser-induced breakdown spectroscopy (LIBS). The experimental setup was designed by using a Q-switched Nd:YAG laser at 1064 nm (5 ns, 10 Hz) and the emission signals were collected by lenses into an optical fiber coupled to an Echelle spectrometer equipped with an intensified charge-coupled device. Experiments were carried out with leaves from 24 sugar cane varieties, with mass fractions varying from ca. 2 to 10 g kg{sup −1} Si. Pellets prepared from cryogenically ground leaves were used as test samples for both method development and validation of the calibration model. Best results were obtained when the test samples were interrogated with laser fluence of 50 J cm{sup −2} (750 μm spot size) and measurements carried out at Si I 212.412 nm emission line. The results obtained by LIBS were compared with those from inductively coupled plasma optical emission spectrometry after oven-induced alkaline digestion, and no significant differences were observed after applying the Student's t-test at 95% confidence level. The trueness of the proposed LIBS method was also confirmed from the analysis of CRM GBW 07603 (Bush branches and leaves). - Highlights: • This is the first application of LIBS for determination of Si in plant materials. • Data indicate that the method is appropriate for Si diagnosis in routine analysis. • Silicon can be simultaneously determined with macro- and

  19. Determination of silicon in plant materials by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    In spite of the importance of Si for improving the productivity of many important crops, such as those from the Poaceae family (e.g. sugar cane, maize, wheat, rice), its quantitative determination in plants is seldom carried out and restricted to few laboratories in the world. There is a survey of methods in the literature, but most of them are either laborious or difficult to validate in view of the low availability of reference materials with a certified Si mass fraction. The aim of this study is to propose a method for the direct determination of Si in pellets of plant materials by laser-induced breakdown spectroscopy (LIBS). The experimental setup was designed by using a Q-switched Nd:YAG laser at 1064 nm (5 ns, 10 Hz) and the emission signals were collected by lenses into an optical fiber coupled to an Echelle spectrometer equipped with an intensified charge-coupled device. Experiments were carried out with leaves from 24 sugar cane varieties, with mass fractions varying from ca. 2 to 10 g kg−1 Si. Pellets prepared from cryogenically ground leaves were used as test samples for both method development and validation of the calibration model. Best results were obtained when the test samples were interrogated with laser fluence of 50 J cm−2 (750 μm spot size) and measurements carried out at Si I 212.412 nm emission line. The results obtained by LIBS were compared with those from inductively coupled plasma optical emission spectrometry after oven-induced alkaline digestion, and no significant differences were observed after applying the Student's t-test at 95% confidence level. The trueness of the proposed LIBS method was also confirmed from the analysis of CRM GBW 07603 (Bush branches and leaves). - Highlights: • This is the first application of LIBS for determination of Si in plant materials. • Data indicate that the method is appropriate for Si diagnosis in routine analysis. • Silicon can be simultaneously determined with macro- and micronutrients

  20. Laser-induced breakdown spectroscopy for analysis of frozen salt solutions under Martian conditions

    Science.gov (United States)

    Schröder, Susanne; Pavlov, Sergey; Hübers, Heinz-Wilhelm; Rauschenbach, Isabelle; Jessberger, Elmar K.

    Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique for determin-ing the elemental composition of materials. It can be applied in-situ to geological surfaces on planetary missions. Since pure liquid water is unstable at the current surface conditions on Mars, i.e. low surface pressure and temperatures ranging from 140 K to 300 K, salt solutions or brines are of particular interest. It has been suggested that salts could stabilize liquid water on Mars lowering the freezing point of the solution and suppressing evaporation rates. The ap-propriate salts have been found on Mars in different locations. In this study LIBS is employed for the investigation of frozen sulphate and chloride solutions under Martian conditions in a dedicated simulation chamber. For the laboratory experiments, various salt solutions were prepared with different concen-trations. To produce ice with only little inclusions of air, the samples were degassed before freezing them in a copper container. The measurements were performed at 240 K by cooling with liquid nitrogen and controlled heating. A constant flow of a Martian atmosphere-like gas mixture at a pressure of approximately 6 hPa was maintained through the chamber during the measurements. A Q-switched Nd:YAG laser operating at 1064nm and at 10 Hz was used to ablate material and to generate a plasma on the frozen sample's surface. The emitted light of the plasma was collected into the entrance slit of an echelle spectrometer (LTB Aryelle But-terfly) by a toroid mirror. A time-gated ICCD camera (Andor) at the exit of the spectrometer recorded the plasma emission signal. The laser beam was focused at a new position for each measurement. The delay time and the integration time of the spectrometer have been optimized to obtain good signal-to-noise ratios up to 150 while at the same time not losing signals from fast recombining ions. First, the spectra of several frozen salt solutions were investigated qualitatively

  1. Analysis of frozen salt solutions with laser-induced breakdown spectroscopy under Martian conditions

    Science.gov (United States)

    Schröder, S.; Pavlov, S. G.; Hübers, H.-W.; Rauschenbach, I.; Jessberger, E. K.

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique for determining the elemental composition of materials. It can be applied in-situ to geological surfaces on planetary missions. Since pure liquid water is unstable at the current surface conditions on Mars, i.e. low surface pressure and temperatures ranging from 140 K to 300 K, salt solutions or brines are of particular interest. It has been suggested that salts could stabilize liquid water on Mars lowering the freezing point of the solution and suppressing evaporation rates. The appropriate salts have been found on Mars in different locations. In this study LIBS is employed for the investigation of frozen sulphate and chloride solutions under Martian conditions in a dedicated simulation chamber. For the laboratory experiments, various salt solutions were prepared with different concentrations. To produce ice with only little inclusions of air, the samples were degassed before freezing them in a copper container. The measurements were performed at 240 K by cooling with liquid nitrogen and controlled heating. A constant flow of a Martian atmosphere-like gas mixture at a pressure of approximately 6 hPa was maintained through the chamber during the measurements. A Q-switched Nd:YAG laser operating at 1064nm and at 10 Hz was used to ablate material and to generate a plasma on the frozen sample's surface. The emitted light of the plasma was collected into the entrance slit of an echelle spectrometer (LTB Aryelle Butterfly) by a toroid mirror. A time-gated ICCD camera (Andor) at the exit of the spectrometer recorded the plasma emission signal. The laser beam was focused at a new position for each measurement. The delay time and the integration time of the spectrometer have been optimized to obtain good signal-to-noise ratios up to 150 while at the same time not losing signals from fast recombining ions. First, the spectra of several frozen salt solutions were investigated qualitatively

  2. LIBS for the Analysis of Metallurgical and Solar Grade Silicon

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) has been employed for the fast and reliable chemical characterization of silicon used for the photovoltaic industry. Silicon for photovoltaic panels is subject to certain constraints on its purity, and notably must contain low concentration of boron. The use of LIBS could be advantageous because it allows rapid and simultaneous multi-elemental chemical analysis of silicon without any sample preparation. LIBS was applied to boron analysis and a detection limit of 0.23 ppmw was found for optimized gas and pressure conditions. (author)

  3. Comparative Study of Two Methods of Orthogonal Double-Pulse Laser-Induced Breakdown Spectroscopy of Aluminum

    Science.gov (United States)

    Safi, A.; Bahreini, M.; Tavassoli, S. H.

    2016-03-01

    Double-pulse laser induced breakdown spectroscopy (DP-LIBS) of aluminum sample is studied experimentally in orthogonal configuration in air. In this configuration, two schemes of reheating and pre-ablation are examined and the results are compared with single pulse one. The effect of delay time between two laser pulses on emission line intensities of plasma is investigated. Some of the parameters that have been involved in different mechanism of signal enhancement such as plasma temperature, sample heating effects, atmospheric effects, and modification of the ablation dynamics are more discussed. Investigation of the effect of laser pulse energy on emission line intensities in single pulse LIBS experiment demonstrate that because of saturation effects the intensities will not increase necessarily by increasing the laser pulse energy. Moreover, the results show that the electron temperature and rate of mass removal in orthogonal configuration of DP-LIBS is higher than that of single pulse with the same total energy. It is suggested that for correct comparison between single and double pulse results, the optimum pulse energy in single pulse should be considered. Overall, our results demonstrate that under optimized conditions the signal enhancement is much more in pre-ablation configuration than re-heating configuration.

  4. Identification and discrimination of Pseudomonas aeruginosa bacteria grown in blood and bile by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Pseudomonas aeruginosa bacteria colonies have been analyzed by laser-induced breakdown spectroscopy using nanosecond laser pulses. LIBS spectra were obtained after transferring the bacteria from a nutrient-rich culture medium to a nutrient-free agar plate for laser ablation. To study the dependence of the LIBS spectrum on growth and environmental conditions, colonies were cultured on three different nutrient media: a trypticase soy agar (TSA) plate, a blood agar plate, and a medium chosen deliberately to induce bacteria membrane changes, a MacConkey agar plate containing bile salts. Nineteen atomic and ionic emission lines in the LIBS spectrum, which was dominated by inorganic elements such as calcium, magnesium and sodium, were used to identify and classify the bacteria. A discriminant function analysis was used to discriminate between the P. aeruginosa bacteria and two strains of E. coli: a non-pathogenic environmental strain and the pathogenic strain enterohemorrhagic E. coli 0157:H7 (EHEC). Nearly identical spectra were obtained from P. aeruginosa grown on the TSA plate and the blood agar plate, while the bacteria grown on the MacConkey plate exhibited easily distinguishable differences from the other two. All P. aeruginosa samples, independent of initial growth conditions, were readily discriminated from the two E. coli strains

  5. Laser induced breakdown spectroscopy for fast elemental analysis and sorting of metallic scrap pieces using certified reference materials

    International Nuclear Information System (INIS)

    A setup utilizing laser induced breakdown spectroscopy (LIBS) for performing elemental analysis in order to classify metallic samples is currently under construction. The setup uses short laser pulses to locally ablate the sample and create luminous plasmas. The emitted light is analyzed spectroscopically for instantaneous determination of the elemental composition. A table-top system based on a compact CCD spectrometer has been constructed and combined with fast software in order to test the concept of remote, single shot material classification with LIBS. Certified reference materials with known elemental compositions were used in the laboratory tests. We report on successful laboratory tests in which samples were classified using an analysis based on optical emission following a single laser pulse and with an operating distance of approximately 1 m. Details regarding field tests of this versatile and promising technique are discussed. - Highlights: ► We give a short background to the area of metallic scrap recycling. ► We present the development of an automatic LIBS-based system for material analysis. ► We present experimental data from laboratory results. ► We discuss the possibility of surface cleaning through laser ablation with this setup.

  6. Effects of pulse width on nascent laser-induced bubbles for underwater laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The reason for the significant advantage offered by long-pulse (150 ns) irradiation in underwater laser-induced breakdown spectroscopy (LIBS) is investigated from the point of view of the behavior of nascent cavitation bubbles. Shadowgraphs of nascent bubbles generated by pulsed laser irradiation of Cu targets in water were observed for two different pulse widths, 20 ns and 150 ns. It is clearly seen that the nascent bubble is formed at the leading edge of the laser pulse profile, regardless of the pulse width. Bubbles generated by a 20-ns pulse are characterized by a flat-shape filled with dense matter with intense optical emission, which is in contrast to more hemispherical low-density bubbles observed under the irradiation by a 150-ns pulse. The behavior of the nascent bubbles is consistent with the behavior of the later plasma in the bubbles, which is crucial for observation of well-defined atomic spectral lines for underwater LIBS. - Highlights: • We observed laser-induced cavitation bubbles in very high time resolution. • Nascent bubbles are found to be generated at leading edge of the laser pulse. • Features of the nascent bubbles depend on the pulse width. • The reason for the advantage of long-pulse irradiation in underwater LIBS is clarified

  7. Laser-induced breakdown spectroscopy-based investigation and classification of pharmaceutical tablets using multivariate chemometric analysis.

    Science.gov (United States)

    Myakalwar, Ashwin Kumar; Sreedhar, S; Barman, Ishan; Dingari, Narahara Chari; Venugopal Rao, S; Prem Kiran, P; Tewari, Surya P; Manoj Kumar, G

    2011-12-15

    We report the effectiveness of laser-induced breakdown spectroscopy (LIBS) in probing the content of pharmaceutical tablets and also investigate its feasibility for routine classification. This method is particularly beneficial in applications where its exquisite chemical specificity and suitability for remote and on site characterization significantly improves the speed and accuracy of quality control and assurance process. Our experiments reveal that in addition to the presence of carbon, hydrogen, nitrogen and oxygen, which can be primarily attributed to the active pharmaceutical ingredients, specific inorganic atoms were also present in all the tablets. Initial attempts at classification by a ratiometric approach using oxygen (∼777 nm) to nitrogen (742.36 nm, 744.23 nm and 746.83 nm) compositional values yielded an optimal value at 746.83 nm with the least relative standard deviation but nevertheless failed to provide an acceptable classification. To overcome this bottleneck in the detection process, two chemometric algorithms, i.e. principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA), were implemented to exploit the multivariate nature of the LIBS data demonstrating that LIBS has the potential to differentiate and discriminate among pharmaceutical tablets. We report excellent prospective classification accuracy using supervised classification via the SIMCA algorithm, demonstrating its potential for future applications in process analytical technology, especially for fast on-line process control monitoring applications in the pharmaceutical industry. PMID:22099648

  8. A Comparative Study of Single-pulse and Double-pulse Laser-Induced Breakdown Spectroscopy with Uranium-containing Samples.

    Science.gov (United States)

    Skrodzki, Patrick J; Becker, Jason R; Diwakar, Prasoon K; Harilal, Sivanandan S; Hassanein, Ahmed

    2016-03-01

    Laser-induced breakdown spectroscopy (LIBS) holds potential advantages in special nuclear material (SNM) sensing and nuclear forensics, which require rapid analysis, minimal sample preparation, and stand-off distance capability. SNM, such as U, however, result in crowded emission spectra with LIBS, and characteristic emission lines are challenging to discern. It is well-known that double-pulse LIBS (DPLIBS) improves the signal intensity for analytes over conventional single-pulse LIBS (SPLIBS). This study investigates the U signal in a glass matrix using DPLIBS and compares it to signal obtained using SPLIBS. Double-pulse LIBS involves sequential firing of a 1.06 µm Nd:YAG pre-pulse and 10.6 µm TEA CO2 heating pulse in a near collinear geometry. Optimization of experimental parameters including inter-pulse delay and energy follows identification of characteristic lines for the bulk analyte Ca and the minor constituent analyte U for both DPLIBS and SPLIBS. Spatial and temporal coupling of the two pulses in the proposed DPLIBS technique yields improvements in analytical merits with a negligible increase in damage to the sample compared to SPLIBS. Subsequently, the study discusses optimum plasma emission conditions of U lines and relative figures of merit in both SPLIBS and DPLIBS. Investigation into plasma characteristics also addresses plausible mechanisms related to the observed U analyte signal variation between SPLIBS and DPLIBS. PMID:26810184

  9. Multivariate classification of edible salts: Simultaneous Laser-Induced Breakdown Spectroscopy and Laser-Ablation Inductively Coupled Plasma Mass Spectrometry Analysis

    Science.gov (United States)

    Lee, Yonghoon; Nam, Sang-Ho; Ham, Kyung-Sik; Gonzalez, Jhanis; Oropeza, Dayana; Quarles, Derrick; Yoo, Jonghyun; Russo, Richard E.

    2016-04-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), both based on laser ablation sampling, can be employed simultaneously to obtain different chemical fingerprints from a sample. We demonstrated that this analysis approach can provide complementary information for improved classification of edible salts. LIBS could detect several of the minor metallic elements along with Na and Cl, while LA-ICP-MS spectra were used to measure non-metallic and trace heavy metal elements. Principal component analysis using LIBS and LA-ICP-MS spectra showed that their major spectral variations classified the sample salts in different ways. Three classification models were developed by using partial least squares-discriminant analysis based on the LIBS, LA-ICP-MS, and their fused data. From the cross-validation performances and confusion matrices of these models, the minor metallic elements (Mg, Ca, and K) detected by LIBS and the non-metallic (I) and trace heavy metal (Ba, W, and Pb) elements detected by LA-ICP-MS provided complementary chemical information to distinguish particular salt samples.

  10. In-situ analysis of the first wall by laser-induced breakdown spectroscopy in the TEXTOR tokamak: Dependence on the magnetic field strength

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) is considered as a promising method for in-situ diagnostic of the co-deposition and fuel retention during and in between plasma discharges in fusion devices. LIBS has been investigated intensively under laboratory conditions, while the application of LIBS in fusion devices is still in early stages. Moreover, the LIB processes are influenced by additional conditions in fusion devices, particularly the magnetic field. The experiments in TEXTOR show a significant enhancement in the spectral line emission and a deeper penetration of the laser-produced plasma into the edge plasma in the presence of magnetic field. These effects can be attributed to an increased confinement of the plasma by the magnetic field. The interference of magnetic field may compromise the quantitative interpretation of LIB spectra. Therefore, quantitative analysis of ITER-like co-deposits was done in laboratory without magnetic field as well as in TEXTOR with a magnetic field of Bt ∼ 2.25 T

  11. Post-mortem characterization of fs laser-generated micro-pillars in Li(Ni1/3Mn1/3Co1/3)O2 electrodes by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Smyrek, P.; Zheng, Y.; Seifert, H. J.; Pfleging, W.

    2016-03-01

    NMC thick films were prepared by tape-casting and subsequent ultrafast laser-structuring. The lithium distribution in electrochemically cycled and unstructured or fs laser-structured NMC cathodes was investigated by using Laser-Induced Breakdown Spectroscopy (LIBS). The main goal is to develop an optimized three dimensional cell architecture with improved electrochemical properties based on studies of the homogeneity of the local State-of-Charge. LIBS experiments were carried out using a LIBS workstation equipped with a mode-locked diode pumped solid state Nd:YAG laser operating at a wavelength of 1063 nm. The element distribution was investigated using two different techniques: element mapping and element depth-profiling of the unstructured / fs laser-structured electrode surface. Results achieved from post-mortem studies using LIBS will be presented.

  12. Proof-of-concept experiment for on-line laser induced breakdown spectroscopy analysis of impurity layer deposited on optical window and other plasma facing components of Aditya tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, Gulab Singh; Kumar, Rohit; Rai, Awadhesh Kumar, E-mail: awadheshkrai@rediffmail.com [Laser Spectroscopy Research Laboratory, Department of Physics, University of Allahabad, UP 211002 (India); Kumar, Ajai [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

    2015-12-15

    In the present manuscript, we demonstrate the design of an experimental setup for on-line laser induced breakdown spectroscopy (LIBS) analysis of impurity layers deposited on specimens of interest for fusion technology, namely, plasma-facing components (PFCs) of a tokamak. For investigation of impurities deposited on PFCs, LIBS spectra of a tokamak wall material like a stainless steel sample (SS304) have been recorded through contaminated and cleaned optical windows. To address the problem of identification of dust and gases present inside the tokamak, we have shown the capability of the apparatus to record LIBS spectra of gases. A new approach known as “back collection method” to record LIBS spectra of impurities deposited on the inner surface of optical window is presented.

  13. Proof-of-concept experiment for on-line laser induced breakdown spectroscopy analysis of impurity layer deposited on optical window and other plasma facing components of Aditya tokamak

    International Nuclear Information System (INIS)

    In the present manuscript, we demonstrate the design of an experimental setup for on-line laser induced breakdown spectroscopy (LIBS) analysis of impurity layers deposited on specimens of interest for fusion technology, namely, plasma-facing components (PFCs) of a tokamak. For investigation of impurities deposited on PFCs, LIBS spectra of a tokamak wall material like a stainless steel sample (SS304) have been recorded through contaminated and cleaned optical windows. To address the problem of identification of dust and gases present inside the tokamak, we have shown the capability of the apparatus to record LIBS spectra of gases. A new approach known as “back collection method” to record LIBS spectra of impurities deposited on the inner surface of optical window is presented

  14. Proof-of-concept experiment for on-line laser induced breakdown spectroscopy analysis of impurity layer deposited on optical window and other plasma facing components of Aditya tokamak.

    Science.gov (United States)

    Maurya, Gulab Singh; Kumar, Rohit; Kumar, Ajai; Rai, Awadhesh Kumar

    2015-12-01

    In the present manuscript, we demonstrate the design of an experimental setup for on-line laser induced breakdown spectroscopy (LIBS) analysis of impurity layers deposited on specimens of interest for fusion technology, namely, plasma-facing components (PFCs) of a tokamak. For investigation of impurities deposited on PFCs, LIBS spectra of a tokamak wall material like a stainless steel sample (SS304) have been recorded through contaminated and cleaned optical windows. To address the problem of identification of dust and gases present inside the tokamak, we have shown the capability of the apparatus to record LIBS spectra of gases. A new approach known as "back collection method" to record LIBS spectra of impurities deposited on the inner surface of optical window is presented. PMID:26724011

  15. Quantitative laser-induced breakdown spectroscopy analysis of calcified tissue samples

    Science.gov (United States)

    Samek, O.; Beddows, D. C. S.; Telle, H. H.; Kaiser, J.; Liška, M.; Cáceres, J. O.; Gonzáles Ureña, A.

    2001-06-01

    We report on the application of laser-induced breakdown spectroscopy (LIBS) to the analysis of important minerals and the accumulation of potentially toxic elements in calcified tissue, to trace e.g. the influence of environmental exposure, and other medical or biological factors. This theme was exemplified for quantitative detection and mapping of Al, Pb and Sr in representative samples, including teeth (first teeth of infants, second teeth of children and teeth of adults) and bones (tibia and femur). In addition to identifying and quantifying major and trace elements in the tissues, one- and two-dimensional profiles and maps were generated. Such maps (a) provide time/concentration relations, (b) allow to follow mineralisation of the hydroxyapatite matrix and the migration of the elements within it and (c) enable to identify disease states, such as caries in teeth. In order to obtain quantitative calibration, reference samples in the form of pressed pellets with calcified tissue-equivalent material (majority compound of pellets is CaCO 3) were used whose physical properties closely resembled hydroxyapatite. Compounds of Al, Sr and Pb were added to the pellets, containing atomic concentrations in the range 100-10 000 ppm relative to the Ca content of the matrix. Analytical results based on this calibration against artificial samples for the trace elements under investigation agree with literature values, and with our atomic absorption spectroscopy (AAS) cross-validation measurements.

  16. Determination of the elemental composition of micrometric and submicrometric particles levitating in a low pressure Radio-Frequency plasma discharge using Laser-Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    The LIBS (Laser-Induced Breakdown Spectroscopy) technique has shown its potential in many fields of applications including that of aerosol analysis. The latter is usually carried out on the particle flow, thereby allowing quantitative detection in various experimental conditions such as ambient air analysis or exhaust stack monitoring, to name but a few. A possible alternative method for particle analysis has been experimented combining a low pressure RF (Radio-Frequency) plasma discharge with the LIBS technique. Such approach has two peculiar features in comparison to the usual LIBS analysis. First, the particles injected in the RF plasma discharge are trapped in levitation. Second, the analysis is performed at a reduced pressure of around 1 mbar. LIBS detection at such low pressure has this peculiarity that particle vaporization is assumed to be achieved through direct laser particle interaction whereas it is caused by laser-induced plasma ignited in the gas at atmospheric pressure. The use of such particle trap could allow improving particle sampling, making organic particle analysis possible (by using an inert gas for RF plasma ignition) and even (depending on the pressure) obtaining a better signal to noise ratio. Detection of the elements of nanoparticle agglomerates made following their injection in the RF discharge has demonstrated the feasibility of such approach. Future experiments are intended to explore its potentialities when tackling issues such as process control or ambient air monitoring. - Highlights: ► Agglomerated composite nanoparticles are maintained in levitation within a trap. ► The trap consists in a low pressure Radio-Frequency (RF) plasma discharge. ► Particles are analyzed using Laser-Induced Breakdown Spectroscopy (LIBS). ► The analysis is done at RF discharge reduced pressure, namely 0.25 mbar

  17. Multi-elemental surface mapping and analysis of carbonaceous shale by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Xu, Tao; Liu, Jie; Shi, Qi; He, Yi; Niu, Guanghui; Duan, Yixiang

    2016-01-01

    Gas shale is one of the important unconventional hydrocarbon source rocks, whose composition, such as mineral components and redox sensitive trace elements, has been proved as important geochemical proxies playing essential roles in indicating the gas potential and gas productivity in recent geological researches. Fast and accurate measurements for the shale composition, especially those with spatial resolution, will reveal rich information for the understanding and evaluation of gas shale reservoirs. In this paper, we demonstrated the potentiality as well as feasibility of laser-induced breakdown spectroscopy as an effective technique to perform spectrochemical analysis for shale samples. In case of the bulk analysis of pressed shale pellet, spectral analysis of the plasma emission revealed high sensitivity of LIBS for major, minor and even trace elements. More than 356 lines emitted by 19 different elements can be found. Among these species, redox sensitive trace elements such as V, Cr, and Ni were detected with high signal-to-ratios. Two-dimensional surface micro-analysis for the concerned major or minor elements with strong emissions was then applied to the smoothed shale slab. Local thermodynamic equilibrium for the plasma was first verified with a line profile point-by-point on the sample surface, the matrix effect was then assessed as negligible by the extracted electron density and temperature of the plasmas induced at each position on the same profile. Concentration mappings for the major elements of Si, Al, Fe, Ca, Mg, Na and K were finally constructed with their measured relative variations of line emission intensities. The distribution and correlations of these elements in concentration may reflect changes of shale mineral components with respected to the variations of the depositional environments and provide an important clue in identifying sedimentary processes when combined with other geological or geochemical evidences. These results well

  18. Comparative analysis of automotive paints by laser induced breakdown spectroscopy and nonparametric permutation tests

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) has been investigated for the discrimination of automobile paint samples. Paint samples from automobiles of different makes, models, and years were collected and separated into sets based on the color, presence or absence of effect pigments and the number of paint layers. Twelve LIBS spectra were obtained for each paint sample, each an average of a five single shot 'drill down' spectra from consecutive laser ablations in the same spot on the sample. Analyses by a nonparametric permutation test and a parametric Wald test were performed to determine the extent of discrimination within each set of paint samples. The discrimination power and Type I error were assessed for each data analysis method. Conversion of the spectral intensity to a log-scale (base 10) resulted in a higher overall discrimination power while observing the same significance level. Working on the log-scale, the nonparametric permutation tests gave an overall 89.83% discrimination power with a size of Type I error being 4.44% at the nominal significance level of 5%. White paint samples, as a group, were the most difficult to differentiate with the power being only 86.56% followed by 95.83% for black paint samples. Parametric analysis of the data set produced lower discrimination (85.17%) with 3.33% Type I errors, which is not recommended for both theoretical and practical considerations. The nonparametric testing method is applicable across many analytical comparisons, with the specific application described here being the pairwise comparison of automotive paint samples.

  19. Detection of visually unrecognizable braking tracks using Laser-Induced Breakdown Spectroscopy, a feasibility study

    Science.gov (United States)

    Prochazka, David; Bilík, Martin; Prochazková, Petra; Brada, Michal; Klus, Jakub; Pořízka, Pavel; Novotný, Jan; Novotný, Karel; Ticová, Barbora; Bradáč, Albert; Semela, Marek; Kaiser, Jozef

    2016-04-01

    Identification of the position, length and mainly beginning of a braking track has proven to be essential for determination of causes of a road traffic accident. With the introduction of modern safety braking systems and assistance systems such as the Anti-lock Braking System (ABS) or Electronic Stability Control (ESC), the visual identification of braking tracks that has been used up until the present is proving to be rather complicated or even impossible. This paper focuses on identification of braking tracks using a spectrochemical analysis of the road surface. Laser-Induced Breakdown Spectroscopy (LIBS) was selected as a method suitable for fast in-situ element detection. In the course of detailed observations of braking tracks it was determined that they consist of small particles of tire treads that are caught in intrusions in the road surface. As regards detection of the "dust" resulting from wear and tear of tire treads in the environment, organic zinc was selected as the identification element in the past. The content of zinc in tire treads has been seen to differ with regard to various sources and tire types; however, the arithmetic mean and modus of these values are approximately 1% by weight. For in-situ measurements of actual braking tracks a mobile LIBS device equipped with a special module was used. Several measurements were performed for 3 different cars and tire types respectively which slowed down with full braking power. Moreover, the influence of different initial speed, vehicle mass and braking track length on detected signal is discussed here.

  20. Application of distance correction to ChemCam laser-induced breakdown spectroscopy measurements

    Science.gov (United States)

    Mezzacappa, A.; Melikechi, N.; Cousin, A.; Wiens, R. C.; Lasue, J.; Clegg, S. M.; Tokar, R.; Bender, S.; Lanza, N. L.; Maurice, S.; Berger, G.; Forni, O.; Gasnault, O.; Dyar, M. D.; Boucher, T.; Lewin, E.; Fabre, C.

    2016-06-01

    Laser-induced breakdown spectroscopy (LIBS) provides chemical information from atomic, ionic, and molecular emissions from which geochemical composition can be deciphered. Analysis of LIBS spectra in cases where targets are observed at different distances, as is the case for the ChemCam instrument on the Mars rover Curiosity, which performs analyses at distances between 2 and 7.4 m is not a simple task. In our previous work we showed that spectral distance correction based on a proxy spectroscopic standard created from first-shot dust observations on Mars targets ameliorates the distance bias in multivariate-based elemental-composition predictions of laboratory data. In this work, we correct an expanded set of neutral and ionic spectral emissions for distance bias in the ChemCam data set. By using and testing different selection criteria to generate multiple proxy standards, we find a correction that minimizes the difference in spectral intensity measured at two different distances and increases spectral reproducibility. When the quantitative performance of distance correction is assessed, there is improvement for SiO2, Al2O3, CaO, FeOT, Na2O, K2O, that is, for most of the major rock forming elements, and for the total major-element weight percent predicted. However, for MgO the method does not provide improvements while for TiO2, it yields inconsistent results. In addition, we have observed that many emission lines do not behave consistently with distance, evidenced from laboratory analogue measurements and ChemCam data. This limits the effectiveness of the method.

  1. Femtosecond Laser-Induced Breakdown Spectroscopy Studies of Nitropyrazoles: The Effect of Varying Nitro Groups.

    Science.gov (United States)

    Rao, Epuru Nageswara; Sunku, Sreedhar; Rao, Soma Venugopal

    2015-11-01

    The technique of femtosecond laser-induced breakdown spectroscopy (FLIBS) was employed to investigate seven explosive molecules of nitropyrazole in three different atmospheres: ambient air, nitrogen, and argon. The FLIBS data illustrated the presence of molecular emissions of cyanide (CN) violet bands, diatomic carbon (C2) Swan bands, and atomic emission lines of C, H, O, and N. To understand the plasma dynamics, the decay times of molecular and atomic emissions were determined from time-resolved spectral data obtained in three atmospheres: air, argon, and nitrogen. The CN decay time was observed to be longest in air, compared to nitrogen and argon atmospheres, for the molecules pyrazole (PY) and 4-nitropyrazole (4-NPY). In the case of C2 emission, the decay time was observed to be the longest in argon, compared to the air and nitrogen environments, for the molecules PY, 4-NPY, and 1-methyl-3,4,5-trinitropyrazole. The intensities of the CN, C2, C, H, O, and N emission lines and various molecular/atomic intensity ratios such as CN/C2, CN(sum)/C2(sum), CN/C, CN(sum)/C, C2/C, C2(sum)/C, (C2 + C) / CN, (C2(sum) + C)/CN(sum), O/H, O/N, and N/H were also deduced from the LIBS spectra obtained in argon atmosphere. A correlation between the observed decay times and molecular emission intensities with respect to the number of nitro groups, the atmospheric nitrogen content, and the oxygen balance of the molecules was investigated. The relationship among the LIBS signal intensity, the molecular/atomic intensity ratios, and the oxygen balance of these organic explosives was also explored. PMID:26647058

  2. Cross-sectional study of kidney stones by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Singh, V K; Rai, A K; Rai, P K; Jindal, P K

    2009-09-01

    We performed laser-induced breakdown spectroscopy (LIBS) for the in situ quantitative estimation of elemental constituents distributed in different parts of kidney stones obtained directly from patients by surgery. We did this by focusing the laser light directly on the center, shell, and surface of the stones to find the spatial distribution of the elements inside the stone. The elements detected in the stones were calcium, magnesium, manganese, copper, iron, zinc, strontium, sodium, potassium, carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, and chlorine (Cl), etc. We optimized the LIBS signals by varying the laser energy from 10 mJ to 40 mJ to obtain the best signal-to-background and signal-to-noise ratios. We estimated the quantities of different elements in the stones by drawing calibration curves, plotting graphs of the analyte signal versus the absolute concentration of the elements in standard samples. The detection limits of the calibration curves were discussed. The concentrations of the different elements were found to be widely different in different stones found in different age groups of patients. It was observed that stones containing higher amounts of copper also possessed higher amounts of zinc. In general, the concentrations of trace elements present in the kidney stones decreased as we moved from center to shell and surface. Our results also revealed that the concentrations of elements present in the stones increased with the age of the patients. The results obtained from the calibration curves were compared with results from inductively coupled plasma mass spectrometry (ICP-MS). We also used the intensity ratios of different elemental lines to find the spatial distribution of different elements inside the kidney stones. PMID:19104906

  3. Development of laser-induced breakdown spectroscopy sensor to assess groundwater quality impacts resulting from geologic carbon sequestration

    Science.gov (United States)

    Carson, Cantwell G.; Goueguel, Christian; Jain, Jinesh; McIntyre, Dustin

    2015-05-01

    The injection of CO2 into deep aquifers can potentially affect the quality of groundwater supplies were leakage to occur from the injection formation or fluids. Therefore, the detection of CO2 and/or entrained contaminants that migrate into shallow groundwater aquifers is important both to assess storage permanence and to evaluate impacts on water resources. Naturally occurring elements (i.e., Li, Sr) in conjunction with isotope ratios can be used to detect such leakage. We propose the use of laser induced breakdown spectroscopy (LIBS) as an analytical technique to detect a suite of elements in water samples. LIBS has real time monitoring capabilities and can be applied for elemental and isotopic analysis of solid, liquid, and gas samples. The flexibility of probe design and use of fiber optics make it a suitable technique for real time measurements in harsh conditions and in hard to reach places. The laboratory scale experiments to measure Li, K, Ca, and Sr composition of water samples indicate that the technique produces rapid and reliable data. Since CO2 leakage from saline aquifers may accompany a brine solution, we studied the effect of sodium salts on the accuracy of LIBS analysis. This work specifically also details the fabrication and application of a miniature ruggedized remotely operated diode pumped solid state passively Q-switched laser system for use as the plasma excitation source for a real time LIBS analysis. This work also proposes the optical distribution of many laser spark sources across a wide area for widespread leak detection and basin monitoring.

  4. Dual-pulse Laser Induced Breakdown Spectroscopy for analysis of gaseous and aerosol systems: Plasma-analyte interactions

    Science.gov (United States)

    Windom, B. C.; Diwakar, P. K.; Hahn, D. W.

    2006-07-01

    Dual-pulse LIBS has been previously investigated to a large extent on solid and liquid phase analytes, where it has been demonstrated to significantly enhance atomic emission signal intensity, and more importantly, to enhance the analyte peak-to-base and signal-to-noise ratios. This study focuses on the effects of an orthogonal dual-pulse laser configuration on the atomic emission response for both purely gaseous and calcium-based aerosol samples. The gaseous sample consisted of purified (i.e. aerosol free) air, from which nitrogen and oxygen spectral emission lines were analyzed. Measurements for the gaseous system resulted in no notable improvements with the dual-pulse configuration as compared to the single-pulse LIBS. Experiments were also conducted in purified air seeded with calcium-rich particles, which revealed a marked improvement in calcium atomic emission peak-to-base (˜ 2-fold increase) and signal-to-noise ratios (˜ 4-fold increase) with the dual-pulse configuration. In addition to increased analyte response, dual-pulse LIBS yielded an enhanced single-particle sampling rate when compared to conventional LIBS. Transmission measurements with respect to the plasma-creating laser pulse were recorded for both single and dual-pulse methods over a range of temporal delays. In consideration of the spectroscopic and transmission data, the plasma-analyte interactions realized with a dual-pulse methodology are explained in terms of the interaction with the initially expanding plasma shock wave, which differs between gaseous and particulate phase analytes, as reported in a recent study [V. Hohreiter, D.W. Hahn, Calibration effects for laser-induced breakdown spectroscopy of gaseous sample streams: analyte response of gas-phase species versus solid-phase species, Anal. Chem. 77 (2005) 1118-1124].

  5. Dual-pulse Laser Induced Breakdown Spectroscopy for analysis of gaseous and aerosol systems: Plasma-analyte interactions

    International Nuclear Information System (INIS)

    Dual-pulse LIBS has been previously investigated to a large extent on solid and liquid phase analytes, where it has been demonstrated to significantly enhance atomic emission signal intensity, and more importantly, to enhance the analyte peak-to-base and signal-to-noise ratios. This study focuses on the effects of an orthogonal dual-pulse laser configuration on the atomic emission response for both purely gaseous and calcium-based aerosol samples. The gaseous sample consisted of purified (i.e. aerosol free) air, from which nitrogen and oxygen spectral emission lines were analyzed. Measurements for the gaseous system resulted in no notable improvements with the dual-pulse configuration as compared to the single-pulse LIBS. Experiments were also conducted in purified air seeded with calcium-rich particles, which revealed a marked improvement in calcium atomic emission peak-to-base (∼ 2-fold increase) and signal-to-noise ratios (∼ 4-fold increase) with the dual-pulse configuration. In addition to increased analyte response, dual-pulse LIBS yielded an enhanced single-particle sampling rate when compared to conventional LIBS. Transmission measurements with respect to the plasma-creating laser pulse were recorded for both single and dual-pulse methods over a range of temporal delays. In consideration of the spectroscopic and transmission data, the plasma-analyte interactions realized with a dual-pulse methodology are explained in terms of the interaction with the initially expanding plasma shock wave, which differs between gaseous and particulate phase analytes, as reported in a recent study [V. Hohreiter, D.W. Hahn, Calibration effects for laser-induced breakdown spectroscopy of gaseous sample streams: analyte response of gas-phase species versus solid-phase species, Anal. Chem. 77 (2005) 1118-1124

  6. Developing mobile LIBS solutions for real world applications

    Science.gov (United States)

    Li, Qun; Li, Jing; Bakeev, Katherine; Wang, Sean

    2015-06-01

    We present a new type of handheld laser-induced breakdown spectroscopy (LIBS) spectrometer for developing mobile atomic spectroscopy solutions for real world applications. A micro diode-pumped passive Q-switched solid-state laser with high repetition rate of well above 1 kHz in comparison to 1-10 Hz as used in a traditional LIBS instrument is employed to produce a train of laser pulses. The laser beam is further fast scanned over a pre-defined area, hence generating several hundreds of micro-plasmas per second at different locations. Synchronized miniature CCD array spectrometer modules collect the LIBS signal and generate LIBS spectra. By adjusting the integration time of the spectrometer to cover a plurality of periods of the laser pulse train, the spectrometer integrates the LIBS signal produced by this plurality of laser pulses. Hence the intensity of the obtained LIBS spectrum can be greatly improved to increase the signal-to-noise ratio (SNR). This unique feature of the high repetition rate laser based LIBS system allows it to measure elements at trace levels, hence reducing the limit of detection (LOD). The increased signal intensity also lessens the sensitivity requirement for the optical spectrometer. In addition, the energy of the individual laser pulse can be reduced in comparison to traditional LIBS system to obtain the same signal level, making the laser pulse less invasive to the sample. The typical measurement time is within 1 second. Several examples of real world applications will be presented.

  7. Sensitive detection of chlorine in iron oxide by single pulse and dual pulse laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The halogen chlorine is hard to detect in laser-induced breakdown spectroscopy (LIBS) mainly due to its high excited state energies of 9.2 and 10.4 eV for the most intense emission lines at 134.72 nm and 837.59 nm, respectively. We report on sensitive detection of Cl in industrial iron oxide Fe2O3 powder by single-pulse (SP) and dual-pulse (DP) LIBS measurements in the near infrared range in air. In compacted powder measured by SP excitation (Nd:YAG laser, 532 nm) Cl was detected with limit of detection LOD = 440 ppm and limit of quantitation LOQ = 720 ppm. Orthogonal DP LIBS was studied on pressed Fe2O3 pellets and Fe3O4 ceramics. The transmission of laser-induced plasma for orthogonal Nd:YAG 1064 nm and ArF 193 nm laser pulses showed a significant dependence on interpulse delay time (ipd) and laser wavelength (λL). The UV pulses (λL = 193 nm) were moderately absorbed in the plasma and the Cl I emission line intensity was enhanced while IR pulses (λL = 1064 nm) were not absorbed and Cl signals were not enhanced at ipd = 3 μs. The UV laser enhancement of Cl signals is attributed to the much higher signal/background ratio for orthogonal DP excitation compared to SP excitation and to the increased plasma temperature and electron number density. This enabled measurement at a very short delay time of td ≥ 0.1 μs with respect to the re-excitation pulse and detection of the very rapidly decaying Cl emission with higher efficiency. - Highlights: • Chlorine in iron oxide is measured by LIBS with LOD = 440 ppm and LOQ = 720 ppm. • The LOD of Cl is among the best values achieved on solid samples by LIBS. • Enhanced emission of Cl is observed by orthogonal UV laser re-excitation of plasma. • Cl signals are enhanced at long interpulse delays and short detector gate delays. • Measured LIBS signals of Cl and Fe qualitatively agree with calculated emissions

  8. Sensitive detection of chlorine in iron oxide by single pulse and dual pulse laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pedarnig, J.D., E-mail: johannes.pedarnig@jku.at [Christian Doppler Laboratory for Laser-assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Haslinger, M.J.; Bodea, M.A.; Huber, N. [Christian Doppler Laboratory for Laser-assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Wolfmeir, H. [voestalpine Stahl GmbH, A-4031 Linz (Austria); Heitz, J. [Christian Doppler Laboratory for Laser-assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria)

    2014-11-01

    The halogen chlorine is hard to detect in laser-induced breakdown spectroscopy (LIBS) mainly due to its high excited state energies of 9.2 and 10.4 eV for the most intense emission lines at 134.72 nm and 837.59 nm, respectively. We report on sensitive detection of Cl in industrial iron oxide Fe{sub 2}O{sub 3} powder by single-pulse (SP) and dual-pulse (DP) LIBS measurements in the near infrared range in air. In compacted powder measured by SP excitation (Nd:YAG laser, 532 nm) Cl was detected with limit of detection LOD = 440 ppm and limit of quantitation LOQ = 720 ppm. Orthogonal DP LIBS was studied on pressed Fe{sub 2}O{sub 3} pellets and Fe{sub 3}O{sub 4} ceramics. The transmission of laser-induced plasma for orthogonal Nd:YAG 1064 nm and ArF 193 nm laser pulses showed a significant dependence on interpulse delay time (ipd) and laser wavelength (λ{sub L}). The UV pulses (λ{sub L} = 193 nm) were moderately absorbed in the plasma and the Cl I emission line intensity was enhanced while IR pulses (λ{sub L} = 1064 nm) were not absorbed and Cl signals were not enhanced at ipd = 3 μs. The UV laser enhancement of Cl signals is attributed to the much higher signal/background ratio for orthogonal DP excitation compared to SP excitation and to the increased plasma temperature and electron number density. This enabled measurement at a very short delay time of t{sub d} ≥ 0.1 μs with respect to the re-excitation pulse and detection of the very rapidly decaying Cl emission with higher efficiency. - Highlights: • Chlorine in iron oxide is measured by LIBS with LOD = 440 ppm and LOQ = 720 ppm. • The LOD of Cl is among the best values achieved on solid samples by LIBS. • Enhanced emission of Cl is observed by orthogonal UV laser re-excitation of plasma. • Cl signals are enhanced at long interpulse delays and short detector gate delays. • Measured LIBS signals of Cl and Fe qualitatively agree with calculated emissions.

  9. Quantitative elemental detection of size-segregated particles using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    In order to simulate coal combustion and develop optimal and stable boiler control systems in real power plants, it is imperative to obtain the detailed information in coal combustion processes as well as to measure species contents in fly ash, which should be controlled and analyzed for enhancing boiler efficiency and reducing environmental pollution. The fly ash consists of oxides (SiO2, Al2O3, Fe2O3, CaO, and so on), unburned carbon, and other minor elements. Recently laser-induced breakdown spectroscopy (LIBS) technique has been applied to coal combustion and other industrial fields because of the fast response, high sensitivity, real-time and non-contact features. In these applications it is important to measure controlling factors without any sample preparation to maintain the real-time measurement feature. The relation between particle content and particle diameter is also one of the vital researches, because compositions of particles are dependent on their diameter. In this study, we have detected the contents of size-segregated particles using LIBS. Particles were classified by an Anderson cascade impactor and their contents were measured using the output of 1064 nm YAG laser, a spectrograph and an ICCD camera. The plasma conditions such as plasma temperature are dependent on the size of particles and these effects must be corrected to obtain quantitative information. The plasma temperature was corrected by the emission intensity ratio from the same atom. Using this correction method, the contents of particles can be measured quantitatively in fixed experimental parameters. This method was applied to coal and fly ash from a coal-fired burner to measure unburned carbon and other contents according to the particle diameter. The acquired results demonstrate that the LIBS technique is applicable to measure size-segregated particle contents in real time and this method is useful for the analysis of coal combustion and its control because of its sensitive and

  10. Comparative study on fast classification of brick samples by combination of principal component analysis and linear discriminant analysis using stand-off and table-top laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Focusing on historical aspect, during archeological excavation or restoration works of buildings or different structures built from bricks it is important to determine, preferably in-situ and in real-time, the locality of bricks origin. Fast classification of bricks on the base of Laser-Induced Breakdown Spectroscopy (LIBS) spectra is possible using multivariate statistical methods. Combination of principal component analysis (PCA) and linear discriminant analysis (LDA) was applied in this case. LIBS was used to classify altogether the 29 brick samples from 7 different localities. Realizing comparative study using two different LIBS setups — stand-off and table-top it is shown that stand-off LIBS has a big potential for archeological in-field measurements. - Highlights: • Comparison of two potentially field-deployable LIBS setups is introduced. • The aim is classification of LIBS spectra of brick samples into several localities. • LDA filled with PCA scores is proposed as an effective classification method. • An influence of brick firing temperature on LIBS spectra is discovered and examined

  11. Evaluation of the laser-induced breakdown spectroscopy technique for determination of the chemical composition of copper concentrates

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS), like many other spectroscopic techniques, is a comparative method. Typically, in qualitative analysis, synthetic certified standard with a well-known elemental composition is used to calibrate the system. Nevertheless, in all laser-induced techniques, such calibration can affect the accuracy through differences in the overall composition of the chosen standard. There are also some intermediate factors, which can cause imprecision in measurements, such as optical absorption, surface structure and thermal conductivity. In this work the calibration performed for the LIBS technique utilizes pellets made directly from the tested materials (old well-characterized samples). This choice produces a considerable improvement in the accuracy of the method. This technique was adopted for the determination of trace elements in industrial copper concentrates, standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for three elements: silver, cobalt and vanadium. We also proposed a method of post-processing the measurement data to minimize matrix effects and permit reliable analysis. It has been shown that the described technique can be used in qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates. It was noted that the final validation of such methodology is limited mainly by the accuracy of the characterization of the standards. - Highlights: • A laser-induced breakdown spectroscopy technique is introduced for composition monitoring in industrial copper concentrates. • Calibration samples consisted of pellets produced from the tested materials. • The proposed method of post-processing significantly minimizes matrix effects. • The possible uses of this technique are limited mainly by accurate characterization of the standard samples

  12. Evaluation of the laser-induced breakdown spectroscopy technique for determination of the chemical composition of copper concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Łazarek, Łukasz, E-mail: lukasz.lazarek@pwr.wroc.pl [Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Antończak, Arkadiusz J.; Wójcik, Michał R. [Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Drzymała, Jan [Faculty of Geoengineering, Mining and Geology, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Abramski, Krzysztof M. [Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland)

    2014-07-01

    Laser-induced breakdown spectroscopy (LIBS), like many other spectroscopic techniques, is a comparative method. Typically, in qualitative analysis, synthetic certified standard with a well-known elemental composition is used to calibrate the system. Nevertheless, in all laser-induced techniques, such calibration can affect the accuracy through differences in the overall composition of the chosen standard. There are also some intermediate factors, which can cause imprecision in measurements, such as optical absorption, surface structure and thermal conductivity. In this work the calibration performed for the LIBS technique utilizes pellets made directly from the tested materials (old well-characterized samples). This choice produces a considerable improvement in the accuracy of the method. This technique was adopted for the determination of trace elements in industrial copper concentrates, standardized by conventional atomic absorption spectroscopy with a flame atomizer. A series of copper flotation concentrate samples was analyzed for three elements: silver, cobalt and vanadium. We also proposed a method of post-processing the measurement data to minimize matrix effects and permit reliable analysis. It has been shown that the described technique can be used in qualitative and quantitative analyses of complex inorganic materials, such as copper flotation concentrates. It was noted that the final validation of such methodology is limited mainly by the accuracy of the characterization of the standards. - Highlights: • A laser-induced breakdown spectroscopy technique is introduced for composition monitoring in industrial copper concentrates. • Calibration samples consisted of pellets produced from the tested materials. • The proposed method of post-processing significantly minimizes matrix effects. • The possible uses of this technique are limited mainly by accurate characterization of the standard samples.

  13. Sensitive cesium measurement in liquid sample using low-pressure laser-induced breakdown spectroscopy

    Science.gov (United States)

    Wang, Zhen Zhen; Yan, Jun Jie; Liu, Ji Ping; Deguchi, Yoshihiro; Katsumori, Shunpei; Ikutomo, Akihiro

    2015-12-01

    The environmental pollution by trace heavy metals is a severe problem for the environment and human health. In this paper, the liquid jet of CsNO3 solution employed was introduced to the measurement chamber and detected using laser-induced breakdown spectroscopy (LIBS) directly at low pressure to determine the detection features of trace Cs element in liquid. The distinct and round plasma can be acquired when reducing the pressure. The interaction between the plasma core of the liquid jet and the surrounding gas can be controlled to enhance Cs detection ability. Cs emission was mainly in the surrounding area in the plasma. The influences of laser focal point and plasma measurement area on the measured signals were studied under low-pressure condition. When employing the defocus mode and varying the measurement area within a certain range, Cs signal and the signal-to-background ratio were improved. Cs detection limit can reach to 22.8 ppb (3σ/ms) at pressure of 26 kPa in this paper. According to the discussion, the detection limit will be enhanced when improving the experimental conditions using this method, which shows the great application potential of liquid sample measurement.

  14. Plasma diagnostics from self-absorbed doublet lines in laser-induced breakdown spectroscopy

    Science.gov (United States)

    D'Angelo, C. A.; Garcimuño, M.; Díaz Pace, D. M.; Bertuccelli, G.

    2015-10-01

    In this paper, a generalized approach is developed and applied for plasma characterization and quantitative purposes in laser-induced breakdown spectroscopy (LIBS) experiences by employing a selected pair of spectral lines belonging to the same multiplet. It is based on the comparison between experimental ratios of line parameters and the theoretical calculus obtained under the framework of a homogeneous plasma in local thermodynamic equilibrium. The applicability of the method was illustrated by using the atomic resonance transitions 279.55-280.27 nm of Mg II, which are usually detected in laser-induced plasma (LIP) during laser ablation of many kinds of targets. The laser induced plasmas were produced using a Nd:YAG laser from a pressed pellet of powdered calcium hydroxide with a concentration of 300 ppm of Mg. The experimental ratios for peak intensities, total intensities and Stark widths were obtained for different time windows and matched to the theoretical calculus. The temperature and the electron density of the plasma, as well as the Mg columnar density (the atom/ion concentration times the length of the plasma along the line-of-sight), were determined. The results were interpreted under the employed approach.

  15. Quantitative determination of sulfur content in concrete with laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy has been employed for the investigation of the sulfur content of concrete. Sulfur compounds are a natural but minor component in building materials. The ingress of sulfates or sulfuric acid constitutes a major risk of chemical aggression for concrete. There is a need for a fast method, which can be used on-site and is able to investigate a wide range of different measuring points, so that damages can be characterized. For quantitative determination the sulfur spectral line at 921.3 nm is used. The optimum ambient atmosphere has been determined by comparison of measurements accomplished under air, argon and helium atmosphere. Reference samples have been produced and calibration curves have been determined, the results of LIBS measurements are compared with results from chemical analysis. Defining a limit for the intensity ratio of a calcium and a oxygen spectral line can reduce the influence of the heterogeneity of the material, so that only spectra with a high amount of cementitious material are evaluated. Depth profiles and spatial resolved sulfur distributions are presented measured on concrete cores originating from a highly sulfate contaminated clarifier

  16. Automatic estimation of varying continuum background emission in laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    In laser-induced breakdown spectroscopy (LIBS), plasma emission is extremely unstable because of many factors, such as the fluctuation of laser energy, inhomogeneity of sample surfaces, and variable distance between lens and samples. Therefore, the detection and correction of varying continuum background emission are not easily accomplished. The aim of this work is to present a method that can automatically estimate and correct varying continuum background emission, which is representative in laser-induced plasma. In this method, we first find all minima on a spectrum, and then deduct the unreasonable minima by a proper threshold. Finally, we use one or multiple polynomial functions through the minima left to approximate the continuum backgrounds. The validity of this method was evaluated by using several spectra with different complexities and wavelength ranges. We also applied this method to optimize the measurement time delays of detectors. In addition, for five aluminum alloy samples, we compared their elemental calibration cures between original spectra and background-corrected spectra. Experimental results proved that the method proposed in this paper can well estimate varying continuum backgrounds over a wide range of wavelengths.

  17. Comparison of brass alloys composition by laser-induced breakdown spectroscopy and self-organizing maps

    International Nuclear Information System (INIS)

    In this paper we face the problem of assessing similarities in the composition of different metallic alloys, using the laser-induced breakdown spectroscopy technique. The possibility of determining the degree of similarity through the use of artificial neural networks and self-organizing maps is discussed. As an example, we present a case study involving the comparison of two historical brass samples, very similar in their composition. The results of the paper can be extended to many other situations, not necessarily associated with cultural heritage and archeological studies, where objects with similar composition have to be compared. - Highlights: • A method for assessing the similarity of materials analyzed by LIBS is proposed. • Two very similar fragments of historical brass were analyzed. • Using a simple artificial neural network the composition of the two alloys was determined. • The composition of the two brass alloys was the same within the experimental error. • Using self-organizing maps, the probability of the alloys to have the same composition was assessed

  18. Comparison of brass alloys composition by laser-induced breakdown spectroscopy and self-organizing maps

    Energy Technology Data Exchange (ETDEWEB)

    Pagnotta, Stefano; Grifoni, Emanuela; Legnaioli, Stefano [Applied and Laser Spectroscopy Laboratory, ICCOM-CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); Lezzerini, Marco [Department of Earth Sciences, University of Pisa, Via S. Maria 53, 56126 Pisa (Italy); Lorenzetti, Giulia [Applied and Laser Spectroscopy Laboratory, ICCOM-CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); Palleschi, Vincenzo, E-mail: vincenzo.palleschi@cnr.it [Applied and Laser Spectroscopy Laboratory, ICCOM-CNR, Research Area of Pisa, Via G. Moruzzi 1, 56124 Pisa (Italy); Department of Civilizations and Forms of Knowledge, University of Pisa, Via L. Galvani 1, 56126 Pisa (Italy)

    2015-01-01

    In this paper we face the problem of assessing similarities in the composition of different metallic alloys, using the laser-induced breakdown spectroscopy technique. The possibility of determining the degree of similarity through the use of artificial neural networks and self-organizing maps is discussed. As an example, we present a case study involving the comparison of two historical brass samples, very similar in their composition. The results of the paper can be extended to many other situations, not necessarily associated with cultural heritage and archeological studies, where objects with similar composition have to be compared. - Highlights: • A method for assessing the similarity of materials analyzed by LIBS is proposed. • Two very similar fragments of historical brass were analyzed. • Using a simple artificial neural network the composition of the two alloys was determined. • The composition of the two brass alloys was the same within the experimental error. • Using self-organizing maps, the probability of the alloys to have the same composition was assessed.

  19. Quantitative determination of sulfur content in concrete with laser-induced breakdown spectroscopy

    Science.gov (United States)

    Weritz, F.; Ryahi, S.; Schaurich, D.; Taffe, A.; Wilsch, G.

    2005-08-01

    Laser-induced breakdown spectroscopy has been employed for the investigation of the sulfur content of concrete. Sulfur compounds are a natural but minor component in building materials. The ingress of sulfates or sulfuric acid constitutes a major risk of chemical aggression for concrete. There is a need for a fast method, which can be used on-site and is able to investigate a wide range of different measuring points, so that damages can be characterized. For quantitative determination the sulfur spectral line at 921.3 nm is used. The optimum ambient atmosphere has been determined by comparison of measurements accomplished under air, argon and helium atmosphere. Reference samples have been produced and calibration curves have been determined, the results of LIBS measurements are compared with results from chemical analysis. Defining a limit for the intensity ratio of a calcium and a oxygen spectral line can reduce the influence of the heterogeneity of the material, so that only spectra with a high amount of cementitious material are evaluated. Depth profiles and spatial resolved sulfur distributions are presented measured on concrete cores originating from a highly sulfate contaminated clarifier.

  20. Laser-induced breakdown spectroscopy for on-line engine equivalence ratio measurements.

    Science.gov (United States)

    Ferioli, Francesco; Puzinauskas, Paulius V; Buckley, Steven G

    2003-09-01

    Laser-induced breakdown spectroscopy (LIBS) has been used to measure the equivalence ratio of a spark-ignited engine in a laboratory setting. Spectral features of C (711.3 nm), O (776.6 nm), N (746.3 and 743.8 nm), and CN (broad emission 707-734 nm) were used to quantify the equivalence ratio over a range from phi = 0.8 to phi = 1.2. The C/N and C/O peak ratios were found to be successful measurement metrics, compared with a standard exhaust gas oxygen analyzer, for averaged measurements. Some variation in the measurements was observed as a function of engine load. Single-shot data based on a CN/air peak ratio were evaluated using a separate calibration from averaged measurements, and the average of the single-shot data was found to agree well with the exhaust gas oxygen analyzer. The scatter in the single-shot data was substantially higher at lower equivalence ratios. The measurements including the CN peak were slightly sensitive to load, possibly due to pressure changes in the sample as the load increases, or possibly due to changes in the particle size distribution in the gas stream. PMID:14611051

  1. Potential of laser-induced breakdown spectroscopy for the rapid identification of carious teeth.

    Science.gov (United States)

    Singh, Vivek K; Rai, Awadhesh K

    2011-05-01

    The importance of laser-induced breakdown spectroscopy (LIBS) for the rapid identification of teeth affected by caries has been demonstrated. The major and minor elemental constituents of teeth samples were analyzed using the prominent transitions of the atomic lines present in the sample. The elements detected in the tooth sample were: calcium, magnesium, copper, zinc, strontium, titanium, carbon, phosphorous, hydrogen, oxygen, sodium, and potassium. The results revealed that the caries-affected part contained a less amount of calcium and phosphorous in comparison to the healthy part of the tooth sample, whereas higher content of magnesium, copper, zinc, strontium, carbon, sodium, and potassium were present in the caries-affected part. For the first time, we have observed that hydrogen and oxygen were less in healthy parts compared to the caries-affected part of the tooth sample. The density of calcium and phosphorous, which are the main matrix of teeth, was less in the caries-affected part than in the healthy part. The variation in densities of the trace constituents like magnesium and carbon, etc., in caries and healthy parts of the tooth sample are also discussed. The presence of different metal elements in healthy and caries-affected parts of the tooth samples and the possible role of different metal elements in the formation of caries have been discussed. PMID:20414707

  2. Laser-induced Breakdown Spectroscopy used to Detect Endophyte-mediated Accumulation of Metals by Tall Fescue

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Madhavi Z [ORNL; Stewart, Arthur J [ORNL; Gwinn, Dr. Kimberley [University of Tennessee, Knoxville (UTK); Waller, John C [ORNL

    2010-01-01

    Laser-induced breakdown spectroscopy was used to determine the impact of endophyte (Neotyphodium sp.) infection on elemental composition of tall fescue (Festuca arundinacea). Leaf material from endophyte-infected (E+) and endophyte-free (E-) tall fescue populations in established plots was examined. Leaf-tissue digestates were also tested for metals, by ICP-MS. Seven of eleven metals (Ca, Mg, Fe, Mn, Cu, Ni and Zn) were measured by both techniques at concentrations great enough to reliably compare. Mg, Zn, and Cd, a toxic metal that can be present in forage, were readily detected by LIBS, even though Cd concentrations in the plants were below levels typically achieved using ICP-MS detection. Implications of these results for research on forage analysis and phytoremediation are discussed.

  3. Space-resolved analysis of trace elements in fresh vegetables using ultraviolet nanosecond laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Juve, Vincent; Portelli, Richard; Boueri, Myriam; Baudelet, Matthieu [Universite de Lyon, F-69622, Lyon, France, Universite Lyon 1, Villeurbanne CNRS, UMR5579, LASIM (France); Yu Jin [Universite de Lyon, F-69622, Lyon, France, Universite Lyon 1, Villeurbanne CNRS, UMR5579, LASIM (France)], E-mail: jin.yu@lasim.univ-lyon1.fr

    2008-10-15

    Laser-induced breakdown spectroscopy (LIBS) has been applied to analyze trace elements contained in fresh vegetables. A quadrupled Nd:YAG laser is used in the experiments for ablation. Analyzed samples come from local markets and represent frequently consumed vegetables. For a typical root vegetable, such as potato, spectral analysis of the plasma emission reveals more than 400 lines emitted by 27 elements and 2 molecules, C{sub 2} and CN. Among these species, one can find trace as well as ultra-trace elements. A space-resolved analysis of several trace elements with strong emissions is then applied to typical root, stem and fruit vegetables. The results from this study demonstrate the potential of an interesting tool for botanical and agricultural studies as well for food quality/safety and environment pollution assessment and control.

  4. Laser-induced breakdown spectroscopy in gases using ungated detection in combination with polarization filtering and online background correction

    Science.gov (United States)

    Kiefer, J.; Tröger, J. W.; Seeger, T.; Leipertz, A.; Li, B.; Li, Z. S.; Aldén, M.

    2010-06-01

    Quantitative and fast analysis of gas mixtures is an important task in the field of chemical, security and environmental analysis. In this paper we present a diagnostic approach based on laser-induced breakdown spectroscopy (LIBS). A polarization filter in the signal collection system enables sufficient suppression of elastically scattered light which otherwise reduces the dynamic range of the measurement. Running the detector with a doubled repetition rate as compared to the laser online background correction is obtained. Quantitative measurements of molecular air components in synthetic, ambient and expiration air are performed and demonstrate the potential of the method. The detection limits for elemental oxygen and hydrogen are in the order of 15 ppm and 10 ppm, respectively.

  5. Comparative investigation of partial least squares discriminant analysis and support vector machines for geological cuttings identification using laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Ye; Wang, Zhennan [Optics and Optoelectronics Laboratory, Ocean University of China, Qingdao, Shandong 266100 (China); Han, Xiaoshuang [Optics and Optoelectronics Laboratory, Ocean University of China, Qingdao, Shandong 266100 (China); College of Electronic Information Engineering, Inner Mongolia University, Hohhot, Inner Mongolia 010021 (China); Hou, Huaming [Optics and Optoelectronics Laboratory, Ocean University of China, Qingdao, Shandong 266100 (China); Zheng, Ronger, E-mail: rzheng@ouc.edu.cn [Optics and Optoelectronics Laboratory, Ocean University of China, Qingdao, Shandong 266100 (China)

    2014-12-01

    With the hope of applying laser-induced breakdown spectroscopy (LIBS) to the geological logging field, a series of cutting samples were classified using LIBS coupled with chemometric methods. In this paper, we focused on a comparative investigation of the linear PLS-DA method and non-linear SVM method. Both the optimal PLS-DA model and SVM model were built by the leave-one-out cross-validation (LOOCV) approach with the calibration LIBS spectra, and then tested by validation spectra. We show that the performance of SVM is significantly better than PLS-DA because of its ability to address the non-linear relationships in LIBS spectra, with a correct classification rate of 91.67% instead of 68.34%, and an unclassification rate of 3.33% instead of 28.33%. To further improve the classification accuracy, we then designed a new classification approach by the joint analysis of PLS-DA and SVM models. With this method, 95% of the validation spectra are correctly classified and no unclassified spectra are observed. This work demonstrated that the coupling of LIBS with the non-linear SVM method has great potential to be used for on-line classification of geological cutting samples, and the combination of PLS-DA and SVM enables the cuttings identification with an excellent performance. - Highlights: • The geological cuttings were classified using LIBS coupled with chemometric methods. • The non-linear SVM showed significantly better performance than PLS-DA. • The joint analysis of PLS-DA and SVMs provided an excellent accuracy of 95%.

  6. Comparative investigation of partial least squares discriminant analysis and support vector machines for geological cuttings identification using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    With the hope of applying laser-induced breakdown spectroscopy (LIBS) to the geological logging field, a series of cutting samples were classified using LIBS coupled with chemometric methods. In this paper, we focused on a comparative investigation of the linear PLS-DA method and non-linear SVM method. Both the optimal PLS-DA model and SVM model were built by the leave-one-out cross-validation (LOOCV) approach with the calibration LIBS spectra, and then tested by validation spectra. We show that the performance of SVM is significantly better than PLS-DA because of its ability to address the non-linear relationships in LIBS spectra, with a correct classification rate of 91.67% instead of 68.34%, and an unclassification rate of 3.33% instead of 28.33%. To further improve the classification accuracy, we then designed a new classification approach by the joint analysis of PLS-DA and SVM models. With this method, 95% of the validation spectra are correctly classified and no unclassified spectra are observed. This work demonstrated that the coupling of LIBS with the non-linear SVM method has great potential to be used for on-line classification of geological cutting samples, and the combination of PLS-DA and SVM enables the cuttings identification with an excellent performance. - Highlights: • The geological cuttings were classified using LIBS coupled with chemometric methods. • The non-linear SVM showed significantly better performance than PLS-DA. • The joint analysis of PLS-DA and SVMs provided an excellent accuracy of 95%

  7. Modeling of low-temperature plasmas generated using laser-induced breakdown spectroscopy: the ChemCam diagnostic tool on the Mars Science Laboratory Rover

    Science.gov (United States)

    Colgan, James

    2016-05-01

    We report on efforts to model the low-temperature plasmas generated using laser-induced breakdown spectroscopy (LIBS). LIBS is a minimally invasive technique that can quickly and efficiently determine the elemental composition of a target and is employed in an extremely wide range of applications due to its ease of use and fast turnaround. In particular, LIBS is the diagnostic tool used by the ChemCam instrument on the Mars Science Laboratory rover Curiosity. In this talk, we report on the use of the Los Alamos plasma modeling code ATOMIC to simulate LIBS plasmas, which are typically at temperatures of order 1 eV and electron densities of order 10 16 - 17 cm-3. At such conditions, these plasmas are usually in local-thermodynamic equilibrium (LTE) and normally contain neutral and singly ionized species only, which then requires that modeling must use accurate atomic structure data for the element under investigation. Since LIBS devices are often employed in a very wide range of applications, it is therefore desirable to have accurate data for most of the elements in the periodic table, ideally including actinides. Here, we discuss some recent applications of our modeling using ATOMIC that have explored the plasma physics aspects of LIBS generated plasmas, and in particular discuss the modeling of a plasma formed from a basalt sample used as a ChemCam standard1. We also highlight some of the more general atomic physics challenges that are encountered when attempting to model low-temperature plasmas. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396. Work performed in conjunction with D. P. Kilcrease, H. M. Johns, E. J. Judge, J. E. Barefield, R. C. Wiens, S. M. Clegg.

  8. Quantitative determination of wear metals in engine oils using laser-induced breakdown spectroscopy: A comparison between liquid jets and static liquids

    International Nuclear Information System (INIS)

    A comparison of laser-induced breakdown spectroscopy (LIBS) sensitivity in laminar liquid jets and at the surface of a static liquid has been performed. Limits of detection (LODs) have been estimated for Na, Mg, Al, Ca, Ti, V, Cr, Mn, Ni, Fe, Cu, Zn, Mo, Ag, Cd, and Ba under similar conditions using both experimental arrangements. LODs in liquid jets are found to be four times lower on average compared to measurements at static surfaces. Data acquisition rates in jet experiments are also generally higher than for static liquids due to reduced problems with splashing effects. The use of LIBS in jets has also been investigated for quantitative analysis of used lubricants. A number of contaminants have been measured in a set of used engine oils and the results compared to analysis via ICP-AES, where a good correlation is obtained

  9. Relationship between the results of laser-induced breakdown spectroscopy and dynamical mechanical analysis in composite solid propellants during their aging.

    Science.gov (United States)

    Farhadian, Amir Hossein; Tehrani, Masoud Kavosh; Keshavarz, Mohammad Hossein; Karimi, Mehran; Reza Darbani, Seyyed Mohammad

    2016-06-01

    Laser-induced breakdown spectroscopy (LIBS) has been used to analyze thermal aging in AP/HTPB composite solid propellants, where AP and HTPB are ammonium perchlorate and hydroxyl-terminated polybutadiene, respectively. The method of accelerated aging was used to obtain samples of different ages. Dynamical mechanical analysis results have been provided in order to validate the LIBS results. Many methods have been used for the accurate investigation of spectra. First, molecular bands, such as CN, C2, and AlO, were compared in different samples so that their intensity ratios could be considered. In order to discriminate more accurately between different sample spectra, principle component analysis (PCA) was used as a suitable chemometric method. All these results represent changes in the chemical structure due to increasing time and temperature. PMID:27411188

  10. Investigation of heavy-metal accumulation in selected plant samples using laser induced breakdown spectroscopy and laser ablation inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Galiová, M.; Kaiser, J.; Novotný, K.; Novotný, J.; Vaculovič, T.; Liška, M.; Malina, R.; Stejskal, K.; Adam, V.; Kizek, R.

    2008-12-01

    Single-pulse Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation Inductively Coupled Plasma Mass-Spectrometry (LA-ICP-MS) were applied for mapping the silver and copper distribution in Helianthus Annuus L. samples treated with contaminant in controlled conditions. For Ag and Cu detection the 328.07 nm Ag(I) and 324.75 nm Cu(I) lines were used, respectively. The LIBS experimental conditions (mainly the laser energy and the observation window) were optimized in order to avoid self-absorption effect in the measured spectra. In the LA-ICP-MS analysis the Ag 107 and Cu 63 isotopes were detected. The capability of these two analytical techniques for high-resolution mapping of selected trace chemical elements was demonstrated.

  11. Determination of inorganic nutrients in wheat flour by laser-induced breakdown spectroscopy and energy dispersive X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) and energy dispersive X-ray fluorescence spectrometry (EDXRF) were evaluated for the determination of P, K, Ca, Mg, S, Fe, Cu, Mn and Zn in pressed pellets of wheat flours. EDXRF and LIBS calibration models were built with analytes mass fractions determined by inductively coupled plasma optical emission spectrometry after microwave-assisted acid digestion in a set of 25 wheat flour laboratory samples. Test samples consisted of pressed pellets prepared from wheat flour mixed with 30% mm−1 cellulose binder. Experiments were carried out with a LIBS setup consisted of a Q-switched Nd:YAG laser and a spectrometer with Echelle optics and ICCD, and a benchtop EDXRF system fitted with a Rh target X-ray tube and a Si(Li) semiconductor detector. The correlation coefficients from the linear calibration models of P, K, Ca, Mg, S, Fe, Mn and Zn determined by LIBS and/or EDXRF varied from 0.9705 for Zn to 0.9990 for Mg by LIBS, and from 0.9306 for S to 0.9974 for K by EDXRF. The coefficients of variation of measurements varied from 1.2 to 20% for LIBS, and from 0.3 to 24% for EDXRF. The predictive capabilities based on RMSEP (root mean square error of prediction) values were appropriate for the determination of P, Ca, Mg, Fe, Mn and Zn by LIBS, and for P, K, S, Ca, Fe, and Zn by EDXRF. In general, results from the analysis of NIST SRM 1567a Wheat flour by LIBS and EDXRF were in agreement with their certified mass fractions. - Highlights: • Combination of LIBS and EDXRF for quantitative analysis of wheat flour. • Validation performed for determination of P, K, Ca, Mg, S, Fe, Cu, Mn and Zn. • Same test samples can be used for both methods. • Appropriate limits of detection for all tested analytes. • Methods are simple and provide fast and accurate results for routine analysis

  12. Determination of inorganic nutrients in wheat flour by laser-induced breakdown spectroscopy and energy dispersive X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Peruchi, Lidiane Cristina; Nunes, Lidiane Cristina; Gustinelli Arantes de Carvalho, Gabriel; Guerra, Marcelo Braga Bueno; Almeida, Eduardo de; Rufini, Iolanda Aparecida [NAPTISA Research Support Center “Technology and Innovation for a Sustainable Agriculture”, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário 303, 13416-000, Piracicaba SP (Brazil); Santos, Dário [Federal University of São Paulo, R. Prof. Artur Riedel 275, 09972-270, Diadema SP (Brazil); Krug, Francisco José, E-mail: fjkrug@cena.usp.br [NAPTISA Research Support Center “Technology and Innovation for a Sustainable Agriculture”, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário 303, 13416-000, Piracicaba SP (Brazil)

    2014-10-01

    Laser-induced breakdown spectroscopy (LIBS) and energy dispersive X-ray fluorescence spectrometry (EDXRF) were evaluated for the determination of P, K, Ca, Mg, S, Fe, Cu, Mn and Zn in pressed pellets of wheat flours. EDXRF and LIBS calibration models were built with analytes mass fractions determined by inductively coupled plasma optical emission spectrometry after microwave-assisted acid digestion in a set of 25 wheat flour laboratory samples. Test samples consisted of pressed pellets prepared from wheat flour mixed with 30% mm{sup −1} cellulose binder. Experiments were carried out with a LIBS setup consisted of a Q-switched Nd:YAG laser and a spectrometer with Echelle optics and ICCD, and a benchtop EDXRF system fitted with a Rh target X-ray tube and a Si(Li) semiconductor detector. The correlation coefficients from the linear calibration models of P, K, Ca, Mg, S, Fe, Mn and Zn determined by LIBS and/or EDXRF varied from 0.9705 for Zn to 0.9990 for Mg by LIBS, and from 0.9306 for S to 0.9974 for K by EDXRF. The coefficients of variation of measurements varied from 1.2 to 20% for LIBS, and from 0.3 to 24% for EDXRF. The predictive capabilities based on RMSEP (root mean square error of prediction) values were appropriate for the determination of P, Ca, Mg, Fe, Mn and Zn by LIBS, and for P, K, S, Ca, Fe, and Zn by EDXRF. In general, results from the analysis of NIST SRM 1567a Wheat flour by LIBS and EDXRF were in agreement with their certified mass fractions. - Highlights: • Combination of LIBS and EDXRF for quantitative analysis of wheat flour. • Validation performed for determination of P, K, Ca, Mg, S, Fe, Cu, Mn and Zn. • Same test samples can be used for both methods. • Appropriate limits of detection for all tested analytes. • Methods are simple and provide fast and accurate results for routine analysis.

  13. A Comparative study of Single-pulse and Double-pulse Laser-Induced Breakdown Spectroscopy with U-containing Samples

    Energy Technology Data Exchange (ETDEWEB)

    Skrodzki, Patrick J.; Becker, Jason R.; Diwakar, P. K.; Harilal, Sivanandan S.; Hassanein, A.

    2016-03-01

    Laser-induced breakdown spectroscopy (LIBS) holds potential advantages in special nuclear material (SNM) sensing and nuclear forensics which require rapid analysis, minimal sample preparation and stand-off distance capability. SNM, such as U, however, result in crowded emission spectra with LIBS, and characteristic emission lines are challenging to discern. It is well-known that double-pulse LIBS (DPLIBS) improves the signal intensity for analytes over conventional single-pulse LIBS (SPLIBS). This study investigates U signal in a glass matrix using DPLIBS and compares to signal features obtained using SPLIBS. DPLIBS involves sequential firing of 1.06 µm Nd:YAG pre-pulse and 10.6 µm TEA CO2 heating pulse in near collinear geometry. Optimization of experimental parameters including inter-pulse delay and energy follows identification of characteristic lines and signals for bulk analyte Ca and minor constituent analyte U for both DPLIBS and SPLIBS. Spatial and temporal coupling of the two pulses in the proposed DPLIBS technique yields improvements in analytical merits with negligible further damage to the sample compared to SPLIBS. Subsequently, the study discusses optimum plasma emission conditions of U lines and relative figures of merit in both SPLIBS and DPLIBS. Investigation into plasma characteristics also addresses plausible mechanisms related to observed U analyte signal variation between SPLIBS and DPLIBS.

  14. An investigation of Laser Induced Breakdown Spectroscopy for use as a control in the laser removal of rock from fossils found at the Malapa hominin site, South Africa

    International Nuclear Information System (INIS)

    Laser Induced Breakdown Spectroscopy (LIBS) was used to study the spectra from fossils and surrounding rock recovered from the Cradle of Mankind site at Malapa, South Africa. The objective was to find a suitable spectral line(s), specific to fossils, which could be used as a control signal to limit damage to fossils during high speed laser removal of the encasing rock. The calcified clastic matrix (rock) encasing the fossils was found to emit a variety of complex LIBS spectra. Nevertheless, it was found possible to distinguish fossils in a single LIBS pulse, and without significant damage to the fossil, using spectral lines of neutral phosphorus. - Highlights: ► LIBS used to discriminate fossils from rock as potential processing control mechanism. ► 2 million year old fossils from Malapa hominin site found to be high in phosphorus. ► Rock spectral lines from silicon, iron and manganese, but no phosphorus. ► Holds great promise for process control in laser preparation of fossils. ► Also promising for accurate identification of fossils at excavation sites.

  15. An investigation of Laser Induced Breakdown Spectroscopy for use as a control in the laser removal of rock from fossils found at the Malapa hominin site, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, D.E., E-mail: troberts@csir.co.za [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Plessis, A. du [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); University of Stellenbosch, Private Bag X1, Matieland, Stellenbosch (South Africa); Steyn, J.; Botha, L.R.; Pityana, S. [CSIR National Laser Centre, PO Box 395, Meiring Naude Road, Pretoria 0001 (South Africa); Berger, L.R. [Institute for Human Evolution, School of GeoSciences, University of Witwatersrand, Private Bag 3, Wits 2050 (South Africa)

    2012-07-15

    Laser Induced Breakdown Spectroscopy (LIBS) was used to study the spectra from fossils and surrounding rock recovered from the Cradle of Mankind site at Malapa, South Africa. The objective was to find a suitable spectral line(s), specific to fossils, which could be used as a control signal to limit damage to fossils during high speed laser removal of the encasing rock. The calcified clastic matrix (rock) encasing the fossils was found to emit a variety of complex LIBS spectra. Nevertheless, it was found possible to distinguish fossils in a single LIBS pulse, and without significant damage to the fossil, using spectral lines of neutral phosphorus. - Highlights: Black-Right-Pointing-Pointer LIBS used to discriminate fossils from rock as potential processing control mechanism. Black-Right-Pointing-Pointer 2 million year old fossils from Malapa hominin site found to be high in phosphorus. Black-Right-Pointing-Pointer Rock spectral lines from silicon, iron and manganese, but no phosphorus. Black-Right-Pointing-Pointer Holds great promise for process control in laser preparation of fossils. Black-Right-Pointing-Pointer Also promising for accurate identification of fossils at excavation sites.

  16. Measurement of Stark broadening parameters of Fe II and Ni II spectral lines by laser induced breakdown spectroscopy using fused glass samples

    International Nuclear Information System (INIS)

    The Stark widths of 36 Fe II and 27 Ni II spectral lines are measured by laser induced breakdown spectroscopy (LIBS). The use of fused glass samples prepared by borate fusion is evaluated for Stark broadening measurements in LIBS experiments. The spectra of laser-induced plasmas generated from fused glass samples containing oxides show improved line-to-background ratios compared to those measured with alloys. The diagnostics of the fused glass laser induced plasmas shows that their characteristic parameters are not very different from those of alloy plasmas. The electron density in the experiment is in the range (0.8–10)×1017 cm−3 and the temperature varies from 12000 K to 17600 K. These experimental Stark width data, most of which had not been measured previously, complete the data for Fe II and Ni II reported in earlier works, determined by LIBS using alloy samples. -- Highlights: • Measurements of Stark broadening parameters of 36 Fe II and 27 Ni II spectral lines. • Fused glass samples shown to be advantageous for Stark width measurements by LIBS. • Fused glass approach provides low homogeneous concentrations of studied element. • Line-to-background ratio is improved with respect to alloy samples. • Very low concentration is necessary for preventing self-absorption of strong lines

  17. Laser induced breakdown spectroscopy for bulk minerals online analyses

    International Nuclear Information System (INIS)

    The purpose of the work was to prove the ability of LIBS to provide on-line analyses for raw ores in field conditions. An industrial LIBS machine was developed and successfully tested for on-belt evaluation of phosphate measuring Mg, Fe, Al, Bone Phosphate Lime (BPL), Insoluble phase and Metal Impurity Ratio (MER) and of coal measuring its ash content. The comparison of LIBS on-line data with control analyses revealed good correlation, which corresponds to the required detection limits and accuracy. With frequent elemental data from a LIBS system, process engineers have the tools to best optimize the process. These processes could be minerals blending and separation to meet customer specifications, monitoring and controlling the efficiency of a minerals process, or a minerals accounting function

  18. Recognition of archaeological materials underwater by laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The detection of different materials immersed in seawater has been studied by means of Laser Induced Breakdown Spectroscopy. The plasma emission was produced by a Q-Switched Nd:YAG laser operated at 1064 nm in a dual pulse mode. Different classes of materials potentially found in the undersea archaeological parks, such as iron, copper-based alloys, precious alloys, marble and wood have been examined. Data acquisition and processing were optimized for better signal control and in order to improve the detection threshold. In all the examined cases but wood, qualitative analysis was successful and allowed for the material recognition. The spectral features necessary to clearly distinguish marble materials from calcareous rocks have been also established. It was found that these characteristic spectral intervals could be also used for the recognition of sedimentary layers deposited on the underwater findings. Quantitative chemical analysis was also performed on submerged bronze samples, after generating calibration curves with standards of similar matrix composition

  19. Chlorine detection in cement with laser-induced breakdown spectroscopy in the infrared and ultraviolet spectral range

    International Nuclear Information System (INIS)

    A significant parameter to monitor the status of concrete buildings like bridges or parking garages is the determination of the depth profile of the chlorine concentration below the exposed concrete surface. This information is required to define the needed volume of restoration for a construction. Conventional methods like wet chemical analysis are time- and cost-intensive so an alternative method is developed using laser-induced breakdown spectroscopy (LIBS). The idea is to deploy LIBS to analyze drill cores by scanning the sample surface with laser pulses. Chlorine spectral lines in the infrared (IR) and ultraviolet (UV)-range were studied for chlorine detection in hydrated cement samples. The excitation energies of these spectral lines are above 9.2 eV. Hence high plasma temperatures and pulse energies in the range of some hundred millijoules are needed to induce sufficient line intensity levels at the required working distance. To further increase the line intensity and to lower the detection limit (LOD) of chlorine a measuring chamber is used where different ambient pressures and gases can be chosen for the measurements. The influences on the line intensity for pressures between 5 mbar and 400 mbar using helium as process gas and the influence of different laser burst modi like single and collinear double pulses are investigated. For the first time a LOD according to DIN 32 645 of 0.1 mass% was achieved for chlorine in hydrated cement using the UV line 134.72 nm.

  20. Instantaneous Measurement of Local Concentration and Vapor Fraction in Liquid-Gas Mixtures by Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Kido, Akihiro; Hoshi, Kenji; Kusaka, Hiroto; Ogawa, Hideyuki; Miyamoto, Noboru

    Laser-induced breakdown spectroscopy (LIBS) with atomic emission excited with a focused high-energy ND: YAG laser was applied to quantify the concentration and the vapor fraction of liquid-gas mixtures. With LIBS it is possible to quantify local concentrations accurately even in liquid-gas mixtures as the ratio of the number of fuel-borne hydrogen atoms to nitrogen or oxygen atoms in the ambient gas. The ratio has a strong linear relation with the ratio of the peak emission intensities regardless of phase of the fuel. As the full width at half maximum (FWHM) of the emission peak from the fuel-borne hydrogen increases linearly with the liquid fraction due to the Doppler shift with micro-explosions, the FWHM yields the fuel vapor fraction. Simultaneous, high-resolution measurements of equivalence ratios and vapor fractions in an intermittent fuel spray in a pressurized atmosphere were obtained with this method. The results showed that the tip of the intermittent spray has a richer mixture with a lower vapor fraction.

  1. Highly sensitive analysis of boron and lithium in aqueous solution using dual-pulse laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Lee, Dong-Hyoung; Han, Sol-Chan; Kim, Tae-Hyeong; Yun, Jong-Il

    2011-12-15

    We have applied a dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) to sensitively detect concentrations of boron and lithium in aqueous solution. Sequential laser pulses from two separate Q-switched Nd:YAG lasers at 532 nm wavelength have been employed to generate laser-induced plasma on a water jet. For achieving sensitive elemental detection, the optimal timing between two laser pulses was investigated. The optimum time delay between two laser pulses for the B atomic emission lines was found to be less than 3 μs and approximately 10 μs for the Li atomic emission line. Under these optimized conditions, the detection limit was attained in the range of 0.8 ppm for boron and 0.8 ppb for lithium. In particular, the sensitivity for detecting boron by excitation of laminar liquid jet was found to be excellent by nearly 2 orders of magnitude compared with 80 ppm reported in the literature. These sensitivities of laser-induced breakdown spectroscopy are very practical for the online elemental analysis of boric acid and lithium hydroxide serving as neutron absorber and pH controller in the primary coolant water of pressurized water reactors, respectively. PMID:22054422

  2. Influence of particle size distribution on the analysis of pellets of plant materials by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gustinelli Arantes de Carvalho, Gabriel [NAPTISA Research Support Center “Technology and Innovation for a Sustainable Agriculture”, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Santos Jr, Dário [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Rua Prof. Artur Riedel, 275, 09972-270 Diadema, SP (Brazil); Silva Gomes, Marcos da; Nunes, Lidiane Cristina; Guerra, Marcelo Braga Bueno [NAPTISA Research Support Center “Technology and Innovation for a Sustainable Agriculture”, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Krug, Francisco José, E-mail: fjkrug@cena.usp.br [NAPTISA Research Support Center “Technology and Innovation for a Sustainable Agriculture”, Center for Nuclear Energy in Agriculture, University of São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil)

    2015-03-01

    Pellets of sieved plant materials (150, 106, 75, 53 and 20 μm sieve apertures) were prepared and analyzed by laser-induced breakdown spectroscopy (LIBS), and the results for Ca, K, Mg, P, B and Mn were discussed as a function of particle size distribution. This parameter is of key importance for appropriate test sample presentation in the form of pressed pellets for quantitative analysis by LIBS. Experiments were carried out with a Q-switched Nd:YAG laser at 1064 nm, and a spectrometer with Echelle optics and an intensified charge-coupled device. Results indicated that smaller particles yielded up to 50% emission signal intensities' enhancement and attained better measurements' precision (site-to-site variation). Moreover, matrix effects were reduced by analyzing pellets prepared from < 75 μm sieved fractions (mean particle size = 32 μm; d{sub 95} = 102 μm) and by using a 50 J cm{sup −2} laser fluence (220 mJ per pulse; 750 μm laser spot size). The preparation of pellets from laboratory samples with monomodal particle size distributions, where most particles were smaller than 100 μm, was decisive for improving analyte micro-homogeneity within the test samples and for attaining lower coefficients of variation of measurements, typically lower than 10% (n = 10 sites per pellet; 20 laser pulses per site). - Highlights: • First systematic study on the effects of particle size distribution. • Most appropriate particle sizes for pellet preparation depend on laser fluence. • Data can be used for sampling strategies aiming at LIBS analysis of plant materials.

  3. Influence of particle size distribution on the analysis of pellets of plant materials by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Pellets of sieved plant materials (150, 106, 75, 53 and 20 μm sieve apertures) were prepared and analyzed by laser-induced breakdown spectroscopy (LIBS), and the results for Ca, K, Mg, P, B and Mn were discussed as a function of particle size distribution. This parameter is of key importance for appropriate test sample presentation in the form of pressed pellets for quantitative analysis by LIBS. Experiments were carried out with a Q-switched Nd:YAG laser at 1064 nm, and a spectrometer with Echelle optics and an intensified charge-coupled device. Results indicated that smaller particles yielded up to 50% emission signal intensities' enhancement and attained better measurements' precision (site-to-site variation). Moreover, matrix effects were reduced by analyzing pellets prepared from < 75 μm sieved fractions (mean particle size = 32 μm; d95 = 102 μm) and by using a 50 J cm−2 laser fluence (220 mJ per pulse; 750 μm laser spot size). The preparation of pellets from laboratory samples with monomodal particle size distributions, where most particles were smaller than 100 μm, was decisive for improving analyte micro-homogeneity within the test samples and for attaining lower coefficients of variation of measurements, typically lower than 10% (n = 10 sites per pellet; 20 laser pulses per site). - Highlights: • First systematic study on the effects of particle size distribution. • Most appropriate particle sizes for pellet preparation depend on laser fluence. • Data can be used for sampling strategies aiming at LIBS analysis of plant materials

  4. On the performance of laser-induced breakdown spectroscopy for direct determination of trace metals in lubricating oils

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) provides a technique to directly determine metals in viscous liquids and especially in lubricating oils. A specific laser ablation configuration of a thin layer of oil applied on the surface of a pure aluminum target was used to evaluate the analytical figures of merit of LIBS for elemental analysis of lubricating oils. Among the analyzed oils, there were a certified 75cSt blank mineral oil, 8 virgin lubricating oils (synthetic, semi-synthetic, or mineral and of 2 different manufacturers), 5 used oils (corresponding to 5 among the 8 virgin oils), and a cooking oil. The certified blank oil and 4 virgin lubricating oils were spiked with metallo-organic standards to obtain laboratory reference samples with different oil matrix. We first established calibration curves for 3 elements, Fe, Cr, Ni, with the 5 sets of laboratory reference samples in order to evaluate the matrix effect by the comparison among the different oils. Our results show that generalized calibration curves can be built for the 3 analyzed elements by merging the measured line intensities of the 5 sets of spiked oil samples. Such merged calibration curves with good correlation of the merged data are only possible if no significant matrix effect affects the measurements of the different oils. In the second step, we spiked the remaining 4 virgin oils and the cooking oils with Fe, Cr and Ni. The accuracy and the precision of the concentration determination in these prepared oils were then evaluated using the generalized calibration curves. The concentrations of metallic elements in the 5 used lubricating oils were finally determined. - Highlights: • Direct determination of wear metals in lubricating oils using LIBS. • Generalized calibration curves for different oils. • Ablation of a thin oil layer on a pure metallic target

  5. Quantitative carbon analysis in coal by combining data processing and spatial confinement in laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Online measurement of carbon content of coal is important for coal-fired power plants to realize the combustion optimization of coal-fired boilers. Given that the measurement of carbon content of coal using laser-induced breakdown spectroscopy (LIBS) suffers from low measurement accuracy because of matrix effects, our previous study has proposed a combination model to improve the measurement accuracy of carbon content of coal. The spatial confinement method, which utilizes the spectral emissions of laser-induced plasmas spatially confined by cavities for quantitative analysis, has potential to improve quantitative analysis performance. In the present study, the combination model was used for coal measurement with cylindrical cavity confinement to further improve the measurement accuracy of carbon content of coal. Results showed that measurement accuracy was improved when the combination model was used with spatial confinement method. The coefficient of determination, root-mean-square error of prediction, average relative error, and average absolute error for the combination model with cylindrical cavity confinement were 0.99, 1.35%, 1.66%, and 1.08%, respectively, whereas values for the combination model without cylindrical cavity confinement were 0.99, 1.63%, 1.82%, and 1.27%, respectively. This is the first time that the average absolute error of carbon measurement for coal analysis has achieved close to 1.0% using LIBS, which is the critical requirement set for traditional chemical processing method by Chinese national standard. These results indicated that LIBS had significant application potential for coal analysis. - Highlights: • Spatial confinement method is applied for the measurement of carbon content in coal. • Previously proposed combination model is used with spatial confinement method. • The final result is firstly close to the critical reproducibility requirement of Chinese national standard

  6. Quantitative carbon analysis in coal by combining data processing and spatial confinement in laser-induced breakdown spectroscopy

    Science.gov (United States)

    Li, Xiongwei; Yin, Hualiang; Wang, Zhe; Fu, Yangting; Li, Zheng; Ni, Weidou

    2015-09-01

    Online measurement of carbon content of coal is important for coal-fired power plants to realize the combustion optimization of coal-fired boilers. Given that the measurement of carbon content of coal using laser-induced breakdown spectroscopy (LIBS) suffers from low measurement accuracy because of matrix effects, our previous study has proposed a combination model to improve the measurement accuracy of carbon content of coal. The spatial confinement method, which utilizes the spectral emissions of laser-induced plasmas spatially confined by cavities for quantitative analysis, has potential to improve quantitative analysis performance. In the present study, the combination model was used for coal measurement with cylindrical cavity confinement to further improve the measurement accuracy of carbon content of coal. Results showed that measurement accuracy was improved when the combination model was used with spatial confinement method. The coefficient of determination, root-mean-square error of prediction, average relative error, and average absolute error for the combination model with cylindrical cavity confinement were 0.99, 1.35%, 1.66%, and 1.08%, respectively, whereas values for the combination model without cylindrical cavity confinement were 0.99, 1.63%, 1.82%, and 1.27%, respectively. This is the first time that the average absolute error of carbon measurement for coal analysis has achieved close to 1.0% using LIBS, which is the critical requirement set for traditional chemical processing method by Chinese national standard. These results indicated that LIBS had significant application potential for coal analysis.

  7. Quantitative analysis of chromium in potatoes by laser-induced breakdown spectroscopy coupled with linear multivariate calibration.

    Science.gov (United States)

    Chen, Tianbing; Huang, Lin; Yao, Mingyin; Hu, Huiqin; Wang, Caihong; Liu, Muhua

    2015-09-01

    Laser-induced breakdown spectroscopy (LIBS) coupled with the linear multivariate regression method was utilized to analyze chromium (Cr) quantitatively in potatoes. The plasma was generated using a Nd:YAG laser, and the spectra were acquired by an Andor spectrometer integrated with an ICCD detector. The models between intensity of LIBS characteristic line(s) and concentration of Cr were constructed to predict quantitatively the content of target. The unary, binary, ternary, and quaternary variables were chosen for verifying the accuracy of linear regression calibration curves. The intensity of characteristic lines Cr (CrI: 425.43, 427.48, 428.97 nm) and Ca (CaI: 422.67, 428.30, 430.25, 430.77, 431.86 nm) were used as input data for the multivariate calculations. According to the results of linear regression, the model of quaternary linear regression was established better in comparing with the other three models. A good agreement was observed between the actual content provided by atomic absorption spectrometry and the predicted value obtained by the quaternary linear regression model. And the relative error was below 5.5% for validation samples S1 and S2. The result showed that the multivariate approach can obtain better predicted accuracy than the univariate ones. The result also suggested that the LIBS technique coupled with the linear multivariate calibration method could be a great tool to predict heavy metals in farm products in a rapid manner even though samples have similar elemental compositions. PMID:26368908

  8. Effect of temperature and CO 2 concentration on laser-induced breakdown spectroscopy measurements of alkali fume

    Science.gov (United States)

    Molina, Alejandro; Shaddix, Christopher R.; Sickafoose, Shane M.; Walsh, Peter M.; Blevins, Linda G.

    2005-08-01

    Laser-induced breakdown spectroscopy (LIBS) was used in the evaluation of aerosol concentration in the exhaust of an oxygen/natural-gas glass furnace. Experiments showed that for a delay time of 10 μs and a gate width of 50 μs, the presence of CO 2 and changes in gas temperature affect the intensity of both continuum emission and the Na D lines. The intensity increased for the neutral Ca and Mg lines in the presence of 21% CO 2 when compared to 100% N 2, whereas the intensity of the Mg and Ca ionic lines decreased. An increase in temperature from 300 to 730 K produced an increase in both continuum emission and Na signal. These laboratory measurements were consistent with measurements in the glass furnace exhaust. Time-resolved analysis of the spark radiation suggested that differences in continuum radiation resulting from changes in bath composition are only apparent at long delay times. The changes in the intensity of ionic and neutral lines in the presence of CO 2 are believed to result from higher free electron number density caused by lower ionization energies of species formed during the spark decay process in the presence of CO 2. For the high Na concentration observed in the glass furnace exhaust, self-absorption of the spark radiation occurred. Power law regression was used to fit laboratory Na LIBS calibration data for sodium loadings, gas temperatures, and a CO 2 content representative of the furnace exhaust. Improvement of the LIBS measurement in this environment may be possible by evaluation of Na lines with weaker emission and through the use of shorter gate delay times.

  9. Effect of temperature and CO2 concentration on laser-induced breakdown spectroscopy measurements of alkali fume

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) was used in the evaluation of aerosol concentration in the exhaust of an oxygen/natural-gas glass furnace. Experiments showed that for a delay time of 10 μs and a gate width of 50 μs, the presence of CO2 and changes in gas temperature affect the intensity of both continuum emission and the Na D lines. The intensity increased for the neutral Ca and Mg lines in the presence of 21% CO2 when compared to 100% N2, whereas the intensity of the Mg and Ca ionic lines decreased. An increase in temperature from 300 to 730 K produced an increase in both continuum emission and Na signal. These laboratory measurements were consistent with measurements in the glass furnace exhaust. Time-resolved analysis of the spark radiation suggested that differences in continuum radiation resulting from changes in bath composition are only apparent at long delay times. The changes in the intensity of ionic and neutral lines in the presence of CO2 are believed to result from higher free electron number density caused by lower ionization energies of species formed during the spark decay process in the presence of CO2. For the high Na concentration observed in the glass furnace exhaust, self-absorption of the spark radiation occurred. Power law regression was used to fit laboratory Na LIBS calibration data for sodium loadings, gas temperatures, and a CO2 content representative of the furnace exhaust. Improvement of the LIBS measurement in this environment may be possible by evaluation of Na lines with weaker emission and through the use of shorter gate delay times

  10. Quantification of fluorite mass-content in powdered ores using a Laser-Induced Breakdown Spectroscopy method based on the detection of minor elements and CaF molecular bands

    International Nuclear Information System (INIS)

    Laser Induced Breakdown Spectroscopy (LIBS) is investigated as a fast and robust method to determine the fluorite (CaF2) mass-content of powdered ore samples