Analysis and analytical techniques

Energy Technology Data Exchange (ETDEWEB)

Batuecas Rodriguez, T [Department of Chemistry and Isotopes, Junta de Energia Nuclear, Madrid (Spain)

1967-01-01

The technology associated with the use of organic coolants in nuclear reactors depends to a large extent on the determination and control of their physical and chemical properties, and particularly on the viability, speed, sensitivity, precision and accuracy (depending on the intended usage) of the methods employed in detection and analytical determination. This has led to the study and development of numerous techniques, some specially designed for the extreme conditions involved in working with the types of product in question and others adapted from existing techniques. In the specific case of polyphenyl and hydropolyphenyl mixtures, which have been the principal subjects of study to date and offer greatest promise, the analytical problems are broadly as follows: Composition of initial product or virgin coolant composition of macro components and amounts of organic and inorganic impurities; Coolant during and after operation. Determination of gases and organic compounds produced by pyrolysis and radiolysis (degradation and polymerization products); Control of systems for purifying and regenerating the coolant after use. Dissolved pressurization gases; Detection of intermediate products during decomposition; these are generally very unstable (free radicals); Degree of fouling and film formation. Tests to determine potential formation of films; Corrosion of structural elements and canning materials; Health and safety. Toxicity, inflammability and impurities that can be activated. Although some of the above problems are closely interrelated and entail similar techniques, they vary as to degree of difficulty. Another question is the difficulty of distinguishing clearly between techniques for determining physical and physico-chemical properties, on one hand, and analytical techniques on the other. Any classification is therefore somewhat arbitrary (for example, in the case of dosimetry and techniques for determining mean molecular weights or electrical conductivity

Technical meeting on commercial applications of nuclear analytical techniques. Meeting report

International Nuclear Information System (INIS)

2004-01-01

This report summarizes the findings of the Technical Meeting on the Commercial Applications of Nuclear Analytical Techniques held in Vienna on 23-26 November 2004, where an assessment was initiated of the world capacity and market potentials for neutron activation analysis and nuclear spectroscopy, including an estimation of economic revenues. Industry and governmental agencies were identified as stakeholders for these laboratories. Examples are given of potential benefits of these techniques to the stakeholders. The potentials for commercial applications of neutron activation analysis and nuclear spectroscopy (measurement of alpha, beta and gamma ray emitting radionuclides) are addressed. First estimates are given of the worldwide capacity of these laboratories, suggestions and examples are given for potential markets and the typical organizational and technical constraints are discussed. Two case studies of commercial neutron activation analysis laboratories at a small and a medium-size reactor are given in the 'individual contributions' section of this document. An assessment of other nuclear analytical techniques such as X ray Fluorescence Spectrometry, Particle Induced X ray Emission Spectrometry or Ion Beam Analysis Spectrometry has been completed after a comprehensive collection of background information

Technical meeting on commercial applications of nuclear analytical techniques. Meeting report

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

This report summarizes the findings of the Technical Meeting on the Commercial Applications of Nuclear Analytical Techniques held in Vienna on 23-26 November 2004, where an assessment was initiated of the world capacity and market potentials for neutron activation analysis and nuclear spectroscopy, including an estimation of economic revenues. Industry and governmental agencies were identified as stakeholders for these laboratories. Examples are given of potential benefits of these techniques to the stakeholders. The potentials for commercial applications of neutron activation analysis and nuclear spectroscopy (measurement of alpha, beta and gamma ray emitting radionuclides) are addressed. First estimates are given of the worldwide capacity of these laboratories, suggestions and examples are given for potential markets and the typical organizational and technical constraints are discussed. Two case studies of commercial neutron activation analysis laboratories at a small and a medium-size reactor are given in the 'individual contributions' section of this document. An assessment of other nuclear analytical techniques such as X ray Fluorescence Spectrometry, Particle Induced X ray Emission Spectrometry or Ion Beam Analysis Spectrometry has been completed after a comprehensive collection of background information.

Implementation of the Fluorescent in Situ Hybridization technique in the Faculty of Medicine, UdelaR

Directory of Open Access Journals (Sweden)

Andrea Cairus

2017-11-01

Full Text Available The Cytogenetic Laboratory of the Faculty of Medicine processes, on average, 300 annual samples of public and private healthcare centers by conventional cytogenetics. It is essential to implement new techniques to improve the quality of the service offered. The purpose of this work was to implement the Fluorescent in situ Hybridization technique (FISH. An observational, cross-sectional, analytical study was performed. Peripheral blood samples from patients with sex chromosomopathies diagnosed by conventional cytogenetics were analyzed. Fluorescent in situ hybridization technique was applied, comparing results with FISH and with conventional cytogenetics. The percentage of mosaicism detected by conventional cytogenetics and Fluorescent in situ Hybridization was studied: 24 samples were analyzed; 19 presented numerical alterations, 3 structural and 2 both. Numerical alterations were Turner syndrome, Klinefelter syndrome, XXX syndrome and XYY syndrome. Concordance in diagnoses was found for both techniques. For Turner syndrome, 8 of 12 samples corresponded to mosaicism, and there were no significant differences between conventional cytogenetics and the technique studied (p0.05. Klinefelter syndrome and XYY were both presented in a non-mosaic karyotype. For XXX syndrome, a normal line (46, XX was observed in three of the samples, in a percentage close to the cut off. From this research, it will be possible to implement Fluorescent in situ Hybridization in this service, to extend it to other pathologies and to enable the training of human resources; consolidating this laboratory as a national academic reference center.

Analytical system availability techniques

NARCIS (Netherlands)

Brouwers, J.J.H.; Verbeek, P.H.J.; Thomson, W.R.

1987-01-01

Analytical techniques are presented to assess the probability distributions and related statistical parameters of loss of production from equipment networks subject to random failures and repairs. The techniques are based on a theoretical model for system availability, which was further developed

Determination of lead in clay enameled by X-ray fluorescence technique in Total reflection and by Scanning Electron Microscopy

International Nuclear Information System (INIS)

Zarazua O, G.; Carapia M, L.

2000-01-01

This work has the objective of determining lead free in the glazed commercial stewing pans using the X-ray fluorescence technique in Total reflection (FRX) and the observation and semiquantitative determination of lead by Analytical Scanning Electron Microscopy (ASEM). (Author)

Confocal fluorescence techniques in industrial application

Science.gov (United States)

Eggeling, Christian; Gall, Karsten; Palo, Kaupo; Kask, Peet; Brand, Leif

2003-06-01

The FCS+plus family of evaluation tools for confocal fluorescence spectroscopy, which was developed during recent years, offers a comprehensive view to a series of fluorescence properties. Originating in fluorescence correlation spectroscopy (FCS) and using similar experimental equipment, a system of signal processing methods such as fluorescence intensity distribution analysis (FIDA) was created to analyze in detail the fluctuation behavior of fluorescent particles within a small area of detection. Giving simultaneous access to molecular parameters like concentration, translational and rotational diffusion, molecular brightness, and multicolor coincidence, this portfolio was enhanced by more traditional techniques of fluorescence lifetime as well as time-resolved anisotropy determination. The cornerstones of the FCS+plus methodology will be shortly described. The inhibition of a phosphatase enzyme activity gives a comprehensive industrial application that demonstrates FCS+plus' versatility and its potential for pharmaceutical drug discovery.

Multispectral fluorescence imaging techniques for nondestructive food safety inspection

Science.gov (United States)

Kim, Moon S.; Lefcourt, Alan M.; Chen, Yud-Ren

2004-03-01

The use of spectral sensing has gained acceptance as a rapid means for nondestructive inspection of postharvest food produce. Current technologies generally use color or a single wavelength camera technology. The applicability and sensitivity of these techniques can be expanded through the use of multiple wavelengths. Reflectance in the Vis/NIR is the prevalent spectral technique. Fluorescence, compared to reflectance, is regarded as a more sensitive technique due to its dynamic responses to subtle changes in biological entities. Our laboratory has been exploring fluorescence as a potential means for detection of quality and wholesomeness of food products. Applications of fluorescence sensing require an understanding of the spectral characteristics emanating from constituents and potential contaminants. A number of factors affecting fluorescence emission characteristics are discussed. Because of relatively low fluorescence quantum yield from biological samples, a system with a powerful pulse light source such as a laser coupled with a gated detection device is used to harvest fluorescence, in the presence of ambient light. Several fluorescence sensor platforms developed in our laboratory, including hyperspectral imaging, and laser-induced fluorescence (LIF) and steady-state fluorescence imaging systems with multispectral capabilities are presented. We demonstrate the potential uses of recently developed fluorescence imaging platforms in food safety inspection of apples contaminated with animal feces.

The capabilities of total reflection X-ray fluorescence in the polymeric analytical field

International Nuclear Information System (INIS)

Vazquez, Cristina

2004-01-01

This paper presents the capabilities of total reflection X-ray fluorescence (TXRF) as analytical technique specially focused in high-viscosity polymer dispersions. Appropriate sample preparation procedures are described taking into account the time stability of these dispersions. Special remarks considering different ways for drying samples in order to obtain the most uniform deposited film are investigated focusing on the behavior of aqueous and viscous systems. Due to the difficulty found for obtaining a homogeneous mixture between sample and internal standard in such systems, the use of Compton incoherent scattering is discussed as an alternative procedure for trace quantification in high viscous systems without any mixing processes

Effects of analytes on the fluorescence properties of CdTe@ZnS quantum dots decorated with cobalt tetraamino-phthalocyanine

Energy Technology Data Exchange (ETDEWEB)

Adegoke, Oluwasesan; Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za

2014-02-15

In this work, we have carried out an investigation on the effects of different biologically active analytes on the fluorescence response of glutathione-capped CdTe@ZnS quantum dots (QDs)-colbalt tetraamino-phthalocyanine nanoconjugate system. Firstly, fluorescence quenching occurred. Experimental results showed that some analytes either “turned on”, others further quenched or showed no effect on the fluorescence emission of the nanoprobe. -- Highlights: • A conjugate between CdTe@ZnS quantum dots and cobalt tetraamino-phthalocyanine is formed. • The fluorescence of quantum dots is quenched on coordination. • The fluorescence is enhanced by analytes such as cystamine, hydroxyl radical, glutathione, and perchlorate.

Use of nuclear and related analytical techniques in environmental research as exemplified by selected air pollution studies

International Nuclear Information System (INIS)

Smodis, B.; Jacimovic, R.; Jeran, Z.; Stropnik, B.; Svetina, M.

2000-01-01

Among nuclear and nuclear related analytical techniques, neutron activation analysis and X-ray fluorescence spectrometry proved to be particularly useful for environmental studies owing to their nondestructive character and multi element capability. This paper emphasizes their importance among other multielement analytical methods by discussing their specific role due to specific physics basis, quite different to other destructive non-nuclear methods, and by summarizing results obtained in several studies related to air pollution research, including analyses of airborne particulate matter, water samples, lichens and mosses. (author)

Quality system implementation for nuclear analytical techniques

International Nuclear Information System (INIS)

2004-01-01

techniques. The methodology provided is appropriate for: (a) Analysis of radionuclides as in alpha, beta, and gamma spectrometry for environmental and human-made radioactivity investigations; (b) Analysis of trace, minor and major elements using nuclear and related analytical techniques such as neutron activation analysis, X ray fluorescence, PIXE, etc. This training guidebook can be used by staff of analytical laboratories as a starting kit to better understand the quality assurance and quality control principles as prescribed in the ISO 17025 standard. It follows a logical order related to practical laboratory work rather than the formal clauses as given by the standard. It can be used as a stand alone textbook. However, in some cases, cross-reference is given to the ISO 17025 clauses hence it is recommended to consult the ISO standard for exact wording of specific requirements

Advanced analytical techniques

International Nuclear Information System (INIS)

Mrochek, J.E.; Shumate, S.E.; Genung, R.K.; Bahner, C.T.; Lee, N.E.; Dinsmore, S.R.

1976-01-01

The development of several new analytical techniques for use in clinical diagnosis and biomedical research is reported. These include: high-resolution liquid chromatographic systems for the early detection of pathological molecular constituents in physiologic body fluids; gradient elution chromatography for the analysis of protein-bound carbohydrates in blood serum samples, with emphasis on changes in sera from breast cancer patients; electrophoretic separation techniques coupled with staining of specific proteins in cellular isoenzymes for the monitoring of genetic mutations and abnormal molecular constituents in blood samples; and the development of a centrifugal elution chromatographic technique for the assay of specific proteins and immunoglobulins in human blood serum samples

The capabilities of total reflection X-ray fluorescence in the polymeric analytical field*1

Science.gov (United States)

Vázquez, Cristina

2004-08-01

This paper presents the capabilities of total reflection X-ray fluorescence (TXRF) as analytical technique specially focused in high-viscosity polymer dispersions. Appropriate sample preparation procedures are described taking into account the time stability of these dispersions. Special remarks considering different ways for drying samples in order to obtain the most uniform deposited film are investigated focusing on the behavior of aqueous and viscous systems. Due to the difficulty found for obtaining a homogeneous mixture between sample and internal standard in such systems, the use of Compton incoherent scattering is discussed as an alternative procedure for trace quantification in high viscous systems without any mixing processes.

Laser induced fluorescence technique for detecting organic matter in East China Sea

Science.gov (United States)

Chen, Peng; Wang, Tianyu; Pan, Delu; Huang, Haiqing

2017-10-01

A laser induced fluorescence (LIF) technique for fast diagnosing chromophoric dissolved organic matter (CDOM) in water is discussed. We have developed a new field-portable laser fluorometer for rapid fluorescence measurements. In addtion, the fluorescence spectral characteristics of fluorescent constituents (e.g., CDOM, chlorophyll-a) were analyzed with a spectral deconvolution method of bi-Gaussian peak function. In situ measurements by the LIF technique compared well with values measured by conventional spectrophotometer method in laboratory. A significant correlation (R2 = 0.93) was observed between fluorescence by the technique and absorption by laboratory spectrophotometer. Influence of temperature variation on LIF measurement was investigated in lab and a temperature coefficient was deduced for fluorescence correction. Distributions of CDOM fluorescence measured using this technique in the East China Sea coast were presented. The in situ result demonstrated the utility of the LIF technique for rapid detecting dissolved organic matter.

Establishment of an analytical procedure for the determination of niobium and tantalum in minerals containing these elements using X-ray fluorescence technique

International Nuclear Information System (INIS)

Nguyen Xuan Chien

2003-01-01

The study of determination of niobium, tantalum in mineral and tin slags using X-ray fluorescence spectrometry was carried out. Analytical samples of powder and pellet were prepared. the interference of the major accompanied elements in sample with the determination of niobium and tantalum was also studied. The analysis of niobium and tantalum in mineral and in tin slags samples was given in this work. (author)

Glycoprotein Enrichment Analytical Techniques: Advantages and Disadvantages.

Science.gov (United States)

Zhu, R; Zacharias, L; Wooding, K M; Peng, W; Mechref, Y

2017-01-01

Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection, while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins, while automated software tools started replacing manual processing to improve the reliability and throughput of the analysis. In this chapter, the current methodologies of glycoprotein analysis were discussed. Multiple analytical techniques are compared, and advantages and disadvantages of each technique are highlighted. © 2017 Elsevier Inc. All rights reserved.

Laser induced uranium fluorescence as an analytical method

International Nuclear Information System (INIS)

Krutman, I.

1985-01-01

A laser induced fluorescence system was developed to measure uranium trace level amounts in aqueous solution with reliable and simple materials and electronics. A nitrogen pulsed laser was built with the storage energy capacitor directly coupled to laser tube electrodes as a transmission line device. This laser operated at 3Hz repetition rate with peak intensity around 21 Kw and temporal width of 4.5 x 10 -9 s. A sample compartment made of rigid PVC and a photomultiplier housing of aluminium were constructed and assembled forming a single integrated device. As a result of this prototype system we made several analytical measurements with U dissolved in nitric acid to obtain a calibration curve. We obtained a straight line from a plot of U concentration versus fluorescence intensity fitted by a least square method that produced a regression coefficient of 0.994. The lower limit of U determination was 30 ppb -+ 3.5%. (Author) [pt

Fluorescence quenching of fluoroquinolones by gold nanoparticles with different sizes and its analytical application

Energy Technology Data Exchange (ETDEWEB)

Amjadi, Mohammad, E-mail: amjadi@tabrizu.ac.ir; Farzampour, Leila

2014-01-15

The interaction of some fluoroquinolones including norfloxacin, ciprofloxacin, danofloxacin and ofloxacin with gold nanoparticles (AuNPs) of different sizes (8, 20 and 75 nm) was studied. In the studied systems, fluoroquinolones are noncovalently adsorbed onto the surface of AuNPs, which results in severe quenching of fluoroquinolones fluorescence possibly as a result of fluorescence resonance energy transfer. Stern–Volmer quenching constants were obtained and found to increase with an increase in the size of AuNPs. Moreover, the interactions between some thiols and fluoroquinolone-adsorbed AuNPs were investigated to explore the analytical applicability of the systems. It was found that upon the addition of thiols to fluoroquinolone-AuNPs systems the fluorescence of fluoroquinolones switches to “turn-on” due to the strong binding of thiols to AuNPs and removal of quinolines from NP surface. Under the optimum conditions, the fluorescence enhancement showed a linear relationship with the concentration of thiols, indicating the analytical usefulness of the system. -- Highlights: • Interaction of fluoroquinolones with AuNPs of different sizes was investigated. • The fluorescence of fluoroquinolones is efficiently quenched by AuNPs. • The fluorescence quenching efficiency increases by increasing NP size. • Fluoroquinolone-AuNPs systems can be used as sensitive turn-on sensors for thiols. • Danofloxacin-20-nm AuNPs system exhibits the highest sensitivity for thiols.

Pollution detection using the spectral fluorescent signatures (SFS technique

Directory of Open Access Journals (Sweden)

Mª Del Carmen Martín

2014-06-01

Full Text Available This work has been developed in the Applied Physics Department at the University of Vigo within the line of research based on the treatment of the degraded water by pollutants through the use of microalgae, reducing the emissions of greenhouse gases through the absorption of CO2 in the process and the reuse of biomass as biofuel. Remote sensing techniques have contributed to a great extent to the development of oil pollution monitoring systems. However, the available detection methods, mainly designed for spaceborne and airborne long distance inspection, are too expensive and complex to be used in an operational way by relatively unskilled personnel. In the framework of DEOSOM project (European AMPERA project, an innovative water monitoring method was proposed, in two steps: early oil spill detection using a portable shipborne laser-induced fluorescence LIDAR (LIF/LIDAR, and analysis of suspicious water samples in laboratory using the Spectral Fluorescent Signature (SFS technique. This work is focused on the second technique. This system aims to optimize the production of microalgae for biofuel and contaminant cleaning applications and was developed and tested in photo-bioreactors in the University of Vigo within the EnerBioAlgae project (SUDOE. In this project, the SFS technique was used as a diagnostic tool employing the fluorescence analyzer INSTANT-SCREENER M53UVC. The Spectral Fluorescence Signature technique (SFS is based on compounds fluorescence properties. The fluorescence intensity of a sample is measured at different excitation and emission wavelengths to produce a 3-dimensional fluorescence matrix, which can also be presented as a 2-dimensional color image where the color shows the intensity of the fluorescence. These matrices offer qualitative and quantitative information, since they can be useful for the identification of different substances from their characteristic excitation and emission spectra of fluorescence. They also

Hyphenated analytical techniques for materials characterisation

International Nuclear Information System (INIS)

Armstrong, Gordon; Kailas, Lekshmi

2017-01-01

This topical review will provide a survey of the current state of the art in ‘hyphenated’ techniques for characterisation of bulk materials, surface, and interfaces, whereby two or more analytical methods investigating different properties are applied simultaneously to the same sample to better characterise the sample than can be achieved by conducting separate analyses in series using different instruments. It is intended for final year undergraduates and recent graduates, who may have some background knowledge of standard analytical techniques, but are not familiar with ‘hyphenated’ techniques or hybrid instrumentation. The review will begin by defining ‘complementary’, ‘hybrid’ and ‘hyphenated’ techniques, as there is not a broad consensus among analytical scientists as to what each term means. The motivating factors driving increased development of hyphenated analytical methods will also be discussed. This introduction will conclude with a brief discussion of gas chromatography-mass spectroscopy and energy dispersive x-ray analysis in electron microscopy as two examples, in the context that combining complementary techniques for chemical analysis were among the earliest examples of hyphenated characterisation methods. The emphasis of the main review will be on techniques which are sufficiently well-established that the instrumentation is commercially available, to examine physical properties including physical, mechanical, electrical and thermal, in addition to variations in composition, rather than methods solely to identify and quantify chemical species. Therefore, the proposed topical review will address three broad categories of techniques that the reader may expect to encounter in a well-equipped materials characterisation laboratory: microscopy based techniques, scanning probe-based techniques, and thermal analysis based techniques. Examples drawn from recent literature, and a concluding case study, will be used to explain the

Hyphenated analytical techniques for materials characterisation

Science.gov (United States)

Armstrong, Gordon; Kailas, Lekshmi

2017-09-01

This topical review will provide a survey of the current state of the art in ‘hyphenated’ techniques for characterisation of bulk materials, surface, and interfaces, whereby two or more analytical methods investigating different properties are applied simultaneously to the same sample to better characterise the sample than can be achieved by conducting separate analyses in series using different instruments. It is intended for final year undergraduates and recent graduates, who may have some background knowledge of standard analytical techniques, but are not familiar with ‘hyphenated’ techniques or hybrid instrumentation. The review will begin by defining ‘complementary’, ‘hybrid’ and ‘hyphenated’ techniques, as there is not a broad consensus among analytical scientists as to what each term means. The motivating factors driving increased development of hyphenated analytical methods will also be discussed. This introduction will conclude with a brief discussion of gas chromatography-mass spectroscopy and energy dispersive x-ray analysis in electron microscopy as two examples, in the context that combining complementary techniques for chemical analysis were among the earliest examples of hyphenated characterisation methods. The emphasis of the main review will be on techniques which are sufficiently well-established that the instrumentation is commercially available, to examine physical properties including physical, mechanical, electrical and thermal, in addition to variations in composition, rather than methods solely to identify and quantify chemical species. Therefore, the proposed topical review will address three broad categories of techniques that the reader may expect to encounter in a well-equipped materials characterisation laboratory: microscopy based techniques, scanning probe-based techniques, and thermal analysis based techniques. Examples drawn from recent literature, and a concluding case study, will be used to explain the

Atomic and nuclear analytical methods. XRF, Moessbauer, XPS, NAA and ion-beam spectroscopic techniques

International Nuclear Information System (INIS)

Verma, H.R.

2007-01-01

This book is a blend of analytical methods based on the phenomenon of atomic and nuclear physics. It comprises comprehensive presentations about X-ray Fluorescence (XRF), Moessbauer Spectroscopy (MS), X-ray Photoelectron Spectroscopy (XPS), Neutron- Activation Analysis (NAA), Particle Induced X-ray Emission Analysis (PIXE), Rutherford Backscattering Analysis (RBS), Elastic Recoil Detection (ERD), Nuclear Reaction Analysis (NRA), Particle Induced Gamma-ray Emission Analysis (PIGE), and Accelerator Mass Spectrometry (AMS). These techniques are commonly applied in the fields of medicine, biology, environmental studies, archaeology or geology et al. and pursued in major international research laboratories. (orig.)

Sampling, storage and sample preparation procedures for X ray fluorescence analysis of environmental materials

International Nuclear Information System (INIS)

1997-06-01

X ray fluorescence (XRF) method is one of the most commonly used nuclear analytical technique because of its multielement and non-destructive character, speed, economy and ease of operation. From the point of view of quality assurance practices, sampling and sample preparation procedures are the most crucial steps in all analytical techniques, (including X ray fluorescence) applied for the analysis of heterogeneous materials. This technical document covers recent modes of the X ray fluorescence method and recent developments in sample preparation techniques for the analysis of environmental materials. Refs, figs, tabs

Semi-analytic techniques for calculating bubble wall profiles

International Nuclear Information System (INIS)

Akula, Sujeet; Balazs, Csaba; White, Graham A.

2016-01-01

We present semi-analytic techniques for finding bubble wall profiles during first order phase transitions with multiple scalar fields. Our method involves reducing the problem to an equation with a single field, finding an approximate analytic solution and perturbing around it. The perturbations can be written in a semi-analytic form. We assert that our technique lacks convergence problems and demonstrate the speed of convergence on an example potential. (orig.)

Neutron activation analysis technique and X-ray fluorescence in bovine liver sample

International Nuclear Information System (INIS)

Maihara, V.A.; Favaro, D.I.T.; Vasconcellos, M.B.A.; Sato, I.M.; Salvador, V.L.

2002-01-01

Many analytical techniques have been used in food and diet analysis in order to determine a great number of nutritional elements, ranging from percentage to ng g -1 , with high sensitivity and accuracy. Instrumental Neutron activation Analysis (INAA) has been employed to certificate many trace elements in biological reference materials. More recently, the X-Ray Fluorescence (FRX-WD) has been also used to determine some essential elements in food samples. The INAA has been applied in nutrition studies in our laboratory at IPEN since the 80 s. For the development of analytical methodologies the use of the reference materials with the same characteristics of the sample analyzed is essential. Several Brazilian laboratories do not have conditions to use these materials due their high cost.In this paper preliminary results of commercial bovine liver sample analyses obtained by INAA and WD-XRF methods are presented. This sample was prepared to be a Brazilian candidate of reference material for a group of laboratories participating in a research project sponsored by FAPESP. The concentrations of some elements like Cl, K, Na, P, S and trace elements Br, Ca, Co, Cu, Fe, Mg, Mn, Mo, Rb, Se and Zn were determined by INAA and WD-XFR. For validation methodology of both techniques, NIST SRM 1577b Bovine Liver reference material was analyzed and the detection limits were calculated. The concentrations of elements determined by both analytical techniques were compared by using the Student's t-test and for Cl, Cu, Fe, K, Mg, Na, Rn and Zn the results do show no statistical difference for 95% significance level. (author)

An approach to estimate spatial distribution of analyte within cells using spectrally-resolved fluorescence microscopy

Science.gov (United States)

Sharma, Dharmendar Kumar; Irfanullah, Mir; Basu, Santanu Kumar; Madhu, Sheri; De, Suman; Jadhav, Sameer; Ravikanth, Mangalampalli; Chowdhury, Arindam

2017-03-01

While fluorescence microscopy has become an essential tool amongst chemists and biologists for the detection of various analyte within cellular environments, non-uniform spatial distribution of sensors within cells often restricts extraction of reliable information on relative abundance of analytes in different subcellular regions. As an alternative to existing sensing methodologies such as ratiometric or FRET imaging, where relative proportion of analyte with respect to the sensor can be obtained within cells, we propose a methodology using spectrally-resolved fluorescence microscopy, via which both the relative abundance of sensor as well as their relative proportion with respect to the analyte can be simultaneously extracted for local subcellular regions. This method is exemplified using a BODIPY sensor, capable of detecting mercury ions within cellular environments, characterized by spectral blue-shift and concurrent enhancement of emission intensity. Spectral emission envelopes collected from sub-microscopic regions allowed us to compare the shift in transition energies as well as integrated emission intensities within various intracellular regions. Construction of a 2D scatter plot using spectral shifts and emission intensities, which depend on the relative amount of analyte with respect to sensor and the approximate local amounts of the probe, respectively, enabled qualitative extraction of relative abundance of analyte in various local regions within a single cell as well as amongst different cells. Although the comparisons remain semi-quantitative, this approach involving analysis of multiple spectral parameters opens up an alternative way to extract spatial distribution of analyte in heterogeneous systems. The proposed method would be especially relevant for fluorescent probes that undergo relatively nominal shift in transition energies compared to their emission bandwidths, which often restricts their usage for quantitative ratiometric imaging in

Study of the analytic quality in the determinations of Cr, Fe, Mn, Cu, Zn, Pb and Hg through conventional and nuclear analytical techniques in mosses of the MATV

International Nuclear Information System (INIS)

Caballero S, B.

2013-01-01

To evaluate the environmental risks of air pollution and to facilitate the decision-making for control, is necessary to have the capacity to generate data with analytical quality. A comparison between nuclear (Neutron activation analysis and total reflection X-ray fluorescence spectrometry) and no nuclear analytical techniques (atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry) for simultaneous determination of metal content (Cr, Cu, Fe, Hg, Mn, Pb and Zn) in mosses from Metropolitan Area of the Toluca Valley (MATV) was performed. Epiphytic mosses (Fabriona ciliaris and Leskea angustata) were sampled in two campaigns, 16 sites (urban, transition and natural) and were prepared for each technique. The biological certified reference materials were used for the quality control and to evaluate accuracy, precision, linearity, detection and quantification limits. Results show that nuclear analytical techniques and no nuclear applied in chemical analysis of Cr, Cu, Fe, Hg, Mn, Pb and Zn in moss from MATV are comparable and therefore all of these can potentially be used for this purpose. However, if its considered both, the performance parameters and economic/operational characteristics is widely recommended inductively coupled plasma optical emission spectrometry, conventional analytical technique, which showed the highest analytical grade quality. Also were observed spatial and temporal variations in the concentrations of Cr, Cu, Fe, Hg, Mn, Pb and Zn in mosses from MATV and was discussed its potential origin. The urban sites had the highest concentration of anthropogenic elements as Cr, Cu, Fe, Hg, Pb and Zn because are strongly impacted by roads with high vehicle traffic. (Author)

Atomic and Nuclear Analytical Methods XRF, Mössbauer, XPS, NAA and Ion-Beam Spectroscopic Techniques

CERN Document Server

Verma, H R

2007-01-01

This book is a blend of analytical methods based on the phenomenon of atomic and nuclear physics. It comprises comprehensive presentations about X-ray Fluorescence (XRF), Mössbauer Spectroscopy (MS), X-ray Photoelectron Spectroscopy (XPS), Neutron- Activation Analysis (NAA), Particle Induced X-ray Emission Analysis (PIXE), Rutherford Backscattering Analysis (RBS), Elastic Recoil Detection (ERD), Nuclear Reaction Analysis (NRA), Particle Induced Gamma-ray Emission Analysis (PIGE), and Accelerator Mass Spectrometry (AMS). These techniques are commonly applied in the fields of medicine, biology, environmental studies, archaeology or geology et al. and pursued in major international research laboratories.

An appraisal of neutron activation analysis and other analytical techniques for the determination of arsenic, selenium and tin in environmental samples

International Nuclear Information System (INIS)

Peterson, P.J.; Girling, C.A.; Klumpp, D.W.; Minski, M.J.

1979-01-01

The paper presents an experimental comparison between neutron activation analysis, atomic absorption spectrophotometry and fluorescence spectrophotometry used for the determination of trace amounts of As, Se and Sn and the other two analytical techniques mentioned. Gamma-ray spectrometry has been used to determine 76 As (tsub(1/2)=26.3 h) after 1 day's irradiation at a thermal neutron flux of 1.6x10 12 n.cm -2 .s -1 . High sensitivity was also obtained using an atomic absorption spectrophotometer coupled with covalent hydride generation. Advantages of the latter technique include simplicity of operation, high speed of analysis and negligible background correction. When used in conjuction with selective reduction and a cold-trap this method quantitatively distinguishes between the valence states and some methylated derivatives. Selenium has been analysed by gamma-ray spectrometry using 77 Sesup(m) (tsub(1/2)=17.5 s) after cyclic activation at a thermal neutron flux of 2x10 12 n.cm -2 .s -1 . Atomic absorption spectrophotometry following hydride generation, or fluorescence spectrophotometry of the 2,3 diaminonaphthalene complex constitute additional sensitive analytical methods for the determination of Se. These have the added advantage that valence states can be selectively measured. Low concentrations of Sn have been determined by neutron activation analysis and by spectrophotometric techniques using phenylfluorone as the complexing reagent, but these methods depend on selective extraction of Sn(IV) iodide. Whilst maintaining high sensitivity, these problems were avoided by using the hydride generation technique with an atomic absorption spectrophotometer. Comparative analytical values for Bowen's kale and NBS orchard leaves are presented

Advanced of X-ray fluorescence logging technique in China

International Nuclear Information System (INIS)

Zhou Sichun; Ge Liangquan; Lai Wanchang; Yang Qiang

2010-01-01

The paper discuses principle of X-ray fluorescence logging, and introduces advanced of X-ray fluorescence logging technique in China. By 2009, third generation XRF logging instrument has been developed in China, and good logging result has been obtained in Lala copper mine. (authors)

Skin fluorescence model based on the Monte Carlo technique

Science.gov (United States)

Churmakov, Dmitry Y.; Meglinski, Igor V.; Piletsky, Sergey A.; Greenhalgh, Douglas A.

2003-10-01

The novel Monte Carlo technique of simulation of spatial fluorescence distribution within the human skin is presented. The computational model of skin takes into account spatial distribution of fluorophores following the collagen fibers packing, whereas in epidermis and stratum corneum the distribution of fluorophores assumed to be homogeneous. The results of simulation suggest that distribution of auto-fluorescence is significantly suppressed in the NIR spectral region, while fluorescence of sensor layer embedded in epidermis is localized at the adjusted depth. The model is also able to simulate the skin fluorescence spectra.

Synchrotron radiation based analytical techniques (XAS and XRF)

International Nuclear Information System (INIS)

Jha, Shambhu Nath

2014-01-01

A brief description of the principles of X-ray absorption spectroscopy (XAS) and X-ray fluorescence (XRF) techniques is given in this article with emphasis on the advantages of using synchrotron radiation-based instrumentation/beamline. XAS technique is described in more detail to emphasize the strength of the technique as a local structural probe. (author)

Determination of low concentrations of thorium in granites using X-ray fluorescence technique

International Nuclear Information System (INIS)

Shigematsu, H.M.; Sato, I.M.; Iyer, S.S.

1981-03-01

An analytical method for the accurate determination of low concentrations of thorium in rocks using X-ray fluorescence technique, was developed. A tungsten tube was utilized for the production of X-rays. The samples were prepared in the form of double layer pressed pellets using boric acid as a binding agent. The concentration of thorium was determined by measuring the intensity of the characteristic first order Th L α line. The calibration was carried out with USGS rock standards AGV-1, GSP-1 and G-2. Seven granite rocks samples from Granite Mountains of Wyoming, USA, supplied by Dr. Stuckless. Also were analysed. The results obtained were compared with values obtained in others laboratories using different analytical methods. The analyses show that the thorium is concentrated in accessory minerals and presented a non-uniform distribution, making sampling an important factor in the analysis of thorium. A discussion of the precision and accuracy of the method is presented. (Author) [pt

Recent Studies on the Speciation and Determination of Mercury in Different Environmental Matrices Using Various Analytical Techniques

Directory of Open Access Journals (Sweden)

Lakshmi Narayana Suvarapu

2017-01-01

Full Text Available This paper reviews the current research on the speciation and determination of mercury by various analytical techniques, including the atomic absorption spectrometry (AAS, voltammetry, inductively coupled plasma optical emission spectrometry (ICP-OES, ICP-mass spectrometry (MS, atomic fluorescence spectrometry (AFS, spectrophotometry, spectrofluorometry, and high performance liquid chromatography (HPLC. Approximately 96 research papers on the speciation and determination of mercury by various analytical instruments published in international journals since 2015 were reviewed. All analytical parameters, including the limits of detection, linearity range, quality assurance and control, applicability, and interfering ions, evaluated in the reviewed articles were tabulated. In this review, we found a lack of information in speciation studies of mercury in recent years. Another important conclusion from this review was that there were few studies regarding the concentration of mercury in the atmosphere.

Determination of Cu, Cr, and As in preserved wood (Eucalyptus sp.) using x-ray fluorescent spectrometry techniques

International Nuclear Information System (INIS)

Sergio Matias Pereira Junior; Vera Akiko Maihara; Edson Goncalves Moreira; Vera Lucia Ribeiro Salvador; Ivone Mulako Sato

2016-01-01

Energy dispersive (EDXRF) and Portable (PXRF) X-ray fluorescence techniques are proposed for wood treatment control process and wood waste assortment. In this study, different retentions of chromated copper arsenate preservative were applied to Eucalyptus sp. sapwood samples. Cu, Cr and As were determined by XRF techniques in treated sapwood massive blocks and treated sapwood sawdust samples were analyzed by FAAS spectrometry (Flame Atomic Absorption) and INAA (Instrumental Neutron Activation Analysis). Cu, Cr and As mean values, obtained by FAASS and INAA, showed to be statically equal; however, XRF analysis showed considerable deviations, presenting the absorption and the enhancement effects in analytical lines. (author)

Macro elemental analysis of food samples by nuclear analytical technique

Science.gov (United States)

Syahfitri, W. Y. N.; Kurniawati, S.; Adventini, N.; Damastuti, E.; Lestiani, D. D.

2017-06-01

Energy-dispersive X-ray fluorescence (EDXRF) spectrometry is a non-destructive, rapid, multi elemental, accurate, and environment friendly analysis compared with other detection methods. Thus, EDXRF spectrometry is applicable for food inspection. The macro elements calcium and potassium constitute important nutrients required by the human body for optimal physiological functions. Therefore, the determination of Ca and K content in various foods needs to be done. The aim of this work is to demonstrate the applicability of EDXRF for food analysis. The analytical performance of non-destructive EDXRF was compared with other analytical techniques; neutron activation analysis and atomic absorption spectrometry. Comparison of methods performed as cross checking results of the analysis and to overcome the limitations of the three methods. Analysis results showed that Ca found in food using EDXRF and AAS were not significantly different with p-value 0.9687, whereas p-value of K between EDXRF and NAA is 0.6575. The correlation between those results was also examined. The Pearson correlations for Ca and K were 0.9871 and 0.9558, respectively. Method validation using SRM NIST 1548a Typical Diet was also applied. The results showed good agreement between methods; therefore EDXRF method can be used as an alternative method for the determination of Ca and K in food samples.

Impurity monitoring by laser-induced fluorescence techniques

International Nuclear Information System (INIS)

Gelbwachs, J.A.

1984-01-01

Laser-induced fluorescence spectroscopy can provide a highly sensitive and selective means of detecting atomic and ionic impurities. Because the photodetector can be physically isolated from the laser-excited region, these techniques can be applied to monitoring in hostile environments. The basic concepts behind fluorescence detection are reviewed. Saturated optical excitation is shown to maximize impurity atom emission yield while mitigating effects of laser intensity fluctuations upon absolute density calibration. Monitoring in high- and low-pressure monitoring environments is compared. Methods to improve detection sensitivity by luminescence background suppression are presented

Development and evaluation of analytical techniques for total chlorine in used oils and oil fuels

International Nuclear Information System (INIS)

Gaskill, A. Jr.; Estes, E.D.; Hardison, D.L.; Friedman, P.H.

1990-01-01

A current EPA regulation prohibits the sale for burning in nonindustrial boilers of used oils and oil fuels. This paper discusses how analytical techniques for determining total chlorine were evaluated to provide regulatory agencies and the regulated community with appropriate chlorine test methods. The techniques evaluated included oxygen bomb combustion followed by chemical titration or ion chromatography, instrumental microcoulometry, field test kits, and instrumental furnace/specific ion electrode determinator, a device based on the Beilstein reaction, and x-ray fluorescence spectrometry. These techniques were subjected to interlaboratory testing to estimate their precision, accuracy, and sensitivity. Virgin and used crankcase oils, hydraulic and metalworking oils, oil fuels and oil fuel blends with used oils were tested. The bomb techniques, one of the test kits, microcoulometry and all but one x-ray analyzer were found to be suitable for this application. The chlorine furnace and the Beilstein device were found to be inapplicable at the levels of interest

Uranium speciation in biofilms studies by laser fluorescence techniques

International Nuclear Information System (INIS)

Arnold, Thuro; Grossmann, Kay; Baumann, Nils

2010-01-01

Biofilms may immobilize toxic heavy metals in the environment and thereby influence their migration behaviour. The mechanisms of these processes are currently not understood, because the complexity of such biofilms creates many discrete geochemical microenvironments which may differ from the surrounding bulk solution in their bacterial diversity, their prevailing geochemical properties, e.g. pH and dissolved oxygen concentration, the presence of organic molecules, e.g. metabolites, and many more, all of which may affect metal speciation. To obtain such information, which is necessary for performance assessment studies or the development of new cost-effective strategies for cleaning waste waters, it is very important to develop new non-invasive methods applicable to study the interactions of metals within biofilm systems. Laser fluorescence techniques have some superior features, above all very high sensitivity for fluorescent heavy metals. An approach combining confocal laser scanning microscopy and laser-induced fluorescence spectroscopy for study of the interactions of biofilms with uranium is presented. It was found that coupling these techniques furnishes a promising tool for in-situ non-invasive study of fluorescent heavy metals within biofilm systems. Information on uranium speciation and uranium redox states can be obtained.

Comparative study of inorganic elements determined in whole blood from Dmd(mdx)/J mice strain by EDXRF and NAA analytical techniques.

Science.gov (United States)

Redígolo, M M; Sato, I M; Metairon, S; Zamboni, C B

2016-04-01

Several diseases can be diagnosed observing the variation of specific elements concentration in body fluids. In this study the concentration of inorganic elements in blood samples of dystrophic (Dmd(mdx)/J) and C57BL/6J (control group) mice strain were determined. The results obtained from Energy Dispersive X-ray Fluorescence (EDXRF) were compared with Neutron Activation Analysis (NAA) technique. Both analytical techniques showed to be appropriate and complementary offering a new contribution for veterinary medicine as well as detailed knowledge of this pathology. Copyright © 2016 Elsevier Ltd. All rights reserved.

X-ray fluorescence in Member States (Spain): Main activities related to the use of XRF techniques at the Analytical and Environmental Chemistry Research Group of the University of Girona (UdG)

International Nuclear Information System (INIS)

Marguí, Eva; Hidalgo, Manuela

2014-01-01

The Analytical and Environmental Chemistry Group (QAA) is a consolidated research group of the Department of Chemistry of the University of Girona (North- East Spain). The main research topics of the group are related to the development and application of analytical methodologies for the determination of inorganic and organic species in different kind of environmental, clinical and industrial samples. From the beginning of the 2000’s, one of the research focuses of the group, is the use of X-ray fluorescence spectrometry (XRF) for the determination of trace amounts of metals and metalloids mostly in samples related to the environmental and industrial fields. For instance, in collaboration with the Institute of Earth Sciences “Jaume Almera” (ICTJA-CSIC, Spain), we have developed and successfully applied several analytical approaches based on the use of EDXRF (Energy dispersive XRF), WDXRF (Wavelength dispersive XRF) and PEDXRF (Polarised EDXRF) for the determination of metals at trace levels in complex liquid samples such as sea water or electroplating waters in vegetation samples collected around mining environments or in active pharmaceutical ingredients. At present, the evaluation of the analytical possibilities of TXRF (Total reflection XRF) in the chemical analysis field is also one of the research topics of QAA. In this sense, several contributions related to the use of this technique for element determination in liquid and solid samples have been developed. A summary of these contributions is summarized in the last section of this review

Analytical techniques for thin films treatise on materials science and technology

CERN Document Server

Tu, K N

1988-01-01

Treatise on Materials Science and Technology, Volume 27: Analytical Techniques for Thin Films covers a set of analytical techniques developed for thin films and interfaces, all based on scattering and excitation phenomena and theories. The book discusses photon beam and X-ray techniques; electron beam techniques; and ion beam techniques. Materials scientists, materials engineers, chemical engineers, and physicists will find the book invaluable.

X-ray fluorescence method for trace analysis and imaging

International Nuclear Information System (INIS)

Hayakawa, Shinjiro

2000-01-01

X-ray fluorescence analysis has a long history as conventional bulk elemental analysis with medium sensitivity. However, with the use of synchrotron radiation x-ray fluorescence method has become a unique analytical technique which can provide tace elemental information with the spatial resolution. To obtain quantitative information of trace elemental distribution by using the x-ray fluorescence method, theoretical description of x-ray fluorescence yield is described. Moreover, methods and instruments for trace characterization with a scanning x-ray microprobe are described. (author)

Determination of Rare Earth Elements in Thai Monazite by Inductively Coupled Plasma and Nuclear Analytical techniques

International Nuclear Information System (INIS)

Busamongkol, Arporn; Ratanapra, Dusadee; Sukharn, Sumalee; Laoharojanaphand, Sirinart

2003-10-01

The inductively coupled plasma atomic emission spectroscopy (ICP-AES) for the determination of individual rare-earth elements (REE) was evaluated by comparison with instrumental neutron activation analysis (INAA) and x-ray fluorescence spectrometry (XRF). The accuracy and precision of INAA and ICP-AES were evaluated by using standard reference material IGS-36, a monazite concentrate. For INAA, the results were close to the certified value while ICP-AES were in good agreement except for some low concentration rare earth. The techniques were applied for the analysis of some rare earth elements in two Thai monazite samples preparing as the in-house reference material for the Rare Earth Research and Development Center, Chemistry Division, Office of Atoms for Peace. The analytical results obtained by these techniques were in good agreement with each other

Applied predictive analytics principles and techniques for the professional data analyst

CERN Document Server

Abbott, Dean

2014-01-01

Learn the art and science of predictive analytics - techniques that get results Predictive analytics is what translates big data into meaningful, usable business information. Written by a leading expert in the field, this guide examines the science of the underlying algorithms as well as the principles and best practices that govern the art of predictive analytics. It clearly explains the theory behind predictive analytics, teaches the methods, principles, and techniques for conducting predictive analytics projects, and offers tips and tricks that are essential for successful predictive mode

Advanced analytical techniques for boiling water reactor chemistry control

Energy Technology Data Exchange (ETDEWEB)

Alder, H P; Schenker, E [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-02-01

The analytical techniques applied can be divided into 5 classes: OFF-LINE (discontinuous, central lab), AT-LINE (discontinuous, analysis near loop), ON-LINE (continuous, analysis in bypass). In all cases pressure and temperature of the water sample are reduced. In a strict sense only IN-LINE (continuous, flow disturbance) and NON-INVASIVE (continuous, no flow disturbance) techniques are suitable for direct process control; - the ultimate goal. An overview of the analytical techniques tested in the pilot loop is given. Apart from process and overall water quality control, standard for BWR operation, the main emphasis is on water impurity characterization (crud particles, hot filtration, organic carbon); on stress corrosion crackling control for materials (corrosion potential, oxygen concentration) and on the characterization of the oxide layer on austenites (impedance spectroscopy, IR-reflection). The above mentioned examples of advanced analytical techniques have the potential of in-line or non-invasive application. They are different stages of development and are described in more detail. 28 refs, 1 fig., 5 tabs.

Application of on-line analytical processing technique in accelerator

International Nuclear Information System (INIS)

Xie Dong; Li Weimin; He Duohui; Liu Gongfa; Xuan Ke

2005-01-01

A method of application of the on-line analytical processing technique in accelerator is described, which includes data pre-processing, the process of constructing of data warehouse and on-line analytical processing. (authors)

Nuclear forensics: strategies and analytical techniques

International Nuclear Information System (INIS)

Marin, Rafael C.; Sarkis, Jorge E.S.; Pestana, Rafael C.B.

2013-01-01

The development of nuclear forensics as a field of science arose in response to international demand for methods to investigate the illicit trafficking of nuclear materials. After being seized, unknown nuclear material is collected and analyzed by a set of analytical methods. The fingerprints of these materials can be identified and further used during the investigations. Data interpretation is an extensive process aiming to validate the hypotheses made by the experts, and can help confirm the origin of seized nuclear materials at the end of the process or investigation. This work presents the set of measures and analytical methods that have been inherited by nuclear forensics from several fields of science. The main characteristics of these methods are evaluated and the analytical techniques employed to determine the fingerprint of nuclear materials are described. (author)

Time-resolved fluorescence microscopy (FLIM) as an analytical tool in skin nanomedicine.

Science.gov (United States)

Alexiev, Ulrike; Volz, Pierre; Boreham, Alexander; Brodwolf, Robert

2017-07-01

The emerging field of nanomedicine provides new approaches for the diagnosis and treatment of diseases, for symptom relief, and for monitoring of disease progression. Topical application of drug-loaded nanoparticles for the treatment of skin disorders is a promising strategy to overcome the stratum corneum, the upper layer of the skin, which represents an effective physical and biochemical barrier. The understanding of drug penetration into skin and enhanced penetration into skin facilitated by nanocarriers requires analytical tools that ideally allow to visualize the skin, its morphology, the drug carriers, drugs, their transport across the skin and possible interactions, as well as effects of the nanocarriers within the different skin layers. Here, we review some recent developments in the field of fluorescence microscopy, namely Fluorescence Lifetime Imaging Microscopy (FLIM)), for improved characterization of nanocarriers, their interactions and penetration into skin. In particular, FLIM allows for the discrimination of target molecules, e.g. fluorescently tagged nanocarriers, against the autofluorescent tissue background and, due to the environmental sensitivity of the fluorescence lifetime, also offers insights into the local environment of the nanoparticle and its interactions with other biomolecules. Thus, FLIM shows the potential to overcome several limits of intensity based microscopy. Copyright © 2017 Elsevier B.V. All rights reserved.

Analytical chemistry: Principles and techniques

International Nuclear Information System (INIS)

Hargis, L.G.

1988-01-01

Although this text seems to have been intended for use in a one-semester course in undergraduate analytical chemistry, it includes the range of topics usually encountered in a two-semester introductory course in chemical analysis. The material is arranged logically for use in a two-semester course: the first 12 chapters contain the subjects most often covered in the first term, and the next 10 chapters pertain to the second (instrumental) term. Overall breadth and level of treatment are standards for an undergraduate text of this sort, and the only major omission is that of kinetic methods (which is a common omission in analytical texts). In the first 12 chapters coverage of the basic material is quite good. The emphasis on the underlying principles of the techniques rather than on specifics and design of instrumentation is welcomed. This text may be more useful for the instrumental portion of an analytical chemistry course than for the solution chemistry segment. The instrumental analysis portion is appropriate for an introductory textbook

Spatial and temporal superresolution concepts to study plasma membrane organization by single molecule fluorescence techniques

International Nuclear Information System (INIS)

Ruprecht, V.

2010-01-01

Fluorescence microscopy techniques are currently among the most important experimental tools to study cellular processes. Ultra-sensitive detection devices nowadays allow for measuring even individual farnesylacetate labeled target molecules with nanometer spatial accuracy and millisecond time resolution. The emergence of single molecule fluorescence techniques especially contributed to the field of membrane biology and provided basic knowledge on structural and dynamic features of the cellular plasma membrane. However, we are still confronted with a rather fragmentary understanding of the complex architecture and functional interrelations of membrane constituents. In this thesis new concepts in one- and dual-color single molecule fluorescence techniques are presented that allow for addressing organization principles and interaction dynamics in the live cell plasma membrane. Two complementary experimental strategies are described which differ in their detection principle: single molecule fluorescence imaging and fluorescence correlation spectroscopy. The presented methods are discussed in terms of their implementation, accuracy, quantitative and statistical data analysis, as well as live cell applications. State-of-the-art dual color single molecule imaging is introduced as the most direct experimental approach to study interaction dynamics between differently labeled target molecules. New analytical estimates for robust data analysis are presented that facilitate quantitative recording and identification of co localizations in dual color single molecule images. A novel dual color illumination scheme is further described that profoundly extends the current range and sensitivity of conventional dual color single molecule experiments. The method enables working at high surface densities of fluorescent molecules - a feature typically incommensurable with single molecule imaging - and is especially suited for the detection of rare interactions by tracking co localized

X-ray fluorescence beamline at LNLS: components and some associated techniques

International Nuclear Information System (INIS)

Perez, CArlos A.; Radtke, Martin; Perez, Carlos; Tolentino, Helio; Vicentin, Flavio; Sanchez, Hector Jorge; Perez, Roberto D.

1997-01-01

Full text. In this work a general description of the Total Reflection X-Ray Fluorescence (TXRF) and the X-Ray Fluorescence Microprobe (XRFM) is presented. Components, equipment and experimental stations for the x-ray fluorescence beamline are described, regarding to the techniques mentioned above. Results from the simulations of a pair bended mirrors in a Kirkpatrick-Baez configuration, are shown. The simulations were performed with Shadow program. (author)

Characterization of sediments laid on Solimoes/Amazonas river flood plains, using energy dispersive X-ray fluorescence technique

International Nuclear Information System (INIS)

Carneiro, Ana E.V.; Nascimento Filho, Virgilio F. do

1997-01-01

This paper proposes sediment analysis with high light elements fraction using dispersive energy X-ray fluorescence technique with radioisotopic excitation, The proposed procedure is based on the Fundamental Parameters for analytical elements (Z ≥ 13) evaluation, and coherent and incoherent scattered radiation for quantification of the light fraction of the matrix (Z < 13). Laid sediments samples on Solimoes/Amazonas river flood plains were analyzed, determining simultaneously the Al, Si, K, Ca, Ti, Fe, Sc, V, Mn, Cu, Zn, Rb, Sr and Zr element concentrations, thus allowing chemical characterization and spatial variability, and some mineralogical and weathering sediments aspects. (author). 15 refs., 11 tabs

Use of zero order diffraction of a grating monochromator towards convenient and sensitive detection of fluorescent analytes in multi fluorophoric systems

Science.gov (United States)

Panigrahi, Suraj Kumar; Mishra, Ashok Kumar

2018-02-01

White light excitation fluorescence (WLEF) is known to possess analytical advantage in terms of enhanced sensitivity and facile capture of the entire fluorescence spectral signature of multi component fluorescence systems. Using the zero order diffraction of the grating monochromator on the excitation side of a commercial spectrofluorimeter, it has been shown that WLEF spectral measurements can be conveniently carried out. Taking analyte multi-fluorophoric systems like (i) drugs and vitamins spiked in urine sample, (ii) adulteration of extra virgin olive oil with olive pomace oil and (iii) mixture of fabric dyes, it was observed that there is a significant enhancement of measurement sensitivity. The total fluorescence spectral response could be conveniently analysed using PLS2 regression. This work brings out the ease of the use of a conventional fluorimeter for WLEF measurements.

Development of analytical techniques for safeguards environmental samples at JAEA

International Nuclear Information System (INIS)

Sakurai, Satoshi; Magara, Masaaki; Usuda, Shigekazu; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, Chi-Gyu; Yasuda, Kenichiro; Inagawa, Jun; Suzuki, Daisuke; Iguchi, Kazunari; Kokubu, Yoko S.; Miyamoto, Yutaka; Ohzu, Akira

2007-01-01

JAEA has been developing, under the auspices of the Ministry of Education, Culture, Sports, Science and Technology of Japan, analytical techniques for ultra-trace amounts of nuclear materials in environmental samples in order to contribute to the strengthened safeguards system. Development of essential techniques for bulk and particle analysis, as well as screening, of the environmental swipe samples has been established as ultra-trace analytical methods of uranium and plutonium. In January 2003, JAEA was qualified, including its quality control system, as a member of the JAEA network analytical laboratories for environmental samples. Since 2004, JAEA has conducted the analysis of domestic and the IAEA samples, through which JAEA's analytical capability has been verified and improved. In parallel, advanced techniques have been developed in order to expand the applicability to the samples of various elemental composition and impurities and to improve analytical accuracy and efficiency. This paper summarizes the trace of the technical development in environmental sample analysis at JAEA, and refers to recent trends of research and development in this field. (author)

Algorithms for a hand-held miniature x-ray fluorescence analytical instrument

International Nuclear Information System (INIS)

Elam, W.T.; Newman, D.; Ziemba, F.

1998-01-01

The purpose of this joint program was to provide technical assistance with the development of a Miniature X-ray Fluorescence (XRF) Analytical Instrument. This new XRF instrument is designed to overcome the weaknesses of spectrometers commercially available at the present time. Currently available XRF spectrometers (for a complete list see reference 1) convert spectral information to sample composition using the influence coefficients technique or the fundamental parameters method. They require either a standard sample with composition relatively close to the unknown or a detailed knowledge of the sample matrix. They also require a highly-trained operator and the results often depend on the capabilities of the operator. In addition, almost all existing field-portable, hand-held instruments use radioactive sources for excitation. Regulatory limits on such sources restrict them such that they can only provide relatively weak excitation. This limits all current hand-held XRF instruments to poor detection limits and/or long data collection times, in addition to the licensing requirements and disposal problems for radioactive sources. The new XRF instrument was developed jointly by Quantrad Sensor, Inc., the Naval Research Laboratory (NRL), and the Department of Energy (DOE). This report describes the analysis algorithms developed by NRL for the new instrument and the software which embodies them

Activities at Forschungszentrum Juelich in Safeguards Analytical Techniques and Measurements

International Nuclear Information System (INIS)

Duerr, M.; Knott, A.; Middendorp, R.; Niemeyer, I.; Kueppers, S.; Zoriy, M.; Froning, M.; Bosbach, D.

2015-01-01

The application of safeguards by the IAEA involves analytical measurements of samples taken during inspections. The development and advancement of analytical techniques with support from the Member States contributes to strengthened and more efficient verification of compliance with non-proliferation obligations. Since recently, a cooperation agreement has been established between Forschungszentrum Juelich and the IAEA in the field of analytical services. The current working areas of Forschungszentrum Juelich are: (i) Production of synthetic micro-particles as calibration standard and reference material for particle analysis, (ii) qualification of the Forschungszentrum Juelich as a member of the IAEA network of analytical laboratories for safeguards (NWAL), and (iii) analysis of impurities in nuclear material samples. With respect to the synthesis of particles, a dedicated setup for the production of uranium particles is being developed, which addresses the urgent need for material tailored for its use in quality assurance and quality control measures for particle analysis of environmental swipe samples. Furthermore, Forschungszentrum Juelich has been nominated as a candidate laboratory for membership in the NWAL network. To this end, analytical capabilities at Forschungszentrum Juelich have been joined to form an analytical service within a dedicated quality management system. Another activity is the establishment of analytical techniques for impurity analysis of uranium-oxide, mainly focusing on inductively coupled mass spectrometry. This contribution will present the activities at Forschungszentrum Juelich in the area of analytical measurements and techniques for nuclear verification. (author)

Fluorescence hyperspectral imaging technique for foreign substance detection on fresh-cut lettuce.

Science.gov (United States)

Mo, Changyeun; Kim, Giyoung; Kim, Moon S; Lim, Jongguk; Cho, Hyunjeong; Barnaby, Jinyoung Yang; Cho, Byoung-Kwan

2017-09-01

Non-destructive methods based on fluorescence hyperspectral imaging (HSI) techniques were developed to detect worms on fresh-cut lettuce. The optimal wavebands for detecting the worms were investigated using the one-way ANOVA and correlation analyses. The worm detection imaging algorithms, RSI-I (492-626)/492 , provided a prediction accuracy of 99.0%. The fluorescence HSI techniques indicated that the spectral images with a pixel size of 1 × 1 mm had the best classification accuracy for worms. The overall results demonstrate that fluorescence HSI techniques have the potential to detect worms on fresh-cut lettuce. In the future, we will focus on developing a multi-spectral imaging system to detect foreign substances such as worms, slugs and earthworms on fresh-cut lettuce. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Analytical Techniques and Pharmacokinetics of Gastrodia elata Blume and Its Constituents.

Science.gov (United States)

Wu, Jinyi; Wu, Bingchu; Tang, Chunlan; Zhao, Jinshun

2017-07-08

Gastrodia elata Blume ( G. elata ), commonly called Tianma in Chinese, is an important and notable traditional Chinese medicine (TCM), which has been used in China as an anticonvulsant, analgesic, sedative, anti-asthma, anti-immune drug since ancient times. The aim of this review is to provide an overview of the abundant efforts of scientists in developing analytical techniques and performing pharmacokinetic studies of G. elata and its constituents, including sample pretreatment methods, analytical techniques, absorption, distribution, metabolism, excretion (ADME) and influence factors to its pharmacokinetics. Based on the reported pharmacokinetic property data of G. elata and its constituents, it is hoped that more studies will focus on the development of rapid and sensitive analytical techniques, discovering new therapeutic uses and understanding the specific in vivo mechanisms of action of G. elata and its constituents from the pharmacokinetic viewpoint in the near future. The present review discusses analytical techniques and pharmacokinetics of G. elata and its constituents reported from 1985 onwards.

Basic design of on-line analyzer for sheet paper using X-ray fluorescence (XRF) technique

International Nuclear Information System (INIS)

Rony Djokorayono; Ahmad Suntoro; Ikhsan Shobari; Usep Setia Gunawan

2016-01-01

Basic design of on-line analyzer for sheet paper using X-ray fluorescence technique has been carried out. Compared with sampling technique, this X-ray fluorescence technique has some advantages in term of analysis accuracy and time. The design activities performed including the establishment of design requirements, functional requirements, technical requirements, technical specification, detection sub-system design, data acquisition sub-system design, and operator computer console design. This program will use silicon drift or CdTe X-ray detector to detect X-ray fluorescence emitted by elements in sheet paper due to X-ray interaction of a X-ray source, 55 Fe (Ferro-55).This basic design of on-line analyzer for sheet paper using X-ray fluorescence technique should be followed up with the development of detailed design, prototype construction, and field testing. (author)

Tools for the quantitative analysis of sedimentation boundaries detected by fluorescence optical analytical ultracentrifugation.

Directory of Open Access Journals (Sweden)

Huaying Zhao

Full Text Available Fluorescence optical detection in sedimentation velocity analytical ultracentrifugation allows the study of macromolecules at nanomolar concentrations and below. This has significant promise, for example, for the study of systems of high-affinity protein interactions. Here we describe adaptations of the direct boundary modeling analysis approach implemented in the software SEDFIT that were developed to accommodate unique characteristics of the confocal fluorescence detection system. These include spatial gradients of signal intensity due to scanner movements out of the plane of rotation, temporal intensity drifts due to instability of the laser and fluorophores, and masking of the finite excitation and detection cone by the sample holder. In an extensive series of experiments with enhanced green fluorescent protein ranging from low nanomolar to low micromolar concentrations, we show that the experimental data provide sufficient information to determine the parameters required for first-order approximation of the impact of these effects on the recorded data. Systematic deviations of fluorescence optical sedimentation velocity data analyzed using conventional sedimentation models developed for absorbance and interference optics are largely removed after these adaptations, resulting in excellent fits that highlight the high precision of fluorescence sedimentation velocity data, thus allowing a more detailed quantitative interpretation of the signal boundaries that is otherwise not possible for this system.

Mesh adaptation technique for Fourier-domain fluorescence lifetime imaging

International Nuclear Information System (INIS)

Soloviev, Vadim Y.

2006-01-01

A novel adaptive mesh technique in the Fourier domain is introduced for problems in fluorescence lifetime imaging. A dynamical adaptation of the three-dimensional scheme based on the finite volume formulation reduces computational time and balances the ill-posed nature of the inverse problem. Light propagation in the medium is modeled by the telegraph equation, while the lifetime reconstruction algorithm is derived from the Fredholm integral equation of the first kind. Stability and computational efficiency of the method are demonstrated by image reconstruction of two spherical fluorescent objects embedded in a tissue phantom

Role of thermo-analytical techniques in compositional characterization of nuclear materials

International Nuclear Information System (INIS)

Raje, Naina

2015-01-01

The study of heat effects on different materials has a long history. Extraction of metals from the ores, pottery production, glasses making etc. are the examples, where the performance of products obtained from raw materials depends on the processing temperatures. Concrete, pottery, bricks etc., are severely damaged due to uncontrolled high temperatures. Therefore, the heating of raw materials in controlled manner is of pivotal importance to get products of the desired quality. Thermo-analytical techniques provide the information on the effect of heat under controlled heating conditions. In thermo-analytical techniques, physical properties of materials are measured as a function of temperature. Simultaneous thermo-analytical techniques are beneficial in comparison to any single thermo-analytical technique. Simultaneous techniques refer to the measurement of two or more signals on the same sample at the same time in the same instrument. Nowadays, simultaneous thermo-analytical technique are extensively in use for the analysis of materials. Ammonium diuranate (ADU) and magnesium diuranate (MDU), also known as yellowcake, are intermediate precursors in fuel fabrication process, with stringent specifications along with the need to understand its thermal behavior. In the processing of lowgrade ores, higher levels of impurities are being encountered in the leach solution that affects the properties of ADU/MDU. In order to meet the fuel specifications, quality assurance of these nuclear materials is essential. Current studies describe the application of simultaneous Thermogravimetry (TG) - differential thermal analysis (DTA) - evolved gas analysis (EGA) techniques for the compositional characterization of ADU/MDU with respect to the impurities present in the matrices

Flame emission, atomic absorption and fluorescence spectrometry

International Nuclear Information System (INIS)

Horlick, G.

1980-01-01

Six hundred and thirty references are cited in this review. The information in the review is divided into 12 major areas: books, reviews, and bibliographies; fundamental studies in flames; developments in instrumentation; measurement techniques and procedure; flame emission spectrometry; flame atomic absorption spectrometry; flame molecular absorption spectrometry; electrothermal atomization atomic absorption spectroscopy; hydride generation techniques; graphite furnace atomic emission spectrometry; atomic fluorescence spectrometry; and analytical comparisons

Alternate gram staining technique using a fluorescent lectin.

Science.gov (United States)

Sizemore, R K; Caldwell, J J; Kendrick, A S

1990-01-01

Fluorescence-labeled wheat germ agglutinin binds specifically to N-acetylglucosamine in the outer peptidoglycan layer of gram-positive bacteria. The peptidoglycan layer of gram-negative bacteria is covered by a membrane and is not labeled by the lectin. By exploiting this phenomenon, an alternative Gram staining technique has been developed. Images PMID:1697149

Some recent developments in the surface-analytical application of X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Gries, W.H.

1987-01-01

Standard depth profiles of an analyte deposited into (diffusion or ion implantation) or on (thin-film deposition) a plane surface can be analyzed for profile type and centroid depth or film thickness by means of a standardless method in which the matrix-attenuated signals of the fluorescing analyte measured at two different take-off angles are related to the mathematical distribution moments of the profile. For a binary thin film the element ratio can also be established. Results obtained on phosphorus profiles in silicon and on zinc sulphide optical coatings are referred to. The quantity or concentration level can be determined by use of a reference standard which may contain the analyte in an entirely different distribution. This simplifies the calibration of secondary reference standards. A good lateral resolution in the sub-millimeter range can be achieved with synchrotron radiation. A further improvement of lateral resolution is possible by direct excitation with electron microbeams, though at significantly inferior detection limits. (orig.)

Proceedings of the 11. ENQA: Brazilian meeting on analytical chemistry. Challenges for analytical chemistry in the 21st century. Book of Abstracts

International Nuclear Information System (INIS)

2001-01-01

The 11th National Meeting on Analytical Chemistry was held from 18 to 21 September, 2001 at the Convention Center of UNICAMP, with the theme Challenges for Analytical Chemistry in the 21st Century. This meeting have discussed on the development of new methods and analytical tools needed to solve new challenges. The papers presented topics related to the different sub-areas of Analytical Chemistry such as Environmental Chemistry; Chemiometry techniques; X-ray Fluorescence Analysis; Spectroscopy; Separation Processes; Electroanalytic Chemistry and others. Were also included lectures on the Past and Future of Analytical Chemistry and on Ethics in Science

Analytical vs. Simulation Solution Techniques for Pulse Problems in Non-linear Stochastic Dynamics

DEFF Research Database (Denmark)

Iwankiewicz, R.; Nielsen, Søren R. K.

Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically-numerical tec......Advantages and disadvantages of available analytical and simulation techniques for pulse problems in non-linear stochastic dynamics are discussed. First, random pulse problems, both those which do and do not lead to Markov theory, are presented. Next, the analytical and analytically...

Statistical evaluation of recorded knowledge in nuclear and other instrumental analytical techniques

International Nuclear Information System (INIS)

Braun, T.

1987-01-01

The main points addressed in this study are the following: Statistical distribution patterns of published literature on instrumental analytical techniques 1981-1984; structure of scientific literature and heuristics for identifying active specialities and emerging hot spot research areas in instrumental analytical techniques; growth and growth rates of the literature in some of the identified hot research areas; quality and quantity in instrumental analytical research output. (orig.)

Atomic Absorption, Atomic Fluorescence, and Flame Emission Spectrometry.

Science.gov (United States)

Horlick, Gary

1984-01-01

This review is presented in six sections. Sections focus on literature related to: (1) developments in instrumentation, measurement techniques, and procedures; (2) performance studies of flames and electrothermal atomizers; (3) applications of atomic absorption spectrometry; (4) analytical comparisons; (5) atomic fluorescence spectrometry; and (6)…

An analytical simulation technique for cone-beam CT and pinhole SPECT

International Nuclear Information System (INIS)

Zhang Xuezhu; Qi Yujin

2011-01-01

This study was aimed at developing an efficient simulation technique with an ordinary PC. The work involved derivation of mathematical operators, analytic phantom generations, and effective analytical projectors developing for cone-beam CT and pinhole SPECT imaging. The computer simulations based on the analytical projectors were developed by ray-tracing method for cone-beam CT and voxel-driven method for pinhole SPECT of degrading blurring. The 3D Shepp-Logan, Jaszczak and Defrise phantoms were used for simulation evaluations and image reconstructions. The reconstructed phantom images were of good accuracy with the phantoms. The results showed that the analytical simulation technique is an efficient tool for studying cone-beam CT and pinhole SPECT imaging. (authors)

Synchrotron X-ray fluorescence analysis in environmental and earth sciences

Directory of Open Access Journals (Sweden)

Adams F.

2010-12-01

Full Text Available Compared to other microscopic analytical tools X-ray microscopy techniques have the advantage that the large penetration depth of X-rays in matter allows one to investigate the interior of an object without destructive sample preparation. In combination with X-ray fluorescence tomography, analytical information from inside of a specimen can be obtained. Different X-ray analytical techniques can be used to produce contrast, X-ray absorption, fluorescence, and diffraction, to yield chemical, elemental, and structural information about the sample. Scanning microscopy on the basis of various lens systems in synchrotron radiation sources provides a routine spatial resolution of now about 100 nanometer but in the foreseeable future a 10–20 nanometer spatial resolution can be expected. X-ray absorption spectrometry can also provide chemical (speciation information on the sample. All this makes X-ray microscopy attractive to many fields of science. In this paper the techniques are briefly reviewed and a number of applications in the earth, planetary and cosmos sciences are illustrated with state-of-the art examples, while applications in the environmental sciences and biology are also briefly discussed.

Analyses of archaeological pottery samples using X-ray fluorescence technique for provenance study

International Nuclear Information System (INIS)

Tamilarasu, S.; Swain, K.K.; Singhal, R.K; Reddy, A.V.R.; Acharya, R.; Velraj, G.

2015-01-01

Archaeological artifacts reveal information on past human activities, artifact preparation technology, art and possible trade. Ceramics are the most stable and abundant material in archaeological context. Pottery is the most abundant tracers in all archaeological excavations. Compared to major elements, elements present at trace concentrations levels are source specific and they maintain same concentration levels in source clay as well as finished products e.g., fired clay potteries. As it is difficult to find out exact source or origin, provenance study is carried out first to establish whether objects under study are from the same or different sources/origin. Various analytical techniques like instrumental neutron activation analysis (INAA), Ion beam analysis (IBA) and X-ray fluorescence (XRF) have been used for obtaining elemental concentrations in archaeological potteries. Portable X-ray fluorescence (pXRF) spectrometry provides a non-destructive means for elemental characterization of a wide range of archaeological materials. Ten archaeological pottery samples were collected from Kottapuram, Kerala under the supervision of archaeological survey of India. Portable X-ray fluorescence (pXRF) spectrometry using a handheld Olympus Innov-X Delta XRF device, ACD BARC, has been used for chemical characterization of the pottery samples. The instrument is equipped with the Delta Rhodium (Rh) anode X-Ray tube and uses a Silicon Drift Detector (resolution <200 eV at 5.95 keV Mn Kα X-ray). NIST 2781 SRM was analyzed for quality control purpose. Ten elements namely Fe, Ti, Mn, Co, Cu, Zn, Pb, Zr, Mo and Se were chosen for cluster analysis and their concentration values were utilized for multivariate statistical analysis using WinSTAT 9.0

Appendix 1: Analytical Techniques (Online supplementary material ...

Indian Academy of Sciences (India)

HP

Further details of analytical techniques are given in http://www.actlabs.com. Zircon U–Pb dating and trace element analysis. The zircons were separated using standard procedures including crushing (in iron mortar and pestle), sieving (375 to 75 micron), tabling, heavy liquid separation (bromoform and methylene iodide) ...

Fluorescence-Based Multiplex Protein Detection Using Optically Encoded Microbeads

Directory of Open Access Journals (Sweden)

Dae Hong Jeong

2012-03-01

Full Text Available Potential utilization of proteins for early detection and diagnosis of various diseases has drawn considerable interest in the development of protein-based multiplex detection techniques. Among the various techniques for high-throughput protein screening, optically-encoded beads combined with fluorescence-based target monitoring have great advantages over the planar array-based multiplexing assays. This review discusses recent developments of analytical methods of screening protein molecules on microbead-based platforms. These include various strategies such as barcoded microbeads, molecular beacon-based techniques, and surface-enhanced Raman scattering-based techniques. Their applications for label-free protein detection are also addressed. Especially, the optically-encoded beads such as multilayer fluorescence beads and SERS-encoded beads are successful for generating a large number of coding.

Development and evaluation of analytical techniques for total chlorine in burner fuels

International Nuclear Information System (INIS)

Gaskill, A. Jr.; Estes, E.D.; Hardison, D.L.; Friedman, P.H.

1987-01-01

A current EPA regulation prohibits the sale for burning in non-industrial boilers of used oils and oil fuels contaminated above specified levels with certain metals and total chlorine. When burned as fuel in a small boiler, the contaminants may be emitted to the ambient air at hazardous levels. This regulation establishes a rebuttable presumption that used oil containing more than 1,000 ppm total chlorine has been mixed with halogenated solvents and is a hazardous waste. Rebutting the presumption requires the seller of the oil to prove that this chlorine is not due to halogenated solvents or other hazardous halogenated organics. If the rebuttal is successful, the oil can be sold as fuel up to a level of 4000 ppm total chlorine. Analytical techniques for determination of total chlorine were evaluated or developed to provide regulatory agencies and the regulated community with appropriate chlorine test methods. The techniques evaluated included chemical titrations following oxygen bomb combustion, disposable field test kits, instrumental microcoulometry, and x-ray fluorescence spectrometry. These candidate techniques were subjected to interlaboratory testing to estimate their precision, accuracy, sensitivity, and susceptibility to matrix effects. Information on ease of use and analysis costs was also collected. Based on this pilot study, test methods will be written for the most promising techniques and subjected to a formal collaborative study to generate precision and accuracy data for each method. These methods are to be proposed in the Federal Register as mandatory for compliance with the existing used oil regulation

Determination of uranium in ground water using different analytical techniques

International Nuclear Information System (INIS)

Sahu, S.K.; Maity, Sukanta; Bhangare, R.C.; Pandit, G.G.; Sharma, D.N.

2014-10-01

The concern over presence of natural radionuclides like uranium in drinking water is growing recently. The contamination of aquifers with radionuclides depends on number of factors. The geology of an area is the most important factor along with anthropogenic activities like mining, coal ash disposal from thermal power plants, use of phosphate fertilizers etc. Whatever may be the source, the presence of uranium in drinking waters is a matter of great concern for public health. Studies show that uranium is a chemo-toxic and nephrotoxic heavy metal. This chemotoxicity affects the kidneys and bones in particular. Seeing the potential health hazards from natural radionuclides in drinking water, many countries worldwide have adopted the guideline activity concentration for drinking water quality recommended by the WHO (2011). For uranium, WHO has set a limit of 30μgL-1 in drinking water. The geological distribution of uranium and its migration in environment is of interest because the element is having environmental and exposure concerns. It is of great interest to use an analytical technique for uranium analysis in water which is highly sensitive especially at trace levels, specific and precise in presence of other naturally occurring major and trace metals and needs small amount of sample. Various analytical methods based on the use of different techniques have been developed in the past for the determination of uranium in the geological samples. The determination of uranium requires high selectivity due to its strong association with other elements. Several trace level wet chemistry analytical techniques have been reported for uranium determination, but most of these involve tedious and pain staking procedures, high detection limits, interferences etc. Each analytical technique has its own merits and demerits. Comparative assessment by different techniques can provide better quality control and assurance. In present study, uranium was analysed in ground water samples

Facility and application of nuclear and supplementary analytical techniques at Dalat Nuclear Research Institute

International Nuclear Information System (INIS)

Nguyen Mong Sinh; Ho Manh Dung; Nguyen Thanh Binh

2006-01-01

The main applications of the nuclear and supplementary analytical techniques (N and SATs) in the Dalat Nuclear Research Institute (DNRI) and the facilities for the techniques are presented. The NATs in DNRI include the neutron activation analysis (NAA) with instrumental, radiochemical and prompt gamma methods (INAA, RNAA, PGNAA), the X-ray fluorescence analysis (XRFA) and the low-level counting and spectrometry. The sample irradiation sites for NAA, the automatic and manual pneumatic transfer systems, were installed at channels 7-1 and 13-2 and rotary rack on the Dalat research reactor. An ORTEC automatic sample changer (model ASC2) for γ-ray counting was equipped. A computer software for NAA based on the k 0 -standardization method for calculation of elemental concentration was developed. The low-level counting and spectrometry techniques have been setup. The devices required for sampling, sample preparation and data processing have also been equipped. The applications of N and SATs for determination of elemental composition, particularly important in providing data so-called trace elements, radionuclides and multi-element have been enlarged for objects of geology, archaeology, bio-agriculture, health-nutrition and environment. The implementation a quality system for N and SATs has been planned and initiated. (author)

Quality assurance and quality control of nuclear analytical techniques

International Nuclear Information System (INIS)

Cincu, Emanuelathor

2001-01-01

Test and analytical laboratories in East and Central European countries need to prove the reliability and credibility of their economic, environmental, medical and legal decisions and their capacity of issuing reliable, verifiable reports. These demands imposed by the European Union aimed at avoiding a possible barrier to trade for the developing countries. In June 1999, in order to help Member States to develop according to EU objectives and the overall situation of the European market, IAEA launched a new co-operation programme designed to help the nuclear analytical laboratories in nuclear institutions and universities of Member States by training in the use of some Nuclear Analytical Techniques (NAT) that include: alpha, beta and gamma-ray spectrometry, radiochemical and neutron activation analysis, total reflection X-ray fluorescence. The Regional IAEA Project, named 'Quality Assurance/Quality Control of Nuclear Analytical Techniques' (NAT) aims at implementing the QA principles via a system of defined consecutive steps leading to a level on which the QA system is self-sustainable for formal accreditation or certification and satisfies the EU technical performance criteria; the requirements are in accordance with the new ISO/IEC 17025 Standard/Dec.1999 'General requirements for the competence of testing and calibration laboratories' - First edition. The Horia Hulubei National Institute for Nuclear Physics and Engineering, IFIN-HH, was admitted for participation in the IAEA Project in June 1999 account taken of its experience in the QA and metrology fields and its performance in the fields of beta and gamma-ray spectrometry, and radiochemical and neutron activation analysis, employed in both basic research and applications for external clients. Two working groups of specialists with the QA and Standardization and Metrology Departments and six analytical groups with the departments of Nuclear Applied Physics, Life Physics and Ionising Radiation Metrology are

In Situ Analytical Characterization of Contaminated Sites Using Nuclear Spectrometry Techniques. Review of Methodologies and Measurements

International Nuclear Information System (INIS)

2017-01-01

Past and current human activities can result in the contamination of sites by radionuclides and heavy metals. The sources of contamination are various. The most important sources for radionuclide release include global fallout from nuclear testing, nuclear and radiological accidents, waste production from nuclear facilities, and activities involving naturally occurring radioactive material (NORM). Contamination of the environment by heavy metals mainly originates from industrial applications and mineralogical background concentration. Contamination of sites by radionuclides and heavy metals can present a risk to people and the environment. Therefore, the estimation of the contamination level and the identification of the source constitute important information for the national authorities with the responsibility to protect people and the environment from adverse health effects. In situ analytical techniques based on nuclear spectrometry are important tools for the characterization of contaminated sites. Much progress has been made in the design and implementation of portable systems for efficient and effective monitoring of radioactivity and heavy metals in the environment directly on-site. Accordingly, the IAEA organized a Technical Meeting to review the current status and trends of various applications of in situ nuclear spectrometry techniques for analytical characterization of contaminated sites and to support Member States in their national environmental monitoring programmes applying portable instrumentation. This publication represents a comprehensive review of the in situ gamma ray spectrometry and field portable X ray fluorescence analysis techniques for the characterization of contaminated sites. It includes papers on the use of these techniques, which provide useful background information for conducting similar studies, in the following Member States: Argentina, Australia, Brazil, Czech Republic, Egypt, France, Greece, Hungary, Italy, Lithuania

Detection of fecal residue on poultry carcasses by laser induced fluorescence imaging techniques

Science.gov (United States)

The potential use of laser-induced fluorescence imaging techniques was investigated for the detection of diluted fecal matters from various parts of the digestive tract, including colon, ceca, small intestine, and duodenum, on poultry carcasses. One of the challenges for using fluorescence imaging f...

Real-time analytics techniques to analyze and visualize streaming data

CERN Document Server

Ellis, Byron

2014-01-01

Construct a robust end-to-end solution for analyzing and visualizing streaming data Real-time analytics is the hottest topic in data analytics today. In Real-Time Analytics: Techniques to Analyze and Visualize Streaming Data, expert Byron Ellis teaches data analysts technologies to build an effective real-time analytics platform. This platform can then be used to make sense of the constantly changing data that is beginning to outpace traditional batch-based analysis platforms. The author is among a very few leading experts in the field. He has a prestigious background in research, development,

Recommendations for fluorescence instrument qualification: the new ASTM Standard Guide.

Science.gov (United States)

DeRose, Paul C; Resch-Genger, Ute

2010-03-01

Aimed at improving quality assurance and quantitation for modern fluorescence techniques, ASTM International (ASTM) is about to release a Standard Guide for Fluorescence, reviewed here. The guide's main focus is on steady state fluorometry, for which available standards and instrument characterization procedures are discussed along with their purpose, suitability, and general instructions for use. These include the most relevant instrument properties needing qualification, such as linearity and spectral responsivity of the detection system, spectral irradiance reaching the sample, wavelength accuracy, sensitivity or limit of detection for an analyte, and day-to-day performance verification. With proper consideration of method-inherent requirements and limitations, many of these procedures and standards can be adapted to other fluorescence techniques. In addition, procedures for the determination of other relevant fluorometric quantities including fluorescence quantum yields and fluorescence lifetimes are briefly introduced. The guide is a clear and concise reference geared for users of fluorescence instrumentation at all levels of experience and is intended to aid in the ongoing standardization of fluorescence measurements.

Nuclear analytical techniques in medicine

International Nuclear Information System (INIS)

Cesareo, R.

1988-01-01

This book acquaints one with the fundamental principles and the instrumentation relevant to analytical technique based on atomic and nuclear physics, as well as present and future biomedical applications. Besides providing a theoretical description of the physical phenomena, a large part of the book is devoted to applications in the medical and biological field, particularly in hematology, forensic medicine and environmental science. This volume reviews methods such as the possibility of carrying out rapid multi-element analysis of trace elements on biomedical samples, in vitro and in vivo, by XRF-analysis; the ability of the PIXE-microprobe to analyze in detail and to map trace elements in fragments of biomedical samples or inside the cells; the potentiality of in vivo nuclear activation analysis for diagnostic purposes. Finally, techniques are described such as radiation scattering (elastic and inelastic scattering) and attenuation measurements which will undoubtedly see great development in the immediate future

Nuclear analytical techniques in medicine

Energy Technology Data Exchange (ETDEWEB)

Cesareo, R.

1988-01-01

This book acquaints one with the fundamental principles and the instrumentation relevant to analytical technique based on atomic and nuclear physics, as well as present and future biomedical applications. Besides providing a theoretical description of the physical phenomena, a large part of the book is devoted to applications in the medical and biological field, particularly in hematology, forensic medicine and environmental science. This volume reviews methods such as the possibility of carrying out rapid multi-element analysis of trace elements on biomedical samples, in vitro and in vivo, by XRF-analysis; the ability of the PIXE-microprobe to analyze in detail and to map trace elements in fragments of biomedical samples or inside the cells; the potentiality of in vivo nuclear activation analysis for diagnostic purposes. Finally, techniques are described such as radiation scattering (elastic and inelastic scattering) and attenuation measurements which will undoubtedly see great development in the immediate future.

Recent Developments in the Speciation and Determination of Mercury Using Various Analytical Techniques

Directory of Open Access Journals (Sweden)

Lakshmi Narayana Suvarapu

2015-01-01

Full Text Available This paper reviews the speciation and determination of mercury by various analytical techniques such as atomic absorption spectrometry, voltammetry, inductively coupled plasma techniques, spectrophotometry, spectrofluorometry, high performance liquid chromatography, and gas chromatography. Approximately 126 research papers on the speciation and determination of mercury by various analytical techniques published in international journals since 2013 are reviewed.

Conference on Nuclear and Conventional Analytical Techniques and their Applications

International Nuclear Information System (INIS)

2010-01-01

Full text : A panoply analytic techniques methods has emerged in recent decades due to the challenges of society in quality of products and the increasing demand of chemical analysis services. The industrial progress which came along with an instrumental perfection of devices with analytical use, led to the development of new techniques more and more advanced in this field. These come as well, to answer the disturbing effects of this industrialization and the wishes of a public increasingly conscious and requiring globally. The leaders in this field of analysis and material characterization are more than ever confronted with problems of identification and quantification of different chemical forms of a multitude of products in varied circles; Industrial pollutants, soil, water, air, food, medicines, ceramics, concrete, plants etc. It was from that perspective that the unifying theme ''geomaterials: characterization to applications '' of the conference on nuclear and conventional analytical techniques and their applications (TANCA 2010) was chosen. It contributes to the debate of these subjects and builds relationships between stakeholders in this field, both technically and practically [fr

Romanian medieval earring analysis by X-ray fluorescence technique

International Nuclear Information System (INIS)

Therese, Laurent; Guillot, Philippe; Muja, Cristina

2011-01-01

Full text: Several instrumental techniques of elemental analysis are now used for the characterization of archaeological materials. The combination between archaeological and analytical information can provide significant knowledge on the constituting material origin, heritage authentication and restoration, provenance, migration, social interaction and exchange. Surface mapping techniques such as X-Ray Fluorescence have become a powerful tool for obtaining qualitative and semi-quantitative information about the chemical composition of cultural heritage materials, including metallic archaeological objects. In this study, the material comes from the Middle Age cemetery of Feldioara (Romania). The excavation of the site located between the evangelical church and the parsonage led to the discovery of several funeral artifacts in 18 graves among a total of 127 excavated. Even if the inventory was quite poor, some of the objects helped in establishing the chronology. Six anonymous Hungarian denarii (silver coins) were attributed to Geza II (1141-1161) and Stefan III (1162-1172), placing the cemetery in the second half of the XII century. This period was also confirmed by three loop shaped earrings with the end in 'S' form (one small and two large earrings). The small earring was found during the excavation in grave number 86, while the two others were discovered together in grave number 113. The anthropological study shown that skeletons excavated from graves 86 and 113 belonged respectively to a child (1 individual, medium level preservation, 9 months +/- 3 months) and to an adult (1 individual). In this work, elemental mapping were obtained by X-ray fluorescence (XRF) technique from Jobin Yvon Horiba XGT-5000 instrument offering detailed elemental images with a spatial resolution of 100μm. The analysis revealed that the earrings were composed of copper, zinc and tin as major elements. Minor elements were also determined. The comparison between the two large earrings

Romanian medieval earring analysis by X-ray fluorescence technique

Energy Technology Data Exchange (ETDEWEB)

Therese, Laurent; Guillot, Philippe, E-mail: philippe.guillot@univ-jfc.fr [Laboratoire Diagnostics des Plasmas, CUFR J.F.C, Albi (France); Muja, Cristina [Laboratoire Diagnostics des Plasmas, CUFR J.F.C, Albi (France); Faculty of Biology, University of Bucharest (Romania); Vasile Parvan Institute of Archaeology, Bucharest, (Romania)

2011-07-01

Full text: Several instrumental techniques of elemental analysis are now used for the characterization of archaeological materials. The combination between archaeological and analytical information can provide significant knowledge on the constituting material origin, heritage authentication and restoration, provenance, migration, social interaction and exchange. Surface mapping techniques such as X-Ray Fluorescence have become a powerful tool for obtaining qualitative and semi-quantitative information about the chemical composition of cultural heritage materials, including metallic archaeological objects. In this study, the material comes from the Middle Age cemetery of Feldioara (Romania). The excavation of the site located between the evangelical church and the parsonage led to the discovery of several funeral artifacts in 18 graves among a total of 127 excavated. Even if the inventory was quite poor, some of the objects helped in establishing the chronology. Six anonymous Hungarian denarii (silver coins) were attributed to Geza II (1141-1161) and Stefan III (1162-1172), placing the cemetery in the second half of the XII century. This period was also confirmed by three loop shaped earrings with the end in 'S' form (one small and two large earrings). The small earring was found during the excavation in grave number 86, while the two others were discovered together in grave number 113. The anthropological study shown that skeletons excavated from graves 86 and 113 belonged respectively to a child (1 individual, medium level preservation, 9 months +/- 3 months) and to an adult (1 individual). In this work, elemental mapping were obtained by X-ray fluorescence (XRF) technique from Jobin Yvon Horiba XGT-5000 instrument offering detailed elemental images with a spatial resolution of 100{mu}m. The analysis revealed that the earrings were composed of copper, zinc and tin as major elements. Minor elements were also determined. The comparison between the two

Indirect Fluorescent Antibody Technique based Prevalence of Surra in Equines

Directory of Open Access Journals (Sweden)

Ahsan Nadeem, Asim Aslam*, Zafar Iqbal Chaudhary, Kamran Ashraf1, Khalid Saeed1, Nisar Ahmad1, Ishtiaq Ahmed and Habib ur Rehman2

2011-04-01

Full Text Available This project was carried out to find the prevalence of trypanosomiasis in equine in District Gujranwala by using indirect fluorescent antibody technique and thin smear method. Blood samples were collected from a total of 200 horses and donkeys of different ages and either sex. Duplicate thin blood smears were prepared from each sample and remaining blood samples were centrifuged to separate the serum. Smears from each animal were processed for giemsa staining and indirect fluorescent antibody test (IFAT. Giemsa stained smears revealed Trypanosome infection in 4/200 (2.0% samples and IFAT in 12/200 (6.0% animals.

Analytical Techniques and the Air Force Logistics Readiness Officer

National Research Council Canada - National Science Library

Main, Bryan D

2008-01-01

.... Over 500 LROs and supervisors provided inputs. Analysis of survey responses found that Forecasting, Graphical Statistics, and Descriptive Statistics are the analytical techniques valued most by both LROs and their supervisors...

Inductively coupled plasma-atomic emission spectrometry: analytical assessment of the technique at the beginning of the 90's

International Nuclear Information System (INIS)

Sanz-Medel, A.

1991-01-01

The main application of the inductively coupled plasma (ICP) today is in atomic emission spectroscopy (AES), as an excitation spectrochemical source, although uses of an ICP for fluorescence as just an atomizer, and specially for mass spectrometry, as an ionization source, are rocketing in the last few years. Since its inception, only a quarter of a century ago, ICP-AES has rapidly evolved to one of the preferred routine analytical techniques for convenient determination of many elements with high speed, at low levels and in the most varied samples. Perhaps its comparatively high kinetic temperature (capable of atomizing virtually every compound of any sample), its high excitation and ionization temperatures, and its favourable spatial structure at the core of the ICP success. By now, the ICP-AES can be considered as having achieved maturity in that a huge amount of analytical problems can be tackled with this technique, while no major or fundamental changes have been adopted for several years. Despite this fact, important driving forces are still in operation to further improve the ICP-AES sensitivity, selectivity, precision, sample throughput, etc. Moreover, proposals to extend the scope of the technique to traditionally elusive fields (e.g. non-metals and organic compound analysis) are also appearing in the recent literature. In this paper the 'state of the art', the last developments and the expectations in trying to circumvent the limitations of the ICP-AES (on the light of literature data and personal experience) are reviewed. (author)

Complementarities of nuclear-based analytical techniques for the characterization of thin film technological materials

International Nuclear Information System (INIS)

Bamford, Samuel; Kregsamer, Peter; Fazinic, Stjepko; Jaksic, Milko; Wegrzynek, Dariusz; Chinea-Cano, Ernesto; Markowicz, Andrzej

2007-01-01

Two thin film technological materials (A/B) from the aerospace industry have been characterized for their elemental composition, for the purpose of determining their purity and trace element distribution. The results contribute to the assessment of the materials' suitability as part of a spacecraft's thermal hardware. Analysis was done using a combination of PIXE/RBS and energy dispersive X-ray fluorescence (EDXRF) analytical techniques. Samples of the materials were analyzed with PIXE/RBS system using 2 MeV proton beam from a 1 MV Tandetron accelerator and also with separate EDXRF systems employing Am-241 and Mo-secondary target as excitation sources. PIXE/RBS measurements enabled identification of the elemental composition and elucidation of the layer structure of the materials. From the PIXE/RBS results, Am-241-excited EDXRF technique was selected for quantitative determination of indium (In) and tin (Sn) by their K-X-rays, after reasonable absorption corrections. A comparison has been made of the results obtained from EDXRF and PIXE/RBS. Material A has been found to be a thin film with three layers, while material B is a thin film comprised of four layers. Thicknesses and compositions (including trace elements) of all layers have been determined. The limitation of EDXRF in the analysis of inhomogeneously distributed elements was overcome by using PIXE/RBS as an appropriate complimentary technique

Nuclear analytical techniques with neutron beams at the Univ. of Texas at Austin

International Nuclear Information System (INIS)

Uenlue, K.; Wehring, B.W.

1996-01-01

Neutron beams produced by nuclear research reactors can be used for analytical chemical analysis by measuring nuclear radiation produced by neutron capture. Prompt gamma activation analysis (PGAA) and neutron depth profiling (NDP) are two such analytical techniques. For the last three decades, these techniques have been applied at a number of research reactors around the world. Within the last 4 yr, we have developed NDP and PGAA facilities at The University of Texas at Austin research reactor, a 1-MW TRIGA Mark II reactor. Brief descriptions of the facilities and summaries of activities for these analytical techniques at the University of Texas at Austin are provided in this paper

Recent advances in nuclear techniques for environmental radioactivity monitoring

International Nuclear Information System (INIS)

Kumar, Ajay; Tripathi, R.M.

2016-01-01

The environmental radioactivity monitoring was first started in the late 1950s following the global fallout from testing of nuclear weapons in the atmosphere. Nuclear analytical techniques are generally classified into two categories: destructive and non-destructive. Destructive techniques are carried out through several analytical methods such as α-spectrometry, liquid Scintillation counting system, solid state nuclear track detector, spectrophotometry, fluorimetry, atomic absorption spectrometry (AAS), inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma optical emission spectrometry (ICP-OES), chromatography techniques, electro-analytical techniques etc. However, nondestructive methods include gamma spectrometry, X-Ray fluorescence (XRF) spectrometry, neutron activation analysis (NAA) etc. The development of radiochemical methods and measurement techniques using alpha and gamma spectrometry have been described in brief

Determination of lead in clay enameled by X-ray fluorescence technique in Total reflection and by Scanning Electron Microscopy; Determinacion de plomo en esmaltado de barro por Fluorescencia de rayos X en reflexion total y Microscopia Electronica de Barrido

Energy Technology Data Exchange (ETDEWEB)

Zarazua O, G.; Carapia M, L. [Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Estado de Mexico (Mexico)

2000-07-01

This work has the objective of determining lead free in the glazed commercial stewing pans using the X-ray fluorescence technique in Total reflection (FRX) and the observation and semiquantitative determination of lead by Analytical Scanning Electron Microscopy (ASEM). (Author)

Total reflection X-ray fluorescence and archaeometry: Application in the Argentinean cultural heritage

Energy Technology Data Exchange (ETDEWEB)

Vazquez, Cristina [Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); Laboratorio de Quimica de Sistemas Heterogeneos, Facultad de Ingenieria, Universidad de Buenos Aires, P. Colon 850 (C1063ACU), Buenos Aires (Argentina)], E-mail: Cristina.Vazquez@cnea.gov.ar; Albornoz, Ana [Agencia Rio Negro Cultura, Museo de la Patagonia F.P.Moreno, Centro Civico s/n Bariloche, Rio Negro (Argentina); Hajduk, Adam [CONICET, Museo de la Patagonia F.P.Moreno, Centro Civico s/n Bariloche, Rio Negro (Argentina); Elkin, Dolores [CONICET Instituto Nacional de Antropologia y Pensamiento Latinoamericano, 3 de febrero 1378 (C1426AEL) Buenos Aires (Argentina); Custo, Graciela; Obrustky, Alba [Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina)

2008-12-15

Archaeometry is an interdisciplinary research area involved in the development and use of scientific methods in order to answer questions concerned with the human history. In this way the knowledge of archaeological objects through advanced chemical and physical analyses permits a better preservation and conservation of the cultural heritage and also reveals materials and technologies used in the past. In this sense, analytical techniques play an important role in order to provide chemical information about cultural objects. Considering the non destructive characteristic of this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Taking into account the irreplaceable character of the archaeological and artistic materials considered in this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Total Reflection X-ray Fluorescence Spectrometry as a geometric variant of conventional X-ray fluorescence is a proved microanalytical technique considering the small amount of sample required for the analysis. A few micrograms are enough in order to reveal valuable information about elemental composition and in this context it is highly recommended for artwork studies. In this paper a case study is presented in which Total Reflection X-Ray Fluorescence Spectrometry has been successfully employed in the archaeometry field. Examples from Argentinean cultural heritage sites related with the determination of pigments in paintings on canvas and in rock sites as well as in underwater archaeology research are shown.

Determination of palladium in biological samples applying nuclear analytical techniques

International Nuclear Information System (INIS)

Cavalcante, Cassio Q.; Sato, Ivone M.; Salvador, Vera L. R.; Saiki, Mitiko

2008-01-01

This study presents Pd determinations in bovine tissue samples containing palladium prepared in the laboratory, and CCQM-P63 automotive catalyst materials of the Proficiency Test, using instrumental thermal and epithermal neutron activation analysis and energy dispersive X-ray fluorescence techniques. Solvent extraction and solid phase extraction procedures were also applied to separate Pd from interfering elements before the irradiation in the nuclear reactor. The results obtained by different techniques were compared against each other to examine sensitivity, precision and accuracy. (author)

Measuring reactive oxygen and nitrogen species with fluorescent probes: challenges and limitations

Science.gov (United States)

Kalyanaraman, Balaraman; Darley-Usmar, Victor; Davies, Kelvin J.A.; Dennery, Phyllis A.; Forman, Henry Jay; Grisham, Matthew B.; Mann, Giovanni E.; Moore, Kevin; Roberts, L. Jackson; Ischiropoulos, Harry

2013-01-01

The purpose of this position paper is to present a critical analysis of the challenges and limitations of the most widely used fluorescent probes for detecting and measuring reactive oxygen and nitrogen species. Where feasible, we have made recommendations for the use of alternate probes and appropriate analytical techniques that measure the specific products formed from the reactions between fluorescent probes and reactive oxygen and nitrogen species. We have proposed guidelines that will help present and future researchers with regard to the optimal use of selected fluorescent probes and interpretation of results. PMID:22027063

Contactless conductivity detection for analytical techniques — Developments from 2014 to 2016

Czech Academy of Sciences Publication Activity Database

Kubáň, Pavel; Hauser, P.C.

2017-01-01

Roč. 38, č. 1 (2017), s. 95-114 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : capacitively coupled contactless conductivity detection * capillary electrophoresis * contactless conductivity detection * analytical techniques * review Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 2.744, year: 2016

A Visual Analytics Technique for Identifying Heat Spots in Transportation Networks

Directory of Open Access Journals (Sweden)

Marian Sorin Nistor

2016-12-01

Full Text Available The decision takers of the public transportation system, as part of urban critical infrastructures, need to increase the system resilience. For doing so, we identified analysis tools for biological networks as an adequate basis for visual analytics in that domain. In the paper at hand we therefore translate such methods for transportation systems and show the benefits by applying them on the Munich subway network. Here, visual analytics is used to identify vulnerable stations from different perspectives. The applied technique is presented step by step. Furthermore, the key challenges in applying this technique on transportation systems are identified. Finally, we propose the implementation of the presented features in a management cockpit to integrate the visual analytics mantra for an adequate decision support on transportation systems.

Pre-concentration technique for reduction in "Analytical instrument requirement and analysis"

Science.gov (United States)

Pal, Sangita; Singha, Mousumi; Meena, Sher Singh

2018-04-01

Availability of analytical instruments for a methodical detection of known and unknown effluents imposes a serious hindrance in qualification and quantification. Several analytical instruments such as Elemental analyzer, ICP-MS, ICP-AES, EDXRF, ion chromatography, Electro-analytical instruments which are not only expensive but also time consuming, required maintenance, damaged essential parts replacement which are of serious concern. Move over for field study and instant detection installation of these instruments are not convenient to each and every place. Therefore, technique such as pre-concentration of metal ions especially for lean stream elaborated and justified. Chelation/sequestration is the key of immobilization technique which is simple, user friendly, most effective, least expensive, time efficient; easy to carry (10g - 20g vial) to experimental field/site has been demonstrated.

International conference on isotopic and nuclear analytical techniques for health and environment. Book of abstracts

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

Decision makers and stakeholders are becoming increasingly dependent on reliable chemical measurements that serve as a basis for decisions related to health, consumer safety, commerce, environment protection and compliance to regulations. Several millions of analytical results are produced annually, thus consuming appreciable amounts of resources. Reliability of these data is of major concern if cost-benefit figures are applied. Nuclear and isotopic analytical techniques (NATs) have been supported by the IAEA as part of their mandate to foster the peaceful use of nuclear energy for many years. Nuclear analytical laboratories have been installed and upgraded through Technical Co-operation assistance in many Member State laboratories. These techniques, including INAA, XRF, PIXE, stable and radioisotopes, spectrometroscopy, etc. have been applied to a wide range of subjects with varying success. Nuclear analytical techniques, featuring some intrinsic quality control aspects, such as multi-nuclide analysis, frequently serve as 'reference methods' to cross-check critical results. As nuclear properties of elements are targeted, matrix problems seem to be negligible to a great extent. The International Conference on Isotopic and Nuclear Analytical Techniques for Health and Environment was held 10-13 June 2003 in Vienna, Austria. The main purpose of this Conference was to bring together scientists, technologists, representatives of industry and regulatory authorities to exchange information and review the status of current developments and applications of isotopic and nuclear analytical techniques, and to discuss future trends and developments. A further objective is to identify potential opportunities for developing countries for applying isotopic and nuclear analytical techniques in health and environmental studies, and to consider the promotion and transfer of such technology. International developments and trends in health care, nutrition, and environmental monitoring

Topics: in vivo measurement of thyroidal iodine content by x-ray fluorescent technique

International Nuclear Information System (INIS)

Imamura, Keiko

1979-01-01

Thyroidal iodine content gives useful informations in the fields of physiology, clinical medicine, health physics etc. Iodine content has been determined mainly for resected thyroids. Recently, x-ray fluorescent analysis has been extended as the in vivo technique first in the clinical medicine. Exciting sources used for the analysis of the thyroid are Am-241 or x-ray tube. Am-241 has a half-life of 438 years and emits #betta#-ray of 60 keV. Thyroid can be imaged by fluorescent scan utilizing strong (10 - 15 Ci) Am-241 source. Examination time is about 15 min and the radiation dose to the gland is about 15 - 60 mrad. Iodine content is determined by static fluorescent technique equipped with weaker source of less than 1 Ci. Thyroidal iodine content in normal subjects were analysed by this technique and the results were in good accordance with those obtained by in vitro analysis. Difference in the thyroidal iodine content between the Japanese population and other countries is not clear. Application to the pathological cases has provided many findings about the iodine content and its distribution which could not be obtained by in vitro analysis. This in vivo technique can be safely performed for infants and for pregnancies, and the relatively compact size of this apparatus could be widely used in the study of health physics and environmental problems. (author)

Application of metabonomic analytical techniques in the modernization and toxicology research of traditional Chinese medicine.

Science.gov (United States)

Lao, Yong-Min; Jiang, Jian-Guo; Yan, Lu

2009-08-01

In the recent years, a wide range of metabonomic analytical techniques are widely used in the modern research of traditional Chinese medicine (TCM). At the same time, the international community has attached increasing importance to TCM toxicity problems. Thus, many studies have been implemented to investigate the toxicity mechanisms of TCM. Among these studies, many metabonomic-based methods have been implemented to facilitate TCM toxicity investigation. At present, the most prevailing methods for TCM toxicity research are mainly single analysis techniques using only one analytical means. These techniques include nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS), etc.; with these techniques, some favourable outcomes have been gained in the toxic reaction studies of TCM, such as the action target organs assay, the establishment of action pattern, the elucidation of action mechanism and the exploration of action material foundation. However, every analytical technique has its advantages and drawbacks, no existing analytical technique can be versatile. Multi-analysed techniques can partially overcome the shortcomings of single-analysed techniques. Combination of GC-MS and LC-MS metabolic profiling approaches has unravelled the pathological outcomes of aristolochic acid-induced nephrotoxicity, which can not be achieved by single-analysed techniques. It is believed that with the further development of metabonomic analytical techniques, especially multi-analysed techniques, metabonomics will greatly promote TCM toxicity research and be beneficial to the modernization of TCM in terms of extending the application of modern means in the TCM safety assessment, assisting the formulation of TCM safety norms and establishing the international standards indicators.

Application of advanced nuclear and instrumental analytical techniques for characterisation of environmental materials

International Nuclear Information System (INIS)

Sudersanan, M.; Pawaskar, P.B.; Kayasth, S.R.; Kumar, S.C.

2002-01-01

Full text: Increasing realisation about the toxic effects of metal ions in environmental materials has given an impetus to research on analytical techniques for their characterization. The large number of analytes present at very low levels has necessitated the use of sensitive, selective and element specific techniques for their characterization. The concern about precision and accuracy on such analysis, which have socio-economic bearing, has emphasized the use of Certified Reference Materials and the use of multi-technique approach for the unambiguous characterization of analytes. The recent work carried out at Analytical Chemistry Division, BARC on these aspects is presented in this paper. Increasing use of fossil fuels has led to the generation of large quantities of fly ash which pose problems of safe disposal. The utilization of these materials for land filling is an attractive option but the presence of trace amounts of toxic metals like mercury, arsenic, lead etc may cause environmental problems. In view of the inhomogeneous nature of the material, efficient sample processing is an important factor, in addition to the validation of the results by the use of proper standards. Analysis was carried out on flyash samples received as reference materials and also as samples from commercial sources using a combination of both nuclear techniques like INAA and RNAA as well as other techniques like AAS, ICPAES, cold vapour AAS for mercury and hydride generation technique for arsenic. Similar analysis using nuclear techniques was employed for the characterization of air particulates. Biological materials often serve as sensitive indicator materials for pollution measurements. They are also employed for studies on the uptake of toxic metals like U, Th, Cd, Pb, Hg etc. The presence of large amounts of organic materials in them necessitate an appropriate sample dissolution procedure. In view of the possibility of loss of certain analytes like Cd, Hg, As, by high

Evaluating empirical/analytical techniques to predict structural integrity of pipe containing surface flaws

International Nuclear Information System (INIS)

Reuter, W.G.; Server, W.L.

1982-01-01

Data from flat-plate specimens containing either triangular-, ellipsoidal- or rectangular-shaped surface flaws were evaluated by several potential analytical techniques. These techniques were modified as needed to predict conditions for initiation of subcritical crack growth, for the defect to penetrate the 6.4 mm (0.25 in.) wall thickness, and for instability (plastic or unstable). The modified analytical techniques developed from the plate specimens were then used to make predictions which are compared with test results obtained from pipe specimens containing triangular-shaped surface flaws

Structural level characterization of base oils using advanced analytical techniques

KAUST Repository

Hourani, Nadim; Muller, Hendrik; Adam, Frederick M.; Panda, Saroj K.; Witt, Matthias; Al-Hajji, Adnan A.; Sarathy, Mani

2015-01-01

cyclotron resonance mass spectrometry (FT-ICR MS) equipped with atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) sources. First, the capabilities and limitations of each analytical technique were evaluated

Recent developments and future trends in solid phase microextraction techniques towards green analytical chemistry.

Science.gov (United States)

Spietelun, Agata; Marcinkowski, Łukasz; de la Guardia, Miguel; Namieśnik, Jacek

2013-12-20

Solid phase microextraction find increasing applications in the sample preparation step before chromatographic determination of analytes in samples with a complex composition. These techniques allow for integrating several operations, such as sample collection, extraction, analyte enrichment above the detection limit of a given measuring instrument and the isolation of analytes from sample matrix. In this work the information about novel methodological and instrumental solutions in relation to different variants of solid phase extraction techniques, solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE) and magnetic solid phase extraction (MSPE) is presented, including practical applications of these techniques and a critical discussion about their advantages and disadvantages. The proposed solutions fulfill the requirements resulting from the concept of sustainable development, and specifically from the implementation of green chemistry principles in analytical laboratories. Therefore, particular attention was paid to the description of possible uses of novel, selective stationary phases in extraction techniques, inter alia, polymeric ionic liquids, carbon nanotubes, and silica- and carbon-based sorbents. The methodological solutions, together with properly matched sampling devices for collecting analytes from samples with varying matrix composition, enable us to reduce the number of errors during the sample preparation prior to chromatographic analysis as well as to limit the negative impact of this analytical step on the natural environment and the health of laboratory employees. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis of Cultural Heritage by Accelerator Techniques and Analytical Imaging

Science.gov (United States)

Ide-Ektessabi, Ari; Toque, Jay Arre; Murayama, Yusuke

2011-12-01

In this paper we present the result of experimental investigation using two very important accelerator techniques: (1) synchrotron radiation XRF and XAFS; and (2) accelerator mass spectrometry and multispectral analytical imaging for the investigation of cultural heritage. We also want to introduce a complementary approach to the investigation of artworks which is noninvasive and nondestructive that can be applied in situ. Four major projects will be discussed to illustrate the potential applications of these accelerator and analytical imaging techniques: (1) investigation of Mongolian Textile (Genghis Khan and Kublai Khan Period) using XRF, AMS and electron microscopy; (2) XRF studies of pigments collected from Korean Buddhist paintings; (3) creating a database of elemental composition and spectral reflectance of more than 1000 Japanese pigments which have been used for traditional Japanese paintings; and (4) visible light-near infrared spectroscopy and multispectral imaging of degraded malachite and azurite. The XRF measurements of the Japanese and Korean pigments could be used to complement the results of pigment identification by analytical imaging through spectral reflectance reconstruction. On the other hand, analysis of the Mongolian textiles revealed that they were produced between 12th and 13th century. Elemental analysis of the samples showed that they contained traces of gold, copper, iron and titanium. Based on the age and trace elements in the samples, it was concluded that the textiles were produced during the height of power of the Mongol empire, which makes them a valuable cultural heritage. Finally, the analysis of the degraded and discolored malachite and azurite demonstrates how multispectral analytical imaging could be used to complement the results of high energy-based techniques.

Energy-dispersive X-ray fluorescence analysis of cerium in ferrosilicon

International Nuclear Information System (INIS)

Marbec, E.R.

1987-01-01

The cerium was determined in ferrosilicon samples by energy-dispersive X-ray fluorescence techniques (XRF) techniques, with a secondary target of gadolinium. The methods employed were: comparison and linear regression with reference materials with cerium concentration between 0.4 and 1.0%. The samples were prepared in the form of pellets and the analytical results are reported as an average of five determinations with a confidence limits at 95% probability. (Author) [es

Analytical techniques for wine analysis: An African perspective; a review

International Nuclear Information System (INIS)

Villiers, André de; Alberts, Phillipus; Tredoux, Andreas G.J.; Nieuwoudt, Hélène H.

2012-01-01

Highlights: ► Analytical techniques developed for grape and wine analysis in Africa are reviewed. ► The utility of infrared spectroscopic methods is demonstrated. ► An overview of separation of wine constituents by GC, HPLC, CE is presented. ► Novel LC and GC sample preparation methods for LC and GC are presented. ► Emerging methods for grape and wine analysis in Africa are discussed. - Abstract: Analytical chemistry is playing an ever-increasingly important role in the global wine industry. Chemical analysis of wine is essential in ensuring product safety and conformity to regulatory laws governing the international market, as well as understanding the fundamental aspects of grape and wine production to improve manufacturing processes. Within this field, advanced instrumental analysis methods have been exploited more extensively in recent years. Important advances in instrumental analytical techniques have also found application in the wine industry. This review aims to highlight the most important developments in the field of instrumental wine and grape analysis in the African context. The focus of this overview is specifically on the application of advanced instrumental techniques, including spectroscopic and chromatographic methods. Recent developments in wine and grape analysis and their application in the African context are highlighted, and future trends are discussed in terms of their potential contribution to the industry.

Analytical techniques for wine analysis: An African perspective; a review

Energy Technology Data Exchange (ETDEWEB)

Villiers, Andre de, E-mail: ajdevill@sun.ac.za [Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch (South Africa); Alberts, Phillipus [Department of Chemistry and Polymer Science, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch (South Africa); Tredoux, Andreas G.J.; Nieuwoudt, Helene H. [Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch (South Africa)

2012-06-12

Highlights: Black-Right-Pointing-Pointer Analytical techniques developed for grape and wine analysis in Africa are reviewed. Black-Right-Pointing-Pointer The utility of infrared spectroscopic methods is demonstrated. Black-Right-Pointing-Pointer An overview of separation of wine constituents by GC, HPLC, CE is presented. Black-Right-Pointing-Pointer Novel LC and GC sample preparation methods for LC and GC are presented. Black-Right-Pointing-Pointer Emerging methods for grape and wine analysis in Africa are discussed. - Abstract: Analytical chemistry is playing an ever-increasingly important role in the global wine industry. Chemical analysis of wine is essential in ensuring product safety and conformity to regulatory laws governing the international market, as well as understanding the fundamental aspects of grape and wine production to improve manufacturing processes. Within this field, advanced instrumental analysis methods have been exploited more extensively in recent years. Important advances in instrumental analytical techniques have also found application in the wine industry. This review aims to highlight the most important developments in the field of instrumental wine and grape analysis in the African context. The focus of this overview is specifically on the application of advanced instrumental techniques, including spectroscopic and chromatographic methods. Recent developments in wine and grape analysis and their application in the African context are highlighted, and future trends are discussed in terms of their potential contribution to the industry.

CMOS Time-Resolved, Contact, and Multispectral Fluorescence Imaging for DNA Molecular Diagnostics

Directory of Open Access Journals (Sweden)

Nan Guo

2014-10-01

Full Text Available Instrumental limitations such as bulkiness and high cost prevent the fluorescence technique from becoming ubiquitous for point-of-care deoxyribonucleic acid (DNA detection and other in-field molecular diagnostics applications. The complimentary metal-oxide-semiconductor (CMOS technology, as benefited from process scaling, provides several advanced capabilities such as high integration density, high-resolution signal processing, and low power consumption, enabling sensitive, integrated, and low-cost fluorescence analytical platforms. In this paper, CMOS time-resolved, contact, and multispectral imaging are reviewed. Recently reported CMOS fluorescence analysis microsystem prototypes are surveyed to highlight the present state of the art.

Preparation and application of new fluorescein-labeled fumonisins B1 in fluorescence polarization analysis technique

Science.gov (United States)

Objective: To prepare a new fluorescent tracer against common mycotoxins such as fumonisin B1 in order to replace 6-(4,6-Dichlorotriazinyl) aminofluorescein (6-DTAF), an expensive marker, and to develop a technique for quick detection of fumonisin B1 based on the principle of fluorescence polarizati...

A Simplified Analytical Technique for High Frequency Characterization of Resonant Tunneling Diode

Directory of Open Access Journals (Sweden)

DESSOUKI, A. A. S.

2014-11-01

Full Text Available his paper proposes a simplified analytical technique for high frequency characterization of the resonant tunneling diode (RTD. An equivalent circuit of the RTD that consists of a parallel combination of conductance, G (V, f, and capacitance, C (V, f is formulated. The proposed approach uses the measured DC current versus voltage characteristic of the RTD to extract the equivalent circuit elements parameters in the entire bias range. Using the proposed analytical technique, the frequency response - including the high frequency range - of many characteristic aspects of the RTD is investigated. Also, the maximum oscillation frequency of the RTD is calculated. The results obtained have been compared with those concluded and reported in the literature. The reported results in literature were obtained through simulation of the RTD at high frequency using either a computationally complicated quantum simulator or through difficult RF measurements. A similar pattern of results and highly concordant conclusion are obtained. The proposed analytical technique is simple, correct, and appropriate to investigate the behavior of the RTD at high frequency. In addition, the proposed technique can be easily incorporated into SPICE program to simulate circuits containing RTD.

Applications of Liquid Chromatography with Fluorescence Detector Diodes and the Analysis of Environmental Pollutants

International Nuclear Information System (INIS)

Garcia, S.; Perez, R. M.

2012-01-01

It presents a review on the determination of major types of organic pollutants in environmental samples by HPLC with diode array or fluorescence molecular detectors. Main objective has been to make a compilation of the analytical potential of the technique based on literature and our laboratory studies on the main aspects of analytical methodology used in the determination of these compounds. (Author) 53 refs.

Technique of sample preparation for analysis of gasoline and lubricating oils by X-ray fluorescence analysis

International Nuclear Information System (INIS)

Avila P, P.

1990-03-01

The X-ray fluorescence laboratory of the National Institute of Nuclear Research when not having a technique for the analysis of oils it has intended, with this work, to develop a preparation technique for the analysis of the metals of Pb, Cr, Ni, V and Mo in gasolines and oils, by means of the spectrometry by X-ray fluorescence analysis. The obtained results, its will be of great utility for the one mentioned laboratory. (Author)

Instrumental analytical techniques in geochemistry: Requirements and applications

International Nuclear Information System (INIS)

Willis, J.P.

1986-01-01

Geochemists must analyse an extremely wide range of terrestrial and planetary materials. The instrumental techniques necessary to cope with this difficult task are considered. The most important analytical techniques in use by the geochemist today are AAS, ICP-OES, INAA, MSID and XRFS, and the electron microscope for in situ mineral analysis. Some applications of these techniques to solving major problems in geochemistry are discussed. The importance of certified reference materials and of high quality geochemical data are emphasized. It is concluded that the general quality of trace element data has improved over the past 25 years, as a direct result of the application of modern instrumental techniques. Surprisingly, the quality of data reported for certain major elements has deteriorated over that time, when compared with data obtainable by classical chemical methods. Predictions are made concerning the instrumentation needs of the next generation of geochemists. (orig.) [de

Rapid analysis of molybdenum contents in molybdenum master alloys by X-ray fluorescence technique

International Nuclear Information System (INIS)

Tongkong, P.

1985-01-01

Determination of molybdenum contents in molybdenum master alloy had been performed using energy dispersive x-ray fluorescence (EDX) technique where analysis were made via standard additions and calibration curves. Comparison of EDX technique with other analyzing techniques, i.e., wavelength dispersive x-ray fluorescence, neutron activation analysis and inductive coupled plasma spectrometry, showed consistency in the results. This technique was found to yield reliable results when molybdenum contents in master alloys were in the range of 13 to 50 percent using HPGe detector or proportional counter. When the required error was set at 1%, the minimum analyzing time was found to be 30 and 60 seconds for Fe-Mo master alloys with molybdenum content of 13.54 and 49.09 percent respectively. For Al-Mo master alloys, the minimum times required were 120 and 300 seconds with molybdenum content of 15.22 and 47.26 percent respectively

Improvement of Analytical Technique for Determination of Gold in ...

African Journals Online (AJOL)

This article elucidates the improvement of analytical technique for determination of gold in geological matrix. Samples suspected to have gold in them were subjected to neutron flux from the Nigeria Research Reactor (NRR-1), a Miniature Neutron Source Reactor (MNSR). Two geological samples – one sample was ...

In-depth characterization of prebiotic galactooligosaccharides by a combination of analytical techniques

NARCIS (Netherlands)

Coulier, L.; Timmermans, J.; Richard, B.; Dool, R. van den; Haaksman, I.; Klarenbeek, B.; Slaghek, T.; Dongen, W. van

2009-01-01

A commercial prebiotic galacto-oligosaccharide mixture (Vivinal GOS) was extensively characterized using a combination of analytical techniques. The different techniques were integrated to give complementary information on specific characteristics of the oligosaccharide mixture, ranging from global

Reviews in fluorescence 2010

CERN Document Server

Geddes, Chris D

2011-01-01

""Reviews in Fluorescence 2010"", the seventh volume of the book serial from Springer, serves as a comprehensive collection of current trends and emerging hot topics in the field of fluorescence and closely related disciplines. It summarizes the year's progress in fluorescence and its applications, with authoritative analytical reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. ""Reviews in Fluorescence"" offers an essential reference material for any lab working in the fluoresc

Proceedings of the 8. Brazilian meeting on analytical chemistry. Abstracts

International Nuclear Information System (INIS)

1995-01-01

Abstracts from theoretical and experimental works on qualitative and quantitative analytical chemistry are presented. Several nuclear and non nuclear techniques have been used, such as neutron activation analysis, absorption spectroscopy, x-ray fluorescence analysis and others. The materials analysed were rocks, rare earths, environmental materials (soil, water, air), complexes and so on. Synthesis, kinetics and radiochemistry were also discussed

Development of analytical techniques in support of waste and effluent characterization

International Nuclear Information System (INIS)

Reed, W.J.

1991-01-01

The Analytical Services Group within Sellafield Technical Department has been established for >40 yr and employs >150 analysts. The group operates >400 analytical methods across a wide range of techniques and has a yearly workload of ∼250,000 determinations. The group operates under a quality system based on statistical process control that has achieved national recognition through the accreditation of its mass spectrometry and radiochemical services to the standard of national testing laboratories. The group offers services ranging from the characterization of highly active wastes to trace elemental and radiochemical measurements in environmental, biological, and effluent streams. The group has vast experience in the management of analytical services to tight time scales and has pioneered developments not only in analytical instrumentation, but also in the adaptation of equipment to radioactive environments and the design of dedicated analytical facilities

Trends in analytical techniques applied to particulate matter characterization: A critical review of fundaments and applications.

Science.gov (United States)

Galvão, Elson Silva; Santos, Jane Meri; Lima, Ana Teresa; Reis, Neyval Costa; Orlando, Marcos Tadeu D'Azeredo; Stuetz, Richard Michael

2018-05-01

Epidemiological studies have shown the association of airborne particulate matter (PM) size and chemical composition with health problems affecting the cardiorespiratory and central nervous systems. PM also act as cloud condensation nuclei (CNN) or ice nuclei (IN), taking part in the clouds formation process, and therefore can impact the climate. There are several works using different analytical techniques in PM chemical and physical characterization to supply information to source apportionment models that help environmental agencies to assess damages accountability. Despite the numerous analytical techniques described in the literature available for PM characterization, laboratories are normally limited to the in-house available techniques, which raises the question if a given technique is suitable for the purpose of a specific experimental work. The aim of this work consists of summarizing the main available technologies for PM characterization, serving as a guide for readers to find the most appropriate technique(s) for their investigation. Elemental analysis techniques like atomic spectrometry based and X-ray based techniques, organic and carbonaceous techniques and surface analysis techniques are discussed, illustrating their main features as well as their advantages and drawbacks. We also discuss the trends in analytical techniques used over the last two decades. The choice among all techniques is a function of a number of parameters such as: the relevant particles physical properties, sampling and measuring time, access to available facilities and the costs associated to equipment acquisition, among other considerations. An analytical guide map is presented as a guideline for choosing the most appropriated technique for a given analytical information required. Copyright © 2018 Elsevier Ltd. All rights reserved.

Green analytical determination of emerging pollutants in environmental waters using excitation-emission photoinduced fluorescence data and multivariate calibration.

Science.gov (United States)

Hurtado-Sánchez, María Del Carmen; Lozano, Valeria A; Rodríguez-Cáceres, María Isabel; Durán-Merás, Isabel; Escandar, Graciela M

2015-03-01

An eco-friendly strategy for the simultaneous quantification of three emerging pharmaceutical contaminants is presented. The proposed analytical method, which involves photochemically induced fluorescence matrix data combined with second-order chemometric analysis, was used for the determination of carbamazepine, ofloxacin and piroxicam in water samples of different complexity without the need of chromatographic separation. Excitation-emission photoinduced fluorescence matrices were obtained after UV irradiation, and processed with second-order algorithms. Only one of the tested algorithms was able to overcome the strong spectral overlapping among the studied pollutants and allowed their successful quantitation in very interferent media. The method sensitivity in superficial and underground water samples was enhanced by a simple solid-phase extraction with C18 membranes, which was successful for the extraction/preconcentration of the pollutants at trace levels. Detection limits in preconcentrated (1:125) real water samples ranged from 0.04 to 0.3 ng mL(-1). Relative prediction errors around 10% were achieved. The proposed strategy is significantly simpler and greener than liquid chromatography-mass spectrometry methods, without compromising the analytical quality of the results. Copyright © 2014 Elsevier B.V. All rights reserved.

Spectral interference of zirconium on 24 analyte elements using CCD based ICP-AES technique

International Nuclear Information System (INIS)

Adya, V.C.; Sengupta, Arijit; Godbole, S.V.

2014-01-01

In the present studies, the spectral interference of zirconium on different analytical lines of 24 critical analytes using CCD based ICP-AES technique is described. Suitable analytical lines for zirconium were identified along with their detection limits. The sensitivity and the detection limits of analytical channels for different elements in presence of Zr matrix were calculated. Subsequently analytical lines with least interference from Zr and better detection limits were selected for their determinations. (author)

Reviews in fluorescence 2008

CERN Document Server

Geddes, Chris D

2010-01-01

This volume serves as a comprehensive collection of current trends and emerging hot topics in the field of fluorescence spectroscopy. It summarizes the year's progress in fluorescence and its applications as well as includes authoritative analytical reviews.

Analytical techniques applied to study cultural heritage objects

Energy Technology Data Exchange (ETDEWEB)

Rizzutto, M.A.; Curado, J.F.; Bernardes, S.; Campos, P.H.O.V.; Kajiya, E.A.M.; Silva, T.F.; Rodrigues, C.L.; Moro, M.; Tabacniks, M.; Added, N., E-mail: rizzutto@if.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica

2015-07-01

The scientific study of artistic and cultural heritage objects have been routinely performed in Europe and the United States for decades. In Brazil this research area is growing, mainly through the use of physical and chemical characterization methods. Since 2003 the Group of Applied Physics with Particle Accelerators of the Physics Institute of the University of Sao Paulo (GFAA-IF) has been working with various methodologies for material characterization and analysis of cultural objects. Initially using ion beam analysis performed with Particle Induced X-Ray Emission (PIXE), Rutherford Backscattering (RBS) and recently Ion Beam Induced Luminescence (IBIL), for the determination of the elements and chemical compounds in the surface layers. These techniques are widely used in the Laboratory of Materials Analysis with Ion Beams (LAMFI-USP). Recently, the GFAA expanded the studies to other possibilities of analysis enabled by imaging techniques that coupled with elemental and compositional characterization provide a better understanding on the materials and techniques used in the creative process in the manufacture of objects. The imaging analysis, mainly used to examine and document artistic and cultural heritage objects, are performed through images with visible light, infrared reflectography (IR), fluorescence with ultraviolet radiation (UV), tangential light and digital radiography. Expanding more the possibilities of analysis, new capabilities were added using portable equipment such as Energy Dispersive X-Ray Fluorescence (ED-XRF) and Raman Spectroscopy that can be used for analysis 'in situ' at the museums. The results of these analyzes are providing valuable information on the manufacturing process and have provided new information on objects of different University of Sao Paulo museums. Improving the arsenal of cultural heritage analysis it was recently constructed an 3D robotic stage for the precise positioning of samples in the external beam setup

Analytical techniques applied to study cultural heritage objects

International Nuclear Information System (INIS)

Rizzutto, M.A.; Curado, J.F.; Bernardes, S.; Campos, P.H.O.V.; Kajiya, E.A.M.; Silva, T.F.; Rodrigues, C.L.; Moro, M.; Tabacniks, M.; Added, N.

2015-01-01

The scientific study of artistic and cultural heritage objects have been routinely performed in Europe and the United States for decades. In Brazil this research area is growing, mainly through the use of physical and chemical characterization methods. Since 2003 the Group of Applied Physics with Particle Accelerators of the Physics Institute of the University of Sao Paulo (GFAA-IF) has been working with various methodologies for material characterization and analysis of cultural objects. Initially using ion beam analysis performed with Particle Induced X-Ray Emission (PIXE), Rutherford Backscattering (RBS) and recently Ion Beam Induced Luminescence (IBIL), for the determination of the elements and chemical compounds in the surface layers. These techniques are widely used in the Laboratory of Materials Analysis with Ion Beams (LAMFI-USP). Recently, the GFAA expanded the studies to other possibilities of analysis enabled by imaging techniques that coupled with elemental and compositional characterization provide a better understanding on the materials and techniques used in the creative process in the manufacture of objects. The imaging analysis, mainly used to examine and document artistic and cultural heritage objects, are performed through images with visible light, infrared reflectography (IR), fluorescence with ultraviolet radiation (UV), tangential light and digital radiography. Expanding more the possibilities of analysis, new capabilities were added using portable equipment such as Energy Dispersive X-Ray Fluorescence (ED-XRF) and Raman Spectroscopy that can be used for analysis 'in situ' at the museums. The results of these analyzes are providing valuable information on the manufacturing process and have provided new information on objects of different University of Sao Paulo museums. Improving the arsenal of cultural heritage analysis it was recently constructed an 3D robotic stage for the precise positioning of samples in the external beam setup

An Example of a Hakomi Technique Adapted for Functional Analytic Psychotherapy

Science.gov (United States)

Collis, Peter

2012-01-01

Functional Analytic Psychotherapy (FAP) is a model of therapy that lends itself to integration with other therapy models. This paper aims to provide an example to assist others in assimilating techniques from other forms of therapy into FAP. A technique from the Hakomi Method is outlined and modified for FAP. As, on the whole, psychotherapy…

International conference on isotopic and nuclear analytical techniques for health and environment. Unedited papers

International Nuclear Information System (INIS)

2004-01-01

The IAEA has been supporting nuclear and isotopic analytical techniques as part of its mandate to foster the peaceful uses of nuclear energy for many years. Nuclear analytical laboratories have been installed and upgraded through technical co-operation assistance in many laboratories of Member States. These techniques, including INAA, CRF, PIXE, stable isotopes and radioisotopes, α, β, γ spectrometry, Moessbauer spectrometry, etc., have been applied to a wide range of subjects with varying success. Nuclear analytical techniques, featuring some intrinsic quality control aspects, such as multi-nuclide analysis, frequently serve as 'reference methods' to crosscheck critical results. As nuclear properties of elements are targeted, matrix problems seem to be negligible. In light of its continued commitment and support, the IAEA organized the International Conference on Isotopic and Nuclear Analytical Techniques for Health and Environment. Out of 220 from 61 countries who applied for participation, 155 official participants and five observers from 47 countries were in attendance, with 67 from 32 developing countries and 21 from international organizations, including the World Health Organization. Eleven plenary sessions were held. Also conducted was a panel discussion on Human Capacity Development Needs in the Areas of Analytical Quality Control Services (AQCS), Radiochemistry and Nutrition. The scientific sessions were divided into several topics, which reflect some of the important activities of the IAEA's Department of Nuclear Sciences and Applications (NA): - Isotopic and nuclear techniques (general); - Metrology and quality assurance in nuclear measurements; - Nuclear analytical techniques for environmental monitoring; - Radioecology; - Environmental monitoring; - Radiological safety of food and water; - Methodological aspects of stable isotope techniques in health and environment; - Applications of isotopic techniques in health and environment; - New

Contribution of CNESTEN to the developpement of analytical nuclear and conventional technic and their applications to the environment

International Nuclear Information System (INIS)

Bounakhla, M.

2008-01-01

Full text: In CNESTEN (National Center for Energy Sciences and Nuclear Techniques), the NAA is considered a main activity to be developed around the reactor Triga Mark 2 (2 MW) of CEN (Center for Nuclear Studies ) of Maamoura. This method allows determining 40 to 50 elements, many of them affect the environment (antimony, arsenic, cadmium, chromium, mercury, selenium, etc. ...). It also allows the determination of important elements such as sodium, chlorine and potassium, and many lanthanides. It presents many advantages and is applied in various areas, however, and as it is the case for any analysis method, it has analytical limits. To supplement this method and then allowing to cover a range analytical widest possible in various matrices, CNESTEN has already installed 4 analytical techniques: fluorescence-X Energy Dispersive (ED-XRF), fluorescence-X dispersion wavelength (WD-XRF), SAA and PCI-SEO. For the AAN, the AAN instrumental is already operational while the technique based on the Prompt Gammas is being developed with the IAEA (International Atomic Energy Agency). Using reactors of Pierre Sue Laboratories (Saclay) in France and Jozef Stefan Institute in Slovenia for the AAN and analytical techniques available in CNESTEN and in partner universities in France and Spain, many projects and studies research has been realized in the field of environment and geochemistry, that is in collaboration with national and/or foreign partners [fr

Comparison of analytical techniques for dynamic trace metal speciation in natural freshwaters.

NARCIS (Netherlands)

Sigg, Laura; Black, Frank; Buffle, Jacques; Cao, Jun; Cleven, Rob; Davison, William; Galceran, Josep; Gunkel, Peggy; Kalis, Erwin; Kistler, David; Martin, Michel; Noël, Stéphane; Nur, Yusuf; Odzak, Niksa; Puy, Jaume; Riemsdijk, Willem van; Temminghoff, Erwin; Tercier-Waeber, Mary-Lou; Toepperwien, Stefanie; Town, Raewyn M; Unsworth, Emily R; Warnken, Kent W; Weng, Liping; Xue, Hanbin; Zhang, Hao

2006-01-01

Several techniques for speciation analysis of Cu, Zn, Cd, Pb, and Ni are used in freshwater systems and compared with respect to their performance and to the metal species detected. The analytical techniques comprise the following: (i) diffusion gradients in thin-film gels (DGT); (ii) gel integrated

Nuclear analytical techniques for on-line elemental analysis in industry

International Nuclear Information System (INIS)

1988-06-01

This report is the result of an advisory group meeting held in Espoo, Finland, 1-5 June, 1987. The purpose of the meeting was to assess the present status and development of nuclear analytical techniques used for industrial process control. The report gives an overview of the different nuclear techniques used for process control and the most important applications. A separate abstract was prepared for each of the 7 papers presented at the meeting. Refs, figs and tabs

Time-Domain Fluorescence Lifetime Imaging Techniques Suitable for Solid-State Imaging Sensor Arrays

Directory of Open Access Journals (Sweden)

Robert K. Henderson

2012-05-01

Full Text Available We have successfully demonstrated video-rate CMOS single-photon avalanche diode (SPAD-based cameras for fluorescence lifetime imaging microscopy (FLIM by applying innovative FLIM algorithms. We also review and compare several time-domain techniques and solid-state FLIM systems, and adapt the proposed algorithms for massive CMOS SPAD-based arrays and hardware implementations. The theoretical error equations are derived and their performances are demonstrated on the data obtained from 0.13 μm CMOS SPAD arrays and the multiple-decay data obtained from scanning PMT systems. In vivo two photon fluorescence lifetime imaging data of FITC-albumin labeled vasculature of a P22 rat carcinosarcoma (BD9 rat window chamber are used to test how different algorithms perform on bi-decay data. The proposed techniques are capable of producing lifetime images with enough contrast.

Survey of immunoassay techniques for biological analysis

International Nuclear Information System (INIS)

Burtis, C.A.

1986-10-01

Immunoassay is a very specific, sensitive, and widely applicable analytical technique. Recent advances in genetic engineering have led to the development of monoclonal antibodies which further improves the specificity of immunoassays. Originally, radioisotopes were used to label the antigens and antibodies used in immunoassays. However, in the last decade, numerous types of immunoassays have been developed which utilize enzymes and fluorescent dyes as labels. Given the technical, safety, health, and disposal problems associated with using radioisotopes, immunoassays that utilize the enzyme and fluorescent labels are rapidly replacing those using radioisotope labels. These newer techniques are as sensitive, are easily automated, have stable reagents, and do not have a disposal problem. 6 refs., 1 fig., 2 tabs

Linear circuit transfer functions an introduction to fast analytical techniques

CERN Document Server

Basso, Christophe P

2016-01-01

Linear Circuit Transfer Functions: An introduction to Fast Analytical Techniques teaches readers how to determine transfer functions of linear passive and active circuits by applying Fast Analytical Circuits Techniques. Building on their existing knowledge of classical loop/nodal analysis, the book improves and expands their skills to unveil transfer functions in a swift and efficient manner. Starting with simple examples, the author explains step-by-step how expressing circuits time constants in different configurations leads to writing transfer functions in a compact and insightful way. By learning how to organize numerators and denominators in the fastest possible way, readers will speed-up analysis and predict the frequency resp nse of simple to complex circuits. In some cases, they will be able to derive the final expression by inspection, without writing a line of algebra. Key features: * Emphasizes analysis through employing time constant-based methods discussed in other text books but not widely us...

Intrinsic Tryptophan Fluorescence in the Detection and Analysis of Proteins: A Focus on Förster Resonance Energy Transfer Techniques

Directory of Open Access Journals (Sweden)

Amar B. T. Ghisaidoobe

2014-12-01

Full Text Available F resonance energy transfer (FRET occurs when the distance between a donor fluorophore and an acceptor is within 10 nm, and its application often necessitates fluorescent labeling of biological targets. However, covalent modification of biomolecules can inadvertently give rise to conformational and/or functional changes. This review describes the application of intrinsic protein fluorescence, predominantly derived from tryptophan (\\(\\uplambda_{\\textsc{ex}}\\sim\\ nm, \\(\\uplambda_{\\textsc{em}}\\sim\\ 350 nm, in protein-related research and mainly focuses on label-free FRET techniques. In terms of wavelength and intensity, tryptophan fluorescence is strongly influenced by its (or the proteinlocal environment, which, in addition to fluorescence quenching, has been applied to study protein conformational changes. Intrinsic F resonance energy transfer (iFRET, a recently developed technique, utilizes the intrinsic fluorescence of tryptophan in conjunction with target-specific fluorescent probes as FRET donors and acceptors, respectively, for real time detection of native proteins.

Fluorescence resonance energy transfer between perylene and riboflavin in micellar solution and analytical application on determination of vitamin B2

International Nuclear Information System (INIS)

Bhattar, S.L.; Kolekar, G.B.; Patil, S.R.

2008-01-01

Fluorescence resonance energy transfer (FRET) between perylene and riboflavin is studied in micellar solution of sodium dodecyl sulfate. The fluorescence of perylene is quenched by riboflavin and quenching is in accordance with Stern-Volmer relation. The efficiency of energy transfer is found to depend on the concentration of riboflavin. The value of critical energy transfer distance (R 0 ) calculated by using Foster relation is 32.13 A, and as it is less than 50 A, it indicates efficient energy transfer in the present system. The analytical relation was established between extent of sensitization and concentration of riboflavin, which helped to estimate vitamin B 2 directly from pharmaceutical tablets

Fluorescence spectroscopy as a tool for determination of organic matter removal efficiency at water treatment works

Directory of Open Access Journals (Sweden)

M. Z. Bieroza

2010-04-01

Full Text Available Organic matter (OM in drinking water treatment is a common impediment responsible for increased coagulant and disinfectant dosages, formation of carcinogenic disinfection-by products, and microbial re-growth in distribution system. The inherent heterogeneity of OM implies the utilization of advanced analytical techniques for its characterization and assessment of removal efficiency. Here, the application of simple fluorescence excitation-emission technique to OM characterization in drinking water treatment is presented. The fluorescence data of raw and clarified water was obtained from 16 drinking water treatment works. The reduction in fulvic-like fluorescence was found to significantly correlate with OM removal measured with total organic carbon (TOC. Fluorescence properties, fulvic- and tryptophan-like regions, were found to discriminate OM fractions of different removal efficiencies. The results obtained in the study show that fluorescence spectroscopy provides a rapid and accurate characterization and quantification of OM fractions and indication of their treatability in conventional water treatment.

Analysis of eight argonne premium coal samples by X-ray fluorescence spectrometry

Science.gov (United States)

Evans, J.R.; Sellers, G.A.; Johnson, R.G.; Vivit, D.V.; Kent, J.

1990-01-01

X-ray fluorescence spectrometric methods were used in the analysis of eight Argonne Premium Coal Samples. Trace elements (Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, La, and Ce) in coal ash were determined by energy-dispersive X-ray fluorescence spectrometry; major elements (Na, Mg, Al, Si, P, S, K, Ca, Ti, Mn, and Fe) in coal ash and trace elements (Cl and P) in whole coal were determined by wavelength-dispersive X-ray fluorescence spectrometry. The results of this study will be used in a geochemical database compiled for these materials from various analytical techniques. The experimental XRF methods and procedures used to determine these major and trace elements are described.

Evaluation of analytical techniques to determine matals in Sodium

International Nuclear Information System (INIS)

Biancifiori, M.A.; Zappa, G.; Amico, A.

1985-01-01

The influence of some instrumental parameters on the analysis of CA, Co, Cr, Cu, Fe, K, Mg, Mn, and Ni in Sodium solutions, by means of Flame Atomic Absorption Spectroscopy (FAAS), is evaluated. The best operating parameters are established and the possibility of application of this analytical technique to the detection of the metallic impurities in Sodium is evaluated, considering the concentration values of nuclear interest

Simultaneous determination of caffeine, caramel and riboflavin in cola-type and energy drinks by synchronous fluorescence technique coupled with partial least squares.

Science.gov (United States)

Ziak, L'udovít; Májek, Pavel; Hroboňová, Katarína; Cacho, František; Sádecká, Jana

2014-09-15

The aim of this work was to develop a multivariate method for the rapid determination of caffeine and Class IV caramel in cola-type soft drinks and of caffeine, Class III caramel and riboflavin in energy drinks using synchronous fluorescence spectra. The synchronous fluorescence spectra were recorded at constant wavelength difference 90 nm from 200 to 500 nm. Reference values of analyte concentrations by high performance liquid chromatography (HPLC) with fluorescence detection combined with the standard addition method were used to create the partial least squares (PLS) models. High coefficients of determination (>0.99) were obtained in 0.2-4.2, 0.25-5.25, 0.4-10.0 and 0.007-0.054 mg L(-1) range for caffeine, Class III caramel, Class IV caramel and riboflavin, respectively. The PLS models were used to determine the concentration of analytes in different drink samples. The method provided comparable results with those found using the HPLC method. Copyright © 2014 Elsevier Ltd. All rights reserved.

Use of nuclear and nuclear-related analytical techniques in studies of trace and minor elements in air pollution

International Nuclear Information System (INIS)

Smodis, Borut; Stropnik, Boris

1994-01-01

Among nuclear and nuclear-related analytical techniques, neutron activation and X-ray fluorescence analysis are particularly useful for environmental studies owing to their non-destructive character and multi-element capability. In this work, procedures for k o -standardized instrumental neutron activation analysis (INAA) and energy-dispersive X-ray fluorescence (EDXRF) spectrometry for trace and minor elements in air pollution studies were investigated. The methods applied were validated by the analysis of suitable reference materials. Using INAA, 20 experimentally obtained elemental values out of 21 certified and all 29 experimentally obtained values compared with 'consensus' values (for the elements where no certified numbers are available) in two SRMs were statistically indistinguishable. Also, the contents of 28 elements in candidate NIST SRM 1573a Tomato Leaves are reported. The EDXRF results were statistically indistinguishable from certified values for eight out of nine elements in NIST SRM 3087. The detection limit for this method is around at 0.1 μg cm -2 per element, so in BCR CRM No. 128, which is intended for ambient air pollution data, only Fe and Zn out of 14 elements reported in the certificate were detected with acceptable precision (i.e., 10%) owing to the very low air particulate matter loading, lying in the region of only 250 μg cm -2 . (Author)

Fluorescence hyperspectral imaging technique for the foreign substance detection on fresh-cut lettuce

Science.gov (United States)

Nondestructive methods based on fluorescence hyperspectral imaging (HSI) techniques were developed in order to detect worms on fresh-cut lettuce. The optimal wavebands for detecting worms on fresh-cut lettuce were investigated using the one-way ANOVA analysis and correlation analysis. The worm detec...

Development of image analysis for graphite pore-structure determination using fluorescence techniques

International Nuclear Information System (INIS)

Stephen, W.J.; Bowden, E.A.T.; Wickham, A.J.

1983-03-01

The use of image analysis to assess the pore structure of graphite has been developed to the point at which it may be considered available for routine use. A definitive pore structure in terms of the geometry-independent ''characteristic pore dimension'' is derived from the computer analysis of polished specimens whose open-pore structure has been impregnated with bismuth or a fluorescent epoxy resin, with the very small pores identified separately by mercury porosimetry as in the past. The pore-size distributions obtained from these combined techniques have been used successfully to predict the corrosion rates of nine graphites, of widely differing pore structure, in a variety of gas compositions and, indirectly, to confirm appropriate mean ranges and rate constants for the reaction of the oxidising species in these gas mixtures. The development of the fluorescent-impregnant technique is discussed in detail and its use is justified in preference to ''traditional'' methods. Further possible refinements are discussed, including the eventual aim of obtaining a computer prediction of the future oxidation behaviour of the graphite directly from the image analyser. (author)

Energy dispersion X-ray fluorescence techniques in water pollution analysis

International Nuclear Information System (INIS)

Holynska, B.

1980-01-01

Advantages and limitations of energy dispersion X-ray fluorescence methods for analysis of pollutants in water are discussed. The necessary equipment for X-ray measurement of insoluble and dissolved trace metals in water is described. Different techniques of enrichment of trace metals are presented: ion exchange on selective Chelex-100 exchanger, precipitation with chelating agents DDTC and APDC, and adsorption on activated carbon. Some results obtained using different preconcentration methods for trace metals determination in different waters are presented. (author)

Investigation of Pink Tourmalines by X-ray Fluorescent Technique

International Nuclear Information System (INIS)

Sangariyavanich, A.; Na Songkhla, S.; Pimjum, S.

1998-01-01

X-ray fluorescent technique has been employed in the study of trace elements in six samples of gamma irradiated pink tourmalines, namely, red-pink (rubellite), light-pink, orange-pink, brownish orange-pink, purple red and purple orange-pink. The analysis of their characteristic X-ray indicated the existence of manganese in all samples. Trace amounts of iron, zinc, lead, bismuth or gallium were also investigated in certain samples. Since these elements were not present in red-pink tourmaline, therefore, we believed that manganese is the major cause of pink color in tourmaline while other elements produce various types of pink color

Flash fluorescence with indocyanine green videoangiography to identify the recipient artery for bypass with distal middle cerebral artery aneurysms: operative technique.

Science.gov (United States)

Rodríguez-Hernández, Ana; Lawton, Michael T

2012-06-01

Distal middle cerebral artery (MCA) aneurysms frequently have nonsaccular morphology that necessitates trapping and bypass. Bypasses can be difficult because efferent arteries lie deep in the opercular cleft and may not be easily identifiable. We introduce the "flash fluorescence" technique, which uses videoangiography with indocyanine green (ICG) dye to identify an appropriate recipient artery on the cortical surface for the bypass, enabling a more superficial and easier anastomosis. Flash fluorescence requires 3 steps: (1) temporary clip occlusion of the involved afferent artery; (2) videoangiography demonstrating fluorescence in uninvolved arteries on the cortical surface; and (3) removal of the temporary clip with flash fluorescence in the involved efferent arteries on the cortical surface, thereby identifying a recipient. Alternatively, temporary clips can occlude uninvolved arteries, and videoangiography will demonstrate initial fluorescence in efferent arteries during temporary occlusion and flash fluorescence in uninvolved arteries during reperfusion. From a consecutive series of 604 MCA aneurysms treated microsurgically, 22 (3.6%) were distal aneurysms and 11 required a bypass. The flash fluorescence technique was used in 3 patients to select the recipient artery for 2 superficial temporal artery-to-MCA bypasses and 1 MCA-MCA bypass. The correct recipient was selected in all cases. The flash fluorescence technique provides quick, reliable localization of an appropriate recipient artery for bypass when revascularization is needed for a distal MCA aneurysm. This technique eliminates the need for extensive dissection of the efferent artery and enables a superficial recipient site that makes the anastomosis safer, faster, and less demanding.

Laser induced fluorescence thermometry (LIF-T) as a non-invasive temperature measurement technique for thermal hydraulic experiments

Energy Technology Data Exchange (ETDEWEB)

Strack, J.; Leung, K.; Walker, A., E-mail: strackj@mcmaster.ca [McMaster Univ., Hamilton, ON (Canada)

2014-07-01

Laser induced fluorescence (LIF) is an experimental technique whereby a scalar field in a fluid system is measured optically from the fluorescence intensity of a tracer dye following excitation by laser light. For laser induced fluorescence thermometry (LIF-T), a temperature sensitive dye is used. Through the use of a temperature sensitive tracer dye, sheet laser optics, optical filters, and photography, a 2D temperature field can be measured non-invasively. An experiment to test the viability of using LIF-T for macroscopic thermal hydraulic experiments was developed and tested. A reference calibration curve to relate fluorescence measurements to temperature is presented. (author)

Fluorescent microangiography is a novel and widely applicable technique for delineating the renal microvasculature.

Directory of Open Access Journals (Sweden)

Andrew Advani

Full Text Available Rarefaction of the renal microvasculature correlates with declining kidney function. However, current technologies commonly used for its evaluation are limited by their reliance on endothelial cell antigen expression and assessment in two dimensions. We set out to establish a widely applicable and unbiased optical sectioning method to enable three dimensional imaging and reconstruction of the renal microvessels based on their luminal filling. The kidneys of subtotally nephrectomized (SNx rats and their sham-operated counterparts were subjected to either routine two-dimensional immunohistochemistry or the novel technique of fluorescent microangiography (FMA. The latter was achieved by perfusion of the kidney with an agarose suspension of fluorescent polystyrene microspheres followed by optical sectioning of 200 µm thick cross-sections using a confocal microscope. The fluorescent microangiography method enabled the three-dimensional reconstruction of virtual microvascular casts and confirmed a reduction in both glomerular and peritubular capillary density in the kidneys of SNx rats, despite an overall increase in glomerular volume. FMA is an uncomplicated technique for evaluating the renal microvasculature that circumvents many of the limitations imposed by conventional analysis of two-dimensional tissue sections.

The Viking X ray fluorescence experiment - Analytical methods and early results

Science.gov (United States)

Clark, B. C., III; Castro, A. J.; Rowe, C. D.; Baird, A. K.; Rose, H. J., Jr.; Toulmin, P., III; Christian, R. P.; Kelliher, W. C.; Keil, K.; Huss, G. R.

1977-01-01

Ten samples of the Martian regolith have been analyzed by the Viking lander X ray fluorescence spectrometers. Because of high-stability electronics, inclusion of calibration targets, and special data encoding within the instruments the quality of the analyses performed on Mars is closely equivalent to that attainable with the same instruments operated in the laboratory. Determination of absolute elemental concentrations requires gain drift adjustments, subtraction of background components, and use of a mathematical response model with adjustable parameters set by prelaunch measurements on selected rock standards. Bulk fines at both Viking landing sites are quite similar in composition, implying that a chemically and mineralogically homogeneous regolith covers much of the surface of the planet. Important differences between samples include a higher sulfur content in what appear to be duricrust fragments than in fines and a lower iron content in fines taken from beneath large rocks than those taken from unprotected surface material. Further extensive reduction of these data will allow more precise and more accurate analytical numbers to be determined and thus a more comprehensive understanding of elemental trends between samples.

Determination of fission products in irradiated fuel by X-ray fluorescence

International Nuclear Information System (INIS)

Mogensen, M.; Als-Nielsen, J.; Hessel Andersen, N.

1986-08-01

X-ray fluorescence is a well established analytical tool for measuring elemental composition of fairly large (approximately 5 cm 2 ) ''cold'' samples. A version of this technique has been developed for analysis of radial distribution of fission products Xe, Cs and Ba in irradiated UO 2 fuel samples. About 0.1 mm thin slices of fuel pellets (full cross sections) are irradiated by 50 keV X-rays. The intensity of the Xe (Cs, Ba) K α fluorescence radiation generated is measured by means of a Ge detector fitted with a collimator. The slit is 0.5 mm wide in the scanning direction and 2 mm long. The measured Xe K α X-ray intensities are converted to absolute concentrations by comparing to the intensity from a Xe gas standard. In the case of Cs and Ba solid standards may be used. The X-ray fluorescence analysis is compared to other techniques used to obtain radial fission product profiles. It is shown how a combination of X-ray fluorescence and electron probe micro analysis is able to reveal the amount of Xe in the grain boundary porosities. (author)

Fluorescence spectroscopy and multi-way techniques. PARAFAC

DEFF Research Database (Denmark)

Murphy, Kathleen R.; Stedmon, Colin A.; Graeber, Daniel

2013-01-01

PARAllel FACtor analysis (PARAFAC) is increasingly used to decompose fluorescence excitation emission matrices (EEMs) into their underlying chemical components. In the ideal case where fluorescence conforms to Beers Law, this process can lead to the mathematical identification and quantification...

Nuclear analytical methods for platinum group elements

International Nuclear Information System (INIS)

2005-04-01

Platinum group elements (PGE) are of special interest for analytical research due to their economic importance like chemical peculiarities as catalysts, medical applications as anticancer drugs, and possible environmental detrimental impact as exhaust from automobile catalyzers. Natural levels of PGE are so low in concentration that most of the current analytical techniques approach their limit of detection capacity. In addition, Ru, Rh, Pd, Re, Os, Ir, and Pt analyses still constitute a challenge in accuracy and precision of quantification in natural matrices. Nuclear analytical techniques, such as neutron activation analysis, X ray fluorescence, or proton-induced X ray emission (PIXE), which are generally considered as reference methods for many analytical problems, are useful as well. However, due to methodological restrictions, they can, in most cases, only be applied after pre-concentration and under special irradiation conditions. This report was prepared following a coordinated research project and a consultants meeting addressing the subject from different viewpoints. The experts involved suggested to discuss the issue according to the (1) application, hence, the concentration levels encountered, and (2) method applied for analysis. Each of the different fields of application needs special consideration for sample preparation, PGE pre-concentration, and determination. Additionally, each analytical method requires special attention regarding the sensitivity and sample type. Quality assurance/quality control aspects are considered towards the end of the report. It is intended to provide the reader of this publication with state-of-the-art information on the various aspects of PGE analysis and to advise which technique might be most suitable for a particular analytical problem related to platinum group elements. In particular, many case studies described in detail from the authors' laboratory experience might help to decide which way to go. As in many cases

Chlorophyll fluorescence analysis: a guide to good practice and understanding some new applications.

Science.gov (United States)

Murchie, E H; Lawson, T

2013-10-01

Chlorophyll fluorescence is a non-invasive measurement of photosystem II (PSII) activity and is a commonly used technique in plant physiology. The sensitivity of PSII activity to abiotic and biotic factors has made this a key technique not only for understanding the photosynthetic mechanisms but also as a broader indicator of how plants respond to environmental change. This, along with low cost and ease of collecting data, has resulted in the appearance of a large array of instrument types for measurement and calculated parameters which can be bewildering for the new user. Moreover, its accessibility can lead to misuse and misinterpretation when the underlying photosynthetic processes are not fully appreciated. This review is timely because it sits at a point of renewed interest in chlorophyll fluorescence where fast measurements of photosynthetic performance are now required for crop improvement purposes. Here we help the researcher make choices in terms of protocols using the equipment and expertise available, especially for field measurements. We start with a basic overview of the principles of fluorescence analysis and provide advice on best practice for taking pulse amplitude-modulated measurements. We also discuss a number of emerging techniques for contemporary crop and ecology research, where we see continual development and application of analytical techniques to meet the new challenges that have arisen in recent years. We end the review by briefly discussing the emerging area of monitoring fluorescence, chlorophyll fluorescence imaging, field phenotyping, and remote sensing of crops for yield and biomass enhancement.

Elemental analysis of the ancient bronze coins by x-ray fluorescence technique using simultaneously radioisotope source and x-ray tube

International Nuclear Information System (INIS)

Nguyen The Quynh; Truong Thi An; Tran Duc Thiep; Nguyen Dinh Chien; Dao Tran Cao; Nguyen Quang Liem

2004-01-01

The results on elemental analysis of the Vietnamese ancient bronze coins during the time of the Nguyen dynasty (19th century) are presented. The samples were provided by the vietnam National Historical Museum and the elemental analysis was performed on the home-made model EDS-XT-99-01 X-ray fluorescence spectrometer in the Institute of Materials Science, NCST of Vietnam. The samples exited simultaneously by radioisotope source and X-ray tube. The analytical results show the similarity in the elemental composition of the coins issued by different kings of the Nguyen dynasty, but there is the difference in the concentration of the used elements. Another interesting point is that all the coins have zinc (Zn) in their composition, which shows clearly the influence of the occidental metallurgical technology on the money-making technique in Vietnam during the 19th century. (author)

Analytical techniques for the study of polyphenol-protein interactions.

Science.gov (United States)

Poklar Ulrih, Nataša

2017-07-03

This mini review focuses on advances in biophysical techniques to study polyphenol interactions with proteins. Polyphenols have many beneficial pharmacological properties, as a result of which they have been the subject of intensive studies. The most conventional techniques described here can be divided into three groups: (i) methods used for screening (in-situ methods); (ii) methods used to gain insight into the mechanisms of polyphenol-protein interactions; and (iii) methods used to study protein aggregation and precipitation. All of these methods used to study polyphenol-protein interactions are based on modifications to the physicochemical properties of the polyphenols or proteins after binding/complex formation in solution. To date, numerous review articles have been published in the field of polyphenols. This review will give a brief insight in computational methods and biosensors and cell-based methods, spectroscopic methods including fluorescence emission, UV-vis adsorption, circular dichroism, Fourier transform infrared and mass spectrometry, nuclear magnetic resonance, X-ray diffraction, and light scattering techniques including small-angle X-ray scattering and small-angle neutron scattering, and calorimetric techniques (isothermal titration calorimetry and differential scanning calorimetry), microscopy, the techniques which have been successfully used for polyphenol-protein interactions. At the end the new methods based on single molecule detection with high potential to study polyphenol-protein interactions will be presented. The advantages and disadvantages of each technique will be discussed as well as the thermodynamic, kinetic or structural parameters, which can be obtained. The other relevant biophysical experimental techniques that have proven to be valuable, such electrochemical methods, hydrodynamic techniques and chromatographic techniques will not be described here.

Fluorescence resonance energy transfer between perylene and riboflavin in micellar solution and analytical application on determination of vitamin B{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Bhattar, S.L.; Kolekar, G.B. [Fluorescence Spectroscopy Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416 004, Maharashtra (India); Patil, S.R. [Fluorescence Spectroscopy Research Laboratory, Department of Chemistry, Shivaji University, Kolhapur 416 004, Maharashtra (India)], E-mail: srp_fsl@rediffmail.com

2008-03-15

Fluorescence resonance energy transfer (FRET) between perylene and riboflavin is studied in micellar solution of sodium dodecyl sulfate. The fluorescence of perylene is quenched by riboflavin and quenching is in accordance with Stern-Volmer relation. The efficiency of energy transfer is found to depend on the concentration of riboflavin. The value of critical energy transfer distance (R{sub 0}) calculated by using Foster relation is 32.13 A, and as it is less than 50 A, it indicates efficient energy transfer in the present system. The analytical relation was established between extent of sensitization and concentration of riboflavin, which helped to estimate vitamin B{sub 2} directly from pharmaceutical tablets.

Study of the experimental parameters for the determination of Ca, Cr, Cu, Fe, Mn and Ni on nuclear grade UO2 by X-ray fluorescence technique

International Nuclear Information System (INIS)

Salvador, V.L.R.

1982-01-01

An analytical method for the simultaneous determinations of low concentrations of Ca, Cr, Cu, Fe, Mn and Ni on the nuclear grade UO 2 by X-ray fluorescence technique, without the use of chemical treatment, is described. The optimization of the experimental conditions was established on the X-ray fluorescence spectrometer and a low limit of detection (4 - 7 μg/gU) was achieved which satisfies the requirement in the nuclear fuel specification. The samples were prepared in the form of double layer pressed pellets using boric acid as a binding agent. The characteristic first order K sub(α) line intensity of each minor component was measured and the values of its concentrations were deduced using respective standard calibrations curves. The precision, accuracy and acceptability of the method were determined for all elements. The values of the precision are in the range of 2 - 10% and the accuracy are lower than 7%. (Author) [pt

Analytical characterization of artists' pigments used in old and modern paintings by total-reflection x-ray fluorescence

International Nuclear Information System (INIS)

Klockenkaemper, R.; Bohlen, A. von; Moens, L.; Devos, W.

1993-01-01

The analytical characterization of artists' pigments is a most helpful tool for art history, conservation and restoration of paintings. A very gentle method of ultra-microsampling was developed that is especially applicable to paintings under restoration. It provides a sample mass of about 1 μg and is virtually non-destructive. This minute amount is sufficient for total-reflection X-ray fluorescence (TXRF) to determine most of those elements building inorganic pigments. The convenient and fast method was applied to oil paintings. Various pigments were identified and their mixing proportion was determined even quantitatively. (author)

A Novel Analytic Technique for the Service Station Reliability in a Discrete-Time Repairable Queue

Directory of Open Access Journals (Sweden)

Renbin Liu

2013-01-01

Full Text Available This paper presents a decomposition technique for the service station reliability in a discrete-time repairable GeomX/G/1 queueing system, in which the server takes exhaustive service and multiple adaptive delayed vacation discipline. Using such a novel analytic technique, some important reliability indices and reliability relation equations of the service station are derived. Furthermore, the structures of the service station indices are also found. Finally, special cases and numerical examples validate the derived results and show that our analytic technique is applicable to reliability analysis of some complex discrete-time repairable bulk arrival queueing systems.

Design and fabrication of fluorescence resonance energy transfer-mediated fluorescent polymer nanoparticles for ratiometric sensing of lysosomal pH.

Science.gov (United States)

Chen, Jian; Tang, Ying; Wang, Hong; Zhang, Peisheng; Li, Ya; Jiang, Jianhui

2016-12-15

The design of effective tools capable of sensing lysosome pH is highly desirable for better understanding its biological functions in cellular behaviors and various diseases. Herein, a lysosome-targetable ratiometric fluorescent polymer nanoparticle pH sensor (RFPNS) was synthesized via incorporation of miniemulsion polymerization and surface modification technique. In this system, the donor: 4-ethoxy-9-allyl-1,8-naphthalimide (EANI) and the acceptor: fluorescein isothiocyanate (FITC) were covalently linked to the polymer nanoparticle to construct pH-responsive fluorescence resonance energy transfer (FRET) system. The FITC moieties on the surface of RFPNS underwent structural and spectral transformation as the presence of pH changes, resulting in ratiometric fluorescent sensing of pH. The as-prepared RFPNS displayed favorable water dispersibility, good pH-induced spectral reversibility and so on. Following the living cell uptake, the as-prepared RFPNS with good cell-membrane permeability can mainly stain in the lysosomes; and it can facilitate visualization of the intracellular lysosomal pH changes. This nanosensor platform offers a novel method for future development of ratiometric fluorescent probes for targeting other analytes, like ions, metabolites,and other biomolecules in biosamples. Copyright © 2016 Elsevier Inc. All rights reserved.

Innovating analytical spectroscopies for the improvement of liquid sodium cooled fast neutron reactors safety

International Nuclear Information System (INIS)

Maury, C.

2012-01-01

In the context of the project of sodium fast reactor ASTRID, CEA is currently developing new analytical techniques to monitor the chemical purity of liquid sodium. Indeed, incidental situations occurring in the reactor, such as fuel clad failures, leakages in the steam generator or in the coolant pumps, and accelerated corrosion, might release several elements in the sodium. Analytical techniques based on laser ablation and emission spectroscopy are well suited for this application. They do not require any sample preparation, and can perform direct on-line analysis. Amongst them, Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation coupled to Laser-Induced Fluorescence (LA-LIF) have been selected for this study. The objective of this work was to characterize the sensitivity of those two techniques for the detection of impurities in liquid sodium. Their limits of detection were calculated for model analytes using calibration lines. Then results were theoretically extrapolated to other analytes of interest. This study shows the feasibility of the detection of steel corrosion products in liquid sodium. However, the LIBS technique is more robust and easier to implement, and would therefore be more suited to nuclear conditions. (author) [fr

Toward greener analytical techniques for the absolute quantification of peptides in pharmaceutical and biological samples.

Science.gov (United States)

Van Eeckhaut, Ann; Mangelings, Debby

2015-09-10

Peptide-based biopharmaceuticals represent one of the fastest growing classes of new drug molecules. New reaction types included in the synthesis strategies to reduce the rapid metabolism of peptides, along with the availability of new formulation and delivery technologies, resulted in an increased marketing of peptide drug products. In this regard, the development of analytical methods for quantification of peptides in pharmaceutical and biological samples is of utmost importance. From the sample preparation step to their analysis by means of chromatographic or electrophoretic methods, many difficulties should be tackled to analyze them. Recent developments in analytical techniques emphasize more and more on the use of green analytical techniques. This review will discuss the progresses in and challenges observed during green analytical method development for the quantification of peptides in pharmaceutical and biological samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Photoacoustic spectroscopy for analytical measurements

International Nuclear Information System (INIS)

Haisch, Christoph

2012-01-01

Many different techniques, such as UV/vis absorption, IR spectroscopy, fluorescence and Raman spectroscopy are routinely applied in chemical (micro-)analysis and chemical imaging, and a large variety of instruments is commercially available. Up to now, opto- or photoacoustic (PA) and other optothermal (OT) methods are less common and only a limited number of instruments reached a level of application beyond prototypes in research laboratories. The underlying principle of all these techniques is the detection of local heating due to the conversion of light into heat by optical absorption. Considering the versatility, robustness and instrumental simplicity of many PA techniques, it is surprising that the number of commercial instruments based on such approaches is so sparse. The impetus of this review is to summarize basic principles and possible applications described in the literature, in order to foster routine application of these techniques in industry, process analysis and environmental screening. While the terms OT and PA methods cover a very wide range of methods and physical phenomena, this review will concentrate on techniques with applications for analytical measurements. (topical review)

On-Line Monitoring of Fermentation Processes by Near Infrared and Fluorescence Spectroscopy

DEFF Research Database (Denmark)

Svendsen, Carina

Monitoring and control of fermentation processes is important to ensure high product yield, product quality and product consistency. More knowledge on on-line analytical techniques such as near infrared and fluorescence spectroscopy is desired in the fermentation industry to increase the efficiency...... of on-line monitoring systems. The primary aim of this thesis is to elucidate and explore the dynamics in fermentation processes by spectroscopy. Though a number of successful on-line lab-scale monitoring systems have been reported, it seems that several challenges are still met, which limits the number...... of full-scale systems implemented in industrial fermentation processes. This thesis seeks to achieve a better understanding of the techniques near infrared and fluorescence spectroscopy and thereby to solve some of the challenges that are encountered. The thesis shows the advantages of applying real...

The use of rapid quantitative x-ray fluorescence analysis in paper manufacturing and construction materials industry

International Nuclear Information System (INIS)

Kocman, V.; Foley, L.; Woodger, S.C.

1985-01-01

A modern analytical laboratory of a large corporation manufacturing paper, construction materials and chemicals must be sufficiently diversified in methodology to provide accurate results in the shortest possible time. Among other techniques the implementation of an automated ''menu'' driven wavelength dispersive spectrometer allowed for the setting-up of a variety of quantitative X-ray fluorescence methods. An overview of these methods is given as presented at the 33rd. Annual Conference on the Application of X-ray Fluorescence Analysis in Denver, Colorado, 1984

Handbook of practical X-ray fluorescence analysis

International Nuclear Information System (INIS)

Beckhoff, B.; Wedell, R.; Wolff, H.

2006-01-01

X-ray fluorescence analysis (XRF) is a reliable multi-elemental and nondestructive analytical method widely used in research and industrial applications. This practical handbook provides self-contained modules featuring XRF instrumentation, quantification methods, and most of the current applications. The broad spectrum of topics is due to the efforts of a large number of authors from a variety of different types of institutions such as universities, research institutes, and companies. The book gives a survey of the theoretical fundamentals, analytical instrumentation, software for data processing, various excitation regimes including gracing incidents and microfocus measurements, quantitative analysis, applications in routine and micro analysis, mineralogy, biology, medicine, criminal investigations, archeology, metallurgy, abrasion, microelectronics, environmental air and water analysis. It gives the basic knowledge on this technique, information on analytical equipment and guides the reader to the various applications. This practical handbook is intended as a resource for graduate students, research scientists, and industrial users. (orig.)

Handbook of practical X-ray fluorescence analysis

Energy Technology Data Exchange (ETDEWEB)

Beckhoff, B. [Physikalisch-Technische Bundesanstalt, Berlin (Germany). X-ray Spectrometry; Kanngiesser, B. [Technische Univ. Berlin (Germany). Inst. fuer Atomare Physik und Fachdidaktik; Langhoff, N. [IfG-Institute for Scientific Instruments GmbH, Berlin (Germany); Wedell, R.; Wolff, H. (eds.) [Institut fuer Angewandte Photonik e.V., Berlin (Germany)

2006-07-01

X-ray fluorescence analysis (XRF) is a reliable multi-elemental and nondestructive analytical method widely used in research and industrial applications. This practical handbook provides self-contained modules featuring XRF instrumentation, quantification methods, and most of the current applications. The broad spectrum of topics is due to the efforts of a large number of authors from a variety of different types of institutions such as universities, research institutes, and companies. The book gives a survey of the theoretical fundamentals, analytical instrumentation, software for data processing, various excitation regimes including gracing incidents and microfocus measurements, quantitative analysis, applications in routine and micro analysis, mineralogy, biology, medicine, criminal investigations, archeology, metallurgy, abrasion, microelectronics, environmental air and water analysis. It gives the basic knowledge on this technique, information on analytical equipment and guides the reader to the various applications. This practical handbook is intended as a resource for graduate students, research scientists, and industrial users. (orig.)

Fluorescence lidar measurements at the archaeological site House of Augustus at Palatino, Rome

Science.gov (United States)

Raimondi, Valentina; Alisi, Chiara; Barup, Kerstin; Bracciale, Maria Paola; Broggi, Alessandra; Conti, Cinzia; Hällström, Jenny; Lognoli, David; Palombi, Lorenzo; Santarelli, Maria Laura; Sprocati, Anna Rosa

2013-10-01

Early diagnostics and documentation fulfill an essential role for an effective planning of conservation and restoration of cultural heritage assets. In particular, remote sensing techniques that do not require the use of scaffolds or lifts, such as fluoresence lidar, can provide useful information to obtain an overall assessment of the status of the investigated surfaces and can be exploited to address analytical studies in selected areas. Here we present the results of a joint Italian-Swedish project focused on documenting and recording the status of some sections of the part closed to the public by using fluorescence hyperspectral imaging lidar. The lidar used a tripled-frequency Nd:YAG laser emitting at 355 nm as excitation source and an intensified, gated 512x512-pixel CCD as detector. The lidar had imaging capabilities thanks to a computer-controlled scanning mirror. The fluorescence characteristics of fresco wall paintings were compared to those of fresco fragments found at the same archaeological site and separately examined in the lab using FT-IR and Raman techniques for the identification of pigments. The fluorescence lidar was also used to remotely detect the growth of phototrophic biodeteriogens on the walls. The fluorescence lidar data were compared with results from biological sampling, cultivation and laboratory analysis by molecular techniques.

Capacity of X-ray fluorescence analysis

International Nuclear Information System (INIS)

Wobrauschek, P.; Kregsamer, P.

1997-01-01

X-Ray fluorescence analysis (XRF) is a powerful analytical tool for the qualitative and quantitative determination of chemical elements in a sample. Two different detection principles are accepted widely: wavelength dispersive and energy dispersive. Various sources for XRF are discussed: X-ray tubes, accelerators for particle induced XRF, radioactive isotopes, and the use of synchrotron radiation. Applications include environmental, technical, medical, fine art, and forensic studies. Due to the demands of research and application special techniques like total reflection XRF (TXRF) were developed with ultimately achievable detection limits in the femtogram region. The elements detectable by XRF range from Be to U. (author)

Rapid fluorescence detection of pathogenic bacteria using magnetic enrichment technique combined with magnetophoretic chromatography.

Science.gov (United States)

Che, Yulan; Xu, Yi; Wang, Renjie; Chen, Li

2017-08-01

A rapid and sensitive analytical method was developed to detect pathogenic bacteria which combined magnetic enrichment, fluorescence labeling with polyethylene glycol (PEG) magnetophoretic chromatography. As pathogenic bacteria usually exist in complex matrixes at low concentration, an efficient enrichment is essential for diagnosis. In order to capture series types of pathogenic bacteria in samples, amino-modified magnetic nanoparticles (Fe 3 O 4 @SiO 2 -NH 2 ) were prepared for efficient enrichment by the electrostatic interaction with pathogenic bacteria. It was shown that the capture efficiency reached up to 95.4% for Escherichia coli (E. coli). Furthermore, quantitative analysis of the bacteria was achieved by using acridine orange (AO) as a fluorescence probe for the captured E. coli due to its ability of staining series types of bacteria and rapid labeling. In order to remove the free magnetic nanoparticles and redundant fluorescent reagent, the labeled suspension was poured into a PEG separation column and was separated by applying an external magnetic field. The presence of 100 cfu mL -1 E. coli could be detected for semi-quantitative analysis by observing the separation column with the naked eye, and the concentration could be further evaluated by fluorescence detection. All the above processes were finished within 80 min. It was demonstrated that a good linear relationship existed between the fluorescence intensity and the concentration of E. coli ranging from 10 2 to 10 6  cfu mL -1 , with a detection limit of 100 cfu mL -1 when E. coli acted as target bacteria. The recovery rate of E. coli was 93.6∼102.0% in tap water and cooked meat samples, and the RSD was lower than 7% (n = 6); the result coincided with the conventional plate count method. Graphical abstract ᅟ.

Fluorescence-based Western blotting for quantitation of protein biomarkers in clinical samples.

Science.gov (United States)

Zellner, Maria; Babeluk, Rita; Diestinger, Michael; Pirchegger, Petra; Skeledzic, Senada; Oehler, Rudolf

2008-09-01

Since most high throughput techniques used in biomarker discovery are very time and cost intensive, highly specific and quantitative analytical alternative application methods are needed for the routine analysis. Conventional Western blotting allows detection of specific proteins to the level of single isotypes while its quantitative accuracy is rather limited. We report a novel and improved quantitative Western blotting method. The use of fluorescently labelled secondary antibodies strongly extends the dynamic range of the quantitation and improves the correlation with the protein amount (r=0.997). By an additional fluorescent staining of all proteins immediately after their transfer to the blot membrane, it is possible to visualise simultaneously the antibody binding and the total protein profile. This allows for an accurate correction for protein load. Applying this normalisation it could be demonstrated that fluorescence-based Western blotting is able to reproduce a quantitative analysis of two specific proteins in blood platelet samples from 44 subjects with different diseases as initially conducted by 2D-DIGE. These results show that the proposed fluorescence-based Western blotting is an adequate application technique for biomarker quantitation and suggest possibilities of employment that go far beyond.

Study of the analytic quality in the determinations of Cr, Fe, Mn, Cu, Zn, Pb and Hg through conventional and nuclear analytical techniques in mosses of the MATV; Estudio de la calidad analitica en las determinaciones de Cr, Fe, Mn, Cu, Zn, Pb y Hg a traves de tecnicas analiticas nucleares y convencionales en musgos de la ZMVT

Energy Technology Data Exchange (ETDEWEB)

Caballero S, B.

2013-07-01

To evaluate the environmental risks of air pollution and to facilitate the decision-making for control, is necessary to have the capacity to generate data with analytical quality. A comparison between nuclear (Neutron activation analysis and total reflection X-ray fluorescence spectrometry) and no nuclear analytical techniques (atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry) for simultaneous determination of metal content (Cr, Cu, Fe, Hg, Mn, Pb and Zn) in mosses from Metropolitan Area of the Toluca Valley (MATV) was performed. Epiphytic mosses (Fabriona ciliaris and Leskea angustata) were sampled in two campaigns, 16 sites (urban, transition and natural) and were prepared for each technique. The biological certified reference materials were used for the quality control and to evaluate accuracy, precision, linearity, detection and quantification limits. Results show that nuclear analytical techniques and no nuclear applied in chemical analysis of Cr, Cu, Fe, Hg, Mn, Pb and Zn in moss from MATV are comparable and therefore all of these can potentially be used for this purpose. However, if its considered both, the performance parameters and economic/operational characteristics is widely recommended inductively coupled plasma optical emission spectrometry, conventional analytical technique, which showed the highest analytical grade quality. Also were observed spatial and temporal variations in the concentrations of Cr, Cu, Fe, Hg, Mn, Pb and Zn in mosses from MATV and was discussed its potential origin. The urban sites had the highest concentration of anthropogenic elements as Cr, Cu, Fe, Hg, Pb and Zn because are strongly impacted by roads with high vehicle traffic. (Author)

X-ray fluorescence spectroscopy technology applied to the materials elementary characterization

International Nuclear Information System (INIS)

Marambio A, Cristian Gilberto.

1997-01-01

A thorough study of the different applications of energy dispersive x-ray fluorescence spectrometry is presented, using different excitation sources and measurement geometries. The adaptation of these systems focuses on the analytical solution for different sample types by studying distinct parameters such as: volume of saturation for liquid samples, inter elemental effects from the matrix and the interferences associated with the measurement reading statistical parameters: as reproducibility, precision and detection limits. The application of the technique using radioisotopic sources gave satisfactory results in the analysis of geologic samples, in analytical control of concentration processes for rare earths and for the manufacturing of fuel elements. In the case of a system with an x-ray generator two measurement geometries were studied: 45 deg geometry and total reflection. There were major results in the analysis of polymer impurities and alloy impurities, aluminums and thin semiconductor films, respectively, after non destructive in situ analysis of the material. The results show that x-ray fluorescence spectrometry is a powerful tool for analysis and process control, with prospects for the solution of analytical problems in the materials area. (author)

Evaluation of the Acridine Orange Fluorescence Technique and the Indirect Fluorescent Antibody as Diagnostic Tests for Tropical Theileriosis

Directory of Open Access Journals (Sweden)

Mahmoud

2011-06-01

Full Text Available This study was carried out to evaluate the use of acridine orange fluorescence technique on blood slides as a rapid diagnostic test for tropical theileriosis in comparison with the Giemsa-stained thin blood film technique. Also the indirect fluorescent antibody test has been employed for the serodiagnosis of tropical theileriosis. The study was carried out on 62 young and 48 adult Friesian cattle suffering from clinical tropical theileriosis in Qassim Region, Central Saudi Arabia, during the period from August 2006 to July 2008. For control, blood samples were also obtained from 25 young and 25 adult, clinically healthy, Friesian cattle, selected at random from different dairy farms in Qassim Region. Thin blood films were fixed with methanol and stained with Giemsa and acridine orange and were examined by two independent microbiologists. There was 100% correlation in the interpretation of slides stained with Giemsa and acridine orange both with respect to positivity and negativity, between the two microbiologists. It is concluded that if facilities are available acridine orange is a valuable alternative for screening tropical theileriosis. The method may also have potential value in the diagnosis of Theileria parva, which causes East Coast fever, and also other Theileria species. Results of the present study also showed that IFA test was not found sufficiently sensitive and specific as has been reported earlier. [Vet. World 2011; 4(8.000: 341-344

Improvement of the qualitative and quantitative detection of simultaneously present fluorescent tracers by systematic sample treatment

International Nuclear Information System (INIS)

Behrens, H.

1982-01-01

The selective instrumental detection of individual fluorescent tracers in mixtures containing further fluorescent dyes is limited by spectral interferences. Therefore additional separations or other suitable procedures have to be included into the analytic technique. With the method described below, the respective tracer to be detected remains with its initial concentration in the sample and is analysed under the appropriate conditions, whereas the interfering tracers are separated or suppressed. The techniques applied for this base on the facts that 1) the fluorescence intensity of the tracers varies differently when the pH-value changes; 2) the tracers show different absorption behaviour and 3) they provide different degrees of light sensitivity. The procedures permit for example to detect uranin when eosin is present in a higher concentration or to detect eosin when amidorhodamin G is present. (orig.) [de

Optimization of analytical techniques to characterize antibiotics in aquatic systems

International Nuclear Information System (INIS)

Al Mokh, S.

2013-01-01

Antibiotics are considered as pollutants when they are present in aquatic ecosystems, ultimate receptacles of anthropogenic substances. These compounds are studied as their persistence in the environment or their effects on natural organisms. Numerous efforts have been made worldwide to assess the environmental quality of different water resources for the survival of aquatic species, but also for human consumption and health risk related. Towards goal, the optimization of analytical techniques for these compounds in aquatic systems remains a necessity. Our objective is to develop extraction and detection methods for 12 molecules of aminoglycosides and colistin in sewage treatment plants and hospitals waters. The lack of analytical methods for analysis of these compounds and the deficiency of studies for their detection in water is the reason for their study. Solid Phase Extraction (SPE) in classic mode (offline) or online followed by Liquid Chromatography analysis coupled with Mass Spectrometry (LC/MS/MS) is the most method commonly used for this type of analysis. The parameters are optimized and validated to ensure the best conditions for the environmental analysis. This technique was applied to real samples of wastewater treatment plants in Bordeaux and Lebanon. (author)

Temperature measurement in a compressible flow field using laser-induced iodine fluorescence

Science.gov (United States)

Fletcher, D. G.; Mcdaniel, J. C.

1987-01-01

The thermometric capability of a two-line fluorescence technique using iodine seed molecules in air is investigated analytically and verified experimentally in a known steady compressible flow field. Temperatures ranging from 165 to 295 K were measured in the flowfield using two iodine transitions accessed with a 30-GHz dye-laser scan near 543 nm. The effect of pressure broadening on temperature measurement is evaluated.

Quantitative analysis of the sediments from the Solimoes/Amazonas river flood plain using energy dispersive x-ray fluorescence technique

International Nuclear Information System (INIS)

Carneiro, Ana E.V.

1995-01-01

A methodology for quantitative analysis of geological, biological and environmental samples with a high fraction of light elements (atomic number less than 13), using energy dispersive X-ray fluorescence technique with radioisotopic excitation, is proposed. The proposed procedure is based on the method of Fundamental Parameters for analytical elements (≥->13 evaluation, and coherent and incoherent scattered radiation for the quantitation of the light fraction of the matrix. In the order to obtain the characteristic X-ray of the elements in the Mn to Zr range a Cd-109 annular radioactive source (1,70 GBq) was used, and for Al to CR, Fe-55 (o,74 GBq). For the X-ray detection a Si (Li) detector coupled to a multichannel emulation card was employed. The characteristic X-ray net intensity as well as the coherent and incoherent scattered intensities were obtained by using the AXL software for spectrum analysis. (author). 89 refs., 37 figs., 32 tabs

Technique for Increasing the Selectivity of the Method of Laser Fragmentation/Laser-Induced Fluorescence

Science.gov (United States)

Bobrovnikov, S. M.; Gorlov, E. V.; Zharkov, V. I.

2018-05-01

A technique for increasing the selectivity of the method of detecting high-energy materials (HEMs) based on laser fragmentation of HEM molecules with subsequent laser excitation of fluorescence of the characteristic NO fragments from the first vibrational level of the ground state is suggested.

Applied research on air pollution using nuclear-related analytical techniques

International Nuclear Information System (INIS)

1994-01-01

A co-ordinated research programme (CRP) on applied research on air pollution using nuclear-related techniques is a global CRP which will run from 1992-1996, and will build upon the experience gained by the Agency from the laboratory support that it has been providing for several years to BAPMoN - the Background Air Pollution Monitoring Network programme organized under the auspices of the World Meterological Organization. The purpose of this CRP is to promote the use of nuclear analytical techniques in air pollution studies, e.g. NAA, XFR, and PIXE for the analysis of toxic and other trace elements in suspended particulate matter (including air filter samples), rainwater and fog-water samples, and in biological indicators of air pollution (e.g. lichens and mosses). The main purposes of the core programme are i) to support the use of nuclear and nuclear-related analytical techniques for practically-oriented research and monitoring studies on air pollution ii) to identify major sources of air pollution affecting each of the participating countries with particular reference to toxic heavy metals, and iii) to obtain comparative data on pollution levels in areas of high pollution (e.g. a city centre or a populated area downwind of a large pollution source) and low pollution (e.g. rural areas). This document reports the discussions held during the first Research Co-ordination Meeting (RCM) for the CRP which took place at the IAEA Headquarters in Vienna. Refs, figs and tabs

Applications of optical fiber to the remote fluorescence analysis

International Nuclear Information System (INIS)

Shin, Jang Soo; Kim, Duck Hueon; Lee, Soo Ho

1992-12-01

The laser fluorometer developed in 1987 has been used in real circumstances for trace uranium analysis. And, we have been trying to improve the instrument to be able to apply in analytical circumstances of remote measurement using optical fiber. The N 2 laser beam and the resulting fluorescence light could be successfully transmitted through a quartz-made optical fiber. The wavelength resolution and the fluorescence decay time resolution induced by pulsed N 2 laser were used to the uranium fluorescence analyses. The fluorescence of uranium in nitric acid medium was measured successfully using the system. The fluorescence signal was analysed using simplex method which is useful to deconvolute the mixed signals. An analytical method using thermal lens effect was developed. The method will be a complementary one for the fluorescence measurement. (Author)

Improving accuracy and capabilities of X-ray fluorescence method using intensity ratios

Energy Technology Data Exchange (ETDEWEB)

Garmay, Andrey V., E-mail: andrew-garmay@yandex.ru; Oskolok, Kirill V.

2017-04-15

An X-ray fluorescence analysis algorithm is proposed which is based on a use of ratios of X-ray fluorescence lines intensities. Such an analytical signal is more stable and leads to improved accuracy. Novel calibration equations are proposed which are suitable for analysis in a broad range of matrix compositions. To apply the algorithm to analysis of samples containing significant amount of undetectable elements a use of a dependence of a Rayleigh-to-Compton intensity ratio on a total content of these elements is suggested. The technique's validity is shown by analysis of standard steel samples, model metal oxides mixture and iron ore samples.

Fourth-derivative synchronous spectrofluorimetry and HPLC with fluorescence detection as two analytical techniques for the simultaneous determination of itopride and domperidone.

Science.gov (United States)

Ibrahim, Fawzia; Nasr, Jenny Jeehan

2016-02-01

Two simple, rapid and sensitive methods, namely, fourth-derivative synchronous spectrofluorimetry (method I) and HPLC with fluorescence detection (method II) were developed for the simultaneous analysis of a binary mixture of itopride HCl (ITP) and domperidone (DOM) without prior separation. The first method was based on measuring the fourth derivative of the synchronous fluorescence spectra of the two drugs at Δλ = 40 nm in methanol. The different experimental parameters affecting the synchronous fluorescence of the studied drugs were carefully optimized. Chromatographic separation was performed in < 6.0 min using a RP C18 column (250 mm × 4.6 mm i.d., 5 µm particle size) with fluorescence detection at 344 nm after excitation at 285 nm. A mobile phase composed of a mixture of 0.02 M phosphate buffer with acetonitrile in a ratio of 55 : 45, pH 4.5, was used at a flow rate of 1 mL/min. Linearity ranges were found to be 0.1-2 µg/mL for ITP in both methods, whereas those for DOM were found to be 0.08-2 and 0.05-1.5 µg/mL in methods I and II, respectively. The proposed methods were successfully applied for the determination of the studied drugs in synthetic mixtures and laboratory-prepared tablets. Copyright © 2015 John Wiley & Sons, Ltd.

Trends in hard X-ray fluorescence mapping: environmental applications in the age of fast detectors

Energy Technology Data Exchange (ETDEWEB)

Lombi, E.; Donner, E. [University of South Australia, Centre for Environmental Risk Assessment and Remediation, Mawson Lakes, South Australia (Australia); CRC CARE, PO Box 486, Salisbury, South Australia (Australia); Jonge, M.D. de; Paterson, D. [Australian Synchrotron, X-ray Fluorescence Microscopy, 800 Blackburn Road, Clayton, Victoria (Australia); Ryan, C.G. [CSIRO Earth Science and Resource Engineering, Normanby Road, Clayton, Victoria (Australia)

2011-06-15

Environmental samples are extremely diverse but share a tendency for heterogeneity and complexity. This heterogeneity poses methodological challenges when investigating biogeochemical processes. In recent years, the development of analytical tools capable of probing element distribution and speciation at the microscale have allowed this challenge to be addressed. Of these available tools, laterally resolved synchrotron techniques such as X-ray fluorescence mapping are key methods for the in situ investigation of micronutrients and inorganic contaminants in environmental samples. This article demonstrates how recent advances in X-ray fluorescence detector technology are bringing new possibilities to environmental research. Fast detectors are helping to circumvent major issues such as X-ray beam damage of hydrated samples, as dwell times during scanning are reduced. They are also helping to reduce temporal beamtime requirements, making particularly time-consuming techniques such as micro X-ray fluorescence ({mu}XRF) tomography increasingly feasible. This article focuses on {mu}XRF mapping of nutrients and metalloids in environmental samples, and suggests that the current divide between mapping and speciation techniques will be increasingly blurred by the development of combined approaches. (orig.)

Simultaneous determination of glycols based on fluorescence anisotropy

International Nuclear Information System (INIS)

Garcia Sanchez, F.; Navas Diaz, A.; Lopez Guerrero, M.M.

2007-01-01

Simultaneous determination of non-fluorescent glycols in mixtures without separation or chemical transformation steps is described. Two methods based in the measure of fluorescence anisotropy of a probe such as fluorescein dissolved in the analyte or analyte mixtures are described. In the first method, the anisotropy spectra of pure and mixtures of analytes are used to quantitative determination (if the fluorophor concentration is in a range where fluorescence intensity is proportional to concentration). In the second method, a calibration curve anisotropy-concentration based on the application of the Perrin equation is established. The methods presented here are capable of directly resolving binary mixtures of non-fluorescent glycols on the basis of differences on the fluorescence anisotropy of a fluorescence tracer. Best analytical performances were obtained by application of the method based on Perrin equation. This method is simple, rapid and allows the determination of mixtures of glycols with reasonable accuracy and precision. Detection limits are limited by the quantum yield and anisotropy values of the tracer in the solvents. Recovery values are related to the differences in anisotropy values of the tracer in the pure solvents. Mixtures of glycerine/ethylene glycol (GL/EG), ethylene glycol/1,2-propane diol (EG/1,2-PPD) and polyethylene glycol 400/1,2-propane diol (PEG 400/1,2-PPD) were analysed and recovery values are within 95-120% in the Perrin method. Relative standard deviation are in the range 1.3-2.9% and detection limits in the range 3.9-8.9%

Nuclear Analytical Techniques for Commercial Applications in China

International Nuclear Information System (INIS)

Chai, Z.; Zhang, Z.; Feng, S.; Yang, J.; Ouyang, H.; Feng, X.; Mao, X.

2013-01-01

Since the establishment of the first Chinese nuclear reactor and accelerator in 1958, the nuclear analytical techniques (NATs) in China have dramatically developed in past half century. Nowadays 10 research nuclear reactors and over 100 small accelerators are available in China. Roughly, about 50 % of the machine time is applied for commercial purpose at the moment. The versatile nuclear analytical methods, mainly NAA, PIXE, XRF, etc., in China have been and are being applied widely and extensively in the following three fields: scientific, training, and commercial. This paper will briefly describe the past experience and present status about NATs for commercial applications. Some practical examples to demonstrate the role of NATs in this aspect will be given as well. Basically, the NATs used for the commercial applications in China can be divided into two types, i.e. off-line and on-line. The former mainly includes instrumental neutron activation analysis (INAA) for compositional determination, particle induced X-ray emission (PIXE) also for compositional analysis, accelerator-based mass-spectrometry (AMS) for analysis of C-14, Be-7, Cl-36 and other long-lived radioactive nuclides, solid state nuclear track detector

X-ray fluorescence microscopy reveals the role of selenium in spermatogenesis

OpenAIRE

Kehr, Sebastian; Malinouski, Mikalai; Finney, Lydia; Vogt, Stefan; Labunskyy, Vyacheslav M.; Kasaikina, Marina V.; Carlson, Bradley A.; Zhou, You; Hatfield, Dolph L.; Gladyshev, Vadim N.

2009-01-01

Selenium (Se) is a trace element with important roles in human health. Several selenoproteins have essential functions in development. However, the cellular and tissue distribution of Se remains largely unknown because of the lack of analytical techniques that image this element with sufficient sensitivity and resolution. Herein, we report that X-ray fluorescence microscopy (XFM) can be used to visualize and quantify the tissue, cellular and subcellular topography of Se. We applied this techn...

Assessing the Value of Structured Analytic Techniques in the U.S. Intelligence Community

Science.gov (United States)

2016-01-01

Analytic Techniques, and Why Do Analysts Use Them? SATs are methods of organizing and stimulating thinking about intelligence problems. These methods... thinking ; and imaginative thinking techniques encourage new perspectives, insights, and alternative scenarios. Among the many SATs in use today, the...more transparent, so that other analysts and customers can bet - ter understand how the judgments were reached. SATs also facilitate group involvement

Determination of minor and trace elements in kidney stones by x-ray fluorescence analysis

Science.gov (United States)

Srivastava, Anjali; Heisinger, Brianne J.; Sinha, Vaibhav; Lee, Hyong-Koo; Liu, Xin; Qu, Mingliang; Duan, Xinhui; Leng, Shuai; McCollough, Cynthia H.

2014-03-01

The determination of accurate material composition of a kidney stone is crucial for understanding the formation of the kidney stone as well as for preventive therapeutic strategies. Radiations probing instrumental activation analysis techniques are excellent tools for identification of involved materials present in the kidney stone. In particular, x-ray fluorescence (XRF) can be very useful for the determination of minor and trace materials in the kidney stone. The X-ray fluorescence measurements were performed at the Radiation Measurements and Spectroscopy Laboratory (RMSL) of department of nuclear engineering of Missouri University of Science and Technology and different kidney stones were acquired from the Mayo Clinic, Rochester, Minnesota. Presently, experimental studies in conjunction with analytical techniques were used to determine the exact composition of the kidney stone. A new type of experimental set-up was developed and utilized for XRF analysis of the kidney stone. The correlation of applied radiation source intensity, emission of X-ray spectrum from involving elements and absorption coefficient characteristics were analyzed. To verify the experimental results with analytical calculation, several sets of kidney stones were analyzed using XRF technique. The elements which were identified from this techniques are Silver (Ag), Arsenic (As), Bromine (Br), Chromium (Cr), Copper (Cu), Gallium (Ga), Germanium (Ge), Molybdenum (Mo), Niobium (Nb), Rubidium (Rb), Selenium (Se), Strontium (Sr), Yttrium (Y), Zirconium (Zr). This paper presents a new approach for exact detection of accurate material composition of kidney stone materials using XRF instrumental activation analysis technique.

SAMAC Analytical Notes II: preliminary results of x-ray fluorescence analysis of archeological materials from southeastern Utah

International Nuclear Information System (INIS)

Snow, D.H.; Fullbright, H.J.

1977-02-01

A series of prehistoric potsherds, local clay samples, and possible tempering materials from archeological excavations in southeastern Utah have been examined by x-ray fluorescence spectroscopy. The results obtained for this small sampling demonstrate the usefulness of the technique in characterizing the clays, the potsherd pastes, and the decorative pigments

Fluorescent nanoparticles for intracellular sensing: A review

International Nuclear Information System (INIS)

Ruedas-Rama, Maria J.; Walters, Jamie D.; Orte, Angel; Hall, Elizabeth A.H.

2012-01-01

Highlights: ► Analytical applications of fluorescent nanoparticles (NPs) in intracellular sensing. ► Critical review on performance of QDots, metal NPs, silica NPs, and polymer NPs. ► Highlighted potential of fluorescence lifetime imaging microscopy (FLIM). - Abstract: Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy.

Quantitative analysis of thorium in the presence of rare earth by X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Jesus, Camila S. de; Taam, Isabel; Vianna, Claudio A.

2013-01-01

The occurrence of Thorium in ores is normally associated to other elements such as Uranium and Cerium, as well as some Rare-Earths (RE). The separation of these elements by traditional analytic chemistry techniques is both time and reagent consuming, thus increasing the analysis cost. The hereby proposed method consists in the direct determination of Thorium in rare earths ores and compounds by X-ray fluorescence spectroscopy without any prior chemical separation from other matrix elements. This non-destructive technique is used to determine which elements are present in solid and liquid samples, as well as their concentrations. The studied matrix contains Lanthanum, Cerium, Praseodymium, Neodymium, Samarium, Gadolinium and Yttrium. This study evaluated the analytical lines of radiation emission for each rare earth contained in the matrix, comparing it to the Thorium main analytical line. The Thorium quantification was measured through the Th L line, where there is no influence or interference from the rare earths analytical lines. The studied samples are certified standards and the obtained results have been compared to Ethylenediaminetetraacetic acid (EDTA) titration results, an already well-established and widely trusted method. We also measured the matrix effect thus using complex rare earths liquor. This liquor contains also elements commonly found in monazites sands: phosphates, aluminum, iron. Obtained results state the efficiency of X-ray Fluorescence to determine Thorium in the presence of rare earths without any prior chemical separation. (author)

Fluorescence Imaging Reveals Surface Contamination

Science.gov (United States)

Schirato, Richard; Polichar, Raulf

1992-01-01

In technique to detect surface contamination, object inspected illuminated by ultraviolet light to make contaminants fluoresce; low-light-level video camera views fluorescence. Image-processing techniques quantify distribution of contaminants. If fluorescence of material expected to contaminate surface is not intense, tagged with low concentration of dye.

Modern trends: analytical chemistry - techniques and application to biodetection

International Nuclear Information System (INIS)

Khurshid, S.J.

1993-01-01

Microorganism isolated from specimens are usually identified by conventional bacterial identification procedures of morphological evaluation and cultural techniques. These complex methods of studying organisms are extremely tedious and time consuming. This causes serious problems by delaying the decision concerning the presence of pathogens and therefore the adequate drug therapy. Frequently, the decision about the presence of pathogens has to be made prior to the results of microbiological tests. In order to overcome these conditions, workers explored new instrumental methods for characterization, rapid acquisition, high reproducibility, computer aided data recording and interpretation of microorganisms. This article brief reviews application of these modern instrumental approaches such as Infrared Spectroscopy (IR), Gas Chromatography (GC), Fluorescence Spectroscopy, Bioluminescence, Chemiluminescence, FLow Cytometry, Micro calorimetry, GC-MASS Spectrometry, Electrical Impedance, Bio sensors and Radiometry. These techniques have increased the capacity of doing basic research with a major impact on both the clinical laboratories and industry. The radiometric procedure is being used for research and biological quality control of radiopharmaceuticals in our laboratory at PINSTECH. (author)

Detection of illicit drugs with the technique of spectral fluorescence signatures (SFS)

Science.gov (United States)

Poryvkina, Larisa; Babichenko, Sergey

2010-10-01

The SFS technology has already proved its analytical capabilities in a variety of industrial and environmental tasks. Recently it has been introduced for forensic applications. The key features of the SFS method - measuring a 3-dimensional spectrum of fluorescence of the sample (intensity versus excitation and emission wavelengths) with following recognition of specific spectral patterns of SFS responsible for individual drugs - provide an effective tool for the analysis of untreated seized samples, without any separation of the substance of interest from its mixture with accompanying cutting agents and diluents as a preparatory step. In such approach the chemical analysis of the sample is substituted by the analysis of SFS matrix visualized as an optical image. The SFS technology of drug detection is realized by NarTest® NTX2000 analyzer, compact device intended to measure suspicious samples in liquid, solid and powder forms. It simplifies the detection process due to fully automated procedures of SFS measuring and integrated expert system for recognition of spectral patterns. Presently the expert system of NTX2000 is able to detect marijuana, cocaine, heroin, MDMA, amphetamine and methamphetamine with the detection limit down to 5% of the drug concentration in various mixtures. The numerous tests with street samples confirmed that the use of SFS method provides reliable results with high sensitivity and selectivity for identification of drugs of abuse. More than 3000 street samples of the aforesaid drugs were analyzed with NTX2000 during validation process, and the correspondence of SFS results and conclusions of standard forensic analyses with GC/MS techniques was in 99.4% cases.

Fluorescence excitation-emission matrix spectroscopy for degradation monitoring of machinery lubricants

Science.gov (United States)

Sosnovski, Oleg; Suresh, Pooja; Dudelzak, Alexander E.; Green, Benjamin

2018-02-01

Lubrication oil is a vital component of heavy rotating machinery defining the machine's health, operational safety and effectiveness. Recently, the focus has been on developing sensors that provide real-time/online monitoring of oil condition/lubricity. Industrial practices and standards for assessing oil condition involve various analytical methods. Most these techniques are unsuitable for online applications. The paper presents the results of studying degradation of antioxidant additives in machinery lubricants using Fluorescence Excitation-Emission Matrix (EEM) Spectroscopy and Machine Learning techniques. EEM Spectroscopy is capable of rapid and even standoff sensing; it is potentially applicable to real-time online monitoring.

Assessment of analytical techniques for characterization of crystalline clopidogrel forms in patent applications

Directory of Open Access Journals (Sweden)

Luiz Marcelo Lira

2014-04-01

Full Text Available The aim of this study was to evaluate two important aspects of patent applications of crystalline forms of drugs: (i the physicochemical characterization of the crystalline forms; and (ii the procedure for preparing crystals of the blockbuster drug clopidogrel. To this end, searches were conducted using online patent databases. The results showed that: (i the majority of patent applications for clopidogrel crystalline forms failed to comply with proposed Brazilian Patent Office guidelines. This was primarily due to insufficient number of analytical techniques evaluating the crystalline phase. In addition, some patent applications lacked assessment of chemical/crystallography purity; (ii use of more than two analytical techniques is important; and (iii the crystallization procedure for clopidogrel bisulfate form II were irreproducible based on the procedure given in the patent application.

L-cysteine-capped core/shell/shell quantum dot-graphene oxide nanocomposite fluorescence probe for polycyclic aromatic hydrocarbon detection.

Science.gov (United States)

Adegoke, Oluwasesan; Forbes, Patricia B C

2016-01-01

Environmental pollutants, such as the polycyclic aromatic hydrocarbons (PAHs), become widely distributed in the environment after emission from a range of sources, and they have potential biological effects, including toxicity and carcinogenity. In this work, we have demonstrated the analytical potential of a covalently linked L-cysteine-capped CdSeTe/ZnSe/ZnS core/shell/shell quantum dot (QD)-graphene oxide (GO) nanocomposite fluorescence probe to detect PAH compounds in aqueous solution. Water-soluble L-cysteine-capped CdSeTe/ZnSe/ZnS QDs were synthesized for the first time and were covalently bonded to GO. The fluorescence of the QD-GO nanocomposite was enhanced relative to the unconjugated QDs. Various techniques including TEM, SEM, HRSEM, XRD, Raman, FT-IR, UV/vis and fluorescence spectrophotometry were employed to characterize both the QDs and the QD-GO nanocomposite. Four commonly found priority PAH analytes namely; phenanthrene (Phe), anthracene (Ant), pyrene (Py) and naphthalene (Naph), were tested and it was found that each of the PAH analytes enhanced the fluorescence of the QD-GO probe. Phe was selected for further studies as the PL enhancement was significantly greater for this PAH. A limit of detection (LOD) of 0.19 µg/L was obtained for Phe under optimum conditions, whilst the LOD of Ant, Py and Naph were estimated to be ~0.26 µg/L. The fluorescence detection mechanism is proposed. Copyright © 2015 Elsevier B.V. All rights reserved.

Fluorescence Spectroscopy and Chemometric Modeling for Bioprocess Monitoring

Directory of Open Access Journals (Sweden)

Saskia M. Faassen

2015-04-01

Full Text Available On-line sensors for the detection of crucial process parameters are desirable for the monitoring, control and automation of processes in the biotechnology, food and pharma industry. Fluorescence spectroscopy as a highly developed and non-invasive technique that enables the on-line measurements of substrate and product concentrations or the identification of characteristic process states. During a cultivation process significant changes occur in the fluorescence spectra. By means of chemometric modeling, prediction models can be calculated and applied for process supervision and control to provide increased quality and the productivity of bioprocesses. A range of applications for different microorganisms and analytes has been proposed during the last years. This contribution provides an overview of different analysis methods for the measured fluorescence spectra and the model-building chemometric methods used for various microbial cultivations. Most of these processes are observed using the BioView® Sensor, thanks to its robustness and insensitivity to adverse process conditions. Beyond that, the PLS-method is the most frequently used chemometric method for the calculation of process models and prediction of process variables.

Fluorescence Spectroscopy and Chemometric Modeling for Bioprocess Monitoring

Science.gov (United States)

Faassen, Saskia M.; Hitzmann, Bernd

2015-01-01

On-line sensors for the detection of crucial process parameters are desirable for the monitoring, control and automation of processes in the biotechnology, food and pharma industry. Fluorescence spectroscopy as a highly developed and non-invasive technique that enables the on-line measurements of substrate and product concentrations or the identification of characteristic process states. During a cultivation process significant changes occur in the fluorescence spectra. By means of chemometric modeling, prediction models can be calculated and applied for process supervision and control to provide increased quality and the productivity of bioprocesses. A range of applications for different microorganisms and analytes has been proposed during the last years. This contribution provides an overview of different analysis methods for the measured fluorescence spectra and the model-building chemometric methods used for various microbial cultivations. Most of these processes are observed using the BioView® Sensor, thanks to its robustness and insensitivity to adverse process conditions. Beyond that, the PLS-method is the most frequently used chemometric method for the calculation of process models and prediction of process variables. PMID:25942644

On-line solid-phase enrichment coupled to packed reactor flow injection analysis in a green analytical procedure to determine low levels of folic acid using fluorescence detection

Directory of Open Access Journals (Sweden)

Emara Samy

2012-12-01

Full Text Available Abstract Background Analysis of folic acid (FA is not an easy task because of its presence in lower concentrations, its lower stability under acidic conditions, and its sensitiveness against light and high temperature. The present study is concerned with the development and validation of an automated environmentally friendly pre-column derivatization combined by solid-phase enrichment (SPEn to determine low levels of FA. Results Cerium (IV trihydroxyhydroperoxide (CTH as a packed oxidant reactor has been used for oxidative cleavage of FA into highly fluorescent product, 2-amino-4-hydroxypteridine-6-carboxylic acid. FA was injected into a carrier stream of 0.04 M phosphate buffer, pH 3.4 at a flow-rate of 0.25 mL/min. The sample zone containing the analyte was passed through the CTH reactor thermostated at 40°C, and the fluorescent product was trapped and enriched on a head of small ODS column (10 mm x 4.6 mm i.d., 5 μm particle size. The enriched product was then back-flush eluted by column-switching from the small ODS column to the detector with a greener mobile phase consisting of ethanol and phosphate buffer (0.04M, pH 3.4 in the ratio of 5:95 (v/v. The eluent was monitored fluorimetrically at emission and excitation wavelengths of 463 and 367 nm, respectively. The calibration graph was linear over concentrations of FA in the range of 1.25-50 ng/mL, with a detection limit of 0.49 ng/mL. Conclusion A new simple and sensitive green analytical procedure including on-line pre-column derivatization combined by SPEn has been developed for the routine quality control and dosage form assay of FA at very low concentration level. The method was a powerful analytical technique that had excellent sensitivity, sufficient accuracy and required relatively simple and inexpensive instrumentation.

Development of a 2D temperature measurement technique for combustion diagnostics using 2-line atomic fluorescence

Energy Technology Data Exchange (ETDEWEB)

Engstroem, Johan

2001-01-01

The present thesis is concerned with the development and application of a novel planar laser-induced fluorescence (PLIF) technique for temperature measurements in a variety of combusting flows. Accurate measurement of temperature is an essential task in combustion diagnostics, since temperature is one of the most fundamental quantities for the characterization of combustion processes. The technique is based on two-line atomic fluorescence (TLAF) from small quantities of atomic indium (In) seeded into the fuel. It has been developed from small-scale experiments in laboratory flames to the point where practical combustion systems can be studied. The technique is conceptually simple and reveals temperature information in the post-flame regions. The viability of the technique has been tested in three extreme measurement situations: in spark ignition engine combustion, in ultra-lean combustion situations such as lean burning aero-engine concepts and, finally, in fuel-rich combustion. TLAF was successfully applied in an optical Sl engine using isooctane as fuel. The wide temperature sensitivity, 700 - 3000 K, of the technique using indium atoms allowed measurements over the entire combustion cycle in the engine to be performed. In applications in lean combustion a potential problem caused by the strong oxidation processes of indium atoms was encountered. This limits measurement times due to deposits of absorbing indium oxide on measurement windows. The seeding requirement is a disadvantage of the technique and can be a limitation in some applications. The results from experiments performed in sooting flames are very promising for thermometry measurements in such environments. Absorption by hydrocarbons and other native species was found to be negligible. Since low laser energies and low seeding concentrations could be used, the technique did not, unlike most other incoherent optical thermometry techniques, suffer interferences from LII of soot particles or LIF from PAH

Environmentally Sensitive Fluorescent Sensors Based on Synthetic Peptides

Directory of Open Access Journals (Sweden)

Laurence Choulier

2010-03-01

Full Text Available Biosensors allow the direct detection of molecular analytes, by associating a biological receptor with a transducer able to convert the analyte-receptor recognition event into a measurable signal. We review recent work aimed at developing synthetic fluorescent molecular sensors for a variety of analytes, based on peptidic receptors labeled with environmentally sensitive fluorophores. Fluorescent indicators based on synthetic peptides are highly interesting alternatives to protein-based sensors, since they can be synthesized chemically, are stable, and can be easily modified in a site-specific manner for fluorophore coupling and for immobilization on solid supports.

Single excitation-emission fluorescence spectrum (EEF) for determination of cetane improver in diesel fuel.

Science.gov (United States)

Insausti, Matías; Fernández Band, Beatriz S

2015-04-05

A highly sensitive spectrofluorimetric method has been developed for the determination of 2-ethylhexyl nitrate in diesel fuel. Usually, this compound is used as an additive in order to improve cetane number. The analytical method consists in building the chemometric model as a first step. Then, it is possible to quantify the analyte with only recording a single excitation-emission fluorescence spectrum (EEF), whose data are introduced in the chemometric model above mentioned. Another important characteristic of this method is that the fuel sample was used without any pre-treatment for EEF. This work provides an interest improvement to fluorescence techniques using the rapid and easily applicable EEF approach to analyze such complex matrices. Exploding EEF was the key to a successful determination, obtaining a detection limit of 0.00434% (v/v) and a limit of quantification of 0.01446% (v/v). Copyright © 2015 Elsevier B.V. All rights reserved.

Fluorescence uranium determination

International Nuclear Information System (INIS)

Fernandez Cellini, R.; Crus Castillo, F. de la; Barrera Pinero, R.

1960-01-01

An equipment for analysis of uranium by fluorescence was developed in order to determine it at such a low concentration that it can not be determined by the most sensible analytical methods. this new fluorimeter was adapted to measure the fluorescence emitted by the phosphorus sodium fluoride-sodium carbonate-potasium carbonate-uranyl, being excited by ultraviolet light of 3,650 A the intensity of the light emitted was measure with a photomultiplicator RCA 5819 and the adequate electronic equipment. (Author) 19 refs

New analytical techniques for cuticle chemical analysis

International Nuclear Information System (INIS)

Schulten, H.R.

1994-01-01

1) The analytical methodology of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and direct pyrolysis-mass spectrometry (Py-MS) using soft ionization techniques by high electric fields (FL) are briefly described. Recent advances of Py-GC/MS and Py-FIMS for the analyses of complex organic matter such as plant materials, humic substances, dissolved organic matter in water (DOM) and soil organic matter (SOM) in agricultural and forest soils are given to illustrate the potential and limitations of the applied methods. 2) Novel applications of Py-GC/MS and Py-MS in combination with conventional analytical data in an integrated, chemometric approach to investigate the dynamics of plant lipids are reported. This includes multivariate statistical investigations on maturation, senescence, humus genesis, and environmental damages in spruce ecosystems. 3) The focal point is the author's integrated investigations on emission-induced changes of selected conifer plant constituents. Pattern recognition of Py-MS data of desiccated spruce needles provides a method for distinguishing needles damaged in different ways and determining the cause. Spruce needles were collected from both controls and trees treated with sulphur dioxide (acid rain), nitrogen dioxide, and ozone under controlled conditions. Py-MS and chemometric data evaluation are employed to characterize and classify leaves and their epicuticular waxes. Preliminary mass spectrometric evaluations of isolated cuticles of different plants such as spruce, ivy, holly, and philodendron, as well as ivy cuticles treated in vivo with air pollutants such as surfactants and pesticides are given. (orig.)

The use of decision analytic techniques in energy policy decisions

International Nuclear Information System (INIS)

Haemaelaeinen, R.P.; Seppaelaeinen, T.O.

1986-08-01

The report reviews decision analytic techniques and their applications to energy policy decision making. Decision analysis consists in techniques for structuring the essential elements of a decision problem and mathematical methods for ranking the alternatives from a set of simple judgments. Because modeling subjective judgments is characteristic of decision analysis, the models can incorporate qualitative factors and values, which escape traditional energy modeling. Decision analysis has been applied to choices among energy supply alternatives, siting energy facilities, selecting nuclear waste repositories, selecting research and development projects, risk analysis and prioritizing alternative energy futures. Many applications are done in universities and research institutions, but during the 70's the use of decision analysis has spread both to the public and the private sector. The settings where decision analysis has been applied range from aiding a single decision maker to clarifying opposing points of view. Decision analytic methods have also been linked with energy models. The most valuable result of decision analysis is the clarification of the problem at hand. Political decisions cannot be made solely on the basis of models, but models can be used to gain insight of the decision situation. Models inevitably simplify reality, so they must be regarded only as aids to judgment. So far there has been only one decision analysis of energy policy issues in Finland with actual political decision makers as participants. The experiences of this project and numerous foreign applications do however suggest that the decision analytic approach is useful in energy policy questions. The report presents a number of Finnish energy policy decisions where decision analysis might prove useful. However, the applicability of the methods depends crucially on the actual circumstances at hand

Nonactivation interaction techniques in the analysis of environmental samples

International Nuclear Information System (INIS)

Tolgyessy, J.

1986-01-01

Nonactivation interaction analytical methods are based on the interaction processes of nuclear and X-ray radiation with a sample, leading to their absorption and backscattering, to the ionization of gases or excitation of fluorescent X-ray by radiation, but not to the activation of determined elements. From the point of view of environmental analysis, the most useful nonactivation interaction techniques are X-ray fluorescence by photon or charged particle excitation, ionization of gases by nuclear radiation, elastic scattering of charged particles and backscattering of beta radiation. The significant advantage of these methods is that they are nondestructive. (author)

Recent Trends in Microextraction Techniques Employed in Analytical and Bioanalytical Sample Preparation

Directory of Open Access Journals (Sweden)

Abuzar Kabir

2017-12-01

Full Text Available Sample preparation has been recognized as a major step in the chemical analysis workflow. As such, substantial efforts have been made in recent years to simplify the overall sample preparation process. Major focusses of these efforts have included miniaturization of the extraction device; minimizing/eliminating toxic and hazardous organic solvent consumption; eliminating sample pre-treatment and post-treatment steps; reducing the sample volume requirement; reducing extraction equilibrium time, maximizing extraction efficiency etc. All these improved attributes are congruent with the Green Analytical Chemistry (GAC principles. Classical sample preparation techniques such as solid phase extraction (SPE and liquid-liquid extraction (LLE are being rapidly replaced with emerging miniaturized and environmentally friendly techniques such as Solid Phase Micro Extraction (SPME, Stir bar Sorptive Extraction (SBSE, Micro Extraction by Packed Sorbent (MEPS, Fabric Phase Sorptive Extraction (FPSE, and Dispersive Liquid-Liquid Micro Extraction (DLLME. In addition to the development of many new generic extraction sorbents in recent years, a large number of molecularly imprinted polymers (MIPs created using different template molecules have also enriched the large cache of microextraction sorbents. Application of nanoparticles as high-performance extraction sorbents has undoubtedly elevated the extraction efficiency and method sensitivity of modern chromatographic analyses to a new level. Combining magnetic nanoparticles with many microextraction sorbents has opened up new possibilities to extract target analytes from sample matrices containing high volumes of matrix interferents. The aim of the current review is to critically audit the progress of microextraction techniques in recent years, which has indisputably transformed the analytical chemistry practices, from biological and therapeutic drug monitoring to the environmental field; from foods to phyto

Direct analysis of biological samples by total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Lue M, Marco P.; Hernandez-Caraballo, Edwin A.

2004-01-01

The technique of total reflection X-ray fluorescence (TXRF) is well suited for the direct analysis of biological samples due to the low matrix interferences and simultaneous multi-element nature. Nevertheless, biological organic samples are frequently analysed after digestion procedures. The direct determination of analytes requires shorter analysis time, low reactive consumption and simplifies the whole analysis process. On the other hand, the biological/clinical samples are often available in minimal amounts and routine studies require the analysis of large number of samples. To overcome the difficulties associated with the analysis of organic samples, particularly of solid ones, different procedures of sample preparation and calibration to approach the direct analysis have been evaluated: (1) slurry sampling, (2) Compton peak standardization, (3) in situ microwave digestion, (4) in situ chemical modification and (5) direct analysis with internal standardization. Examples of analytical methods developed by our research group are discussed. Some of them have not been previously published, illustrating alternative strategies for coping with various problems that may be encountered in the direct analysis by total reflection X-ray fluorescence spectrometry

Fluorescent nanoparticles for intracellular sensing: A review

Energy Technology Data Exchange (ETDEWEB)

Ruedas-Rama, Maria J., E-mail: mjruedas@ugr.esmailto [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071, Granada (Spain); Walters, Jamie D. [Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, UK CB2 1QT (United Kingdom); Orte, Angel [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071, Granada (Spain); Hall, Elizabeth A.H., E-mail: lisa.hall@biotech.cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT (United Kingdom)

2012-11-02

Highlights: Black-Right-Pointing-Pointer Analytical applications of fluorescent nanoparticles (NPs) in intracellular sensing. Black-Right-Pointing-Pointer Critical review on performance of QDots, metal NPs, silica NPs, and polymer NPs. Black-Right-Pointing-Pointer Highlighted potential of fluorescence lifetime imaging microscopy (FLIM). - Abstract: Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy.

Application of Fluorescence In Situ Hybridization (FISH) Technique for the Detection of Genetic Aberration in Medical Science

Science.gov (United States)

Ratan, Zubair Ahmed; Zaman, Sojib Bin; Haidere, Mohammad Faisal; Runa, Nusrat Jahan; Akter, Nasrin

2017-01-01

Fluorescence in situ hybridization (FISH) is a macromolecule recognition technique, which is considered as a new advent in the field of cytology. Initially, it was developed as a physical mapping tool to delineate genes within chromosomes. The accuracy and versatility of FISH were subsequently capitalized upon in biological and medical research. This visually appealing technique provides an intermediate degree of resolution between DNA analysis and chromosomal investigations. FISH consists of a hybridizing DNA probe, which can be labeled directly or indirectly. In the case of direct labeling, fluorescent nucleotides are used, while indirect labeling is incorporated with reporter molecules that are subsequently detected by fluorescent antibodies or other affinity molecules. FISH is applied to detect genetic abnormalities that include different characteristic gene fusions or the presence of an abnormal number of chromosomes in a cell or loss of a chromosomal region or a whole chromosome. It is also applied in different research applications, such as gene mapping or the identification of novel oncogenes. This article reviews the concept of FISH, its application, and its advantages in medical science.  PMID:28690958

Characterization of energy response for photon-counting detectors using x-ray fluorescence

International Nuclear Information System (INIS)

Ding, Huanjun; Cho, Hyo-Min; Molloi, Sabee; Barber, William C.; Iwanczyk, Jan S.

2014-01-01

Purpose: To investigate the feasibility of characterizing a Si strip photon-counting detector using x-ray fluorescence. Methods: X-ray fluorescence was generated by using a pencil beam from a tungsten anode x-ray tube with 2 mm Al filtration. Spectra were acquired at 90° from the primary beam direction with an energy-resolved photon-counting detector based on an edge illuminated Si strip detector. The distances from the source to target and the target to detector were approximately 19 and 11 cm, respectively. Four different materials, containing silver (Ag), iodine (I), barium (Ba), and gadolinium (Gd), were placed in small plastic containers with a diameter of approximately 0.7 cm for x-ray fluorescence measurements. Linear regression analysis was performed to derive the gain and offset values for the correlation between the measured fluorescence peak center and the known fluorescence energies. The energy resolutions and charge-sharing fractions were also obtained from analytical fittings of the recorded fluorescence spectra. An analytical model, which employed four parameters that can be determined from the fluorescence calibration, was used to estimate the detector response function. Results: Strong fluorescence signals of all four target materials were recorded with the investigated geometry for the Si strip detector. The average gain and offset of all pixels for detector energy calibration were determined to be 6.95 mV/keV and −66.33 mV, respectively. The detector’s energy resolution remained at approximately 2.7 keV for low energies, and increased slightly at 45 keV. The average charge-sharing fraction was estimated to be 36% within the investigated energy range of 20–45 keV. The simulated detector output based on the proposed response function agreed well with the experimental measurement. Conclusions: The performance of a spectral imaging system using energy-resolved photon-counting detectors is very dependent on the energy calibration of the

Bioanalytical Applications of Fluorescence Line-Narrowing and Non-Line-Narrowing Spectroscopy Interfaced with Capillary Electrophoresis and High-Performance Liquid Chromatography

Energy Technology Data Exchange (ETDEWEB)

Roberts, Kenneth Paul [Iowa State Univ., Ames, IA (United States)

2001-01-01

Capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) are widely used analytical separation techniques with many applications in chemical, biochemical, and biomedical sciences. Conventional analyte identification in these techniques is based on retention/migration times of standards; requiring a high degree of reproducibility, availability of reliable standards, and absence of coelution. From this, several new information-rich detection methods (also known as hyphenated techniques) are being explored that would be capable of providing unambiguous on-line identification of separating analytes in CE and HPLC. As further discussed, a number of such on-line detection methods have shown considerable success, including Raman, nuclear magnetic resonance (NMR), mass spectrometry (MS), and fluorescence line-narrowing spectroscopy (FLNS). In this thesis, the feasibility and potential of combining the highly sensitive and selective laser-based detection method of FLNS with analytical separation techniques are discussed and presented. A summary of previously demonstrated FLNS detection interfaced with chromatography and electrophoresis is given, and recent results from on-line FLNS detection in CE (CE-FLNS), and the new combination of HPLC-FLNS, are shown.

Fluorescence spectral studies of Gum Arabic: Multi-emission of Gum Arabic in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Dhenadhayalan, Namasivayam, E-mail: ndhena@gmail.com [Department of Chemistry, National Taiwan University, Taipei, Taiwan (China); Mythily, Rajan, E-mail: rajanmythily@gmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600 106 (India); Kumaran, Rajendran, E-mail: kumaranwau@rediffmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600 106 (India)

2014-11-15

Gum Arabic (GA), a food hydrocolloid is a natural composite obtained from the stems and branches of Acacia Senegal and Acacia Seyal trees. GA structure is made up of highly branched arabinogalactan polysaccharides. Steady-state absorption, fluorescence, and time-resolved fluorescence spectral studies of acid hydrolyzed GA solutions were carried out at various pH conditions. The fluorescence in GA is predominantly attributed to the presence of tyrosine and phenylalanine amino acids. The presence of multi-emissive peaks at different pH condition is attributed to the exposure of the fluorescing amino acids to the aqueous phase, which contains several sugar units, hydrophilic and hydrophobic moieties. Time-resolved fluorescence studies of GA exhibits a multi-exponential decay with different fluorescence lifetime of varying amplitude which confirms that tyrosine is confined to a heterogeneous microenvironment. The existence of multi-emissive peaks with large variation in the fluorescence intensities were established by 3D emission contour spectral studies. The probable location of the fluorophore in a heterogeneous environment was further ascertained by constructing a time-resolved emission spectrum (TRES) and time-resolved area normalized emission spectrum (TRANES) plots. Fluorescence spectral technique is used as an analytical tool in understanding the photophysical properties of a water soluble complex food hydrocolloid containing an intrinsic fluorophore located in a multiple environment is illustrated. - Highlights: • The Manuscript deals with the steady state absorption, emission, fluorescence lifetime and time-resolved emission spectrum studies of Gum Arabic in aqueous medium at various pH conditions. • The fluorescence emanates from the tyrosine amino acid present in GA. • Change in pH results in marked variation in the fluorescence spectral properties of tyrosine. • Fluorescence spectral techniques are employed as a tool in establishing the

Investigation of three flavonoids binding to bovine serum albumin using molecular fluorescence technique

International Nuclear Information System (INIS)

Bi Shuyun; Yan Lili; Pang Bo; Wang Yu

2012-01-01

The three flavonoids including naringenin, hesperetin and apigenin binding to bovine serum albumin (BSA) at pH 7.4 was studied by fluorescence quenching, synchronous fluorescence and UV-vis absorption spectroscopic techniques. The results obtained revealed that naringenin, hesperetin and apigenin strongly quenched the intrinsic fluorescence of BSA. The Stern-Volmer curves suggested that these quenching processes were all static quenching processes. At 291 K, the value and the order of the binding constant were K A n aringenin) =4.08x10 4 A(hesperetin) =5.40x10 4 ∼K A(apigenin) =5.32x10 4 L mol -1 . The main binding force between the flavonoid and BSA was hydrophobic and electrostatic force. According to the Foerster theory of non-radiation energy transfer, the binding distances (r 0 ) were obtained as 3.36, 3.47 and 3.30 nm for naringenin-BSA, hesperetin-BSA and apigenin-BSA, respectively. The effect of some common ions such as Fe 3+ , Cu 2+ , Mg 2+ , Mn 2+ , Zn 2+ and Ca 2+ on the binding was also studied in detail. The competition binding was also performed. The apparent binding constant (K' A ) obtained suggested that one flavonoid had an obvious effect on the binding of another flavonoid to protein when they coexisted in BSA solution. - Highlights: → Quenchings of BSA fluorescence by the flavonoids was all static quenchings. → Synchronous fluorescence was applied to study the structural change of BSA. → Binding constant, binding site and binding force were determined. → Competition binding experiments were performed. → One flavonoid had an obvious effect on the binding of another one to BSA.

Harmonization of health related environmental measurements using nuclear and isotopic techniques. Proceedings of an international symposium

International Nuclear Information System (INIS)

1997-01-01

One of the particular strengths of nuclear methods is in analytical quality assurance, including the validation of analytical methods and the development of new analytical reference materials. These methodologies are therefore helping to harmonize the data produced not only by nuclear techniques themselves, but also by other non-nuclear methods of analysis. The aim of this symposium was to provide an international forum for discussion of these topics. Its programme covered a wide variety of applications of nuclear (and related) analytical techniques (mainly neutron activation analysis, energy dispersive X ray fluorescence, particle induced X ray emission and inductively coupled plasma-mass spectrometry) as used in the study of air particulates, solid waste products, sediments, food, water, human tissues, biomonitors and other kinds of environmental samples

Remote sensing of chlorophyll a fluorescence of vegetation canopies. 1. Near and far field measurement techniques

International Nuclear Information System (INIS)

Cecchi, G.; Mazzinghi, P.; Pantani, L.; Valentini, R.; Tirelli, D.; De Angelis, P.

1994-01-01

This article presents instruments and techniques, used in several vegetation monitoring experiments. Simultaneous monitoring was performed with different approaches, including fluorescence lidar and passive remote sensing, leaf level reflectance, and laser fluorimetry, and compared with physiological measurements. Most of the instrumentation described was designed and built for this application. Experiments were carried out in the laboratory and in the field, to investigate the relationship between chlorophyll fluorescence spectra and plant ecophysiology. Remote sensing, spectroscopy, and ecophysiology data were then collected by an intensive research team, joining different experiences and working in national and international projects

An Accurate Approximate-Analytical Technique for Solving Time-Fractional Partial Differential Equations

Directory of Open Access Journals (Sweden)

M. Bishehniasar

2017-01-01

Full Text Available The demand of many scientific areas for the usage of fractional partial differential equations (FPDEs to explain their real-world systems has been broadly identified. The solutions may portray dynamical behaviors of various particles such as chemicals and cells. The desire of obtaining approximate solutions to treat these equations aims to overcome the mathematical complexity of modeling the relevant phenomena in nature. This research proposes a promising approximate-analytical scheme that is an accurate technique for solving a variety of noninteger partial differential equations (PDEs. The proposed strategy is based on approximating the derivative of fractional-order and reducing the problem to the corresponding partial differential equation (PDE. Afterwards, the approximating PDE is solved by using a separation-variables technique. The method can be simply applied to nonhomogeneous problems and is proficient to diminish the span of computational cost as well as achieving an approximate-analytical solution that is in excellent concurrence with the exact solution of the original problem. In addition and to demonstrate the efficiency of the method, it compares with two finite difference methods including a nonstandard finite difference (NSFD method and standard finite difference (SFD technique, which are popular in the literature for solving engineering problems.

Atomic fluorescence spectrometry with the inductively coupled plasma

International Nuclear Information System (INIS)

Omenetto, N.; Winefordner, J.D.

1987-01-01

Atomic fluorescence spectrometry (AFS) is based on the radiational activation of atoms and ions produced in a suitable atomizer (ionizer) and the subsequent measurement of the resulting radiational deactivation, called fluorescence. Atomic fluorescence spectrometry has been of considerable interest to researchers in atomic spectrometry because of its use for both analytical and diagnostic purposes. Unfortunately, the analytical applications of AFS have suffered from the lack of commercial instrumentation until the recent marketing of the Baird multiple-element, hollow cathode lamp-excited inductively coupled plasma system. This chapter is concerned strictly with the use of the inductively coupled plasma (ICP) as a cell and as a source for AFS. Many of the major references concerning the ICP in analytical AFS are categorized in Table 9.1, along with several reviews and diagnostical studies. For more detailed discussions of the fundamental aspects of AFS, the reader is referred to previous reviews

Dose distribution calculation for in-vivo X-ray fluorescence scanning

International Nuclear Information System (INIS)

Figueroa, R. G.; Lozano, E.; Valente, M.

2013-01-01

In-vivo X-ray fluorescence constitutes a useful and accurate technique, worldwide established for constituent elementary distribution assessment. Actually, concentration distributions of arbitrary user-selected elements can be achieved along sample surface with the aim of identifying and simultaneously quantifying every constituent element. The method is based on the use of a collimated X-ray beam reaching the sample. However, one common drawback for considering the application of this technique for routine clinical examinations was the lack of information about associated dose delivery. This work presents a complete study of the dose distribution resulting from an in-vivo X-ray fluorescence scanning for quantifying biohazard materials on human hands. Absorbed dose has been estimated by means of dosimetric models specifically developed to this aim. In addition, complete dose distributions have been obtained by means of full radiation transport calculations in based on stochastic Monte Carlo techniques. A dedicated subroutine has been developed using the Penelope 2008 main code also integrated with dedicated programs -Mat Lab supported- for 3 dimensional dose distribution visualization. The obtained results show very good agreement between approximate analytical models and full descriptions by means of Monte Carlo simulations. (Author)

Reviews in fluorescence 2007

CERN Document Server

Lakowicz, Joseph R; Geddes, Chris D

2009-01-01

This fourth volume in the Springer series summarizes the year's progress in fluorescence, with authoritative analytical reviews specialized enough for professional researchers, yet also appealing to a wider audience of scientists in related fields.

Critical review of analytical techniques for safeguarding the thorium-uranium fuel cycle

International Nuclear Information System (INIS)

Hakkila, E.A.

1978-10-01

Conventional analytical methods applicable to the determination of thorium, uranium, and plutonium in feed, product, and waste streams from reprocessing thorium-based nuclear reactor fuels are reviewed. Separations methods of interest for these analyses are discussed. Recommendations concerning the applicability of various techniques to reprocessing samples are included. 15 tables, 218 references

A Fluorescence Recovery After Photobleaching (FRAP) Technique for the Measurement of Solute Transport Across Surfactant-Laden Interfaces

Science.gov (United States)

Browne, Edward P.; Hatton, T. Alan

1996-01-01

The technique of Fluorescence Recovery After Photobleaching (FRAP) has been applied to the measurement of interfacial transport in two-phase systems. FRAP exploits the loss of fluorescence exhibited by certain fluorophores when over-stimulated (photobleached), so that a two-phase system, originally at equilibrium, can be perturbed without disturbing the interface by strong light from an argon-ion laser and its recovery monitored by a microscope-mounted CCD camera as it relaxes to a new equilibrium. During this relaxation, the concentration profiles of the probe solute are measured on both sides of the interface as a function of time, yielding information about the transport characteristics of the system. To minimize the size of the meniscus between the two phases, a photolithography technique is used to selectively treat the glass walls of the cell in which the phases are contained. This allows concentration measurements to be made very close to the interface and increases the sensitivity of the FRAP technique.

A Planar-Fluorescence Imaging Technique for Studying Droplet-Turbulence Interactions in Vaporizing Sprays

Science.gov (United States)

Santavicca, Dom A.; Coy, E.

1990-01-01

Droplet turbulence interactions directly affect the vaporization and dispersion of droplets in liquid sprays and therefore play a major role in fuel oxidizer mixing in liquid fueled combustion systems. Proper characterization of droplet turbulence interactions in vaporizing sprays require measurement of droplet size velocity and size temperature correlations. A planar, fluorescence imaging technique is described which is being developed for simultaneously measuring the size, velocity, and temperature of individual droplets in vaporizing sprays. Preliminary droplet size velocity correlation measurements made with this technique are presented. These measurements are also compared to and show very good agreement with measurements made in the same spray using a phase Doppler particle analyzer.

Nuclear analytical techniques applied to forensic chemistry

International Nuclear Information System (INIS)

Nicolau, Veronica; Montoro, Silvia; Pratta, Nora; Giandomenico, Angel Di

1999-01-01

Gun shot residues produced by firing guns are mainly composed by visible particles. The individual characterization of these particles allows distinguishing those ones containing heavy metals, from gun shot residues, from those having a different origin or history. In this work, the results obtained from the study of gun shot residues particles collected from hands are presented. The aim of the analysis is to establish whether a person has shot a firing gun has been in contact with one after the shot has been produced. As reference samples, particles collected hands of persons affected to different activities were studied to make comparisons. The complete study was based on the application of nuclear analytical techniques such as Scanning Electron Microscopy, Energy Dispersive X Ray Electron Probe Microanalysis and Graphite Furnace Atomic Absorption Spectrometry. The essays allow to be completed within time compatible with the forensic requirements. (author)

DNA conformation on surfaces measured by fluorescence self-interference.

Science.gov (United States)

Moiseev, Lev; Unlü, M Selim; Swan, Anna K; Goldberg, Bennett B; Cantor, Charles R

2006-02-21

The conformation of DNA molecules tethered to the surface of a microarray may significantly affect the efficiency of hybridization. Although a number of methods have been applied to determine the structure of the DNA layer, they are not very sensitive to variations in the shape of DNA molecules. Here we describe the application of an interferometric technique called spectral self-interference fluorescence microscopy to the precise measurement of the average location of a fluorescent label in a DNA layer relative to the surface and thus determine specific information on the conformation of the surface-bound DNA molecules. Using spectral self-interference fluorescence microscopy, we have estimated the shape of coiled single-stranded DNA, the average tilt of double-stranded DNA of different lengths, and the amount of hybridization. The data provide important proofs of concept for the capabilities of novel optical surface analytical methods of the molecular disposition of DNA on surfaces. The determination of DNA conformations on surfaces and hybridization behavior provide information required to move DNA interfacial applications forward and thus impact emerging clinical and biotechnological fields.

Analytical Technique of Selection of Constructive Parameters Pneumatichydraulic Springs

Directory of Open Access Journals (Sweden)

A. A. Tsipilev

2014-01-01

Full Text Available The article "Technique for Analytical Selection of Design Parameters of Pneumatichydraulic Springs concerns the ride smoothness of high-speed vehicles. Author of article Tsipilev A.A. is an assistant at chair "Multi-purpose Tracked Vehicles and Mobile Robots" of BMSTU. The article represents a synthesis of known information on the springing systems and an analysis of relation between spring design data and running gear. It describes standard units of running gear of vehicle in the context of springing systems. Classification of springing systems is considered. Modernization general policy for existing suspensions and prospects for creation of new ones are given. The article considers a design of various pneumatic-hydraulic springs to be set on domestic tracked vehicles. A developed technique allows us to have elastic characteristics of pneumatic-hydraulic springs of various types using these design data and kinematics of the running gear. The article provides recommendations to calculate characteristics of springing systems. The adequacy analysis of the given technique based on the comparison of real and rated characteristics of the existing suspension is conducted. This article can be useful to the experts dealing with springing systems of wheel and tracked vehicles.

ARPEFS as an analytic technique

International Nuclear Information System (INIS)

Schach von Wittenau, A.E.

1991-04-01

Two modifications to the ARPEFS technique are introduced. These are studied using p(2 x 2)S/Cu(001) as a model system. The first modification is the obtaining of ARPEFS χ(k) curves at temperatures as low as our equipment will permit. While adding to the difficulty of the experiment, this modification is shown to almost double the signal-to-noise ratio of normal emission p(2 x 2)S/Cu(001) χ(k) curves. This is shown by visual comparison of the raw data and by the improved precision of the extracted structural parameters. The second change is the replacement of manual fitting of the Fourier filtered χ(k) curves by the use of the simplex algorithm for parameter determination. Again using p(2 x 2)S/Cu(001) data, this is shown to result in better agreement between experimental χ(k) curves and curves calculated based on model structures. The improved ARPEFS is then applied to p(2 x 2)S/Ni(111) and (√3 x √3) R30 degree S/Ni(111). For p(2 x 2)S/Cu(001) we find a S-Cu bond length of 2.26 Angstrom, with the S adatom 1.31 Angstrom above the fourfold hollow site. The second Cu layer appears to be corrugated. Analysis of the p(2 x 2)S/Ni(111) data indicates that the S adatom adatom adsorbs onto the FCC threefold hollow site 1.53 Angstrom above the Ni surface. The S-Ni bond length is determined to be 2.13 Angstrom, indicating an outwards shift of the first layer Ni atoms. We are unable to assign a unique structure to (√3 x √3)R30 degree S/Ni(111). An analysis of the strengths and weaknesses of ARPEFS as an experimental and analytic technique is presented, along with a summary of problems still to be addressed

Simultaneous analysis of gaseous and particulate sulphur in the atmosphere by x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Matsuda, Yatsuka; Mamuro, Tetsuo

1975-01-01

An analytical technique for the simultaneous measurements of the atmospheric concentrations of SO 2 gas and sulphur absorbed by aerosol particles has been developed. Aerosol particles are collected on membrane filter and at the same time SO 2 gas is captured on alkali impregnated filter. The sulphur content in each filter is measured by an energy dispersive X -ray fluorescence spectrometer consisting of a Si(Li) semiconductor detector connected to a multi-channel pulse height analyzer and an excitation source of 55 Fe. Two methods are acceptable for the determination of the sulphur content in impregnated filter by X-ray fluorescence analysis. In the first method X-ray fluorescence analysis is made after the collected sulphur gas diffused and distributed uniformly enough throughout the filter, and in the second method X-ray fluorescence analysis gas to be finished before the diffusion of the collected sulphur becomes appreciable. (author)

Determination of Ca/P molar ratio in hydroxyapatite (HA) by X-ray fluorescence technique

International Nuclear Information System (INIS)

Scapin, Marcos A.; Guilhen, Sabine N.; Cotrim, Marycel E.B.; Pires, Maria Ap. F.

2015-01-01

Hydroxyapatite (HA) is a mineral composed of calcium phosphate employed for endodontics, restorative dentistry and other applications in orthopedics and prosthesis. Additionally, this biomaterial is an inexpensive but efficient adsorbent for the removal of heavy metals and other unwanted species of contaminated liquid effluents. This is especially interesting when low-cost effective remediation is required. A Ca / P molar ratio of 1.667 is consistent with the theoretical Ca / P ratio for calcium hydroxyapatite with a compositional formula of Ca 10 (PO 4 ) 6 (OH) 2 , which properties are well discussed in the literature. The aim of this work was to implement and validate a methodology for simultaneous determination of major and minor constituents in the hydroxyapatite (HA) as well as providing the Ca / P molar ratio. To accomplish these achievements, wavelength dispersive X-ray fluorescence spectroscopy (WDXRF) was applied. This is a non-destructive technique that requires no chemical treatment, enabling fast chemical analysis in a wide variety of samples, with no hazardous waste being generated as a result of the process of determination. A standard reference material from NIST (SRM 1400 – Bone Ash) was used to validate the methodology for the determination of magnesium, phosphorus, potassium, calcium, iron, zinc, strontium and the Ca / P ratio in HA samples by WDXRF. The Z-score test was applied as a statistical tool and showed that the calculated values were of less than 1.8 for all the measured analytes. (author)

Determination of Ca/P molar ratio in hydroxyapatite (HA) by X-ray fluorescence technique

Energy Technology Data Exchange (ETDEWEB)

Scapin, Marcos A.; Guilhen, Sabine N.; Cotrim, Marycel E.B.; Pires, Maria Ap. F., E-mail: mascapin@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Hydroxyapatite (HA) is a mineral composed of calcium phosphate employed for endodontics, restorative dentistry and other applications in orthopedics and prosthesis. Additionally, this biomaterial is an inexpensive but efficient adsorbent for the removal of heavy metals and other unwanted species of contaminated liquid effluents. This is especially interesting when low-cost effective remediation is required. A Ca / P molar ratio of 1.667 is consistent with the theoretical Ca / P ratio for calcium hydroxyapatite with a compositional formula of Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}, which properties are well discussed in the literature. The aim of this work was to implement and validate a methodology for simultaneous determination of major and minor constituents in the hydroxyapatite (HA) as well as providing the Ca / P molar ratio. To accomplish these achievements, wavelength dispersive X-ray fluorescence spectroscopy (WDXRF) was applied. This is a non-destructive technique that requires no chemical treatment, enabling fast chemical analysis in a wide variety of samples, with no hazardous waste being generated as a result of the process of determination. A standard reference material from NIST (SRM 1400 – Bone Ash) was used to validate the methodology for the determination of magnesium, phosphorus, potassium, calcium, iron, zinc, strontium and the Ca / P ratio in HA samples by WDXRF. The Z-score test was applied as a statistical tool and showed that the calculated values were of less than 1.8 for all the measured analytes. (author)

High resolution x-ray fluorescence spectroscopy - a new technique for site- and spin-selectivity

International Nuclear Information System (INIS)

Wang, Xin

1996-12-01

X-ray spectroscopy has long been used to elucidate electronic and structural information of molecules. One of the weaknesses of x-ray absorption is its sensitivity to all of the atoms of a particular element in a sample. Through out this thesis, a new technique for enhancing the site- and spin-selectivity of the x-ray absorption has been developed. By high resolution fluorescence detection, the chemical sensitivity of K emission spectra can be used to identify oxidation and spin states; it can also be used to facilitate site-selective X-ray Absorption Near Edge Structure (XANES) and site-selective Extended X-ray Absorption Fine Structure (EXAFS). The spin polarization in K fluorescence could be used to generate spin selective XANES or spin-polarized EXAFS, which provides a new measure of the spin density, or the nature of magnetic neighboring atoms. Finally, dramatic line-sharpening effects by the combination of absorption and emission processes allow observation of structure that is normally unobservable. All these unique characters can enormously simplify a complex x-ray spectrum. Applications of this novel technique have generated information from various transition-metal model compounds to metalloproteins. The absorption and emission spectra by high resolution fluorescence detection are interdependent. The ligand field multiplet model has been used for the analysis of Kα and Kβ emission spectra. First demonstration on different chemical states of Fe compounds has shown the applicability of site selectivity and spin polarization. Different interatomic distances of the same element in different chemical forms have been detected using site-selective EXAFS

Application of nuclear analytical techniques to investigate trace element content in foodstuffs

International Nuclear Information System (INIS)

Gharib, A.

1985-01-01

The study performed as a joint project with the IAEA includes those foodstuffs which are being used widely in Iran. It was investigated their nutritional requirements, interrelations and the role of their trace elements in metabolism. Various analytical techniques was assessed and compared. The methods involved in the study were ASS, PIXE and NAA (instrumental and radiochemical)

Evaluation of a fluorescent lectin-based staining technique for some acidophilic mining bacteria

International Nuclear Information System (INIS)

Fife, D.J.; Bruhn, D.F.; Miller, K.S.; Stoner, D.L.

2000-01-01

A fluorescence-labeled wheat germ agglutinin staining technique was modified and found to be effective for staining gram-positive, acidophilic mining bacteria. Bacteria identified by others as being gram positive through 16S rRNA sequence analyses, yet clustering near the divergence of that group, stained weakly. Gram-negative bacteria did not stain. Background staining of environmental samples was negligible, and pyrite and soil particles in the samples did not interfere with the staining procedure

Fluorescence technique application of X-ray in labeling with Mn, Sr and Cu, of the parasitoid and host: Muscidifuax uniraptor Kogan and Legner, 1970 (Hymenoptera: Pteromalidae) and Musca domestica L., 1758 (Diptera: Muscidae)

International Nuclear Information System (INIS)

Itepan, Natanael Marcio

2003-01-01

The objective of this work was to develop the methodology of the labeling adult of Musca domestica and Muscidifurax uniraptor using the elements Mn, Sr and Cu with the use of x-ray fluorescence. This work was carried out in the Laboratory of Biological Control of House Flies, 'Eduardo Hiroshi Mizumoto', of the 'Entomology, Phytopatology and Zoology Department of the College of Agriculture 'Luiz de Queiroz' ESALQ/USP), and the Division of Methods the Development and Nuclear Analytics Techniques, of CENA/USP, Piracicaba, Sao Paulo, Brazil. The larvae was removed to the labeled diet with increasing level of the elements Mn, Sr and Cu. The levels tested for all element were: 0 (control); 0,25; 0,50; 1,00; 2,00; 4,00; 8,00; 16,00; 32,00 and 64,00 mg/gr of diet. Labeled pupae with 1,00 to 4,00 (Mn) and 1,00 (Sr and Cu) mg/gr of diet were tested for the pupal parasitoid M. uniraptor. The concentration quantity of the chemical elements was realized by the Analytical Technique denominated (EDXRF) energy dispersive X-ray fluorescence. Concentrations of 2,00 (Mn) and 1,00 (Sr) supplemented to the diet of M. domestica were sufficient for the adult insect labeled, however, not affecting its life expectancy. Pupae originated from the larvae of M. domestica treated with dose of 2,00 (Mn) and 1,00 (Sr and Cu) mg supplemented to the diet, and used as hosts of the parasitoid M. uniraptor, affected the viability of the immature phase and did not label the adults. (author)

A Novel Analytical Technique for Optimal Allocation of Capacitors in Radial Distribution Systems

Directory of Open Access Journals (Sweden)

Sarfaraz Nawaz

2017-07-01

Full Text Available In this paper, a novel analytical technique is proposed to determine the optimal size and location of shunt capacitor units in radial distribution systems. An objective function is formulated to reduce real power loss, to improve the voltage profile and to increase annual cost savings. A new constant, the Loss Sensitivity Constant (LSC, is proposed here. The value of LSC decides the location and size of candidate buses. The technique is demonstrated on an IEEE-33 bus system at different load levels and the 130-bus distribution system of Jamawa Ramgarh village, Jaipur city. The obtained results are compared with the latest optimization techniques to show the effectiveness and robustness of the proposed technique.

Ultratrace determination of lead in whole blood using electrothermal atomization laser-excited atomic fluorescence spectrometry.

Science.gov (United States)

Wagner, E P; Smith, B W; Winefordner, J D

1996-09-15

Laser-excited atomic fluorescence has been used to detect lead that was electrothermally atomized from whole blood in a graphite furnace. A 9 kHz repetition rate copper vapor laser pumped dye laser was used to excite the lead at 283.3 nm, and the resulting atomic fluorescence was detected at 405.8 nm. No matrix modification was used other than a 1:21 dilution of the whole blood with high-purity water. Using the atomic fluorescence peak area as the analytical measure and a background correction technique based upon a simultaneous measurement of the transmitted laser intensity, excellent agreement for NIST and CDC certified whole blood reference samples was obtained with aqueous standards. A limit of detection in blood of 10 fg/mL (100 ag absolute) was achieved.

Analytical techniques for the determination of radiochemical purity of radiopharmaceuticals prepared from kits

International Nuclear Information System (INIS)

McLean, J.R.; Rockwell, L.J.; Welsh, W.J.

1977-01-01

The evaluation of efficacy of commercially available kits used for the preparation of radiopharmaceuticals is one aspect of the Radiation Protection Bureau's radiopharmaceutical quality control program. This report describes some of the analytical methodology employed in the program. The techniques may be of interest to hospital radiopharmacy personnel as many of the tests can be performed rapidly and with a minimum of special equipment, thus enabling the confirmation of radiopharmaceutical purity prior to patient administration. Manufacturers of kits may also be interested in learning of the analytical methods used in the assessment of their products. (auth)

Corrections of residual fluorescence distortions for a glancing-emergence-angle x-ray-absorption technique

International Nuclear Information System (INIS)

Brewe, D.L.; Pease, D.M.; Budnick, J.I.

1994-01-01

Distortions appear in x-ray-absorption spectra obtained by monitoring the fluorescence from thick samples with concentrated absorbing species. The glancing-emergence-angle technique for obtaining spectra from this type of sample eliminates distortions from the measured spectra by monitoring the fluorescence leaving the sample at a small angle relative to the sample surface. This technique is limited by the small signal available from the inherently limited detector solid angle. In addition, no precise estimate of the required restriction on maximum emergent angle θ max has been available. We have calculated residual extended x-ray-absorption fine structure distortions as a function of θ max , and performed experimental tests of the calculations. These calculations provide a means to estimate the required detector geometry for negligible distortions, or alternatively, allow the use of a larger θ max , increasing the available signal, with the remaining residual distortions removed by application of the calculations. The calculations are also applicable to other detector geometries, and account for detectors subtending a large solid angle by an integration over the subtended angle. This represents an improvement over previous calculations. The application to more general detector configurations is also discussed

Nuclear analytical techniques for nanotoxicology studies

International Nuclear Information System (INIS)

Zhang, Z.Y.; Zhao, Y.L.; Chai, Z.F.

2011-01-01

With the rapid development of nanotechnology and its applications, a wide variety of nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and industries. The potential interactions of nanomaterials with living systems and the environment have attracted increasing attention from the public, as well as from manufacturers of nanomaterial-based products, academic researchers and policymakers. It is important to consider the environmental, health and safety aspects at an early stage of nanomaterial development and application in order to more effectively identify and manage potential human and environmental health impacts from nanomaterial exposure. This will require research in a range of areas, including detection and characterization, environmental fate and transport, ecotoxicology and toxicology. Nuclear analytical techniques (NATs) can play an important role in such studies due to their intrinsic merits such as high sensitivity, good accuracy, high space resolution, ability to distinguish the endogenous or exogenous sources of materials, and ability of in situ and in vivo analysis. In this paper, the applications of NATs in nanotoxicological and nano-ecotoxicological studies are outlined, and some recent results obtained in our laboratory are reported. (orig.)

Ambient measurements of biological aerosol particles near Killarney, Ireland: a comparison between real-time fluorescence and microscopy techniques

Science.gov (United States)

Healy, D. A.; Huffman, J. A.; O'Connor, D. J.; Pöhlker, C.; Pöschl, U.; Sodeau, J. R.

2014-08-01

Primary biological aerosol particles (PBAPs) can contribute significantly to the coarse particle burden in many environments. PBAPs can thus influence climate and precipitation systems as cloud nuclei and can spread disease to humans, animals, and plants. Measurement data and techniques for PBAPs in natural environments at high time- and size resolution are, however, sparse, and so large uncertainties remain in the role that biological particles play in the Earth system. In this study two commercial real-time fluorescence particle sensors and a Sporewatch single-stage particle impactor were operated continuously from 2 August to 2 September 2010 at a rural sampling location in Killarney National Park in southwestern Ireland. A cascade impactor was operated periodically to collect size-resolved particles during exemplary periods. Here we report the first ambient comparison of a waveband integrated bioaerosol sensor (WIBS-4) with a ultraviolet aerodynamic particle sizer (UV-APS) and also compare these real-time fluorescence techniques with results of fluorescence and optical microscopy of impacted samples. Both real-time instruments showed qualitatively similar behavior, with increased fluorescent bioparticle concentrations at night, when relative humidity was highest and temperature was lowest. The fluorescent particle number from the FL3 channel of the WIBS-4 and from the UV-APS were strongly correlated and dominated by a 3 μm mode in the particle size distribution. The WIBS FL2 channel exhibited particle modes at approx. 1 and 3 μm, and each was correlated with the concentration of fungal spores commonly observed in air samples collected at the site (ascospores, basidiospores, Ganoderma spp.). The WIBS FL1 channel exhibited variable multimodal distributions turning into a broad featureless single mode after averaging, and exhibited poor correlation with fungal spore concentrations, which may be due to the detection of bacterial and non-biological fluorescent

Practical applications of activation analysis and other nuclear techniques

International Nuclear Information System (INIS)

Lyon, W.S.

1982-01-01

Neeutron activation analysis (NAA) is a versatile, sensitive multielement, usually nondestructive analytical technique used to determine elemental concentrations in a variety of materials. Samples are irradiated with neutrons in a nuclear reactor, removed, and for the nondestructive technique, the induced radioactivity measured. This measurement of γ rays emitted from specific radionuclides makes possible the quantitative determination of elements present. The method is described, advantages and disadvantages listed and a number of examples of its use given. Two other nuclear methods, particle induced x-ray emission and synchrotron produced x-ray fluorescence are also briefly discussed

Determination of Fission Products in Irradiated Fuel by X-Ray Fluorescence

DEFF Research Database (Denmark)

Mogensen, Mogens Bjerg; Als-Nielsen, Jens Aage; Andersen, Niels Hessel

X-ray fluorescence i s a well e s t a b l i s h e d analytical tool for measuring elemental composition of fairly large (~ 5 cm2) "cold" samples. A version of t h i s technique has been developed for a n a l y s i s of radial d i s t r i b u t i o n of f i s s i o n products Xe, Cs and Ba...... in the scanning d i rection and 2 mm long. The measured Xe Ko x-ray i n t e n s i t i e s are converted to absolute concentrations by comparing to the intens i t y from a Xe gas standard. In the case of Cs and Ba s o l id standards may be used. The X-ray fluorescence analysis i s compared to other techniques used...... to obtain radial f i s s i o n product profiles, i t i s shown how a combination of X-ray fluorescence and electron probe micro a n a l y s i s i s able to reveal the amount of Xe in the grain boundary porosities....

Synthesis, characterization and bioimaging of fluorescent labeled polyoxometalates.

Science.gov (United States)

Geisberger, Georg; Gyenge, Emina Besic; Hinger, Doris; Bösiger, Peter; Maake, Caroline; Patzke, Greta R

2013-07-21

A fluorescent labeled Wells-Dawson type POM ({P2W17O61Fluo}) was newly synthesized and characterized by a wide range of analytical methods. {P2W17O61Fluo} was functionalized with fluorescein amine through a stable amide bond, and its long time stability was verified by UV/vis spectroscopic techniques at physiologically relevant pH values. No significant impact on the cell viability or morphology of HeLa cells was observed for POM concentrations up to 100 μg mL(-1). Cellular uptake of fluorescent {P2W17O61Fluo} was monitored by confocal laser scanning microscopy. POM uptake occurs mainly after prolonged incubation times of 24 h resulting in different intracellular patterns, i.e. randomly distributed over the entire cytoplasm, or aggregated in larger clusters. This direct monitoring strategy for the interaction of POMs with cells opens up new pathways for elucidating their unknown mode of action on the way to POM-based drug development.

Molecularly imprinted fluorescent probe based on FRET for selective and sensitive detection of doxorubicin

Energy Technology Data Exchange (ETDEWEB)

Xu, Zhifeng, E-mail: 897061147@qq.com [College of Chemistry and Materials Science, Hengyang Normal University, Key Laboratory of Functional Organometallic Materials of Hunan Province University, Hengyang 421008 (China); Deng, Peihong; Li, Junhua [College of Chemistry and Materials Science, Hengyang Normal University, Key Laboratory of Functional Organometallic Materials of Hunan Province University, Hengyang 421008 (China); Xu, Li [Department of Applied Chemistry, College of Materials and Energy, South China Agricultural University, Guangzhou 510642 (China); Tang, Siping [College of Chemistry and Materials Science, Hengyang Normal University, Key Laboratory of Functional Organometallic Materials of Hunan Province University, Hengyang 421008 (China)

2017-04-15

Highlights: • FRET-based molecularly imprinted probe for detection of doxorubicin was prepared. • The detection limit of the probe was 13.8 nM for doxorubicin. • The FRET-based probe had a higher selectivity for the template than ordinary MIMs. - Abstract: In this work, a new type of fluorescent probe for detection of doxorubicin has been constructed by the combined use of fluorescence resonance energy transfer (FRET) technology and molecular imprinting technique (MIT). Using doxorubicin as the template, the molecularly imprinted polymer thin layer was fabricated on the surfaces of carbon dot (CD) modified silica by sol-gel polymerization. The excitation energy of the fluorescent donor (CDs) could be transferred to the fluorescent acceptor (doxorubicin). The FRET based fluorescent probe demonstrated high sensitivity and selectivity for doxorubicin. The detection limit was 13.8 nM. The fluorescent probe was successfully applied for detecting doxorubicin in doxorubicin-spiked plasmas with a recovery of 96.8–103.8%, a relative standard deviation (RSD) of 1.3–2.8%. The strategy for construction of FRET-based molecularly imprinted materials developed in this work is very promising for analytical applications.

Dispersive liquid–liquid microextraction using diethyldithiocarbamate as a chelating agent and the dried-spot technique for the determination of Fe, Co, Ni, Cu, Zn, Se and Pb by energy-dispersive X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Kocot, Karina; Zawisza, Beata; Sitko, Rafal

2012-01-01

Dispersive liquid–liquid microextraction (DLLME) using sodium diethyldithiocarbamate (DDTC) as a chelating agent was investigated for the simultaneous determination of iron, cobalt, nickel, copper, zinc, selenium and lead ions in water samples. The procedure was performed using 5 mL of the sample, 100 μL of a 0.5% solution of DDTC, 30 μL of carbon tetrachloride (extraction phase) and 500 μL of methanol (disperser solvent). The experiments showed that Fe, Co, Ni, Cu, Zn and Pb can be simultaneously extracted at a pH of 5 and that Se can be extracted at a pH of 2–3. The results were compared with those obtained using ammonium pyrrolidine dithiocarbamate as a chelating agent. For all analytes, a linear range was observed up to 0.4 μg mL −1 . If Fe and Zn are present in concentrations 10 times higher than those of the other analytes, then the linearity is observed up to 0.2 μg mL −1 . In the present study, the organic phase that contained preconcentrated elements was deposited onto a Millipore filter and measured using energy-dispersive X-ray fluorescence spectrometry. The obtained detection limits were 2.9, 1.5, 2.0, 2.3, 2.5, 2.0 and 3.9 ng mL −1 for Fe, Co, Ni, Cu, Zn, Se and Pb, respectively. This combination of DLLME and the dried-spot technique is promising for multielement analyses using other spectroscopy techniques, such as laser ablation‐inductively coupled plasma‐mass spectrometry, laser-induced breakdown spectroscopy or total-reflection X-ray fluorescence spectrometry. - Highlights: ► Multielement trace analysis using dried-spot technique and dispersive liquid–liquid microextraction. ► Possibility of combination of LPME with EDXRF, LIBS or LA-ICP-MS. ► Comparison of APDC and DDTC as chelating agents.

Fluorescent chemosensor for pyridine based on N-doped carbon dots.

Science.gov (United States)

Campos, B B; Abellán, C; Zougagh, M; Jimenez-Jimenez, J; Rodríguez-Castellón, E; Esteves da Silva, J C G; Ríos, A; Algarra, M

2015-11-15

Fluorescent carbon dots (CDs) and its nitrogen doped (N-CDs) nanoparticles have been synthesized from lactose as precursor using a bottom-up hydrothermal methodology. The synthesized nanoparticles have been characterized by elemental analysis, FTIR, Raman, TEM, DLS, XPS, and steady-state and life-time fluorescence. The synthesized carbon nanoparticles, CDs and N-CDs, have a size at about 7.7±2.4 and 50±15nm, respectively, and quantum yields of 8% (CDs) and 11% (N-CDs). These techniques demonstrated the effectiveness of the synthesis procedure and the functionalization of the CDs surface with amine and amide groups in the presence of NH3 in aqueous media. The effect of excitation wavelength and pH on the luminescent properties was studied. Under the optimal conditions, the nitrogen doped nanoparticles can be used as pyridine sensor in aqueous media because they show an enhancement of its fluorescence with a good linear relationship. The analytical method is simple, reproducible and very sensitive for pyridine determination. Copyright © 2015 Elsevier Inc. All rights reserved.

An Overview of Analytical Determination of Diltiazem, Cimetidine, Ranitidine, and Famotidine by UV Spectrophotometry and HPLC Technique

Directory of Open Access Journals (Sweden)

Nighat Shafi

2013-01-01

Full Text Available This review article recapitulates the analytical methods for the quantitative determinations of diltiazem and three H2 receptor antagonists (cimetidine, ranitidine, and famotidine by one of the spectroscopic technique (UV spectrophotometery and separation technique such as high-performance liquid chromatography (HPLC. The clinical and pharmaceutical analysis of these drugs requires effective analytical procedures for quality control, pharmaceutical dosage formulations, and biological fluids. An extensive survey of the literature published in various analytical and pharmaceutical chemistry-related journals has been compiled in its review. A synopsis of reported spectrophotometric and high-performance liquid chromatographic methods for individual drug is integrated. This appraisal illustrates that majority of the HPLC methods reviewed are based on the quantitative analysis of drugs in biological fluids, and they are appropriate for therapeutic drug monitoring purpose.

Europium Uptake and Partitioning in Oat (Avena sativa) Roots as studied By Laser-Induced Fluorescence Spectroscopy and Confocal Microscopy Profiling Technique

International Nuclear Information System (INIS)

Fellows, Robert J.; Wang, Zheming; Ainsworth, Calvin C.

2003-01-01

The uptake of Eu3+ by elongating oat plant roots was studied by fluorescence spectroscopy, fluorescence lifetime measurement, as well as laser excitation time-resolved confocal fluorescence profiling technique. The results of this work indicated that the initial uptake of Eu(III) by oat root was most evident within the apical meristem of the root just proximal to the root cap. Distribution of assimilated Eu(III) within the roots differentiation and elongation zone was non-uniform. Higher concentrations were observed within the vascular cylinder, specifically in the phloem and developing xylem parenchyma. Elevated levels of the metal were also observed in the root hairs of the mature root. The concentration of assimilated Eu3+ dropped sharply from the apical meristem to the differentiation and elongation zone and then gradually decreased as the distance from the root cap increased. Fluorescence spectroscopic characteristics of the assimilated Eu3+ suggested that the Eu3+ exists a s inner-sphere mononuclear complexes inside the root. This work has also demonstrated the effectiveness of a time-resolved Eu3+ fluorescence spectroscopy and confocal fluorescence profiling techniques for the in vivo, real-time study of metal[Eu3+] accumulation by a functioning intact plant root. This approach can prove valuable for basic and applied studies in plant nutrition and environmental uptake of actinide radionuclides

Indirect fluorescence detection of native amino acids in capillary zone electrophoresis

Energy Technology Data Exchange (ETDEWEB)

Kuhr, W.G.; Yeung, E.S.

1988-09-01

Amino acids are but one of several important classes of small chemical compounds in biological chemistry that have an inherent lack of analytically useful physical properties. Amino acids, peptides, fatty acids, sugars, many mono-, di-, and tricarboxylic acids, and phosphorylated intermediates in glycolysis and metabolism show little, if any, UV or visible absorption, fluorescence, or electrochemical activity. As the emphasis of biochemical research shifts to smaller samples where, for example, picomolar quantities of amino acids are analyzed in gas phase protein sequencing or in microliter samples of the extracellular fluid of the mammalian brain, the analytical problem becomes even more challenging due to the small volume of sample available for analysis. In this work, laser-induced fluorescence spectroscopy is performed on-column to detect the bands separated with capillary zone electrophoresis (CZE). CZE is an instrumental form of zone electrophoresis where chemical species are separated purely on the basis of their electrophoretic mobility, since no supporting gel is utilized. Both anions and cations can be separated in the same run because of the large electroosmotic flow generated in small diameter capillaries. This technique has already been used successfully in the rapid, efficient separation of dansyl-amino acids.

A review of analytical techniques for the determination of carbon-14 in environmental samples

International Nuclear Information System (INIS)

Milton, G.M.; Brown, R.M.

1993-11-01

This report contains a brief summary of analytical techniques commonly used for the determination of radiocarbon in a variety of environmental samples. Details of the applicable procedures developed and tested in the Environmental Research Branch at Chalk River Laboratories are appended

Application of Fluorescence In Situ Hybridization (FISH) Technique for the Detection of Genetic Aberration in Medical Science

OpenAIRE

Ratan, Zubair Ahmed; Zaman, Sojib Bin; Mehta, Varshil; Haidere, Mohammad Faisal; Runa, Nusrat Jahan; Akter, Nasrin

2017-01-01

Fluorescence in situ hybridization (FISH) is a macromolecule recognition technique, which is considered as a new advent in the field of cytology.?Initially, it was developed as a physical mapping tool to delineate genes within chromosomes. The accuracy and versatility of FISH were subsequently capitalized upon in biological and medical research. This visually appealing technique provides an intermediate degree of resolution between DNA analysis and chromosomal investigations. FISH consists of...

MS-Based Analytical Techniques: Advances in Spray-Based Methods and EI-LC-MS Applications

Science.gov (United States)

Medina, Isabel; Cappiello, Achille; Careri, Maria

2018-01-01

Mass spectrometry is the most powerful technique for the detection and identification of organic compounds. It can provide molecular weight information and a wealth of structural details that give a unique fingerprint for each analyte. Due to these characteristics, mass spectrometry-based analytical methods are showing an increasing interest in the scientific community, especially in food safety, environmental, and forensic investigation areas where the simultaneous detection of targeted and nontargeted compounds represents a key factor. In addition, safety risks can be identified at the early stage through online and real-time analytical methodologies. In this context, several efforts have been made to achieve analytical instrumentation able to perform real-time analysis in the native environment of samples and to generate highly informative spectra. This review article provides a survey of some instrumental innovations and their applications with particular attention to spray-based MS methods and food analysis issues. The survey will attempt to cover the state of the art from 2012 up to 2017.

Studies on Pt–Mo phases using analytical techniques with high resolution

Energy Technology Data Exchange (ETDEWEB)

Topic, M., E-mail: mtopic@tlabs.ac.za [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Khumalo, Z. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); University of Cape Town, Physics Department, Private Bag X3, Rondebosch 7701 (South Africa); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Faculty of Health and Wellness Sciences, CPUT, Belville (South Africa)

2014-01-01

Pt–Mo coated system annealed at 1050 °C for 24 h was investigated using several analytical techniques with high resolution (SEM/EDX, μ-PIXE, RBS and XRD). These techniques provide structural and compositional data throughout the material depth and probing area. The results depend on the applied beam, its energy and size. They contribute to a better understanding of thermal annealing effects on the solid-state phase transformation and morphological changes in Pt–Mo coatings. The results indicate the presence of Pt- and Mo-solid solutions and two Pt–Mo phases (PtMo and Pt{sub 2}Mo{sub 3}), changes in the coating morphology, such as increased surface roughness and formation of “lace morphology”, as well as an increase in coating thickness.

Analytical Energy Dispersive X-Ray Fluorescence Measurements with a Scanty Amounts of Plant and Soil Materials

Science.gov (United States)

Mittal, R.; Rao, P.; Kaur, P.

2018-01-01

Elemental evaluations in scanty powdered material have been made using energy dispersive X-ray fluorescence (EDXRF) measurements, for which formulations along with specific procedure for sample target preparation have been developed. Fractional amount evaluation involves an itinerary of steps; (i) collection of elemental characteristic X-ray counts in EDXRF spectra recorded with different weights of material, (ii) search for linearity between X-ray counts and material weights, (iii) calculation of elemental fractions from the linear fit, and (iv) again linear fitting of calculated fractions with sample weights and its extrapolation to zero weight. Thus, elemental fractions at zero weight are free from material self absorption effects for incident and emitted photons. The analytical procedure after its verification with known synthetic samples of macro-nutrients, potassium and calcium, was used for wheat plant/ soil samples obtained from a pot experiment.

A very thin light sheet technique used to investigate meniscus shapes by laser induced fluorescence

International Nuclear Information System (INIS)

Khan, M.A.

2003-01-01

In this paper a light sheet technique is described to accurately (50 μm) measure meniscus profiles in film formation problems. The use of a slit to create the thin (0.1 mm) laser sheet makes the technique easy to implement, and allows tunable sheet thickness. The low light intensity obtained through the slit is compensated by the induced fluorescence of the tested fluid, which provides good picture contrast. After video recording through a microscope, the actual meniscus is recovered by image processing and proper calibration. The efficiency of the technique is demonstrated on a coating flow experiment. Due to its good accuracy and ease of use, this technique is expected to provide useful quantitative information about meniscus problems, in particular for the validation of computational fluid dynamics CFD solutions of coating flows. (author)

Determination of some main elements and traces by x-ray fluorescence analysis in silicate rocks: a comparative study of two analytical techniques

International Nuclear Information System (INIS)

Andrade, M.D. de.

1977-01-01

The determinations of silicon, magnesium, iron, potassium, calcium, titanium, manganese, barium, strontium, rubidium, zirconium and scandium in felsic and mafic rocks, by X ray fluorescence analysis are presented. (author)

Time-resolved fluorescence spectroscopy

International Nuclear Information System (INIS)

Gustavsson, Thomas; Mialocq, Jean-Claude

2007-01-01

This article addresses the evolution in time of light emitted by a molecular system after a brief photo-excitation. The authors first describe fluorescence from a photo-physical point of view and discuss the characterization of the excited state. Then, they explain some basic notions related to fluorescence characterization (lifetime and decays, quantum efficiency, so on). They present the different experimental methods and techniques currently used to study time-resolved fluorescence. They discuss basic notions of time resolution and spectral reconstruction. They briefly present some conventional methods: intensified Ccd cameras, photo-multipliers and photodiodes associated with a fast oscilloscope, and phase modulation. Other methods and techniques are more precisely presented: time-correlated single photon counting (principle, examples, and fluorescence lifetime imagery), streak camera (principle, examples), and optical methods like the Kerr optical effect (principle and examples) and fluorescence up-conversion (principle and theoretical considerations, examples of application)

Multielement determination in Cuban red mangrove samples using nuclear and related analytical techniques

International Nuclear Information System (INIS)

Estevez Alvarez, J.R.; Aguiar Lambert, D.; Montero Alvarez, A.; Pupo Gonzalez, I.; Padilla Alvarez, R.; Gonzalez Garcia, H.; Ramirez Sasco, M.

1998-01-01

In the present work the contents of Al; K; Ca; Mn; Fe; Ni; Cu; Zn; Sr; Cd and Pb in red mangroves (Rhizophora mangle) from different Cuban regions are determined, using Energy Dispersive X-Ray Fluorescence (Emission-Transmission (Et) and I/C methods), Atomic Absorption Spectrophotometry (AAS), and Polarography (Anodic Stripping Voltametry method). Biological Certified Reference Materials (CRM) are employed for the tracing of the tracing of the curves of the relative I/C method and for the evaluation of the analytical results accuracy. The reliability of the results is also checked by statistical means. Standard deviations and the detection limits of each method are reported. Finally, the obtained values for the concentration of the different elements in each studied ecosystem are presented; a detailed discussion about their significance will be performed in a further paper

Ultraviolet-Visible and Fluorescence Spectroscopy Techniques Are Important Diagnostic Tools during the Progression of Atherosclerosis: Diet Zinc Supplementation Retarded or Delayed Atherosclerosis

Science.gov (United States)

Abdelhalim, Mohamed Anwar K.; Moussa, Sherif A. Abdelmottaleb; AL-Mohy, Yanallah Hussain

2013-01-01

Background. In this study, we examined whether UV-visible and fluorescence spectroscopy techniques detect the progression of atherosclerosis in serum of rabbits fed on high-cholesterol diet (HCD) and HCD supplemented with zinc (HCD + Zn) compared with the control. Methods. The control rabbits group was fed on 100 g/day of normal diet. The HCD group was fed on Purina Certified Rabbit Chow supplemented with 1.0% cholesterol plus 1.0% olive oil (100 g/day) for the same period. The HCD + Zn group was fed on normal Purina Certified Rabbit Chow plus 1.0% cholesterol and 1.0% olive oil supplemented with 470 ppm Zn for the same feeding period. UV-visible and fluorescence spectroscopy and biochemistry in Rabbit's blood serum and blood hematology were measured in Rabbit's blood. Results. We found that the fluorescent peak of HCD shifted toward UV-visible wavelength compared with the control using fluorescent excitation of serum at 192 nm. In addition, they showed that supplementation of zinc (350 ppm) restored the fluorescent peak closely to the control. By using UV-visible spectroscopy approach, we found that the peak absorbance of HCD (about 280 nm) was higher than that of control and that zinc supplementation seemed to decrease the absorbance. Conclusions. This study demonstrates that ultraviolet-visible and fluorescence spectroscopy techniques can be applied as noninvasive techniques on a sample blood serum for diagnosing or detecting the progression of atherosclerosis. The Zn supplementation to rabbits fed on HCD delays or retards the progression of atherosclerosis. Inducing anemia in rabbits fed on HCD delays the progression of atherosclerosis. PMID:24350281

Simultaneous analyses of gaseous and particulate sulphur compounds in the atmosphere by x-ray fluorescence spectrometry, (1)

International Nuclear Information System (INIS)

Matsuda, Yatsuka; Mamuro, Tetsuo

1974-01-01

An analytical technique for the simultaneous measurements of the atmospheric concentrations of SO 2 gas and sulphur absorbed by aerosol particles has been developed. Aerosol particles are collected on membrane filter and at the same time SO 2 gas is captured on alkali impregnated filter. The sulphur content in each filter is measured by an energy dispersive X-ray fluorescence spectrometer consisting of a Si(Li) semiconductor detector connected to a multichannel pulse hight analyzer and an excitation source of 55 Fe. Two methods are acceptable for the determination of the sulphur content in impregnated filter by X-ray fluorescence analysis. In the first method X-ray fluorescence analysis is made after the collected sulphur has diffused and distributed uniformly enough throughout filter, and in the second method X-ray fluorescence analysis has to be finished before the diffusion of the collected sulphur becomes appreciable. (auth.)

Nanogap embedded silver gratings for surface plasmon enhanced fluorescence

Science.gov (United States)

Bhatnagar, Kunal

Plasmonic nanostructures have been extensively used in the past few decades for applications in sub-wavelength optics, data storage, optoelectronic circuits, microscopy and bio-photonics. The enhanced electromagnetic field produced at the metal and dielectric interface by the excitation of surface plasmons via incident radiation can be used for signal enhancement in fluorescence and surface enhanced Raman scattering studies. Novel plasmonic structures have shown to provide very efficient and extreme light concentration at the nano-scale in recent years. The enhanced electric field produced within a few hundred nanometers of these surfaces can be used to excite fluorophores in the surrounding environment. Fluorescence based bio-detection and bio-imaging are two of the most important tools in the life sciences and improving the qualities and capabilities of fluorescence based detectors and imaging equipment remains a big challenge for industry manufacturers. We report a novel fabrication technique for producing nano-gap embedded periodic grating substrates on the nanoscale using a store bought HD-DVD and conventional soft lithography procedures. Polymethylsilsesquioxane (PMSSQ) polymer is used as the ink for the micro-contact printing process with PDMS stamps obtained from the inexpensive HD-DVDs as master molds. Fluorescence enhancement factors of up to 118 times were observed with these silver nanostructures in conjugation with Rhodamine-590 fluorescent dye. These substrates are ideal candidates for a robust and inexpensive optical system with applications such as low-level fluorescence based analyte detection, single molecule imaging, and surface enhanced Raman studies. Preliminary results in single molecule experiments have also been obtained by imaging individual 3 nm and 20 nm dye-doped nanoparticles attached to the silver plasmonic gratings using epi-fluorescence microscopy.

Measurements of low density, high velocity flow by electron beam fluorescence technique

International Nuclear Information System (INIS)

Soga, Takeo; Takanishi, Masaya; Yasuhara, Michiru

1981-01-01

A low density chamber with an electron gun system was made for the measurements of low density, high velocity (high Mach number) flow. This apparatus is a continuous running facility. The number density and the rotational temperature in the underexpanding free jet of nitrogen were measured along the axis of the jet by the electron beam fluorescence technique. The measurements were carried out from the vicinity of the exit of the jet to far downstream of the first Mach disk. Rotational nonequilibrium phenomena were observed in the hypersonic flow field as well as in the shock wave (Mach disk). (author)

In Situ Live-Cell Nucleus Fluorescence Labeling with Bioinspired Fluorescent Probes.

Science.gov (United States)

Ding, Pan; Wang, Houyu; Song, Bin; Ji, Xiaoyuan; Su, Yuanyuan; He, Yao

2017-08-01

Fluorescent imaging techniques for visualization of nuclear structure and function in live cells are fundamentally important for exploring major cellular events. The ideal cellular labeling method is capable of realizing label-free, in situ, real-time, and long-term nucleus labeling in live cells, which can fully obtain the nucleus-relative information and effectively alleviate negative effects of alien probes on cellular metabolism. However, current established fluorescent probes-based strategies (e.g., fluorescent proteins-, organic dyes-, fluorescent organic/inorganic nanoparticles-based imaging techniques) are unable to simultaneously realize label-free, in situ, long-term, and real-time nucleus labeling, resulting in inevitable difficulties in fully visualizing nuclear structure and function in live cells. To this end, we present a type of bioinspired fluorescent probes, which are highly efficacious for in situ and label-free tracking of nucleus in long-term and real-time manners. Typically, the bioinspired polydopamine (PDA) nanoparticles, served as fluorescent probes, can be readily synthesized in situ within live cell nucleus without any further modifications under physiological conditions (37 °C, pH ∼7.4). Compared with other conventional nuclear dyes (e.g., propidium iodide (PI), Hoechst), superior spectroscopic properties (e.g., quantum yield of ∼35.8% and high photostability) and low cytotoxicity of PDA-based probes enable long-term (e.g., 3 h) fluorescence tracking of nucleus. We also demonstrate the generality of this type of bioinspired fluorescent probes in different cell lines and complex biological samples.

Analytical techniques for assessment of coastal impact of natural disasters Tsunami

International Nuclear Information System (INIS)

Jha, S.K.; Gothankar, S.S.; Tripathi, R.M.; Puranik, V.D.

2010-01-01

Tsunami is a less known and less frequent coastal hazard, in comparison to the other commonly occurring hazards namely the storm surge, oil spills, coastal pollution, coastal erosion, algal bloom and effect of climate change on flora and fauna. Marine sediments contain a record of past events and proved to be an interesting indicator matrix for this study. Instrumental Neutron Activation Analysis (INAA) and Energy Dispersive X-ray Fluorescence (EDXRF) techniques offer adequate sensitivity for analysis of trace elements for conducting geo-chemical studies. Grain size analysis of sediment samples before and after tsunami showed a shift in textural characteristics of the sediment which is not observed during regular monsoon and seasonal changes

Fiber optical assembly for fluorescence spectrometry

Science.gov (United States)

Carpenter, II, Robert W.; Rubenstein, Richard; Piltch, Martin; Gray, Perry

2010-12-07

A system for analyzing a sample for the presence of an analyte in a sample. The system includes a sample holder for containing the sample; an excitation source, such as a laser, and at least one linear array radially disposed about the sample holder. Radiation from the excitation source is directed to the sample, and the radiation induces fluorescent light in the sample. Each linear array includes a plurality of fused silica optical fibers that receive the fluorescent light and transmits a fluorescent light signal from the first end to an optical end port of the linear array. An end port assembly having a photo-detector is optically coupled to the optical end port. The photo-detector detects the fluorescent light signal and converts the fluorescent light signal into an electrical signal.

Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique

International Nuclear Information System (INIS)

Abdel-Kareem, O.; Eltokhy, A.; Harith, M. A.

2011-01-01

This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as standard dyed textile samples. These selected natural dyes will be used as known references that can be used a guide to identify unknown archaeological dyes. The dyed textile samples were investigated with laser radiation in different wavelengths to detect the best wavelengths for identification each dye. This study confirms that Laser Florescent is very useful and a rapid technique can be used as a non-destructive technique for identification of natural dyes on archaeological textile objects. The results obtained with this study can be a guide for all conservators in identification of natural organic dyes on archaeological textile objects.

Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique

Science.gov (United States)

Abdel-Kareem, O.; Eltokhy, A.; Harith, M. A.

2011-09-01

This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as standard dyed textile samples. These selected natural dyes will be used as known references that can be used a guide to identify unknown archaeological dyes. The dyed textile samples were investigated with laser radiation in different wavelengths to detect the best wavelengths for identification each dye. This study confirms that Laser Florescent is very useful and a rapid technique can be used as a non-destructive technique for identification of natural dyes on archaeological textile objects. The results obtained with this study can be a guide for all conservators in identification of natural organic dyes on archaeological textile objects.

Identification of scleractinian coral recruits using fluorescent censusing and DNA barcoding techniques.

Directory of Open Access Journals (Sweden)

Chia-Min Hsu

Full Text Available The identification of coral recruits has been problematic due to a lack of definitive morphological characters being available for higher taxonomic resolution. In this study, we tested whether fluorescent detection of coral recruits used in combinations of different DNA-barcoding markers (cytochrome oxidase I gene [COI], open reading frame [ORF], and nuclear Pax-C intron [PaxC] could be useful for increasing the resolution of coral spat identification in ecological studies. One hundred and fifty settlement plates were emplaced at nine sites on the fringing reefs of Kenting National Park in southern Taiwan between April 2011 and September 2012. A total of 248 living coral spats and juveniles (with basal areas ranging from 0.21 to 134.57 mm(2 were detected on the plates with the aid of fluorescent light and collected for molecular analyses. Using the COI DNA barcoding technique, 90.3% (224/248 of coral spats were successfully identified into six genera, including Acropora, Isopora, Montipora, Pocillopora, Porites, and Pavona. PaxC further separated I. cuneata and I. palifera of Isopora from Acropora, and ORF successfully identified the species of Pocillopora (except P. meandrina and P. eydouxi. Moreover, other cnidarian species such as actinarians, zoanthids, and Millepora species were visually found using fluorescence and identified by COI DNA barcoding. This combination of existing approaches greatly improved the taxonomic resolution of early coral life stages, which to date has been mainly limited to the family level based on skeletal identification. Overall, this study suggests important improvements for the identification of coral recruits in ecological studies.

Identification of scleractinian coral recruits using fluorescent censusing and DNA barcoding techniques.

Science.gov (United States)

Hsu, Chia-Min; de Palmas, Stéphane; Kuo, Chao-Yang; Denis, Vianney; Chen, Chaolun Allen

2014-01-01

The identification of coral recruits has been problematic due to a lack of definitive morphological characters being available for higher taxonomic resolution. In this study, we tested whether fluorescent detection of coral recruits used in combinations of different DNA-barcoding markers (cytochrome oxidase I gene [COI], open reading frame [ORF], and nuclear Pax-C intron [PaxC]) could be useful for increasing the resolution of coral spat identification in ecological studies. One hundred and fifty settlement plates were emplaced at nine sites on the fringing reefs of Kenting National Park in southern Taiwan between April 2011 and September 2012. A total of 248 living coral spats and juveniles (with basal areas ranging from 0.21 to 134.57 mm(2)) were detected on the plates with the aid of fluorescent light and collected for molecular analyses. Using the COI DNA barcoding technique, 90.3% (224/248) of coral spats were successfully identified into six genera, including Acropora, Isopora, Montipora, Pocillopora, Porites, and Pavona. PaxC further separated I. cuneata and I. palifera of Isopora from Acropora, and ORF successfully identified the species of Pocillopora (except P. meandrina and P. eydouxi). Moreover, other cnidarian species such as actinarians, zoanthids, and Millepora species were visually found using fluorescence and identified by COI DNA barcoding. This combination of existing approaches greatly improved the taxonomic resolution of early coral life stages, which to date has been mainly limited to the family level based on skeletal identification. Overall, this study suggests important improvements for the identification of coral recruits in ecological studies.

SEM-based characterization techniques

International Nuclear Information System (INIS)

Russell, P.E.

1986-01-01

The scanning electron microscope is now a common instrument in materials characterization laboratories. The basic role of the SEM as a topographic imaging system has steadily been expanding to include a variety of SEM-based analytical techniques. These techniques cover the range of basic semiconductor materials characterization to live-time device characterization of operating LSI or VLSI devices. This paper introduces many of the more commonly used techniques, describes the modifications or additions to a conventional SEM required to utilize the techniques, and gives examples of the use of such techniques. First, the types of signals available from a sample being irradiated by an electron beam are reviewed. Then, where applicable, the type of spectroscopy or microscopy which has evolved to utilize the various signal types are described. This is followed by specific examples of the use of such techniques to solve problems related to semiconductor technology. Techniques emphasized include: x-ray fluorescence spectroscopy, electron beam induced current (EBIC), stroboscopic voltage analysis, cathodoluminescnece and electron beam IC metrology. Current and future trends of some of the these techniques, as related to the semiconductor industry are discussed

Homogeneous non-competitive bioaffinity assay based on fluorescence resonance energy transfer

International Nuclear Information System (INIS)

Kokko, Tiina; Kokko, Leena; Soukka, Tero; Loevgren, Timo

2007-01-01

A homogeneous non-competitive assay principle for measurement of small analytes based on quenching of fluorescence is described. Fluorescence resonance energy transfer (FRET) occurs between the donor, intrinsically fluorescent europium(III)-chelate conjugated to streptavidin, and the acceptor, quencher dye conjugated to biotin derivative when the biotin-quencher is bound to Eu-streptavidin. Fluorescence can be measured only from those streptavidins that are bound to biotin of the sample, while the fluorescence of the streptavidins that are not occupied by biotin are quenched by quencher-biotin conjugates. The quenching efficiencies of the non-fluorescent quencher dyes were over 95% and one dye molecule was able to quench the fluorescence of more than one europium(III)-chelate. This, however, together with the quadrovalent nature of streptavidin limited the measurable range of the assay to 0.2-2 nmol L -1 . In this study we demonstrated that FRET could be used to design a non-competitive homogeneous assay for a small analyte resulting in equal performance with competitive heterogeneous assay

Fluorescence-based assay as a new screening tool for toxic chemicals

Science.gov (United States)

Moczko, Ewa; Mirkes, Evgeny M.; Cáceres, César; Gorban, Alexander N.; Piletsky, Sergey

2016-09-01

Our study involves development of fluorescent cell-based diagnostic assay as a new approach in high-throughput screening method. This highly sensitive optical assay operates similarly to e-noses and e-tongues which combine semi-specific sensors and multivariate data analysis for monitoring biochemical processes. The optical assay consists of a mixture of environmental-sensitive fluorescent dyes and human skin cells that generate fluorescence spectra patterns distinctive for particular physico-chemical and physiological conditions. Using chemometric techniques the optical signal is processed providing qualitative information about analytical characteristics of the samples. This integrated approach has been successfully applied (with sensitivity of 93% and specificity of 97%) in assessing whether particular chemical agents are irritating or not for human skin. It has several advantages compared with traditional biochemical or biological assays and can impact the new way of high-throughput screening and understanding cell activity. It also can provide reliable and reproducible method for assessing a risk of exposing people to different harmful substances, identification active compounds in toxicity screening and safety assessment of drugs, cosmetic or their specific ingredients.

Waste minimization in analytical chemistry through innovative sample preparation techniques

International Nuclear Information System (INIS)

Smith, L. L.

1998-01-01

water samples. In this SPME technique, a fused-silica fiber coated with a polymeric film is exposed to the sample, extraction is allowed to take place, and then the analytes are thermally desorbed for GC analysis. Unlike liquid-liquid extraction or solid-phase extraction, SPME consumes all of the extracted sample in the analysis, significantly reducing the required sample volume

Study of trace elements in milk by nuclear analytical techniques

International Nuclear Information System (INIS)

Gharib, A.; Rahimi, H.; Pyrovan, H.; Raoffi, N.J.; Taherpoor, H.

1985-01-01

This work is part of project with the IAEA in a coordinated program on 'Trace Elements in Human and Bio-environmental Systems' to evaluate their nutritional requierements, interrelations and the role of trace elements in health, metabolism, etc. Cow's milk is regarded to be one of the most important and most nutritious foodstuffs of mankind. Hence, as a first step, an elemental analysis for milk was carried out: a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of the project was the assessment of various analytical techniques involved. AAS, PIXE and NAA are presented here. The latter was applied both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is, however, some justification to clarify this internal inconsistency. PIXE analysis is very fast and rather routine, but the technique for trace element analysis needs certain adaptations and improvement. (author)

Theory of analytical curves in atomic fluorescence flame spectrometry

NARCIS (Netherlands)

Hooymayers, H.P.

An explicit expression for the intensity of atomic resonance fluorescence as a function of atomic concentration in a flame is derived under certain idealized conditions. The expression is generally valid for a pure Doppler absorption line profile as well as for a combined Doppler and collisional

A Technique to Define Extrahepatic Biliary Anatomy Using Robotic Near-Infrared Fluorescent Cholangiography.

Science.gov (United States)

Maker, Ajay V; Kunda, Nicholas

2017-11-01

Bile duct injury is a rare but serious complication of minimally invasive cholecystectomy. Traditionally, intraoperative cholangiogram has been used in difficult cases to help delineate anatomical structures, however, new imaging modalities are currently available to aid in the identification of extrahepatic biliary anatomy, including near-infrared fluorescent cholangiography (NIFC) using indocyanine green (ICG).1-5 The objective of the study was to evaluate if this technique may aid in safe dissection to obtain the critical view. Thirty-five consecutive multiport robotic cholecystectomies using NIFC with ICG were performed using the da Vinci Firefly Fluorescence Imaging System. All patients received 2.5 mg ICG intravenously at the time of intubation, followed by patient positioning, draping, and establishment of pneumoperitoneum. No structures were divided until the critical view of safety was achieved. Real-time toggling between NIFC and bright-light illumination was utilized throughout the case to define the extrahepatic biliary anatomy. ICG was successfully administered to all patients without complication, and in all cases the extrahepatic biliary anatomy was able to be identified in real-time 3D. All procedures were completed without biliary injury, conversion to an open procedure, or need for traditional cholangiography to obtain the critical view. Specific examples of cases where x-ray cholangiography or conversion to open was avoided and NIFC aided in safe dissection leading to the critical view are demonstrated, including (1) evaluation for aberrant biliary anatomy, (2) confirmation of non-biliary structures, and (3) use in cases where the infundibulum is fused to the common bile duct. NIFC using ICG is demonstrated as a useful technique to rapidly identify and aid in the visualization of extrahepatic biliary anatomy. Techniques that selectively utilize this technology specifically in difficult cases where the anatomy is unclear are demonstrated in order

Xanthines Studied via Femtosecond Fluorescence Spectroscopy

Directory of Open Access Journals (Sweden)

Pascale Changenet-Barret

2016-12-01

Full Text Available Xanthines represent a wide class of compounds closely related to the DNA bases adenine and guanine. Ubiquitous in the human body, they are capable of replacing natural bases in double helices and give rise to four-stranded structures. Although the use of their fluorescence for analytical purposes was proposed, their fluorescence properties have not been properly characterized so far. The present paper reports the first fluorescence study of xanthine solutions relying on femtosecond spectroscopy. Initially, we focus on 3-methylxanthine, showing that this compound exhibits non-exponential fluorescence decays with no significant dependence on the emission wavelength. The fluorescence quantum yield (3 × 10−4 and average decay time (0.9 ps are slightly larger than those found for the DNA bases. Subsequently, we compare the dynamical fluorescence properties of seven mono-, di- and tri-methylated derivatives. Both the fluorescence decays and fluorescence anisotropies vary only weakly with the site and the degree of methylation. These findings are in line with theoretical predictions suggesting the involvement of several conical intersections in the relaxation of the lowest singlet excited state.

Applications of Liquid Chromatography with Fluorescence Detector Diodes and the Analysis of Environmental Pollutants; Aplicaciones de la Cromatografia Liquida con Detector de Diodos y Fluorescencia al Analisis de Contaminantes Medioambientales

Energy Technology Data Exchange (ETDEWEB)

Garcia, S; Perez, R M

2012-04-11

It presents a review on the determination of major types of organic pollutants in environmental samples by HPLC with diode array or fluorescence molecular detectors. Main objective has been to make a compilation of the analytical potential of the technique based on literature and our laboratory studies on the main aspects of analytical methodology used in the determination of these compounds. (Author) 53 refs.

Determination of cesium and selenium in cultivated mushrooms using radionuclide X-ray fluorescence technique

International Nuclear Information System (INIS)

Racz, L.; Bumbalova, A.; Harangozo, M.; Toelgyessy, J.; Tomecek, O.

2000-01-01

Cesium and selenium intake of cultivated mushrooms (Agaricus bisporus), with these elements previously added to culture medium, has been examined from the viewpoint of health- and environmental protection. The process of measuring has been carried out by the radionuclide X-ray fluorescence technique. Treatments of the elementary substance with Se salt appears to influence the Se content of the mushrooms to a significant extent. Cs intake is of considerable importance, as this element is accumulated by mushrooms. (author)

Analysis of kiwi fruit (Accented deliciosa) by energy dispersive X-ray fluorescence spectra

International Nuclear Information System (INIS)

Oliveira, Ana Claudia S.; Oliveira, Marcia L. de; Silva, Lucia C.A.S.; Arthur, Valter; Almeida, Eduardo

2011-01-01

The search for a healthy life has led consumers to eat fruits and vegetables in place of manufactured products, however, the demand for minimally processed products has evolved rapidly. The kiwi has at least eight nutrients beneficial to health: calcium, magnesium, manganese, phosphorus, iron, potassium, sodium and has also high vitamin C, which has wide acceptance in consumer markets. Energy dispersive spectroscopy X-ray (EDX) is the analytical technique used for elemental analysis or chemical characterization of a sample. It is a variant of fluorescence spectroscopy X-ray based on the sample through an investigation of interactions between electromagnetic radiation and matter, analyzing X-rays emitted by matter in response to being struck by charged particles. The aim of this study were to determine potassium, calcium, iron and bromine (K, Ca, Fe and Br, respectively) present in kiwifruit using the technique of fluorescence X-ray energy dispersive (EDXRF). Kiwifruit were peeled, washed and cut into slices and freeze-dried. After drying the sample was held digestion and subsequent reading of the same equipment in the X-ray fluorescence energy dispersive (EDXRF). The results indicated that the contents of potassium, calcium, iron and bromine are present in kiwifruit as expected when compared to Brazilian Table of Food Composition. (author)

Molecules for Fluorescence Detection of Specific Chemicals

Science.gov (United States)

Fedor, Steve

2008-01-01

A family of fluorescent dye molecules has been developed for use in on-off fluorescence detection of specific chemicals. By themselves, these molecules do not fluoresce. However, when exposed to certain chemical analytes in liquid or vapor forms, they do fluoresce (see figure). These compounds are amenable to fixation on or in a variety of substrates for use in fluorescence-based detection devices: they can be chemically modified to anchor them to porous or non-porous solid supports or can be incorporated into polymer films. Potential applications for these compounds include detection of chemical warfare agents, sensing of acidity or alkalinity, and fluorescent tagging of proteins in pharmaceutical research and development. These molecules could also be exploited for use as two-photon materials for photodynamic therapy in the treatment of certain cancers and other diseases. A molecule in this family consists of a fluorescent core (such as an anthracene or pyrene) attached to two end groups that, when the dye is excited by absorption of light, transfer an electron to the core, thereby quenching the fluorescence. The end groups can be engineered so that they react chemically with certain analytes. Upon reaction, electrons on the end groups are no longer available for transfer to the core and, consequently, the fluorescence from the core is no longer quenched. The chemoselectivity of these molecules can be changed by changing the end groups. For example, aniline end groups afford a capability for sensing acids or acid halides (including those contained in chemical warfare agents). Pyridine or bipyridyl end groups would enable sensing of metal ions. Other chemicals that can be selectively detected through suitable choice of end groups include glucose and proteins. Moreover, the fluorescent cores can be changed to alter light-absorption and -emission characteristics: anthracene cores fluoresce at wavelengths around 500 nm, whereas perylene cores absorb and emit at

Membranes and Fluorescence microscopy

DEFF Research Database (Denmark)

Bagatolli, Luis

2009-01-01

Fluorescence spectroscopy-based techniques using conventional fluorimeters have been extensively applied since the late 1960s to study different aspects of membrane-related phenomena, i.e., mainly relating to lipid-lipid and lipid-protein (peptide) interactions. Even though fluorescence...

Analytical techniques for the determination of radiochemical purity of radiopharmaceuticals prepared from kits. Pt. III

International Nuclear Information System (INIS)

McLean, J.R.; Rockwell, L.J.; Welsh, W.J.

1982-01-01

The evaluation of efficacy of commercially available kits used for the preparation of radiopharmaceuticals is one aspect of the Radiation Protection Bureau's radiopharmaceutical quality control program. This report describes some of the analytical methodology employed in the program. The techniques may be of interest to hospital radiopharmacy personnel since many of the tests can be performed rapidly and with a minimum of special equipment, thus enabling the confirmation of radiopharmaceutical purity prior to patient administration. Manufacturers of kits may also be interested in learning of the analytical methods used in the assessment of their products

Fluorescent Biosensors Based on Single-Molecule Counting.

Science.gov (United States)

Ma, Fei; Li, Ying; Tang, Bo; Zhang, Chun-Yang

2016-09-20

Biosensors for highly sensitive, selective, and rapid quantification of specific biomolecules make great contributions to biomedical research, especially molecular diagnostics. However, conventional methods for biomolecular assays often suffer from insufficient sensitivity and poor specificity. In some case (e.g., early disease diagnostics), the concentration of target biomolecules is too low to be detected by these routine approaches, and cumbersome procedures are needed to improve the detection sensitivity. Therefore, there is an urgent need for rapid and ultrasensitive analytical tools. In this respect, single-molecule fluorescence approaches may well satisfy the requirement and hold promising potential for the development of ultrasensitive biosensors. Encouragingly, owing to the advances in single-molecule microscopy and spectroscopy over past decades, the detection of single fluorescent molecule comes true, greatly boosting the development of highly sensitive biosensors. By in vitro/in vivo labeling of target biomolecules with proper fluorescent tags, the quantification of certain biomolecule at the single-molecule level is achieved. In comparison with conventional ensemble measurements, single-molecule detection-based analytical methods possess the advantages of ultrahigh sensitivity, good selectivity, rapid analysis time, and low sample consumption. Consequently, single-molecule detection may be potentially employed as an ideal analytical approach to quantify low-abundant biomolecules with rapidity and simplicity. In this Account, we will summarize our efforts for developing a series of ultrasensitive biosensors based on single-molecule counting. Single-molecule counting is a member of single-molecule detection technologies and may be used as a very simple and ultrasensitive method to quantify target molecules by simply counting the individual fluorescent bursts. In the fluorescent sensors, the signals of target biomolecules may be translated to the

Modified Hyperbranched Polymers for Fluorescence Sensing Applications

Science.gov (United States)

2012-06-01

sensors. The HBPs transported the fluorescent groups to the fiber mat surface where they interacted with mercury (Hg(II)) or cytochrome c as the analyte...coworkers (27, 28) have employed fluorescence quenching using a binol-based dendrimer sensor, which exhibited differential sensitivity to enantiomeric...based sensors using HBP-based fluorophores was demonstrated in this report. Low concentrations of fluorophore were transported to the surface of

Charge-transfer-based terbium MOF nanoparticles as fluorescent pH sensor for extreme acidity.

Science.gov (United States)

Qi, Zewan; Chen, Yang

2017-01-15

Newly emerged metal organic frameworks (MOFs) have aroused the great interest in designing functional materials by means of its flexible structure and component. In this study, we used lanthanide Tb 3+ ions and small molecular ligands to design and assemble a kind of pH-sensitive MOF nanoparticle based on intramolecular-charge-transfer effect. This kind of made-to-order MOF nanoparticle for H + is highly specific and sensitive and could be used to fluorescently indicate pH value of strong acidic solution via preset mechanism through luminescence of Tb 3+ . The long luminescence lifetime of Tb 3+ allows eliminating concomitant non-specific fluorescence by time-revised fluorescence techniques, processing an advantage in sensing H + in biological media with strong autofluorescence. Our method showed a great potential of MOF structures in designing and constructing sensitive sensing materials for specific analytes directly via the assembly of functional ions/ligands. Copyright © 2016 Elsevier B.V. All rights reserved.

Applications of nuclear analytical techniques to environmental studies

International Nuclear Information System (INIS)

Freitas, M.C.; Marques, A.P.; Reis, M.A.; Pacheco, A.M.G.; Barros, L.I.C.

2001-01-01

A few examples of application of nuclear-analytical techniques to biological monitors - natives and transplants - are given herein. Parmelia sulcata Taylor transplants were set up in a heavily industrialized area of Portugal - the Setubal peninsula, about 50 km south of Lisbon - where indigenous lichens are rare. The whole area was 10x15 km around an oil-fired power station, and a 2.5x2.5 km grid was used. In north-western Portugal, native thalli of the same epiphytes (Parmelia spp., mostly Parmelia sulcata Taylor) and bark from olive trees (Olea europaea) were sampled across an area of 50x50 km, using a 10x10 km grid. This area is densely populated and features a blend of rural, urban-industrial and coastal environments, together with the country's second-largest metro area (Porto). All biomonitors have been analyzed by INAA and PIXE. Results were put through nonparametric tests and factor analysis for trend significance and emission sources, respectively

Smart Drug Delivery System-Inspired Enzyme-Linked Immunosorbent Assay Based on Fluorescence Resonance Energy Transfer and Allochroic Effect Induced Dual-Modal Colorimetric and Fluorescent Detection.

Science.gov (United States)

Miao, Luyang; Zhu, Chengzhou; Jiao, Lei; Li, He; Du, Dan; Lin, Yuehe; Wei, Qin

2018-02-06

Numerous analytical techniques have been undertaken for the detection of protein biomarkers because of their extensive and significant applications in clinical diagnosis, whereas there are few strategies to develop dual-readout immunosensors to achieve more accurate results. To the best of our knowledge, inspired by smart drug delivery system (DDS), a novel pH-responsive modified enzyme-linked immunosorbent assay (ELISA) was innovatively developed for the first time, realizing dual-modal colorimetric and fluorescent detection of cardiac troponin I (cTnI). Curcumin (CUR) was elaborately selected as a reporter molecule, which played the same role of drugs in DDS based on the following considerations: (1) CUR can be used as a kind of pH indicator by the inherited allochroic effect induced by basic pH value; (2) the fluorescence of CUR can be quenched by certain nanocarriers as the acceptor because of the occurrence of fluorescence resonance energy transfer (FRET), while recovered by the stimuli of basic pH value, which can produce "signal-on" fluorescence detection. Three-dimensional MoS 2 nanoflowers (3D-MoS 2 NFs) were employed in immobilizing CUR to constitute a nanoprobe for the determination of cTnI by virtue of good biocompatibility, high absorption capacity, and fluorescence quench efficiency toward CUR. The proposed DDS-inspired ELISA offered dual-modal colorimetric and fluorescent detection of cTnI, thereby meeting the reliable and precise analysis requirements. We believe that the developed dual-readout ELISA will create a new avenue and bring innovative inspirations for biological detections.

Quantitative analysis by computer controlled X-ray fluorescence spectrometer

International Nuclear Information System (INIS)

Balasubramanian, T.V.; Angelo, P.C.

1981-01-01

X-ray fluorescence spectroscopy has become a widely accepted method in the metallurgical field for analysis of both minor and major elements. As encountered in many other analytical techniques, the problem of matrix effect generally known as the interelemental effects is to be dealt with effectively in order to make the analysis accurate. There are several methods by which the effects of matrix on the analyte are minimised or corrected for and the mathematical correction is one among them. In this method the characteristic secondary X-ray intensities are measured from standard samples and correction coefficients. If any, for interelemental effects are evaluated by mathematical calculations. This paper describes attempts to evaluate the correction coefficients for interelemental effects by multiple linear regression programmes using a computer for the quantitative analysis of stainless steel and a nickel base cast alloy. The quantitative results obtained using this method for a standard stainless steel sample are compared with the given certified values. (author)

Raman and fluorescent scattering by molecules embedded in small particles

International Nuclear Information System (INIS)

Chew, H.W.; McNulty, P.J.

1983-01-01

We have formulated a model for fluorescent and Raman scattering by molecules embedded in or in the vicinity of small particles. The model takes into account the size, shape, refractive index, and morphology of the host particles. Analytic and numerical results have been obtained for spherical (one and more layers, including magnetic dipole transitions) cylindrical and spheroidal particles. Particular attention has been given to the spherical case with fluorescent/Raman scatterers uniformly distributed in the particles radiating both coherently and incohorently. Depolarization effects have been studied with suitable averaging process, and good agreement with experiment has been obtained. Analytic and numerical results have been obtained for the elastic scattering of evanescent waves; these results are useful for the study of fluorescent under excitation by evanescent waves

Quantitative X ray analysis system. User's manual and guide to X ray fluorescence technique

International Nuclear Information System (INIS)

2009-01-01

This guide covers trimmed and re-arranged version 3.6 of the Quantitative X ray Analysis System (QXAS) software package that includes the most frequently used methods of quantitative analysis. QXAS is a comprehensive quantitative analysis package that has been developed by the IAEA through research and technical contracts. Additional development has also been carried out in the IAEA Laboratories in Seibersdorf where QXAS was extensively tested. New in this version of the manual are the descriptions of the Voigt-profile peak fitting, the backscatter fundamental parameters' and emission-transmission methods of chemical composition analysis, an expanded chapter on the X ray fluorescence physics, and completely revised and increased number of practical examples of utilization of the QXAS software package. The analytical data accompanying this manual were collected in the IAEA Seibersdorf Laboratories in the years 2006/2007

Ion beam induced fluorescence imaging in biological systems

International Nuclear Information System (INIS)

Bettiol, Andrew A.; Mi, Zhaohong; Vanga, Sudheer Kumar; Chen, Ce-belle; Tao, Ye; Watt, Frank

2015-01-01

Imaging fluorescence generated by MeV ions in biological systems such as cells and tissue sections requires a high resolution beam (<100 nm), a sensitive detection system and a fluorescent probe that has a high quantum efficiency and low bleaching rate. For cutting edge applications in bioimaging, the fluorescence imaging technique needs to break the optical diffraction limit allowing for sub-cellular structure to be visualized, leading to a better understanding of cellular function. In a nuclear microprobe this resolution requirement can be readily achieved utilizing low beam current techniques such as Scanning Transmission Ion Microscopy (STIM). In recent times, we have been able to extend this capability to fluorescence imaging through the development of a new high efficiency fluorescence detection system, and through the use of new novel fluorescent probes that are resistant to ion beam damage (bleaching). In this paper we demonstrate ion beam induced fluorescence imaging in several biological samples, highlighting the advantages and challenges associated with using this technique

Development of analytical techniques for water and environmental samples (2)

Energy Technology Data Exchange (ETDEWEB)

Eum, Chul Hun; Jeon, Chi Wan; Jung, Kang Sup; Song, Kyung Sun; Kim, Sang Yeon [Korea Institute of Geology Mining and Materials, Taejon (Korea)

1998-12-01

The purpose of this study is to develop new analytical methods with good detection limit for toxic inorganic and organic compounds. The analyses of CN, organic acids, particulate materials in environmental samples have been done using several methods such as Ion Chromatography, SPE, SPME, GC/MS, GC/FID, SPLITT (split-flow thin cell fractionation) during the second year of this project. Advantage and disadvantage of several distillation method (by KS, JIS, EPA) for CN analysis in wastewater were investigated. As the results, we proposed new distillation apparatus for CN analysis, which was proved to be simpler, faster and to get better recovery than conventional apparatus. And ion chromatograph/pulsed amperometric detector (IC/PAD) system instead of colorimetry for CN detection was setup to solve matrix interference. And SPE(solid phase extraction) and SPME (solid phase micro extraction) as liquid-solid extraction technique were applied to the analysis of phenols in wastewater. Optimum experimental conditions and factors influencing analytical results were determined. From these results, It could be concluded that C{sub 18} cartridge and polystyrene-divinylbenzene disk in SPE method, polyacrylate fiber in SPME were proper solid phase adsorbent for phenol. Optimum conditions to analyze phenol derivatives simultaneously were established. Also, Continuous SPLITT (Split-flow thin cell) Fractionation (CSF) is a new preparative separation technique that is useful for fractionation of particulate and macromolecular materials. CSF is carried out in a thin ribbon-like channel equipped with two splitters at both inlet and outlet of the channel. In this work, we set up a new CSF system, and tested using polystyrene latex standard particles. And then we fractionated particles contained in air and underground water based on their sedimentation coefficients using CSF. (author). 27 refs., 13 tabs., 31 figs.

Enhanced fluorescence sensitivity by coupling yttrium-analyte complexes and three-way fast high-performance liquid chromatography data modeling

Energy Technology Data Exchange (ETDEWEB)

Alcaraz, Mirta R.; Culzoni, María J., E-mail: mculzoni@fbcb.unl.edu.ar; Goicoechea, Héctor C., E-mail: hgoico@fbcb.unl.edu.ar

2016-01-01

The present study reports a sensitive chromatographic method for the analysis of seven fluoroquinolones (FQs) in environmental water samples, by coupling yttrium-analyte complex and three-way chromatographic data modeling. This method based on the use of HPLC-FSFD does not require complex or tedious sample treatments or enrichment processes before the analysis, due to the significant fluorescence increments of the analytes reached by the presence of Y{sup 3+}. Enhancement achieved for the FQs signals obtained after Y{sup 3+} addition reaches 103- to 1743-fold. Prediction results corresponding to the application of MCR-ALS to the validation set showed relative error of prediction (REP%) values below 10% in all cases. A recovery study that includes the simultaneous determination of the seven FQs in three different environmental aqueous matrices was conducted. The recovery studies assert the efficiency and the accuracy of the proposed method. The LOD values calculated are in the order of part per trillion (below 0.5 ng mL{sup −1} for all the FQs, except for enoxacin). It is noteworthy to mention that the method herein proposed, which does not include pre-concentration steps, allows reaching LOD values in the same order of magnitude than those achieved by more sophisticated methods based on SPE and UHPLC-MS/MS. - Highlights: • Highly sensitive method for the analysis of seven fluoroquinolones. • Coupling of yttrium-analyte complex and three-way modeling. • Complex or tedious sample treatments or enrichment processes are nor required. • Accuracy on the quantitation of fluoroquinolones in real water river samples.

Fluorescence detection of pesticides using quantum dot materials – A review

Energy Technology Data Exchange (ETDEWEB)

Nsibande, S.A.; Forbes, P.B.C., E-mail: patricia.forbes@up.ac.za

2016-11-16

High pesticide use, especially in agriculture, can lead to environmental pollution and potentially adverse health effects. As result, pesticide residues end up in different media, including water and food products, which may serve as direct routes for human exposure. There is thus a continuous drive to develop analytical methods for screening and quantification of these compounds in the different environmental media in which they may occur. Development of quantum dot (QD) based sensors for monitoring pesticides has gained momentum in recent years. QD materials have excellent and unique optical properties and have high fluorescence quantum yields compared to other fluorophores. They have thus been used in numerous studies for the development of probes for organic pollutants. In this paper we specifically review their application as fluorescence probes for pesticide detection in different media including water and in fruits and vegetables. The low detection limits reported demonstrate the potential use of these methods as alternatives to expensive and time-consuming conventional techniques. We also highlight potential limitations that these probes may present when it comes to routine application. Finally we discuss possible future improvements to enhance the selectivity and robustness of these sensors. We note that there is still a need for researchers to develop standardized QD based sensors which could lead to their commercialization and routine application. - Highlights: • Application of quantum dots as fluorescence probes in pesticide detection. • Recognition elements and modification strategies towards selective pesticide detection. • Sensitive detection below regulatory limits in various matrices. • Challenges and possible solutions towards standardization of quantum dot based analytical methods.

Analytical and numerical techniques for predicting the interfacial stresses of wavy carbon nanotube/polymer composites

NARCIS (Netherlands)

Yazdchi, K.; Salehi, M.; Shokrieh, M.M.

2009-01-01

By introducing a new simplified 3D representative volume element for wavy carbon nanotubes, an analytical model is developed to study the stress transfer in single-walled carbon nanotube-reinforced polymer composites. Based on the pull-out modeling technique, the effects of waviness, aspect ratio,

Problems of fluorescent imaging and its solution using nanofluorophores. Part I: Advantages of fluorescent nanoparticles over conventional organic fluorophores

International Nuclear Information System (INIS)

Zhelev, Z.; Hadjidekov, G.; Zlateva, G.; Spasov, L.; Bakalova, R.

2011-01-01

The application of fluorescence in deep-tissue imaging is rapidly expanding in fast several years. The progress in fluorescent molecular probes and fluorescent imaging techniques gives an opportunity to detect single cells and even molecules in live organisms. The highly sensitive and high-speed fluorescent molecular sensors and detection devices allow the application of fluorescence in functional imaging. With development of novel bright fluorophores based on nano-technologies and fluorescence scanners with high spatial and temporal resolution, the fluorescent imaging has a potential to become an alternative of the other non-invasive imaging techniques as magnetic resonance imaging, positron-emission tomography, X-ray, computing tomography. This review outlines the current status and future trends of fluorescent nanoparticles - quantum dots (QDs), as a new generation of fluorophores in experimental and pre-clinical fluorescent imaging diagnostic. Part 1 focuses on the advantages of quantum dots over conventional organic fluorophores and defines the major requirements to the 'perfect' fluorophore for fluorescent deep-tissue imaging diagnostic. The analysis is based on the limitations of fluorescent imaging in vivo and overcome by using quantum dots

Impact of accelerator-based analytical techniques on the knowledge and conservation of cultural heritage

International Nuclear Information System (INIS)

Dran, Jean Claude

2001-01-01

A large set of modern analytical techniques is currently applied to get a better insight on art and archaeological objects as well as to contribute to their conservation and restoration. Because of the precious and sometimes unique character of the works, non-destructive techniques and even those requiring no (or only minute) sampling, are preferred. From this standpoint, ion beam analysis (IBA) constitutes one of the best choices, since it combines quite good analytical performance and non-destructiveness. For over 10 years, an IBA facility has been installed in the Research Laboratory of the Museums of France. Until now it is the only facility of this kind entirely devoted to the study of cultural heritage. A special set-up, namely an external beam line, has been developed which permits the in-air analysis of large or fragile works of art without sampling. This facility is used for both short investigations at the request of museum curators and extensive research works in art history and archaeology. Numerous examples will be given to highlight the impact of this tool on cultural heritage. (author)

X-ray fluorescence in IAEA Member States: Greece

International Nuclear Information System (INIS)

Karydas, A.

2004-01-01

The Laboratory of Material Analysis (LMA) of the Institute of Nuclear Physics (INP) at the National Center for Scientific Research (NCSR) 'Demokritos', has been involved very actively during the past few years in the development, evaluation and analytical application of portable X-Ray Fluorescence (XRF) instruments, applied in particular for the non-destructive analysis of cultural materials. The study, conservation and preservation of cultural materials are considered nowadays issues of main concern for countries and international cultural organizations. Due to the strong interest and motivation from archaeologists, conservators and archaeometrical scientists in Greece and elsewhere, a large network has been developed involving the LMA and archaeologists/conservator scientists from Museums (Benaki Museum in Athens), Cultural Foundations (Thera Foundation P. Nomikos), the Greek Ministry of Culture-Conservation Department, Foreign Schools in Greece (American School of Classical Studies, French School of Athens), Universities (Department of Conservation of Antiquities and Works of Art in the Technological Educational Institution of Athens, University of Cincinnatti, Universite de Paris I, Pantheon Sorbonne), private sectors (THETIS, Thetis Authentics - Science and Techniques for Art History Conservation Ltd) and Institutions (Centre de Recherche et de Rastauration des Musees de France, LNS-INFN, LANDIS group). A variety of cultural materials/artifacts have been examined so far, including ceramic vases with colored decoration, bronze artifacts, wall-painting pigments, traces of polychromy on marble sculptures, Gold and Silver ancient jewelry, Gemstones, Roman Coins. Our research and analytical applications of the in-situ XRF analysis have been focused so far on the following: 1) optimum selection and integration of portable XRF instrumentation for improving analytical and sensitivity range; 2) evaluation of the potential of in-situ XRF analysis to provide specific

Fluorescence molecular tomography in the presence of background fluorescence

International Nuclear Information System (INIS)

Soubret, Antoine; Ntziachristos, Vasilis

2006-01-01

Fluorescence molecular tomography is an emerging imaging technique that resolves the bio-distribution of engineered fluorescent probes developed for in vivo reporting of specific cellular and sub-cellular targets. The method can detect fluorochromes in picomole amounts or less, imaged through entire animals, but the detection sensitivity and imaging performance drop in the presence of background, non-specific fluorescence. In this study, we carried out a theoretical and an experimental investigation on the effect of background fluorescence on the measured signal and on the tomographic reconstruction. We further examined the performance of three subtraction methods based on physical models of photon propagation, using experimental data on phantoms and small animals. We show that the data pre-processing with subtraction schemes can improve image quality and quantification when non-specific background florescence is present

An automated protocol for performance benchmarking a widefield fluorescence microscope.

Science.gov (United States)

Halter, Michael; Bier, Elianna; DeRose, Paul C; Cooksey, Gregory A; Choquette, Steven J; Plant, Anne L; Elliott, John T

2014-11-01

Widefield fluorescence microscopy is a highly used tool for visually assessing biological samples and for quantifying cell responses. Despite its widespread use in high content analysis and other imaging applications, few published methods exist for evaluating and benchmarking the analytical performance of a microscope. Easy-to-use benchmarking methods would facilitate the use of fluorescence imaging as a quantitative analytical tool in research applications, and would aid the determination of instrumental method validation for commercial product development applications. We describe and evaluate an automated method to characterize a fluorescence imaging system's performance by benchmarking the detection threshold, saturation, and linear dynamic range to a reference material. The benchmarking procedure is demonstrated using two different materials as the reference material, uranyl-ion-doped glass and Schott 475 GG filter glass. Both are suitable candidate reference materials that are homogeneously fluorescent and highly photostable, and the Schott 475 GG filter glass is currently commercially available. In addition to benchmarking the analytical performance, we also demonstrate that the reference materials provide for accurate day to day intensity calibration. Published 2014 Wiley Periodicals Inc. Published 2014 Wiley Periodicals Inc. This article is a US government work and, as such, is in the public domain in the United States of America.

Elemental Characterization of minerals in Chenopodium quinoa grains by the X-ray fluorescence technique

International Nuclear Information System (INIS)

Olivera de Lescano, Paula; Nieto Aco, Daniel

2014-01-01

In order to characterize by the technique of X-ray fluorescence energy dispersive quinoa grain for human consumption, 8 samples of different trademarks of quinoa, which are distributed in the local market were analyzed; together one reference materials certified by the International Atomic Energy Agency (IAEA) was analyzed. The results show the presence of elements such as K, Ca, Mn, Fe, Cu, Zn, Rb and Sr, the same as compared to data reported in various studies in neighboring countries like Ecuador, Chile and Bolivia. (authors).

Applications of the X-ray fluorescence technique to medical dynamic studies

International Nuclear Information System (INIS)

Magrini, A.; Cesareo, R.; Salmi, M.; Gigante, G.E.

1978-01-01

The energy dispersive X ray fluorescence technique (XRF) was employed to follow the evolution of the concentration of stable tracers for diagnostic purposes. A simple and relatively inexpensive XRF system, based on the use of a small sealed-off radioisotopic source and a proportional gas counter, was utilized in the study of human blood platelet survival 'in vitro', rabbit platelet survival 'in vivo' and in clearance studies of the human knee joint 'in vivo'. The survival curves of human and rabbit platelets were determined employing stable Rubidium as a tracer. The clearance rate of a stable Iodinate compound from the synovial cavity was measured in normal and pathological conditions. Results obtained suggest that the method can be usefully employed to monitor the course of disease and to establish the efficacy of treatment

A REVIEW ON THE ANALYTICAL TECHNIQUES USED FOR THE DETERMINATION OF PARACETAMOL IN PHARMACEUTICAL FORMULATIONS AND BIOLOGICAL FLUIDS

Directory of Open Access Journals (Sweden)

Aisha Noreen

2016-12-01

Full Text Available Paracetamol (PM is an active metabolite of phenacetin and belongs to p-aminophenol derivatives. It is also termed as acetaminophen. PM is one of the non-steroidal anti-inflammatory drugs (NSAIDs which is used as an analgesic and antipyretic agent. It is an OTC drug and is used as a common household analgesic. It is not used as a substitute of aspirin or any other NSAIDs. It is a weak cyclooxygenase (COX 1 and 2 inhibitor but may inhibit COX-3 in the central nervous system. Many analytical techniques have been used for the assay of PM in pharmaceutical preparations and biological fluids. These techniques include spectrometry, chromatography, spectrofluorimetry, chemiluminescence, electrochemical techniques, flow injection spectrometry and chronoamperometry. In many pharmaceutical preparations PM is also used in combination with other drugs and these techniques have also been used for their simultaneous determination. A detailed review of various analytical techniques used for the assay of PM has been carried out which would be of great help to the chemists and pharmacists involved in the analysis and quality control of drugs.

The application of nuclear analytical techniques in the study of elements distribution pattern associated with Gubrunde Uranium occurrence in North-Eastern Nigeria

International Nuclear Information System (INIS)

Ige, T. A.

1994-01-01

Prospecting for high grade uranium deposits in North-East Nigeria has, over the years, amongst other reasons, been handicapped by lack of adequate understanding of the elemental primary and secondary dispersion patterns associated with known occurrences in the region. One hundred and forty-four samples from low grade Uranium occurrences at Gubrunde horst consisting of disseminated ores and host rocks, bark and soil samples were therefore, analysed for forty-four elements using Neutron Activation Analysis (with Gamma Spectrometry - INAA and Delayed Neutron Counting - DNC) and Energy Dispersive X-ray Fluorescence Techniques. The analytical data have been evaluated using multivariate statistical techniques. The results show some major element groupings (association). The first group consists of Ph, Ba, Ce and Sm (LREE) that are enriched with increasing uranium concentration in the mineralized zone and are therefore, capable of serving as path-finder elements for uranium. The second group comprising of K 2 O, CaO, Na 2 O and the HREE are depleted in the mineralized zones due to the action of hydrothermal fluids and are indicative of altered/mineralized rocks. The third group consists of the other elements which feature little or no significant enrichment with uranium but may be associated with ferruginisation (hematite) and possibly refractory minerals. It is found that iron does not correlate well with uranium in this report which may indicate ferruginization and mineralization as two independent processes

X-Ray fluorescence determination of the mobile forms of toxic elements in meadow chernozems

International Nuclear Information System (INIS)

Belikov, K.N.; Blank, A.B.; Shevtsov, N.I.

1997-01-01

An X-ray fluorescence method for determining mobile forms of Mn, V, Cr, Co, Ni, Zn, and Pb in meadow chernozems was developed. It is based on the extraction of analytes with an acetate-ammonia buffer solution and the evaporation of the obtained filtrate with carbon powder followed by the X-ray fluorescence analysis of the dry residue. The effect of concomitants on the analytical signals of elements under determination was examined. It was suggested to spike samples with barium in order to decrease analytical errors. (author)

Cu,Cr and As determination in preserved woods (Eucalyptus ssp.) by X-ray fluorescence spectrometries

International Nuclear Information System (INIS)

Pereira Junior, Sergio Matias

2014-01-01

Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined. (author)

Application gives the technique the analytic tree in the evaluation the effectiveness programs to radiological protection

International Nuclear Information System (INIS)

Perez Gonzalez, F.; Perez Velazquez, R.S.; Fornet Rodriguez, O.; Mustelier Hechevarria, A.; Miller Clemente, A.

1998-01-01

In the work we develop the IAEA recommendations in the application the analytic tree as instrument for the evaluation the effectiveness the occupational radiological protection programs. Is reflected like it has been assimilated and converted that technique in daily work istruments in the evaluation process the security conditions in the institutions that apply the nuclear techniques with a view to its autorization on the part of the regulatory organ

Photobleaching correction in fluorescence microscopy images

International Nuclear Information System (INIS)

Vicente, Nathalie B; Diaz Zamboni, Javier E; Adur, Javier F; Paravani, Enrique V; Casco, Victor H

2007-01-01

Fluorophores are used to detect molecular expression by highly specific antigen-antibody reactions in fluorescence microscopy techniques. A portion of the fluorophore emits fluorescence when irradiated with electromagnetic waves of particular wavelengths, enabling its detection. Photobleaching irreversibly destroys fluorophores stimulated by radiation within the excitation spectrum, thus eliminating potentially useful information. Since this process may not be completely prevented, techniques have been developed to slow it down or to correct resulting alterations (mainly, the decrease in fluorescent signal). In the present work, the correction by photobleaching curve was studied using E-cadherin (a cell-cell adhesion molecule) expression in Bufo arenarum embryos. Significant improvements were observed when applying this simple, inexpensive and fast technique

Escape probabilities for fluorescent x-rays

International Nuclear Information System (INIS)

Dance, D.R.; Day, G.J.

1985-01-01

Computation of the energy absorption efficiency of an x-ray photon detector involves consideration of the histories of the secondary particles produced in any initial or secondary interaction which may occur within the detector. In particular, the K or higher shell fluorescent x-rays which may be emitted following a photoelectric interaction can carry away a large fraction of the energy of the incident photon, especially if this energy is just above an absorption edge. The effects of such photons cannot be ignored and a correction term, depending upon the probability that the fluorescent x-rays will escape from the detector, must be applied to the energy absorption efficiency. For detectors such as x-ray intensifying screens, it has been usual to calculate this probability by numerical integration. In this note analytic expressions are derived for the escape probability of fluorescent photons from planar detectors in terms of exponential integral functions. Rational approximations for these functions are readily available and these analytic expressions therefore facilitate the computation of photon absorption efficiencies. A table is presented which should obviate the need for calculating the escape probability for most cases of interest. (author)

Multi-elemental analysis of marine sediments of Sorsogon Bay using x-ray fluorescence spectroscopy

International Nuclear Information System (INIS)

Gonzales, Ralph Roly A.; Quirit, Leni L.; Rosales, Colleen Marciel F.; Pabroa, Preciosa Corazon B.; Sta Maria, Efren J.

2011-01-01

Metal composition and nutrient loadings of our bodies of water, when uncontrolled, may cause harmful bacterial contamination and pose threats in aquatic and human life. Toxic and trace element inputs in Sorsogon Bay sediments were determined using nuclear analytical techniques, more specifically, x-ray fluorescence spectrometry, in this study. Pre-treated marine sediment samples from Sorsogon Bay were homogenized using SPEX # 8000 mixer/mill and agate mortar and pestle, pelletized into 31-mm flat discs using SPEX 3630 X-Press and analyzed using PAN Analytical Epsilon 5 EDX X-ray Fluorescence Spectrometer with the emission and transmission method using silver and germanium secondary targets. Spectrum fitting performed using AXIL (Analysis of X-ray Spectra by Iterative Least-Squares Fitting), a subprogram in Quantitative X-ray Analysis System developed by the International Atomic Energy Agency and Quantitative Analysis of Environmental Samples program, was used for quantification of results. Results indicate generally moderate to high metal enrichment, specifically manganese, lead, cadmium, zinc and copper. Mercury and iron level enrichment are found to be low, marking an improvement from previous studies indicating high enrichment of these metals. (author)

Total reflection X-ray fluorescence analysis

International Nuclear Information System (INIS)

Michaelis, W.; Prange, A.

1987-01-01

In the past few years, total reflection X-ray flourescence analysis (TXRF) has found an increasing number of assignments and applications. Experience of trace element analysis using TXRF and examples of applications are already widespread. Therefore, users of TXRF had the opportunity of an intensive exchange of their experience at the 1st workshop on total reflection X-ray fluorescence analysis which took place on May 27th and 28th 1986 at the GKSS Research Centre at Geesthacht. In a series of lectures and discussions dealing with the analytical principle itself, sample preparation techniques and applications as well as comuter programs for spectrum evaluation, the present state of development and the range of applications were outlined. 3 studies out of a total of 14 were included separately in the INIS and ENERGY databases. With 61 figs., 12 tabs [de

Direct on-strip analysis of size- and time-resolved aerosol impactor samples using laser induced fluorescence spectra excited at 263 and 351 nm

International Nuclear Information System (INIS)

Wang, Chuji; Pan, Yong-Le; James, Deryck; Wetmore, Alan E.; Redding, Brandon

2014-01-01

Highlights: • A dual wavelength UV-LIF spectra-rotating drum impactor (RDI) technique was developed. • The technique was demonstrated by direct on-strip analysis of size- and time-resolved LIF spectra of atmospheric aerosol particles. • More than 2000 LIF spectra of atmospheric aerosol particles collected over three weeks in Djibouti were obtained and assigned to various fluorescence clusters. • The LIF spectra showed size- and time-sensitivity behavior with a time resolution of 3.6 h. - Abstract: We report a novel atmospheric aerosol characterization technique, in which dual wavelength UV laser induced fluorescence (LIF) spectrometry marries an eight-stage rotating drum impactor (RDI), namely UV-LIF-RDI, to achieve size- and time-resolved analysis of aerosol particles on-strip. The UV-LIF-RDI technique measured LIF spectra via direct laser beam illumination onto the particles that were impacted on a RDI strip with a spatial resolution of 1.2 mm, equivalent to an averaged time resolution in the aerosol sampling of 3.6 h. Excited by a 263 nm or 351 nm laser, more than 2000 LIF spectra within a 3-week aerosol collection time period were obtained from the eight individual RDI strips that collected particles in eight different sizes ranging from 0.09 to 10 μm in Djibouti. Based on the known fluorescence database from atmospheric aerosols in the US, the LIF spectra obtained from the Djibouti aerosol samples were found to be dominated by fluorescence clusters 2, 5, and 8 (peaked at 330, 370, and 475 nm) when excited at 263 nm and by fluorescence clusters 1, 2, 5, and 6 (peaked at 390 and 460 nm) when excited at 351 nm. Size- and time-dependent variations of the fluorescence spectra revealed some size and time evolution behavior of organic and biological aerosols from the atmosphere in Djibouti. Moreover, this analytical technique could locate the possible sources and chemical compositions contributing to these fluorescence clusters. Advantages, limitations, and

Direct on-strip analysis of size- and time-resolved aerosol impactor samples using laser induced fluorescence spectra excited at 263 and 351 nm

Energy Technology Data Exchange (ETDEWEB)

Wang, Chuji [U.S. Army Research Laboratory, Adelphi, MD 20783 (United States); Mississippi State University, Starkville, MS, 39759 (United States); Pan, Yong-Le, E-mail: yongle.pan.civ@mail.mil [U.S. Army Research Laboratory, Adelphi, MD 20783 (United States); James, Deryck; Wetmore, Alan E. [U.S. Army Research Laboratory, Adelphi, MD 20783 (United States); Redding, Brandon [Yale University, New Haven, CT 06510 (United States)

2014-04-01

Highlights: • A dual wavelength UV-LIF spectra-rotating drum impactor (RDI) technique was developed. • The technique was demonstrated by direct on-strip analysis of size- and time-resolved LIF spectra of atmospheric aerosol particles. • More than 2000 LIF spectra of atmospheric aerosol particles collected over three weeks in Djibouti were obtained and assigned to various fluorescence clusters. • The LIF spectra showed size- and time-sensitivity behavior with a time resolution of 3.6 h. - Abstract: We report a novel atmospheric aerosol characterization technique, in which dual wavelength UV laser induced fluorescence (LIF) spectrometry marries an eight-stage rotating drum impactor (RDI), namely UV-LIF-RDI, to achieve size- and time-resolved analysis of aerosol particles on-strip. The UV-LIF-RDI technique measured LIF spectra via direct laser beam illumination onto the particles that were impacted on a RDI strip with a spatial resolution of 1.2 mm, equivalent to an averaged time resolution in the aerosol sampling of 3.6 h. Excited by a 263 nm or 351 nm laser, more than 2000 LIF spectra within a 3-week aerosol collection time period were obtained from the eight individual RDI strips that collected particles in eight different sizes ranging from 0.09 to 10 μm in Djibouti. Based on the known fluorescence database from atmospheric aerosols in the US, the LIF spectra obtained from the Djibouti aerosol samples were found to be dominated by fluorescence clusters 2, 5, and 8 (peaked at 330, 370, and 475 nm) when excited at 263 nm and by fluorescence clusters 1, 2, 5, and 6 (peaked at 390 and 460 nm) when excited at 351 nm. Size- and time-dependent variations of the fluorescence spectra revealed some size and time evolution behavior of organic and biological aerosols from the atmosphere in Djibouti. Moreover, this analytical technique could locate the possible sources and chemical compositions contributing to these fluorescence clusters. Advantages, limitations, and

Laser based analytical spectroscopy of uranium

International Nuclear Information System (INIS)

Argekar, A.A.; Kulkarni, M.J.; Godbole, S.V.; Page, A.G.; Samuel, J.K.; Paranjape, D.B.; Singh Mudher, K.D.

1992-01-01

Analytical spectroscopy of uranium has been studied using a XeCl excimer laser, using the fluorescence emission of U(VI) ions doped in a solid solution of sodium fluoride (NaF) and sodium chloride (NaCl) in 3:2 proportion. An electronic circuitry involving time-gating of the photomultiplier tube and facility to integrate the analytical signal over ten laser pulses has been developed to enable laser operation and signal detection with high S/N ratio. The matrix enhanced U(VI) fluorescence emission is free from chemical and spectral interferences due to the concomitant presence of ten metallic elements generally associated with uranium. The digital signal output is highly precise and does not saturate upto 5 ppm uranium concentration. X-ray diffraction patterns obtained for uranium doped compounds at 2.5% and 10% dopant concentrations are broadly similar to that of Na 2 U 2 O 7 . The detailed studies have, however, revealed fine structure for individual peaks, thereby, revealing the formation of sodium fluoro-uranate complex which is responsible for the enhanced intensity of fluorescence emission. (author). 10 refs., 6 figs., 2 tabs

Fluorescence intensity dependence on the propagation plane inclination

International Nuclear Information System (INIS)

Fernandez, J.E.; Rubio, Marcelo; Sanchez, H.J.

1987-01-01

A theoretical study of the emission from layers of primary and secondary fluorescent components for a sample of infinite thickness was made, finding out that this emission depends mainly on the α angle as a maximum emission selector of a certain layer, which means 'tuning' the fluorescent radiation that comes primarily from a certain depth. These results can be applied to the study of both selective emission by layers and to the selection of superficial fluorescence. The analytical results have been confirmed by a Monte Carlo simulation. (Author) [es

Separation-oriented derivatization of native fluorescent compounds through fluorous labeling followed by liquid chromatography with fluorous-phase.

Science.gov (United States)

Sakaguchi, Yohei; Yoshida, Hideyuki; Todoroki, Kenichiro; Nohta, Hitoshi; Yamaguchi, Masatoshi

2009-06-15

We have developed a new and simple method based on "fluorous derivatization" for LC of native fluorescent compounds. This method involves the use of a column with a fluorous stationary phase. Native fluorescent analytes with target functional groups are precolumn derivatized with a nonfluorescent fluorous tag, and the fluorous-labeled analytes are retained in the column, whereas underivatized substances are not. Only the retained fluorescent analytes are detected fluorometrically at appropriate retention times, and retained substrates without fluorophores are not detected. In this study, biologically important carboxylic acids (homovanillic acid, vanillylmandelic acid, and 5-hydroxyindoleacetic acid) and drugs (naproxen, felbinac, flurbiprofen, and etodolac) were used as model native fluorescent compounds. Experimental results indicate that the fluorous-phase column can selectively retain fluorous compounds including fluorous-labeled analytes on the basis of fluorous separation. We believe that separation-oriented derivatization presented here is the first step toward the introduction of fluorous derivatization in quantitative LC analysis.

Heavy metals analysis in fishes by the X-ray fluorescence method

International Nuclear Information System (INIS)

Perez Novara, Ana Ma.

1986-04-01

Among the sources of contamination in human beings we find ingestion of heavy metals. As it is common practice to pour industrial wastes in waters where fishes feed, some toxic elements present in water may pass to human beings through ingestion. It is therefore important to determine the concentrations of heavy metals present in fishes, mainly in those living in waters close to industrial zones or villages. Concentrations of heavy metals in tissue of fishes amount to ppm, hence making necessary the use of very sensitive analytical techniques which do not require a too complex preparation of the sample in order to avoid the loss or contamination of interesting elements of analysis while handling them, thus falsifying the results. The X-Ray Fluorescence method covers these requirements and is not destructive nor multi-elemental. The development of the technique of element analysis in fishes by X-Ray Fluorescence comprised several aspects. from sampling and storage to quantification, specially stressing the preparation of samples. The work was carried out with a Si-Li detector/monitor for solid state and associated electronic equipment. Cd-109 and Pu-238 sources were used to produce excitation, detection limits near 1 ppm were obtained in the majority of elements the technique attained for the analysis of this kind of samples fulfills the celerity, precision, accuracy, and sensitivity requirements. (author)

Multispectral fluorescence imaging technique for discrimination of cucumber (Cucumis Sativus) seed viability

Science.gov (United States)

In this study, we developed a nondestructive method for discriminating viable cucumber (Cucumis sativus) seeds based on hyperspectral fluorescence imaging. The fluorescence spectra of cucumber seeds in the 420–700 nm range were extracted from hyperspectral fluorescence images obtained using 365 nm u...

Widefield fluorescence sectioning with HiLo microscopy.

Science.gov (United States)

Mertz, Jerome; Lim, Daryl; Chu, Kengyeh K; Bozinovic, Nenad; Ford, Timothy

2009-01-01

HiLo microscopy is a widefield fluorescence imaging technique that provides depth discrimination by combining two images, one with non-uniform illumination and one with uniform illumination. We discuss the theory of this technique and a variety of practical implementations in brain-tissue imaging and fluorescence endomicroscopy.

Thorium determination by X-ray Fluorescence Spectrometry in simulated thorex process solutions

International Nuclear Information System (INIS)

Yamaura, M.; Matsuda, H.T.

1989-01-01

The X-ray fluorescence method for thorium determination in aqueous and organic (TBP-n-dodecane) solutions is described. The thin film-technique for sample preparation and a suitable internal standard have been used. Some parameters as analytical line, internal standard, filter paper, paper geometry, sample volume and measurement conditions were studied. Uranium, fission products, corrosion products and thorex reagent components were studied as interfering elements in the thorium analysis, as well as the matrix effect by using the thorex process simulated solutions the method to thorium determination in irradiated thorium solutions was applied. (M.J.C.) [pt

A pirólise como técnica analítica Pyrolysis as an analytical technique

Directory of Open Access Journals (Sweden)

Flaviano Oliveira Silvério

2008-01-01

Full Text Available In this paper historical aspects of analytical pyrolysis, the equipment used, the fundamentals and the mechanisms of pyrolysis of different polymeric materials are discussed. The latest work on analytical pyrolysis applied to various types of synthetic and natural samples is reviewed. Current applications of this technique that are discussed include identification of microorganisms, analysis of trace compounds by forensic laboratories, investigation of food and agricultural products, study of the chemical composition of wood, authentication and conservation of artworks, and the study of environmental and geochemical samples.

A sole multi-analyte receptor responds with three distinct fluorescence signals: traffic signal like sensing of Al(3+), Zn(2+) and F(-).

Science.gov (United States)

Datta, Barun Kumar; Thiyagarajan, Durairaj; Ramesh, Aiyagari; Das, Gopal

2015-08-07

A dialdehyde-based multi-analyte sensor renders distinctive emission spectra for Al(3+), Zn(2+) and F(-) ions. The ligand exhibited different types of interactions with these three different ions resulting in the enhancement of fluorescence intensity at three different wavelengths. All the sensing processes were studied in detail by absorption spectroscopy, emission spectroscopy and (1)H-NMR titration experiment. The ligand has the working ability in a wide pH range including the physiological pH. The ligand is non-toxic and amicable for sensing intracellular Al(3+) and Zn(2+) in live HeLa cells.

Fluorescent standards for photodynamic therapy

Science.gov (United States)

Belko, N.; Kavalenka, S.; Samtsov, M.

2016-08-01

Photodynamic therapy is an evolving technique for treatment of various oncological diseases. This method employs photosensitizers - species that lead to death of tumor cells after the photoactivation. For further development and novel applications of photodynamic therapy new photosensitizers are required. After synthesis of a new photosensitizer it is important to know its concentration in different biological tissues after its administration and distribution. The concentration is frequently measured by the extraction method, which has some disadvantages, e.g. it requires many biological test subjects that are euthanized during the measurement. We propose to measure the photosensitizer concentration in tissue by its fluorescence. For this purpose fluorescent standards were developed. The standards are robust and simple to produce; their fluorescence signal does not change with time. The fluorescence intensity of fluorescent standards seems to depend linearly on the dye concentration. A set of standards thus allow the calibration of a spectrometer. Finally, the photosensitizer concentration can be determined by the fluorescence intensity after comparing the corresponding spectrum with spectra of the set of fluorescent standards. A biological test subject is not euthanized during this kind of experiment. We hope this more humane technique can be used in future instead of the extraction method.

Tracer-based laser-induced fluorescence measurement technique for quantitative fuel/air-ratio measurements in a hydrogen internal combustion engine.

Science.gov (United States)

Blotevogel, Thomas; Hartmann, Matthias; Rottengruber, Hermann; Leipertz, Alfred

2008-12-10

A measurement technique for the quantitative investigation of mixture formation processes in hydrogen internal combustion engines (ICEs) has been developed using tracer-based laser-induced fluorescence (TLIF). This technique can be employed to fired and motored engine operation. The quantitative TLIF fuel/air-ratio results have been verified by means of linear Raman scattering measurements. Exemplary results of the simultaneous investigation of mixture formation and combustion obtained at an optical accessible hydrogen ICE are shown.

Fluorescent microthermographic imaging

Energy Technology Data Exchange (ETDEWEB)

Barton, D.L.

1993-09-01

In the early days of microelectronics, design rules and feature sizes were large enough that sub-micron spatial resolution was not needed. Infrared or IR thermal techniques were available that calculated the object`s temperature from infrared emission. There is a fundamental spatial resolution limitation dependent on the wavelengths of light being used in the image formation process. As the integrated circuit feature sizes began to shrink toward the one micron level, the limitations imposed on IR thermal systems became more pronounced. Something else was needed to overcome this limitation. Liquid crystals have been used with great success, but they lack the temperature measurement capabilities of other techniques. The fluorescent microthermographic imaging technique (FMI) was developed to meet this need. This technique offers better than 0.01{degrees}C temperature resolution and is diffraction limited to 0.3 {mu}m spatial resolution. While the temperature resolution is comparable to that available on IR systems, the spatial resolution is much better. The FMI technique provides better spatial resolution by using a temperature dependent fluorescent film that emits light at 612 nm instead of the 1.5 {mu}m to 12 {mu}m range used by IR techniques. This tutorial starts with a review of blackbody radiation physics, the process by which all heated objects emit radiation to their surroundings, in order to understand the sources of information that are available to characterize an object`s surface temperature. The processes used in infrared thermal imaging are then detailed to point out the limitations of the technique but also to contrast it with the FMI process. The FMI technique is then described in detail, starting with the fluorescent film physics and ending with a series of examples of past applications of FMI.

Characterization of Zircaloy-2 and Zircaloy-4 by X-Ray fluorescence

International Nuclear Information System (INIS)

Sato, I.M.; Imakuma, K.; Salvador, V.L.R.

1981-03-01

The analytical characterization of zircaloy-2 and zircaloy-4 is intimataly connected with the determination of Sn, Fe, Cr, Ni, O, N, H, and Hf. An analytical method developed in this laboratory is discribed for the determination of metallic elements like Sn, Fe, Cr and Ni using the technique of X-ray fluorescence. The samples are prepared in the form of double-layer pellets using boric acid as a binding agent. The zircaloy-4 is dissolved in hydrofluoric acid and the metallic elements are converted to fluorides. The standard samples used for calibration are prepared from synthetic materials. The elements are determined by measuring the characteristic first order K α lines. A Zircaloy-4 sample analysed yielded the following values: Sn=1.30+-0.03%, Fe=0.18+-0.01%, Cr=0.088+-0.004% and Ni=14+-3 ppm. The reproducibility, precision, as well as the theoretical limit of detection of the method are discussed. The determination of the elements O, N and H present as occluded gas in the zircaloy is nearing completion. These analyses are being carried out by a Mass Spectrometric technique where an aliquot of the released gas is analysed. (Author) [pt

Phenotyping of Arabidopsis Drought Stress Response Using Kinetic Chlorophyll Fluorescence and Multicolor Fluorescence Imaging

Directory of Open Access Journals (Sweden)

Jieni Yao

2018-05-01

Full Text Available Plant responses to drought stress are complex due to various mechanisms of drought avoidance and tolerance to maintain growth. Traditional plant phenotyping methods are labor-intensive, time-consuming, and subjective. Plant phenotyping by integrating kinetic chlorophyll fluorescence with multicolor fluorescence imaging can acquire plant morphological, physiological, and pathological traits related to photosynthesis as well as its secondary metabolites, which will provide a new means to promote the progress of breeding for drought tolerant accessions and gain economic benefit for global agriculture production. Combination of kinetic chlorophyll fluorescence and multicolor fluorescence imaging proved to be efficient for the early detection of drought stress responses in the Arabidopsis ecotype Col-0 and one of its most affected mutants called reduced hyperosmolality-induced [Ca2+]i increase 1. Kinetic chlorophyll fluorescence curves were useful for understanding the drought tolerance mechanism of Arabidopsis. Conventional fluorescence parameters provided qualitative information related to drought stress responses in different genotypes, and the corresponding images showed spatial heterogeneities of drought stress responses within the leaf and the canopy levels. Fluorescence parameters selected by sequential forward selection presented high correlations with physiological traits but not morphological traits. The optimal fluorescence traits combined with the support vector machine resulted in good classification accuracies of 93.3 and 99.1% for classifying the control plants from the drought-stressed ones with 3 and 7 days treatments, respectively. The results demonstrated that the combination of kinetic chlorophyll fluorescence and multicolor fluorescence imaging with the machine learning technique was capable of providing comprehensive information of drought stress effects on the photosynthesis and the secondary metabolisms. It is a promising

Nuclear analytical techniques applied to characterization of atmospheric aerosols in Amazon Region

International Nuclear Information System (INIS)

Gerab, Fabio; Artaxo, Paulo

1996-01-01

This work presents the atmospheric aerosols characterization that exist in different regions of Amazon basin. The biogenic aerosol emission by forest, as well as the atmospheric emissions of particulate materials due to biomass burning, were analyzed. Samples of aerosol particles were collected during three years in two different locations of Amazon region using Stacked Unit Filters. In order to study these samples some analytical nuclear techniques were used. The high concentrations of aerosols as a result of biomass burning process were observed in the period of june-september

Spectroscopic studies of fluorescent complexes of tyrosine 8-hydroxyquinoline and tyrosine-8-hydroxyquinaldine in aqueous phase

International Nuclear Information System (INIS)

Jakhrani, M.A.; Kazi, T.G.

2002-01-01

A new method has been developed by preparing complexes involving condensation of tyrosine with 8-hydroxyquinoline (Oxine) and 8-hydroxyquinaldine (Quinaldine) respectively, producing fluorescent products. The products obtained have been investigated for identification and quantitative estimation using different spectroscopic techniques including fluorescence activity of newly synthesized products. 8-hydroxyquinaldine and 8-hydroxyquinoline (Oxine) condensed with tyrosine separately produced water soluble fluorescent complexes. The complexes have been investigated for identification and quantitative estimation of amino acids. Identification of amino acids in nano mole or below than nano mole has become possible by present fluorometric activity of these complexes involving different excitation and emission wavelengths. The fluorometric activity of complexes has been observed to be 100 to 1000 times higher than assay method involving ninhydrin and amino acid analyzer. The method adopted in our laboratory is rapid, versatile with good reproducibility and provides excellent results for adoption by analytical, agricultural and biomedical laboratories to estimate amino acids and metals in composite matrix. (author)

Worldwide proficiency test for X ray fluorescence laboratories PTXRFIAEA/05 determination of minor and trace elements in marine sediment

International Nuclear Information System (INIS)

2009-01-01

The proficiency test (code PTXRFIAEA05) was the fifth worldwide exercise organized by the IAEA Seibersdorf Laboratories in order to assist X ray fluorescence laboratories in assessment and improvement of their analytical performance. The test was carried out within the IAEA Project 1.4.3.4 (D.3.03) on Nuclear Spectrometry for Analytical Applications, under the Nuclear Science Programme. The main objective of the project was to enhance capability of interested Member States in effective utilization of nuclear spectrometries and analytical services in industry, human health, agriculture, and in monitoring and evaluation of environmental pollution. Marine sediment test samples with established homogeneity and well characterized known target values of the mass fractions of analytes were distributed to participating laboratories. The laboratories were requested to analyze the sample using established techniques following their analytical procedures. Based on the results of the proficiency test presented in the report each participating laboratory should assess its analytical performance results by using the specified criteria and, if appropriate, to identify discrepancies, and to correct relevant analytical procedures. The next proficiency test exercise will be executed in 2009

Laser-induced fluorescence imaging of bacteria

Science.gov (United States)

Hilton, Peter J.

1998-12-01

This paper outlines a method for optically detecting bacteria on various backgrounds, such as meat, by imaging their laser induced auto-fluorescence response. This method can potentially operate in real-time, which is many times faster than current bacterial detection methods, which require culturing of bacterial samples. This paper describes the imaging technique employed whereby a laser spot is scanned across an object while capturing, filtering, and digitizing the returned light. Preliminary results of the bacterial auto-fluorescence are reported and plans for future research are discussed. The results to date are encouraging with six of the eight bacterial strains investigated exhibiting auto-fluorescence when excited at 488 nm. Discrimination of these bacterial strains against red meat is shown and techniques for reducing background fluorescence discussed.

Analytical Techniques in the Pharmaceutical Sciences

DEFF Research Database (Denmark)

Leurs, Ulrike; Mistarz, Ulrik Hvid; Rand, Kasper Dyrberg

2016-01-01

Mass spectrometry (MS) offers the capability to identify, characterize and quantify a target molecule in a complex sample matrix and has developed into a premier analytical tool in drug development science. Through specific MS-based workflows including customized sample preparation, coupling...

Study of trace elements in milk by nuclear analytical techniques

Energy Technology Data Exchange (ETDEWEB)

Gharib, A.; Rahimi, H.; Peyrovan, H.; Raofei, H.N.J.; Taherpour, H. (Atomic Energy Organization of Iran, Teheran. Nuclear Research Centre)

This work is part of a project with the IAEA, in a coordinated programme on ''trace elements in Human Nutrition and Bio-Environmental Systems'' to evaluate their nutritional requirements, interrelations and the role of trace elements in health, metabolism etc. Cow's milk is regarded as one of the most important and nutritious foodstuffs consumed by people. Hence, as a first step, an elemental analysis for milk was carried out for this purpose so a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of this project was the assessment of various analytical techniques involved. However, in the present work, the methods involved were AAS, PIXE and NAA. The latter method applied, both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is however, some justification to clarify this internal inconsistency. The precision for NAA and AAS allows greater degree of acceptance respectively. Although PIXE is very fast and rather routine, the technique of trace element analysis needs certain adaptations and developments.

Characterization of sediments laid on Solimoes/Amazonas river flood plains, using energy dispersive X-ray fluorescence technique; Caracterizacao dos sedimentos depositados nas planicies de inundacao do Rio Solimoes/Amazonas, utilizando a tecnica de fluorescencia de raios-X por dispersao de energia

Energy Technology Data Exchange (ETDEWEB)

Carneiro, Ana E.V. [Universidade Metodista de Piracicaba (UNIMEP), Sao Paulo, SP (Brazil); Nascimento Filho, Virgilio F. do [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]|[Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

1997-10-01

This paper proposes sediment analysis with high light elements fraction using dispersive energy X-ray fluorescence technique with radioisotopic excitation, The proposed procedure is based on the Fundamental Parameters for analytical elements (Z {>=} 13) evaluation, and coherent and incoherent scattered radiation for quantification of the light fraction of the matrix (Z < 13). Laid sediments samples on Solimoes/Amazonas river flood plains were analyzed, determining simultaneously the Al, Si, K, Ca, Ti, Fe, Sc, V, Mn, Cu, Zn, Rb, Sr and Zr element concentrations, thus allowing chemical characterization and spatial variability, and some mineralogical and weathering sediments aspects. (author). 15 refs., 11 tabs.

Laser induced fluorescence of some plant leaves

International Nuclear Information System (INIS)

Helmi, M.S.; Mohamed, M.M.; Amer, R.; Elshazly, O.; Elraey, M.

1992-01-01

Laser induced fluorescence (LIF) is successfully used as a technique for remote detection of spectral characteristics of some plants. A pulsed nitrogen laser at 337.1 nm is used to excite cotton, corn and rice leaves. The fluorescence spectrum is detected in the range from 340 nm to 820 nm. It is found that, these plant leaves have common fluorescence maxima at 440 nm, 685 nm and 740 nm. plant leaves are also found to be identifiable by the ratio of the fluorescence intensity at 440 nm to that at 685 nm. The present technique can be further used as a means of assessing, remotely, plant stresses. 5 fig

Nuclear Resonance Fluorescence to Measure Plutonium Mass in Spent Nuclear Fuel

Energy Technology Data Exchange (ETDEWEB)

Ludewigt, Bernhard A; Quiter, Brian J.; Ambers, Scott D.

2011-01-14

The Next Generation Safeguard Initiative (NGSI) of the U.S Department of Energy is supporting a multi-lab/university collaboration to quantify the plutonium (Pu) mass in spent nuclear fuel (SNF) assemblies and to detect the diversion of pins with non-destructive assay (NDA) methods. The following 14 NDA techniques are being studied: Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Lead Slowing Down Spectrometer, Neutron Multiplicity, Passive Neutron Albedo Reactivity, Total Neutron (Gross Neutron), X-Ray Fluorescence, {sup 252}Cf Interrogation with Prompt Neutron Detection, Delayed Gamma, Nuclear Resonance Fluorescence, Passive Prompt Gamma, Self-integration Neutron Resonance Densitometry, and Neutron Resonance Transmission Analysis. Understanding and maturity of the techniques vary greatly, ranging from decades old, well-understood methods to new approaches. Nuclear Resonance Fluorescence (NRF) is a technique that had not previously been studied for SNF assay or similar applications. Since NRF generates isotope-specific signals, the promise and appeal of the technique lies in its potential to directly measure the amount of a specific isotope in an SNF assay target. The objectives of this study were to design and model suitable NRF measurement methods, to quantify capabilities and corresponding instrumentation requirements, and to evaluate prospects and the potential of NRF for SNF assay. The main challenge of the technique is to achieve the sensitivity and precision, i.e., to accumulate sufficient counting statistics, required for quantifying the mass of Pu isotopes in SNF assemblies. Systematic errors, considered a lesser problem for a direct measurement and only briefly discussed in this report, need to be evaluated for specific instrument designs in the future. Also, since the technical capability of using NRF to measure Pu in SNF has not been established, this report does not directly address issues such as cost, size

Measurement of resistance to solute transport across surfactant-laden interfaces using a Fluorescence Recovery After Photobleaching (FRAP) technique

Science.gov (United States)

Browne, Edward P.; Nivaggioli, Thierry; Hatton, T. Alan

1994-01-01

A noninvasive fluorescence recovery after photobleaching (FRAP) technique is under development to measure interfacial transport in two phase systems without disturbing the interface. The concentration profiles of a probe solute are measured in both sides of the interface by argon-ion laser, and the system relaxation is then monitored by a microscope-mounted CCD camera.

Fluorescent IgG fusion proteins made in E. coli

Science.gov (United States)

Luria, Yael; Raichlin, Dina; Benhar, Itai

2012-01-01

Antibodies are among the most powerful tools in biological and biomedical research and are presently the fastest growing category of new bio-pharmaceutics. The most common format of antibody applied for therapeutic, diagnostic and analytical purposes is the IgG format. For medical applications, recombinant IgGs are made in cultured mammalian cells in a process that is too expensive to be considered for producing antibodies for diagnostic and analytical purposes. Therefore, for such purposes, mouse monoclonal antibodies or polyclonal sera from immunized animals are used. While looking for an easier and more rapid way to prepare full-length IgGs for therapeutic purposes, we recently developed and reported an expression and purification protocol for full-length IgGs, and IgG-based fusion proteins in E. coli, called “Inclonals.” By applying the Inclonals technology, we could generate full-length IgGs that are genetically fused to toxins. The aim of the study described herein was to evaluate the possibility of applying the “Inclonals” technology for preparing IgG-fluorophore fusion proteins. We found that IgG fused to the green fluorescent proteins enhanced GFP (EGFP) while maintaining functionality in binding, lost most of its fluorescence during the refolding process. In contrast, we found that green fluorescent Superfolder GFP (SFGFP)-fused IgG and red fluorescent mCherry-fused IgG were functional in antigen binding and maintained fluorescence intensity. In addition, we found that we can link several SFGFPs in tandem to each IgG, with fluorescence intensity increasing accordingly. Fluorescent IgGs made in E. coli may become attractive alternatives to monoclonal or polyclonal fluorescent antibodies derived from animals. PMID:22531449

Ultra-small dye-doped silica nanoparticles via modified sol-gel technique

Science.gov (United States)

Riccò, R.; Nizzero, S.; Penna, E.; Meneghello, A.; Cretaio, E.; Enrichi, F.

2018-05-01

In modern biosensing and imaging, fluorescence-based methods constitute the most diffused approach to achieve optimal detection of analytes, both in solution and on the single-particle level. Despite the huge progresses made in recent decades in the development of plasmonic biosensors and label-free sensing techniques, fluorescent molecules remain the most commonly used contrast agents to date for commercial imaging and detection methods. However, they exhibit low stability, can be difficult to functionalise, and often result in a low signal-to-noise ratio. Thus, embedding fluorescent probes into robust and bio-compatible materials, such as silica nanoparticles, can substantially enhance the detection limit and dramatically increase the sensitivity. In this work, ultra-small fluorescent silica nanoparticles (NPs) for optical biosensing applications were doped with a fluorescent dye, using simple water-based sol-gel approaches based on the classical Stöber procedure. By systematically modulating reaction parameters, controllable size tuning of particle diameters as low as 10 nm was achieved. Particles morphology and optical response were evaluated showing a possible single-molecule behaviour, without employing microemulsion methods to achieve similar results. [Figure not available: see fulltext.

Quantitative and qualitative sensing techniques for biogenic volatile organic compounds and their oxidation products.

Science.gov (United States)

Kim, Saewung; Guenther, Alex; Apel, Eric

2013-07-01

The physiological production mechanisms of some of the organics in plants, commonly known as biogenic volatile organic compounds (BVOCs), have been known for more than a century. Some BVOCs are emitted to the atmosphere and play a significant role in tropospheric photochemistry especially in ozone and secondary organic aerosol (SOA) productions as a result of interplays between BVOCs and atmospheric radicals such as hydroxyl radical (OH), ozone (O3) and NOX (NO + NO2). These findings have been drawn from comprehensive analysis of numerous field and laboratory studies that have characterized the ambient distribution of BVOCs and their oxidation products, and reaction kinetics between BVOCs and atmospheric oxidants. These investigations are limited by the capacity for identifying and quantifying these compounds. This review highlights the major analytical techniques that have been used to observe BVOCs and their oxidation products such as gas chromatography, mass spectrometry with hard and soft ionization methods, and optical techniques from laser induced fluorescence (LIF) to remote sensing. In addition, we discuss how new analytical techniques can advance our understanding of BVOC photochemical processes. The principles, advantages, and drawbacks of the analytical techniques are discussed along with specific examples of how the techniques were applied in field and laboratory measurements. Since a number of thorough review papers for each specific analytical technique are available, readers are referred to these publications rather than providing thorough descriptions of each technique. Therefore, the aim of this review is for readers to grasp the advantages and disadvantages of various sensing techniques for BVOCs and their oxidation products and to provide guidance for choosing the optimal technique for a specific research task.

Fluorescence diagnosis of pre-tumor and tumor pathology of endometrium

Directory of Open Access Journals (Sweden)

E. V. Filonenko

2014-01-01

Full Text Available The technique of fluorescence hysteroscopy with Alasens includes visual assessment of fluorescence of Alasens-induced protoporphyrin IX and local fluorescence spectroscopy. The technique allows to improve the efficacy of early diagnosis for endometrial pathology including early endometrial cancer, to assess definitely an extent of pre-tumor and tumor process. The sensitivity of fluorescence hysteroscopy accounts for 100%, the specificity – 98%. 

DIRECT AND INDIRECT FLUORESCENT-ANTIBODY TECHNIQUES FOR THE PSITTACOSIS-LYMPHOGRANULOMA VENEREUM-TRACHOMA GROUP OF AGENTS1

Science.gov (United States)

Ross, Martin R.; Borman, Earle K.

1963-01-01

Ross, Martin R. (Connecticut State Department of Health, Hartford) and Earle K. Borman. Direct and indirect fluorescent-antibody techniques for the psittacosis-lymphogranuloma venereum-trachoma group of agents. J. Bacteriol. 85:851–858. 1963.—Direct and indirect fluorescent-antibody (FA) techniques were developed for the detection of group antigen in infected tissue cultures and the titration of group antibody in human antiserum. The growth of the agent of meningopneumonitis (MP) in mouse embryo lung cell monolayers was followed by infectivity and complement-fixing (CF) antigen titrations, and cytological examination of FA stained cultures. Although infectivity and CF antigen reached a peak at 2 days and remained constant for an additional 3 days, only cells tested 2 to 3 days after infection were suitable for FA staining with labeled anti-MP serum because of excessive artifacts in the older cultures. Fluorescein isothiocyanate-labeled rooster and guinea pig anti-MP serums and human antipsittacosis serums were titrated in direct FA and hemagglutination-inhibition (HI) tests. The rooster conjugate showed brighter staining and higher antibody titers than the guinea pig or human conjugates and was more effective in detecting minimal amounts of virus antigen. FA staining reactions with 1 and 2 units of labeled rooster serum were inhibited by unlabeled rooster serum but clear-cut inhibition with human antipsittacosis serum could not be demonstrated. The indirect FA technique was successfully used for the titration of group antibody in human serum. A comparison of the indirect FA, HI, and CF tests showed the indirect FA technique to be intermediate in sensitivity between the HI and CF tests. None of the three tests showed significant cross reactions with human serums reactive for influenza A and B; parainfluenza 1, 2, and 3; respiratory syncytial virus; Q fever; or the primary atypical pneumonia agent. PMID:14044954

Feasibility of UV-VIS-Fluorescence spectroscopy combined with pattern recognition techniques to authenticate a new category of plant food supplements.

Science.gov (United States)

Boggia, Raffaella; Turrini, Federica; Anselmo, Marco; Zunin, Paola; Donno, Dario; Beccaro, Gabriele L

2017-07-01

Bud extracts, named also "gemmoderivatives", are a new category of natural products, obtained macerating meristematic fresh tissues of trees and plants. In the European Community these botanical remedies are classified as plant food supplements. Nowadays these products are still poorly studied, even if they are widely used and commercialized. Several analytical tools for the quality control of these very expensive supplements are urgently needed in order to avoid mislabelling and frauds. In fact, besides the usual quality controls common to the other botanical dietary supplements, these extracts should be checked in order to quickly detect if the cheaper adult parts of the plants are deceptively used in place of the corresponding buds whose harvest-period and production are extremely limited. This study aims to provide a screening analytical method based on UV-VIS-Fluorescence spectroscopy coupled to multivariate analysis for a rapid, inexpensive and non-destructive quality control of these products.

Quantitative microanalysis of hafnium - zirconium system by X-ray fluorescence

International Nuclear Information System (INIS)

Majid, C.A.; Hussain, M.A.; Saeed, K.

1986-01-01

X-ray fluorescence technique has been used for the analysis of Hf in the presence of Zr by developing a method. In this method the spectral interference of Hf lines by Zr is eliminated completely and the Hf detection is accomplished using the most efficient Li line of its L-series. The principle of the method is based on the extinction properties of crystals for some orders of reflection. Ge(III) is used as the analyzing crystal. This method can be used accurately to detect Hf in any concentration of Zr at least from about 20 ppm to 100%. Also no information about the expected range of the analyte sample, is required in advance. (authors)

Critical Assessment of Analytical Techniques in the Search for Biomarkers on Mars: A Mummified Microbial Mat from Antarctica as a Best-Case Scenario

Science.gov (United States)

Blanco, Yolanda; Gallardo-Carreño, Ignacio; Ruiz-Bermejo, Marta; Puente-Sánchez, Fernando; Cavalcante-Silva, Erika; Quesada, Antonio; Prieto-Ballesteros, Olga; Parro, Víctor

2017-10-01

The search for biomarkers of present or past life is one of the major challenges for in situ planetary exploration. Multiple constraints limit the performance and sensitivity of remote in situ instrumentation. In addition, the structure, chemical, and mineralogical composition of the sample may complicate the analysis and interpretation of the results. The aim of this work is to highlight the main constraints, performance, and complementarity of several techniques that have already been implemented or are planned to be implemented on Mars for detection of organic and molecular biomarkers on a best-case sample scenario. We analyzed a 1000-year-old desiccated and mummified microbial mat from Antarctica by Raman and IR (infrared) spectroscopies (near- and mid-IR), thermogravimetry (TG), differential thermal analysis, mass spectrometry (MS), and immunological detection with a life detector chip. In spite of the high organic content (ca. 20% wt/wt) of the sample, the Raman spectra only showed the characteristic spectral peaks of the remaining beta-carotene biomarker and faint peaks of phyllosilicates over a strong fluorescence background. IR spectra complemented the mineralogical information from Raman spectra and showed the main molecular vibrations of the humic acid functional groups. The TG-MS system showed the release of several volatile compounds attributed to biopolymers. An antibody microarray for detecting cyanobacteria (CYANOCHIP) detected biomarkers from Chroococcales, Nostocales, and Oscillatoriales orders. The results highlight limitations of each technique and suggest the necessity of complementary approaches in the search for biomarkers because some analytical techniques might be impaired by sample composition, presentation, or processing.

Azadioxatriangulenium: exploring the effect of a 20 ns fluorescence lifetime in fluorescence anisotropy measurements

Science.gov (United States)

Bogh, Sidsel A.; Bora, Ilkay; Rosenberg, Martin; Thyrhaug, Erling; Laursen, Bo W.; Just Sørensen, Thomas

2015-12-01

Azaoxatriangulenium (ADOTA) has been shown to be highly emissive despite a moderate molar absorption coefficient of the primary electronic transition. As a result, the fluorescence lifetime is ~20 ns, longer than all commonly used red fluorescent organic probes. The electronic transitions in ADOTA are highly polarised (r 0  =  0.38), which in combination with the long fluorescence lifetime extents the size-range of biomolecular weights that can be detected in fluorescence polarisation-based experiments. Here, the rotational dynamics of bovine serum albumin (BSA) are monitored with three different ADOTA derivatives, differing only in constitution of the reactive linker. A detailed study of the degree of labelling, the steady-state anisotropy, and the time-resolved anisotropy of the three different ADOTA-BSA conjugates are reported. The fluorescence quantum yields (ϕ fl) of the free dyes in PBS solution are determined to be ~55%, which is reduced to ~20% in the ADOTA-BSA conjugates. Despite the reduction in ϕ fl, a ~20 ns intensity averaged lifetime is maintained, allowing for the rotational dynamics of BSA to be monitored for up to 100 ns. Thus, ADOTA can be used in fluorescence polarisation assays to fill the gap between commonly used organic dyes and the long luminescence lifetime transition metal complexes. This allows for efficient steady-state fluorescence polarisation assays for detecting binding of analytes with molecular weights of up to 100 kDa.

Whole-slide imaging is a robust alternative to traditional fluorescent microscopy for fluorescence in situ hybridization imaging using break-apart DNA probes.

Science.gov (United States)

Laurent, Camille; Guérin, Maxime; Frenois, François-Xavier; Thuries, Valérie; Jalabert, Laurence; Brousset, Pierre; Valmary-Degano, Séverine

2013-08-01

Fluorescence in situ hybridization is an indispensable technique used in routine pathology and for theranostic purposes. Because fluorescence in situ hybridization techniques require sophisticated microscopic workstations and long procedures of image acquisition with sometimes subjective and poorly reproducible results, we decided to test a whole-slide imaging system as an alternative approach. In this study, we used the latest generation of Pannoramic 250 Flash digital microscopes (P250 Flash digital microscopes; 3DHISTECH, Budapest, Hungary) to digitize fluorescence in situ hybridization slides of diffuse large B cells lymphoma cases for detecting MYC rearrangement. The P250 Flash digital microscope was found to be precise with better definition of split signals in cells containing MYC rearrangement with fewer truncated signals as compared to traditional fluorescence microscopy. This digital technique is easier thanks to the preview function, which allows almost immediate identification of the tumor area, and the panning and zooming functionalities as well as a shorter acquisition time. Moreover, fluorescence in situ hybridization analyses using the digital technique appeared to be more reproducible between pathologists. Finally, the digital technique also allowed prolonged conservation of photos. In conclusion, whole-slide imaging technologies represent rapid, robust, and highly sensitive methods for interpreting fluorescence in situ hybridization slides with break-apart probes. In addition, these techniques offer an easier way to interpret the signals and allow definitive storage of the images for pathology expert networks or e-learning databases. Copyright © 2013 Elsevier Inc. All rights reserved.

Proximal Sensing of Plant-Pathogen Interactions in Spring Barley with Three Fluorescence Techniques

Directory of Open Access Journals (Sweden)

Georg Leufen

2014-06-01

Full Text Available In the last years fluorescence spectroscopy has come to be viewed as an essential approach in key research fields of applied plant sciences. However, the quantity and particularly the quality of information produced by different equipment might vary considerably. In this study we investigate the potential of three optical devices for the proximal sensing of plant-pathogen interactions in four genotypes of spring barley. For this purpose, the fluorescence lifetime, the image-resolved multispectral fluorescence and selected indices of a portable multiparametric fluorescence device were recorded at 3, 6, and 9 days after inoculation (dai from healthy leaves as well as from leaves inoculated with powdery mildew (Blumeria graminis or leaf rust (Puccinia hordei. Genotype-specific responses to pathogen infections were revealed already at 3 dai by higher fluorescence mean lifetimes in the spectral range from 410 to 560 nm in the less susceptible varieties. Noticeable pathogen-induced modifications were also revealed by the ‘Blue-to-Far-Red Fluorescence Ratio’ and the ‘Simple Fluorescence Ratio’. Particularly in the susceptible varieties the differences became more evident in the time-course of the experiment i.e., following the pathogen development. The relevance of the blue and green fluorescence to exploit the plant-pathogen interaction was demonstrated by the multispectral fluorescence imaging system. As shown, mildewed leaves were characterized by exceptionally high blue fluorescence, contrasting the values observed in rust inoculated leaves. Further, we confirm that the intensity of green fluorescence depends on the pathogen infection and the stage of disease development; this information might allow a differentiation of both diseases. Moreover, our results demonstrate that the detection area might influence the quality of the information, although it had a minor impact only in the current study. Finally, we highlight the relevance of

A fluorescence scanning electron microscope

International Nuclear Information System (INIS)

Kanemaru, Takaaki; Hirata, Kazuho; Takasu, Shin-ichi; Isobe, Shin-ichiro; Mizuki, Keiji; Mataka, Shuntaro; Nakamura, Kei-ichiro

2009-01-01

Fluorescence techniques are widely used in biological research to examine molecular localization, while electron microscopy can provide unique ultrastructural information. To date, correlative images from both fluorescence and electron microscopy have been obtained separately using two different instruments, i.e. a fluorescence microscope (FM) and an electron microscope (EM). In the current study, a scanning electron microscope (SEM) (JEOL JXA8600 M) was combined with a fluorescence digital camera microscope unit and this hybrid instrument was named a fluorescence SEM (FL-SEM). In the labeling of FL-SEM samples, both Fluolid, which is an organic EL dye, and Alexa Fluor, were employed. We successfully demonstrated that the FL-SEM is a simple and practical tool for correlative fluorescence and electron microscopy.

Assessing Photosynthesis by Fluorescence Imaging

Science.gov (United States)

Saura, Pedro; Quiles, Maria Jose

2011-01-01

This practical paper describes a novel fluorescence imaging experiment to study the three processes of photochemistry, fluorescence and thermal energy dissipation, which compete during the dissipation of excitation energy in photosynthesis. The technique represents a non-invasive tool for revealing and understanding the spatial heterogeneity in…

Characterisation of Inorganic Pigments Used by Selected Painters by Using Ion Microprobe and Other Complementary Techniques

International Nuclear Information System (INIS)

Fazinic, S.; Pastuovic, Z.; Jaksic, M.; Kusijanovic, K.; Mudronja, D.; Braun, M.; Desnica, V.

2011-01-01

The aim of the presentation is to show results of the collaboration between the Croatian Conservation Institute (CCI) and the Laboratory for Ion Beam Interactions of the Rudjer Boskovic Institute (RBI) established within the present CRP. CCI is the central Croatian institution for conservation and restoration of cultural heritage objects. Prior to restoration/conservation CCI performs scientific analysis of an object, primarily to enable selection of the best strategy for its restoration/conservation. In many occasions such analysis is also helpful to resolve issues such as clarification of authenticity and/or authorship of an object. CCI has its analytical laboratory which is fully dedicated to the analysis of cultural heritage and art objects. CCI analytical laboratory is equipped with various microscopy techniques, photography methods, portable X-ray Fluorescence Spectrometer (XRF) and X-ray radiography instrumentation. Access to complementary microanalytical techniques like Raman Spectroscopy or Ion Beam Analytical (IBA) techniques is provided through already long and successful collaboration with RBI. The RBI Laboratory for Ion Beam Interactions provides complementary analysis of layered microsamples by using IBA techniques, such as Particle Induced X-ray Emission (PIXE) and Rutherford Back-scattering (RBS), and for the miniature samples by using ion microprobe. (author)

Radiography and X-ray fluorescence used to analyze cultural and artistic artifacts

International Nuclear Information System (INIS)

Rizzutto, Marcia A.; Kajiya, Elizabeth M.; Campos, Pedro H.O.V. de; Almeida, Paula A.D.

2013-01-01

Since 2003 the analyses of artistic and cultural heritage objects at LAMFI-USP (Laboratorio de Analises de Materiais com Feixes Ionicos), initially restricted to ion beam methods, are growing steadily. Since then, alternative methodologies and procedures have been incorporated to better characterize these objects, which possess distinct physical characteristics and also high cultural and monetary value. The examinations in this kind of objects were expanded to other non-destructive analytical techniques like portable EDXRF (Energy Dispersive X-ray Fluorescence) analysis, X-ray radiography, visible photography, UV (ultraviolet) and IR (infrared) light imaging that are helping to better understand these art objects, particularly paintings. These techniques are helping the analyses of the conservation state of the objects and also revealing characteristics of the painter such as underlying drawings, which help understand the creative process of the artist. These new procedures of analysis are aimed to enable better analytic research in archaeology and artistic and cultural heritage objects and to provide results that subsidize authentic investigations of art objects as well as the origin of archaeological artifacts, while stimulating archeometry and 'arteometry' research in Brazilian Museums. (author)

Radiography and X-ray fluorescence used to analyze cultural and artistic artifacts

Energy Technology Data Exchange (ETDEWEB)

Rizzutto, Marcia A.; Kajiya, Elizabeth M.; Campos, Pedro H.O.V. de; Almeida, Paula A.D., E-mail: rizzutto@if.usp.br, E-mail: elizabethkajiya@gmail.com [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil)

2013-07-01

Since 2003 the analyses of artistic and cultural heritage objects at LAMFI-USP (Laboratorio de Analises de Materiais com Feixes Ionicos), initially restricted to ion beam methods, are growing steadily. Since then, alternative methodologies and procedures have been incorporated to better characterize these objects, which possess distinct physical characteristics and also high cultural and monetary value. The examinations in this kind of objects were expanded to other non-destructive analytical techniques like portable EDXRF (Energy Dispersive X-ray Fluorescence) analysis, X-ray radiography, visible photography, UV (ultraviolet) and IR (infrared) light imaging that are helping to better understand these art objects, particularly paintings. These techniques are helping the analyses of the conservation state of the objects and also revealing characteristics of the painter such as underlying drawings, which help understand the creative process of the artist. These new procedures of analysis are aimed to enable better analytic research in archaeology and artistic and cultural heritage objects and to provide results that subsidize authentic investigations of art objects as well as the origin of archaeological artifacts, while stimulating archeometry and 'arteometry' research in Brazilian Museums. (author)

Efficient fluorescence energy transfer system between CdTe-doped silica nanoparticles and gold nanoparticles for turn-on fluorescence detection of melamine.

Science.gov (United States)

Gao, Feng; Ye, Qingqing; Cui, Peng; Zhang, Lu

2012-05-09

We here report an efficient and enhanced fluorescence energy transfer system between confined quantum dots (QDs) by entrapping CdTe into the mesoporous silica shell (CdTe@SiO₂) as donors and gold nanoparticles (AuNPs) as acceptors. At pH 6.50, the CdTe@SiO₂-AuNPs assemblies coalesce to form larger clusters due to charge neutralization, leading to the fluorescence quenching of CdTe@SiO₂ as a result of energy transfer. As compared with the energy transfer system between unconfined CdTe and AuNPs, the maximum fluorescence quenching efficiency of the proposed system is improved by about 27.0%, and the quenching constant, K(sv), is increased by about 2.4-fold. The enhanced quenching effect largely turns off the fluorescence of CdTe@SiO₂ and provides an optimal "off-state" for sensitive "turn-on" assay. In the present study, upon addition of melamine, the weak fluorescence system of CdTe@SiO₂-AuNPs is enhanced due to the strong interactions between the amino group of melamine and the gold nanoparticles via covalent bond, leading to the release of AuNPs from the surfaces of CdTe@SiO₂; thus, its fluorescence is restored. A "turn-on" fluorimetric method for the detection of melamine is proposed based on the restored fluorescence of the system. Under the optimal conditions, the fluorescence enhanced efficiency shows a linear function against the melamine concentrations ranging from 7.5 × 10⁻⁹ to 3.5 × 10⁻⁷ M (i.e., 1.0-44 ppb). The analytical sensitivity is improved by about 50%, and the detection limit is decreased by 5.0-fold, as compared with the analytical results using the CdTe-AuNPs system. Moreover, the proposed method was successfully applied to the determination of melamine in real samples with excellent recoveries in the range from 97.4 to 104.1%. Such a fluorescence energy transfer system between confined QDs and AuNPs may pave a new way for designing chemo/biosensing.

The study of trace elements in milk by nuclear analytical techniques

International Nuclear Information System (INIS)

Gharib, A.; Rahimi, H.; Peyrovan, H.; Raofei, H.N.J.; Taherpour, H.

1983-01-01

This work is part of a project with the IAEA, in a coordinated programme on ''Trace Elements in Human Nutrition and Bio-Environmental Systems'' to evaluate their nutritional requirements, interrelations and the role of Trace Elements in health, metabolism etc. Cow's milk being regarded as one of the most important and nutritious foodstuffs consumed by people. Hence as a first step, an elemental analysis for milk was carried out for this purpose so a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of this project was the assessment of various analytical techniques involved. However, in the present work, the methods involved were AAS, PIXE and NAA. The latter method applied, both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is however, some justification to clarify this internal inconsistency. The precision for NAA and AAS allows greater degree of acceptance respectively. Although PIXE is a very fast and rather a routine but the technique of trace element analysis needs certain adaptations and developments

Analysis of Indium Tin Oxide Film Using Argon Fluroide (ArF) Laser-Excited Atomic Fluorescence of Ablated Plumes.

Science.gov (United States)

Ho, Sut Kam; Garcia, Dario Machado

2017-04-01

A two-pulse laser-excited atomic fluorescence (LEAF) technique at 193 nm wavelength was applied to the analysis of indium tin oxide (ITO) layer on polyethylene terephthalate (PET) film. Fluorescence emissions from analytes were induced from plumes generated by first laser pulse. Using this approach, non-selective LEAF can be accomplished for simultaneous multi-element analysis and it overcomes the handicap of strict requirement for laser excitation wavelength. In this study, experimental conditions including laser fluences, times for gating and time delay between pulses were optimized to reveal high sensitivity with minimal sample destruction and penetration. With weak laser fluences of 100 and 125 mJ/cm 2 for 355 and 193 nm pulses, detection limits were estimated to be 0.10% and 0.43% for Sn and In, respectively. In addition, the relation between fluorescence emissions and number of laser shots was investigated; reproducible results were obtained for Sn and In. It shows the feasibility of depth profiling by this technique. Morphologies of samples were characterized at various laser fluences and number of shots to examine the accurate penetration. Images of craters were also investigated using scanning electron microscopy (SEM). The results demonstrate the imperceptible destructiveness of film after laser shot. With such weak laser fluences and minimal destructiveness, this LEAF technique is suitable for thin-film analysis.

Metallation of protoporphyrins used as fluorescent chemo sensor for imidazole recognition

International Nuclear Information System (INIS)

Panpae, Kornvalai; Krikrutthee, Chaiwat; Porntaweethum, Phumthan; Weerachiwcharnchai, Panya; Chenwittayayos, Aekapoj

2008-01-01

Metalloporphyrin Complexes play significant roles in many biological and catalytic systems. The diversity of their functions is due in part to the variety of metals that bind in the pocket of the porphyrin ring system. Two kinds of metalloporphyrin derivatives, Cu (II) and Zn (II) protoporphyrins (PP) were microscale synthesized and characterized by spectroscopic methods and magnetic measurements. A PP ligand bound to each metal center in a tetradentate fashion including four amine nitrogen atoms in the equatorial planes. These complexes were found to recognize imidazolyl groups of histidine and histamine derivatives as guest molecules by coordination and additional non-covalent interactions. These added analytes displace the selective fluorescent indicator, which when released to the solution displays its full fluorescence. Thus, analyte recognition is signaled by the sharp appearance of the fluorescence of the indicators. The binding affinities to histidine and histamine were investigated and accounted for different complexation properties. Moreover, we demonstrated that careful choice of a fluorescent indicator with tuned affinity toward the receptor can provide discrimination in sensing of a desired substrate and the role that the metal coordination plays on the hypochromic shift and loss of fluorescence distincted characteristics of hypsoporphyrins were also discussed. (author)

Hazardous Waste Landfill Siting using GIS Technique and Analytical Hierarchy Process

Directory of Open Access Journals (Sweden)

Ozeair Abessi

2010-07-01

Full Text Available Disposal of large amount of generated hazardous waste in power plants, has always received communities' and authori¬ties attentions. In this paper using site screening method and Analytical Hierarchy Process (AHP a sophisticated approach for siting hazardous waste landfill in large areas is presented. This approach demonstrates how the evaluation criteria such as physical, socio-economical, technical, environmental and their regulatory sub criteria can be introduced into an over layer technique to screen some limited appropriate zones in the area. Then, in order to find the optimal site amongst the primary screened site utilizing a Multiple Criteria Decision Making (MCDM method for hierarchy computations of the process is recommended. Using the introduced method an accurate siting procedure for environmental planning of the landfills in an area would be enabled. In the study this approach was utilized for disposal of hazardous wastes of Shahid Rajaee thermal power plant located in Qazvin province west central part of Iran. As a result of this study 10 suitable zones were screened in the area at first, then using analytical hierarchy process a site near the power plant were chosen as the optimal site for landfilling of the hazardous wastes in Qazvin province.

Twelfth ISAS national symposium on analytical techniques for safety and sufficiency of natural resources/products: technical papers

International Nuclear Information System (INIS)

Padmanabhan, P.K.; Page, A.G.

1997-02-01

This volume contains the proceedings of the ISAS (Indian Society of Analytical Scientists) national symposium. The main thrust of the symposium was on new fuel cycle technologies relevant to thorium utilisation programmes. The technologies for different separation processes, techniques for measurements of various process parameters and highly sensitive analytical methods for the determination of the chemical constituents were among the other topics covered. Quality upgradation, standardisation of methods and validation of measurements which are integral parts of product evaluation were also discussed. Papers relevant to INIS are indexed separately

Analytic chemistry of molybdenum

International Nuclear Information System (INIS)

Parker, G.A.

1983-01-01

Electrochemical, colorimetric, gravimetric, spectroscopic, and radiochemical methods for the determination of molybdenum are summarized in this book. Some laboratory procedures are described in detail while literature citations are given for others. The reader is also referred to older comprehensive reviews of the analytical chemistry of molybdenum. Contents, abridged: Gravimetric methods. Titrimetric methods. Colorimetric methods. X-ray fluorescence. Voltammetry. Catalytic methods. Molybdenum in non-ferrous alloys. Molydbenum compounds

Is Chemically Synthesized Graphene ‘Really’ a Unique Substrate for SERS and Fluorescence Quenching?

Science.gov (United States)

Sil, Sanchita; Kuhar, Nikki; Acharya, Somnath; Umapathy, Siva

2013-11-01

We demonstrate observation of Raman signals of different analytes adsorbed on carbonaceous materials, such as, chemically reduced graphene, graphene oxide (GO), multi-walled carbon nanotube (MWCNT), graphite and activated carbon. The analytes selected for the study were Rhodamine 6G (R6G) (in resonant conditions), Rhodamine B (RB), Nile blue (NBA), Crystal Violet (CV) and acetaminophen (paracetamol). All the analytes except paracetamol absorb and fluoresce in the visible region. In this article we provide experimental evidence of the fact that observation of Raman signals of analytes on such carbonaceous materials are more due to resonance effect, suppression of fluorescence and efficient adsorption and that this property in not unique to graphene or nanotubes but prevalent for various type of carbon materials.

Is Chemically Synthesized Graphene ‘Really’ a Unique Substrate for SERS and Fluorescence Quenching?

Science.gov (United States)

Sil, Sanchita; Kuhar, Nikki; Acharya, Somnath; Umapathy, Siva

2013-01-01

We demonstrate observation of Raman signals of different analytes adsorbed on carbonaceous materials, such as, chemically reduced graphene, graphene oxide (GO), multi-walled carbon nanotube (MWCNT), graphite and activated carbon. The analytes selected for the study were Rhodamine 6G (R6G) (in resonant conditions), Rhodamine B (RB), Nile blue (NBA), Crystal Violet (CV) and acetaminophen (paracetamol). All the analytes except paracetamol absorb and fluoresce in the visible region. In this article we provide experimental evidence of the fact that observation of Raman signals of analytes on such carbonaceous materials are more due to resonance effect, suppression of fluorescence and efficient adsorption and that this property in not unique to graphene or nanotubes but prevalent for various type of carbon materials. PMID:24275718

Does leaf chemistry differentially affect breakdown in tropical vs temperate streams? Importance of standardized analytical techniques to measure leaf chemistry

Science.gov (United States)

Marcelo Ard& #243; n; Catherine M. Pringle; Susan L. Eggert

2009-01-01

Comparisons of the effects of leaf litter chemistry on leaf breakdown rates in tropical vs temperate streams are hindered by incompatibility among studies and across sites of analytical methods used to measure leaf chemistry. We used standardized analytical techniques to measure chemistry and breakdown rate of leaves from common riparian tree species at 2 sites, 1...

Demonstration of lipofuscin and Nissl bodies in crystal violet stained sections using a fluorescence technique or pyronin Y stain.

Science.gov (United States)

Terr, L I

1986-09-01

This paper presents two simple, reliable methods for identification of lipofuscin and Nissl bodies in the same section. One method shows that lipofuscin stained with crystal violet retains its ability to fluoresce and can be observed under the fluorescence microscope after the stain has faded. Fading is accompanied by a gradual increase in the intensity of the fluorescence and is complete in about 5 min. Exciting illumination from this part of the spectrum also substantially fades staining of other autofluorescing tissue elements, such as lipids. Nonfluorescing structures, such as Nissl bodies, remain stained. By changing from transillumination with tungsten light to epifluorescent illumination and vice versa, both types of structures--Nissl bodies and lipofuscin--can be identified in the same section. The second technique uses pyronin Y for staining Nissl bodies in preparations previously stained with crystal violet. Nissl bodies are stained pink but lipofuscin remains violet. Lipofuscin in these sections also remains autofluorescent after the crystal violet stain has faded under violet or near-UV light.

Numerical evaluation of droplet sizing based on the ratio of fluorescent and scattered light intensities (LIF/Mie technique)

International Nuclear Information System (INIS)

Charalampous, Georgios; Hardalupas, Yannis

2011-01-01

The dependence of fluorescent and scattered light intensities from spherical droplets on droplet diameter was evaluated using Mie theory. The emphasis is on the evaluation of droplet sizing, based on the ratio of laser-induced fluorescence and scattered light intensities (LIF/Mie technique). A parametric study is presented, which includes the effects of scattering angle, the real part of the refractive index and the dye concentration in the liquid (determining the imaginary part of the refractive index). The assumption that the fluorescent and scattered light intensities are proportional to the volume and surface area of the droplets for accurate sizing measurements is not generally valid. More accurate sizing measurements can be performed with minimal dye concentration in the liquid and by collecting light at a scattering angle of 60 deg. rather than the commonly used angle of 90 deg. Unfavorable to the sizing accuracy are oscillations of the scattered light intensity with droplet diameter that are profound at the sidescatter direction (90 deg.) and for droplets with refractive indices around 1.4.

Pedestrian-vehicle crashes and analytical techniques for stratified contingency tables.

Science.gov (United States)

Al-Ghamdi, Ali S

2002-03-01

In 1999 there were 450 fatalities due to road crashes in Riyadh, the capital of Saudi Arabia, of which 130 were pedestrians. Hence, every fourth person killed on the roads is a pedestrian. The aim of this study is to investigate pedestrian-vehicle crashes in this fast-growing city with two objectives in mind: to analyze pedestrian collisions with regard to their causes, characteristics, location of injury on the victim's body, and most common patterns and to determine the potential for use of the odds ratio technique in the analysis of stratified contingency tables. Data from 638 pedestrian-vehicle crashes reported by police, during the period 1997-1999, were used. A systematic sampling technique was followed in which every third record was used. The analysis showed that the pedestrian fatality rate per 10(5) population is 2.8. The rates were relatively high within the childhood (1-9 years) and young adult (10-19 years) groups, and the old-age groups (60 - > 80 years), which indicate that young as well as the elderly people in this city are more likely to be involved in fatal accidents of this type than are those in other age groups. The analysis revealed that 77.1% of pedestrians were probably struck while crossing a roadway either not in a crosswalk or where no crosswalk existed. In addition, the distribution of injuries on the victims' bodies was determined from hospital records. More than one-third of the fatal injuries were located on the head and chest. An attempt was made to conduct an association analysis between crash severity (i.e. injury or fatal) and some of the study variables using chi-square and odds ratio techniques. The categorical nature of the data helped in using these analytical techniques.

Automated x-ray fluorescence analysis

International Nuclear Information System (INIS)

O'Connell, A.M.

1977-01-01

A fully automated x-ray fluorescence analytical system is described. The hardware is based on a Philips PW1220 sequential x-ray spectrometer. Software for on-line analysis of a wide range of sample types has been developed for the Hewlett-Packard 9810A programmable calculator. Routines to test the system hardware are also described. (Author)

Photoacoustic-fluorescence in vitro flow cytometry for quantification of absorption, scattering and fluorescence properties of the cells

Science.gov (United States)

Nedosekin, D. A.; Sarimollaoglu, M.; Foster, S.; Galanzha, E. I.; Zharov, V. P.

2013-03-01

Fluorescence flow cytometry is a well-established analytical tool that provides quantification of multiple biological parameters of cells at molecular levels, including their functional states, morphology, composition, proliferation, and protein expression. However, only the fluorescence and scattering parameters of the cells or labels are available for detection. Cell pigmentation, presence of non-fluorescent dyes or nanoparticles cannot be reliably quantified. Herewith, we present a novel photoacoustic (PA) flow cytometry design for simple integration of absorbance measurements into schematics of conventional in vitro flow cytometers. The integrated system allow simultaneous measurements of light absorbance, scattering and of multicolor fluorescence from single cells in the flow at rates up to 2 m/s. We compared various combinations of excitation laser sources for multicolor detection, including simultaneous excitation of PA and fluorescence using a single 500 kHz pulsed nanosecond laser. Multichannel detection scheme allows simultaneous detection of up to 8 labels, including 4 fluorescent tags and 4 PA colors. In vitro PA-fluorescence flow cytometer was used for studies of nanoparticles uptake and for the analysis of cell line pigmentation, including genetically encoded melanin expression in breast cancer cell line. We demonstrate that this system can be used for direct nanotoxicity studies with simultaneous quantification of nanoparticles content and assessment of cell viability using a conventional fluorescent apoptosis assays.

Application of multivariate techniques to analytical data on Aegean ceramics

International Nuclear Information System (INIS)

Bieber, A.M.; Brooks, D.W.; Harbottle, G.; Sayre, E.V.

1976-01-01

The general problems of data collection and handling for multivariate elemental analyses of ancient pottery are considered including such specific questions as the level of analytical precision required, the number and type of elements to be determined and the need for comprehensive multivariate statistical analysis of the collected data in contrast to element by element statistical analysis. The multivariate statistical procedures of clustering in a multidimensional space and determination of the numerical probabilities of specimens belonging to a group through calculation of the Mahalanobis distances for these specimens in multicomponent space are described together with supporting univariate statistical procedures used at Brookhaven. The application of these techniques to the data on Late Bronze Age Aegean pottery (largely previously analysed at Oxford and Brookhaven with some new specimens considered) have resulted in meaningful subdivisions of previously established groups. (author)

Fluorescent nanoparticles for intracellular sensing: a review.

Science.gov (United States)

Ruedas-Rama, Maria J; Walters, Jamie D; Orte, Angel; Hall, Elizabeth A H

2012-11-02

Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy. Copyright © 2012 Elsevier B.V. All rights reserved.

An alternative technique for the implementation of an analytical approximation for transients with temperature feedback

Energy Technology Data Exchange (ETDEWEB)

Palma, Daniel A.P. [Instituto Federal do Rio de Janeiro, Nilopolis, RJ (Brazil)], e-mail: dpalmaster@gmail.com; Silva, Adilson C. da; Goncalves, Alessandro C.; Martinez, Aquilino S. [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear], e-mail: asilva@con.ufrj.br, e-mail: agoncalves@con.ufrj.br, e-mail: aquilino@lmp.ufrj.br

2009-07-01

The analytical solution of point kinetics equations with a group of delayed neutrons is useful in predicting neutron density variation during the operation of a nuclear reactor. Although different approximate solutions for the system of point kinetics equations with temperature feedback may be found in literature, some of them do not present an explicit dependence in time, which makes the computing implementation difficult and, as a result, its applicability in practical cases. The present paper uses the polynomial adjustment technique to overcome this problem in the analytical approximation as proposed by Nahla. In a systematic comparison with other existing approximations it is concluded that the method is adequate, presenting small deviations in relation to the reference values obtained from the reference numerical method. (author)

An alternative technique for the implementation of an analytical approximation for transients with temperature feedback

International Nuclear Information System (INIS)

Palma, Daniel A.P.; Silva, Adilson C. da; Goncalves, Alessandro C.; Martinez, Aquilino S.

2009-01-01

The analytical solution of point kinetics equations with a group of delayed neutrons is useful in predicting neutron density variation during the operation of a nuclear reactor. Although different approximate solutions for the system of point kinetics equations with temperature feedback may be found in literature, some of them do not present an explicit dependence in time, which makes the computing implementation difficult and, as a result, its applicability in practical cases. The present paper uses the polynomial adjustment technique to overcome this problem in the analytical approximation as proposed by Nahla. In a systematic comparison with other existing approximations it is concluded that the method is adequate, presenting small deviations in relation to the reference values obtained from the reference numerical method. (author)

Sample sizing of biological materials analyzed by energy dispersion X-ray fluorescence

International Nuclear Information System (INIS)

Paiva, Jose D.S.; Franca, Elvis J.; Magalhaes, Marcelo R.L.; Almeida, Marcio E.S.; Hazin, Clovis A.

2013-01-01

Analytical portions used in chemical analyses are usually less than 1g. Errors resulting from the sampling are barely evaluated, since this type of study is a time-consuming procedure, with high costs for the chemical analysis of large number of samples. The energy dispersion X-ray fluorescence - EDXRF is a non-destructive and fast analytical technique with the possibility of determining several chemical elements. Therefore, the aim of this study was to provide information on the minimum analytical portion for quantification of chemical elements in biological matrices using EDXRF. Three species were sampled in mangroves from the Pernambuco, Brazil. Tree leaves were washed with distilled water, oven-dried at 60 deg C and milled until 0.5 mm particle size. Ten test-portions of approximately 500 mg for each species were transferred to vials sealed with polypropylene film. The quality of the analytical procedure was evaluated from the reference materials IAEA V10 Hay Powder, SRM 2976 Apple Leaves. After energy calibration, all samples were analyzed under vacuum for 100 seconds for each group of chemical elements. The voltage used was 15 kV and 50 kV for chemical elements of atomic number lower than 22 and the others, respectively. For the best analytical conditions, EDXRF was capable of estimating the sample size uncertainty for further determination of chemical elements in leaves. (author)

Sample sizing of biological materials analyzed by energy dispersion X-ray fluorescence

Energy Technology Data Exchange (ETDEWEB)

Paiva, Jose D.S.; Franca, Elvis J.; Magalhaes, Marcelo R.L.; Almeida, Marcio E.S.; Hazin, Clovis A., E-mail: dan-paiva@hotmail.com, E-mail: ejfranca@cnen.gov.br, E-mail: marcelo_rlm@hotmail.com, E-mail: maensoal@yahoo.com.br, E-mail: chazin@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

2013-07-01

Analytical portions used in chemical analyses are usually less than 1g. Errors resulting from the sampling are barely evaluated, since this type of study is a time-consuming procedure, with high costs for the chemical analysis of large number of samples. The energy dispersion X-ray fluorescence - EDXRF is a non-destructive and fast analytical technique with the possibility of determining several chemical elements. Therefore, the aim of this study was to provide information on the minimum analytical portion for quantification of chemical elements in biological matrices using EDXRF. Three species were sampled in mangroves from the Pernambuco, Brazil. Tree leaves were washed with distilled water, oven-dried at 60 deg C and milled until 0.5 mm particle size. Ten test-portions of approximately 500 mg for each species were transferred to vials sealed with polypropylene film. The quality of the analytical procedure was evaluated from the reference materials IAEA V10 Hay Powder, SRM 2976 Apple Leaves. After energy calibration, all samples were analyzed under vacuum for 100 seconds for each group of chemical elements. The voltage used was 15 kV and 50 kV for chemical elements of atomic number lower than 22 and the others, respectively. For the best analytical conditions, EDXRF was capable of estimating the sample size uncertainty for further determination of chemical elements in leaves. (author)

Laser-based analytical monitoring in nuclear-fuel processing plants

International Nuclear Information System (INIS)

Hohimer, J.P.

1978-09-01

The use of laser-based analytical methods in nuclear-fuel processing plants is considered. The species and locations for accountability, process control, and effluent control measurements in the Coprocessing, Thorex, and reference Purex fuel processing operations are identified and the conventional analytical methods used for these measurements are summarized. The laser analytical methods based upon Raman, absorption, fluorescence, and nonlinear spectroscopy are reviewed and evaluated for their use in fuel processing plants. After a comparison of the capabilities of the laser-based and conventional analytical methods, the promising areas of application of the laser-based methods in fuel processing plants are identified

Sampling and analytical methodologies for energy dispersive X-ray fluorescence analysis of airborne particulate matter

International Nuclear Information System (INIS)

1993-01-01

The present document represents an attempt to summarize the most important features of the different forms of ED-XFR as applied to the analysis of airborne particulate matter. It is intended to serve as a set of guidelines for use by participants in the IAEA's own programmes, and other scientists, who are not yet fully experienced in the application of ED-XRF to airborne particulate samples, and who wish either to make a start on using this technique or to improve their existing procedures. The methodologies for sampling described in this document are of rather general applicability. Emphasis is also placed on the sources of errors affecting the sampling of airborne particulate matter. The analytical part of the document describes the different forms of ED-XRF and their potential applications. Spectrum evaluation, a key step in X-ray spectrometry, is covered in depth, including discussion on several calibration and peak fitting techniques and computer programs especially designed for this purpose. 148 refs, 25 figs, 13 tabs

Time-resolved UV-excited microarray reader for fluorescence energy transfer (FRET) measurements

Science.gov (United States)

Orellana, Adelina; Hokkanen, Ari P.; Pastinen, Tomi; Takkinen, Kristina; Soderlund, Hans

2001-05-01

Analytical systems based on immunochemistry are largely used in medical diagnostics and in biotechnology. There is a significant pressure to develop the present assay formats to become easier to use, faster, and less reagent consuming. Further developments towards high density array--like multianalyte measurement systems would be valuable. To this aim we have studied the applicability of fluorescence resonance energy transfer and time-resolved fluorescence resonance energy transfer in immunoassays on microspots and in microwells. We have used engineered recombinant antibodies detecting the pentameric protein CRP as a model analyte system, and tested different assay formats. We describe also the construction of a time-resolved scanning epifluorometer with which we could measure the FRET interaction between the slow fluorescence decay from europium chelates and its energy transfer to the rapidly decaying fluorophore Cy5.

S - and N-alkylating agents diminish the fluorescence of fluorescent dye-stained DNA.

Science.gov (United States)

Giesche, Robert; John, Harald; Kehe, Kai; Schmidt, Annette; Popp, Tanja; Balzuweit, Frank; Thiermann, Horst; Gudermann, Thomas; Steinritz, Dirk

2017-01-25

Sulfur mustard (SM), a chemical warfare agent, causes DNA alkylation, which is believed to be the main cause of its toxicity. SM DNA adducts are commonly used to verify exposure to this vesicant. However, the required analytical state-of-the-art mass-spectrometry methods are complex, use delicate instruments, are not mobile, and require laboratory infrastructure that is most likely not available in conflict zones. Attempts have thus been made to develop rapid detection methods that can be used in the field. The analysis of SM DNA adducts (HETE-G) by immunodetection is a convenient and suitable method. For a diagnostic assessment, HETE-G levels must be determined in relation to the total DNA in the sample. Total DNA can be easily visualized by the use of fluorescent DNA dyes. This study examines whether SM and related compounds affect total DNA staining, an issue that has not been investigated before. After pure DNA was extracted from human keratinocytes (HaCaT cells), DNA was exposed to different S- and N-alkylating agents. Our experiments revealed a significant, dose-dependent decrease in the fluorescence signal of fluorescent dye-stained DNA after exposure to alkylating agents. After mass spectrometry and additional fluorescence measurements ruled out covalent modifications of ethidium bromide (EthBr) by SM, we assumed that DNA crosslinks caused DNA condensation and thereby impaired access of the fluorescent dyes to the DNA. DNA digestion by restriction enzymes restored fluorescence, a fact that strengthened our hypothesis. However, monofunctional agents, which are unable to crosslink DNA, also decreased the fluorescence signal. In subsequent experiments, we demonstrated that protons produced during DNA alkylation caused a pH decrease that was found responsible for the reduction in fluorescence. The use of an appropriate buffer system eliminated the adverse effect of alkylating agents on DNA staining with fluorescent dyes. An appropriate buffer system is thus

How to simplify the analytics for input-output accountability measurements in a reprocessing plant

International Nuclear Information System (INIS)

Ottmar, H.; Eberle, H.; Matussek, P.; Michel-Piper, I.

1986-02-01

An analytical approach to high-performance uranium and plutonium accountancy measurements in reprocessing input and output solutions is presented, which provides larger operational simplicity than the conventionally applied chemical methods. The proposed alternative is based on energy-dispersive absorption edge and fluorescence X-ray spectrometry, using the proven and reliable K-edge densitometry technique as reference method. Two X-ray densitometers developed for accurate and reliable uranium and plutonium analysis in both the feed and product solutions are described. Practical experiences and results from their performance evaluation on actual process solutions from a reprocessing plant are presented and discussed. (orig.) [de

Optimal Fluorescence Waveband Determination for Detecting Defective Cherry Tomatoes Using a Fluorescence Excitation-Emission Matrix

Directory of Open Access Journals (Sweden)

In-Suck Baek

2014-11-01

Full Text Available A multi-spectral fluorescence imaging technique was used to detect defective cherry tomatoes. The fluorescence excitation and emission matrix was used to measure for defects, sound surface and stem areas to determine the optimal fluorescence excitation and emission wavelengths for discrimination. Two-way ANOVA revealed the optimal excitation wavelength for detecting defect areas was 410 nm. Principal component analysis (PCA was applied to the fluorescence emission spectra of all regions at 410 nm excitation to determine the emission wavelengths for defect detection. The major emission wavelengths were 688 nm and 506 nm for the detection. Fluorescence images combined with the determined emission wavebands demonstrated the feasibility of detecting defective cherry tomatoes with >98% accuracy. Multi-spectral fluorescence imaging has potential utility in non-destructive quality sorting of cherry tomatoes.

High-Throughput Accurate Single-Cell Screening of Euglena gracilis with Fluorescence-Assisted Optofluidic Time-Stretch Microscopy.

Directory of Open Access Journals (Sweden)

Baoshan Guo

Full Text Available The development of reliable, sustainable, and economical sources of alternative fuels is an important, but challenging goal for the world. As an alternative to liquid fossil fuels, algal biofuel is expected to play a key role in alleviating global warming since algae absorb atmospheric CO2 via photosynthesis. Among various algae for fuel production, Euglena gracilis is an attractive microalgal species as it is known to produce wax ester (good for biodiesel and aviation fuel within lipid droplets. To date, while there exist many techniques for inducing microalgal cells to produce and accumulate lipid with high efficiency, few analytical methods are available for characterizing a population of such lipid-accumulated microalgae including E. gracilis with high throughout, high accuracy, and single-cell resolution simultaneously. Here we demonstrate high-throughput, high-accuracy, single-cell screening of E. gracilis with fluorescence-assisted optofluidic time-stretch microscopy-a method that combines the strengths of microfluidic cell focusing, optical time-stretch microscopy, and fluorescence detection used in conventional flow cytometry. Specifically, our fluorescence-assisted optofluidic time-stretch microscope consists of an optical time-stretch microscope and a fluorescence analyzer on top of a hydrodynamically focusing microfluidic device and can detect fluorescence from every E. gracilis cell in a population and simultaneously obtain its image with a high throughput of 10,000 cells/s. With the multi-dimensional information acquired by the system, we classify nitrogen-sufficient (ordinary and nitrogen-deficient (lipid-accumulated E. gracilis cells with a low false positive rate of 1.0%. This method holds promise for evaluating cultivation techniques and selective breeding for microalgae-based biofuel production.

Developing DNA nanotechnology using single-molecule fluorescence.

Science.gov (United States)

Tsukanov, Roman; Tomov, Toma E; Liber, Miran; Berger, Yaron; Nir, Eyal

2014-06-17

CONSPECTUS: An important effort in the DNA nanotechnology field is focused on the rational design and manufacture of molecular structures and dynamic devices made of DNA. As is the case for other technologies that deal with manipulation of matter, rational development requires high quality and informative feedback on the building blocks and final products. For DNA nanotechnology such feedback is typically provided by gel electrophoresis, atomic force microscopy (AFM), and transmission electron microscopy (TEM). These analytical tools provide excellent structural information; however, usually they do not provide high-resolution dynamic information. For the development of DNA-made dynamic devices such as machines, motors, robots, and computers this constitutes a major problem. Bulk-fluorescence techniques are capable of providing dynamic information, but because only ensemble averaged information is obtained, the technique may not adequately describe the dynamics in the context of complex DNA devices. The single-molecule fluorescence (SMF) technique offers a unique combination of capabilities that make it an excellent tool for guiding the development of DNA-made devices. The technique has been increasingly used in DNA nanotechnology, especially for the analysis of structure, dynamics, integrity, and operation of DNA-made devices; however, its capabilities are not yet sufficiently familiar to the community. The purpose of this Account is to demonstrate how different SMF tools can be utilized for the development of DNA devices and for structural dynamic investigation of biomolecules in general and DNA molecules in particular. Single-molecule diffusion-based Förster resonance energy transfer and alternating laser excitation (sm-FRET/ALEX) and immobilization-based total internal reflection fluorescence (TIRF) techniques are briefly described and demonstrated. To illustrate the many applications of SMF to DNA nanotechnology, examples of SMF studies of DNA hairpins and

X-ray fluorescence holography

CERN Document Server

Hayashi, K; Takahashi, Y

2003-01-01

X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

Synthesis and characterization of a fluorescent water-soluble paclitaxel prodrug.

Science.gov (United States)

Sohn, Jeong-Sun; Choi, Eun-Sun; Jo, Byung-Wook; Hess, Michael; Han, Song-Hee

2010-05-01

A fluorescence susceptible water-soluble paclitaxel was synthesized by a condensation reaction between PEGylated paclitaxel (namely, PP7) and 1-pyrene butyric acid (PBA) in order to obtain a better understanding of the mechanism of action of paclitaxel as well as of the environment of the paclitaxel-binding site. The reaction was performed successfully and the resulting paclitaxel was characterized by FT-NMR, analytical-HPLC, UV spectro photometry, and fluorescence spectrometry. The synthesized paclitaxel analogue showed a high susceptibility to fluorescence in both excitation and emission spectra. And we have investigated the time-resolved fluorescence behavior of them in different solvents and at different excitation wavelengths.

The earrings of Pancas treasure: Analytical study by X-ray based techniques – A first approach

International Nuclear Information System (INIS)

Tissot, I.; Tissot, M.; Manso, M.; Alves, L.C.; Barreiros, M.A.; Marcelo, T.; Carvalho, M.L.; Corregidor, V.; Guerra, M.F.

2013-01-01

The development of new metallurgical technologies in the Iberian Peninsula during the Iron Age is well represented by the 10 gold earrings from the treasure of Pancas. This work presents a first approach to the analytical study of these earrings and contributes to the construction of a typological evolution of the Iberian earrings. The manufacture techniques and the alloys composition were studied with three complementary X-ray spectroscopy techniques: portable EDXRF, μ-PIXE and SEM–EDS. The results were compared with earrings from the same and previous periods

Fluorescent detection of C-reactive protein using polyamide beads

Science.gov (United States)

Jagadeesh, Shreesha; Chen, Lu; Aitchison, Stewart

2016-03-01

Bacterial infection causes Sepsis which is one of the leading cause of mortality in hospitals. This infection can be quantified from blood plasma using C - reactive protein (CRP). A quick diagnosis at the patient's location through Point-of- Care (POC) testing could give doctors the confidence to prescribe antibiotics. In this paper, the development and testing of a bead-based procedure for CRP quantification is described. The size of the beads enable them to be trapped in wells without the need for magnetic methods of immobilization. Large (1.5 mm diameter) Polyamide nylon beads were used as the substrate for capturing CRP from pure analyte samples. The beads captured CRP either directly through adsorption or indirectly by having specific capture antibodies on their surface. Both methods used fluorescent imaging techniques to quantify the protein. The amount of CRP needed to give a sufficient fluorescent signal through direct capture method was found suitable for identifying bacterial causes of infection. Similarly, viral infections could be quantified by the more sensitive indirect capture method. This bead-based assay can be potentially integrated as a disposable cartridge in a POC device due to its passive nature and the small quantities needed.

Strategies of molecular imprinting-based fluorescence sensors for chemical and biological analysis.

Science.gov (United States)

Yang, Qian; Li, Jinhua; Wang, Xiaoyan; Peng, Hailong; Xiong, Hua; Chen, Lingxin

2018-07-30

One pressing concern today is to construct sensors that can withstand various disturbances for highly selective and sensitive detecting trace analytes in complicated samples. Molecularly imprinted polymers (MIPs) with tailor-made binding sites are preferred to be recognition elements in sensors for effective targets detection, and fluorescence measurement assists in highly sensitive detection and user-friendly control. Accordingly, molecular imprinting-based fluorescence sensors (MI-FL sensors) have attracted great research interest in many fields such as chemical and biological analysis. Herein, we comprehensively review the recent advances in MI-FL sensors construction and applications, giving insights on sensing principles and signal transduction mechanisms, focusing on general construction strategies for intrinsically fluorescent or nonfluorescent analytes and improvement strategies in sensing performance, particularly in sensitivity. Construction strategies are well overviewed, mainly including the traditional indirect methods of competitive binding against pre-bound fluorescent indicators, employment of fluorescent functional monomers and embedding of fluorescence substances, and novel rational designs of hierarchical architecture (core-shell/hollow and mesoporous structures), post-imprinting modification, and ratiometric fluorescence detection. Furthermore, MI-FL sensor based microdevices are discussed, involving micromotors, test strips and microfluidics, which are more portable for rapid point-of-care detection and in-field diagnosing. Finally, the current challenges and future perspectives of MI-FL sensors are proposed. Copyright © 2018 Elsevier B.V. All rights reserved.

Emerging biomedical applications of time-resolved fluorescence spectroscopy

Science.gov (United States)

Lakowicz, Joseph R.; Szmacinski, Henryk; Koen, Peter A.

1994-07-01

Time-resolved fluorescence spectroscopy is presently regarded as a research tool in biochemistry, biophysics, and chemical physics. Advances in laser technology, the development of long-wavelength probes, and the use of lifetime-based methods are resulting in the rapid migration of time-resolved fluorescence to the clinical chemistry lab, to the patient's bedside, to flow cytometers, to the doctor's office, and even to home health care. Additionally, time-resolved imaging is now a reality in fluorescence microscopy, and will provide chemical imaging of a variety of intracellular analytes and/or cellular phenomena. In this overview paper we attempt to describe some of the opportunities available using chemical sensing based on fluorescence lifetimes, and to predict those applications of lifetime-based sensing which are most likely in the near future.

Proceedings of the national seminar on recent developments in electro analytical techniques: souvenir and abstracts

International Nuclear Information System (INIS)

2012-01-01

In view of deliberations on 'Recent Developments in Electro Analytical Techniques' with special emphasis on batteries, fuel cells, biosensors, chemical sensors modified electrodes, nano electrodes, electrode synthesis and co-ordination compounds, go a long way in creating the necessary awareness and enthusiasm amongst students, young scholars and industrialists to lay their attention on the subject. Papers relevant to INIS are indexed separately

Beta Autoradiography. An analytical technique to investigate radionuclides contamination on surface

International Nuclear Information System (INIS)

Ficher, P.; Goutelard, F.; Siitari-Kauppi, M.

2012-01-01

In decommissioning of old buildings and after disposal of nuclear facilities (materials, glove boxes,...), the inventory of the radioactive contamination of various building materials needs to be obtained in order to fix the working condition for dismantling. The challenge of this study was to classify different building materials of a whole research laboratory that was dedicated to research on organic molecules labeled with H-3 and C-14. The problem of waste classification is essential for safety treatment of waste and also for its cost. The analytical technique of beta autoradiography particularly well known for biological researches has been tested to investigate radionuclides contamination on surface. This technique is mainly interesting for beta and alpha emitters but also sensitive to gamma radiation. The first step of this technique is the deposit of a film on the surface of material to be analyzed. Films can be deposited on the ground or also fixed on the walls or even on the ceiling. The film is a plastic sheet covered with an emulsion containing photostimulable crystals and Eu that is activated when the film is exposed on radioactive source. The exposed films are then scanned with the Cyclone Plus equipment to get a digitized image. This image represents the radioactivity of the surface studied. The possibility to re-use the films is very important to investigate a large area. This autoradiography technique has retained our attention for its sensitivity and moreover the possibility of 2-dimensional investigation has been found as a real advantage. However it remains now as a qualitative technique and new studies must be launched to prove its quantitative potentialities. The high spatial resolution was not as important as in biological observation, and the mm resolution is totally sufficient

A highly flexible polymerization technique to prepare fluorescent nanospheres for trace ammonia detection

International Nuclear Information System (INIS)

Waich, K.; Sandholzer, M.; Mayr, T.; Slugovc, C.; Klimant, I.

2010-01-01

The preparation of pH-sensitive nanospheres by emulsion polymerization for the detection of trace levels of ammonia is described. A fluorescent, polymerizable xanthene dye was copolymerized with styrene, crosslinkers and further copolymers aimed at enhancing the sensitivity to obtain materials for sensing of ammonia. A half-seeded technique was used to obtain stable emulsions of the monomers which were cured to obtain nanospheres with covalently attached active components. The nanospheres were embedded in a silicon matrix and the sensor films obtained were investigated regarding their response to ammonia at concentrations between 25 and 1,000 ppb. Sensors containing polystyrene nanospheres crosslinked with divinylbenzene showed the best performance in ammonia measurements exhibiting detection limits (LODs) of less than 25 ppb ammonia.

Fluorescent sensing of nitroaromatics by two coordination polymers having potential active sites

Energy Technology Data Exchange (ETDEWEB)

Lu, Lu [College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Institute of Functional Materials, Sichuan University of Science & Engineering, Zigong 643000 (China); Wang, Jun, E-mail: scwangjun2011@126.com [College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Institute of Functional Materials, Sichuan University of Science & Engineering, Zigong 643000 (China); Wu, Wei-Ping [College of Chemistry and Environmental Engineering, Sichuan University of Science & Engineering, Zigong 643000 (China); Institute of Functional Materials, Sichuan University of Science & Engineering, Zigong 643000 (China); Ma, Aiqing, E-mail: maqandght@126.com [School of Pharmacy, Guangdong Medical University, Dongguan 523808 (China); Liu, Jian-Qiang [School of Pharmacy, Guangdong Medical University, Dongguan 523808 (China); Yadav, Reena [Department of Chemistry, Faculty of Science, University of Lucknow, Lucknow 226 007 (India); Kumar, Abhinav, E-mail: abhinavmarshal@gmail.com [Department of Chemistry, Faculty of Science, University of Lucknow, Lucknow 226 007 (India)

2017-06-15

Two new d{sup 10} based coordination polymers having formula [Cd(HL1)(L2)] (1) and [Zn(HL1)(L2)] (2) (H{sub 3}L1=5-(4-carboxyphenoxy)isophthalic acid and L2=3-(4-methyl-6-(pyridine-3-yl)pyridine-2-yl)pyridine) have been synthesized and characterized using IR, thermogravimetric analyses (TGA), photoluminescence and single-crystal X-ray diffraction techniques. The single-crystal X-ray investigation reveals that both of 1 and 2 show 2D layer architectures with square lattice topology. The photoluminescence investigation indicates that both 1 and 2 could be a prospective candidate for developing luminescence sensors for the highly sensing of nitroaromatic analytes. Furthermore, the luminescent property of 1 and 2 in different solvents analytes as well as nitrobenzene derivative have been investigated and the observed quenching in fluorescence have been corroborated by theoretical calculations. - Graphical abstract: Two new d{sup 10}-based luminescent MOFs synthesized and their sensing properties towards different nitroaromatics investigated.

FLEX (Fluorescence Explorer mission: Observation fluorescence as a new remote sensing technique to study the global terrestrial vegetation state

Directory of Open Access Journals (Sweden)

J. Moreno

2014-06-01

Full Text Available FLEX (Fluorescence EXplorer is a candidate for the 8th ESA’s Earth Explorer mission. Is the first space mission specifically designed for the estimation of vegetation fluorescence on a global scale. The mission is proposed to fly in tandem with the future ESA´s Sentinel-3 satellite. It is foreseen that the information obtained by Sentinel-3 will be supplemented with that provided by FLORIS (Fluorescence Imaging Spectrometer onboard FLEX. FLORIS will measure the radiance between 500 and 800 nm with a bandwidth between 0.1 nm and 2 nm, providing images with a 150 km swath and 300 m pixel size. This information will allow a detailed monitoring of vegetation dynamics, by improving the methods for the estimation of classical biophysical parameters, and by introducing a new one: fluorescence. This paper presents the current status of FLEX mission in A/B1 phase and the different ongoing studies, campaigns and projects carried out in support of the FLEX mission.

Applied research on air pollution using nuclear-related analytical techniques. Report on the second research co-ordination meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

A co-ordinated research programme (CRP) on applied research on air pollution using nuclear-related techniques is a global CRP which started in 1992, and is scheduled to run until early 1997. The purpose of this CRP is to promote the use of nuclear analytical techniques in air pollution studies, e.g. NAA, XRF, and PIXE for the analysis of toxic and other trace elements in air particulate matter. The main purposes of the core programme are i) to support the use of nuclear and nuclear-related analytical techniques for research and monitoring studies on air pollution, ii) to identify major sources of air pollution affecting each of the participating countries with particular reference to toxic heavy metals, and iii) to obtain comparative data on pollution levels in areas of high pollution (e.g. a city centre or a populated area downwind of a large pollution source) and low pollution (e.g. rural area). This document reports the discussions held during the second Research Co-ordination Meeting (RCM) for the CRP which took place at ANSTO in Menai, Australia. (author)

Applied research on air pollution using nuclear-related analytical techniques. Report on the second research co-ordination meeting

International Nuclear Information System (INIS)

1995-01-01

A co-ordinated research programme (CRP) on applied research on air pollution using nuclear-related techniques is a global CRP which started in 1992, and is scheduled to run until early 1997. The purpose of this CRP is to promote the use of nuclear analytical techniques in air pollution studies, e.g. NAA, XRF, and PIXE for the analysis of toxic and other trace elements in air particulate matter. The main purposes of the core programme are i) to support the use of nuclear and nuclear-related analytical techniques for research and monitoring studies on air pollution, ii) to identify major sources of air pollution affecting each of the participating countries with particular reference to toxic heavy metals, and iii) to obtain comparative data on pollution levels in areas of high pollution (e.g. a city centre or a populated area downwind of a large pollution source) and low pollution (e.g. rural area). This document reports the discussions held during the second Research Co-ordination Meeting (RCM) for the CRP which took place at ANSTO in Menai, Australia. (author)

Biomonitoring of air pollution in Jamaica through trace-element analysis of epiphytic plants using nuclear and related analytical techniques

International Nuclear Information System (INIS)

Vutchkov, Mitko

2001-01-01

The main goal of the Coordinated Research Project (No:9937/R0), entitled 'Biomonitoring of Air Pollution in Jamaica Through Trace-Element Analysis of Epiphytic Plants Using Nuclear and Related Analytical Techniques', is to identify and validate site specific epiphytic plants for biomonitoring the atmospheric pollution in Jamaica using nuclear analytical techniques at the International Centre for Environmental and Nuclear Sciences (ICENS). The specific objectives for the second year of the project were: Development of HOP for sampling epiphytic plants in Jamaica; Sampling design and sample collection; Sample preparation and analysis; Development of an in-house SRM and participation in the NAT-5 inter-laboratory study; Data analysis and interpretation of the results; Development of a work plan of the third year of the project

Nuclear techniques and the disposal of non-radioactive solid wastes

International Nuclear Information System (INIS)

Landsberger, S.; Buchholz, B.

1993-01-01

One of the most vital and persistent public health challenges facing local, state, and national governments is the disposal of solid waste produced from industrial, utility, and municipal sources. There is a growing interest in the monitoring, control, and safe disposal of the chemical constituents arising from these sources. For instance, it is now well known that the release of by products from coal-fired power plants - namely airborne particulates, bottom ash, and fly ash - can have adverse effects on air and water quality. It is therefore important that reliable chemical analytical techniques are readily available to assess the impact of widespread disposal practices of organic and inorganic chemicals. The use of nuclear and nuclear-related analytical techniques - such as neutron activation analysis, energy dispersive x-ray fluorescence and particle induced X-ray emission - have become widespread in major areas of science and technology. These methods and techniques have important applications in such work since they can be used for both the determination of specific individual pollutants (e.g. toxic heavy metals) and multi-elemental analyses for source identification and apportionment purposes. Other nuclear techniques, such as isotope tracers, have also had wide acceptance in characterizing diffusion patterns for metals in soil and aqueous environments and water pollution flows. 1 graph., 1 tab

Limitations on the use of the planar laser induced exciplex fluorescence technique in diesel sprays

Energy Technology Data Exchange (ETDEWEB)

J.M. Desantes; J.V. Pastor; J.M. Pastor; J.E. Julia [Universidad Politecnica de Valencia, Valencia (Spain). CMT Motores Termicos

2005-12-01

The Planar Laser Induced Exciplex Fluorescence (PLIEF) technique is widely used to visualize and measure the fuel concentration fields in both liquid and vapor phases of DI Diesel sprays. However, the real limitations of the PLIEF technique in Diesel sprays and the accuracy of the results obtained are still a source of controversy. In this work, a complete methodology for maximum penetration and fuel concentration measurements in evaporating conditions in Diesel sprays has been developed and the reliability of the results obtained has been investigated. The methodology includes new procedures for measuring both liquid and vapor phases, adapting, when necessary, correlations available in the literature for calibration. An experimental matrix of nine test points with different injection pressures and combustion chamber densities has been performed. A critical analysis of the different error sources for proper quantification is made. Results have shown that macroscopic features can be accurately determined using the PLIEF technique, but for fuel concentration measurements special considerations have to be taken into account, particularly in the regions where liquid and vapor coexist. 37 refs., 15 figs., 2 tabs.

Mass spectrometry based approach for identification and characterisation of fluorescent proteins from marine organisms

DEFF Research Database (Denmark)

Wojdyla, Katarzyna Iwona; Rogowska-Wrzesinska, Adelina; Wrzesinski, Krzysztof

2011-01-01

We present here a new analytical strategy for identification and characterisation of fluorescent proteins from marine organisms. By applying basic proteomics tools it is possible to screen large sample collections for fluorescent proteins of desired characteristics prior to gene cloning. Our...

Determination and identification of synthetic cannabinoids and their metabolites in different matrices by modern analytical techniques – a review

International Nuclear Information System (INIS)

Znaleziona, Joanna; Ginterová, Pavlína; Petr, Jan; Ondra, Peter; Válka, Ivo; Ševčík, Juraj; Chrastina, Jan; Maier, Vítězslav

2015-01-01

Highlights: • Synthetic cannabinoids from analytical point of view. • Determination and identification methods of synthetic cannabinoids in different matrices. • Analytical techniques used from thin layer chromatography to high resolution mass spectrometry. • Detailed survey of gas and liquid chromatography methods for synthetic cannabinoids analysis. - Abstract: Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry

Determination and identification of synthetic cannabinoids and their metabolites in different matrices by modern analytical techniques – a review

Energy Technology Data Exchange (ETDEWEB)

Znaleziona, Joanna; Ginterová, Pavlína; Petr, Jan [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic); Ondra, Peter; Válka, Ivo [Department of Forensic Medicine and Medical Law Faculty Hospital, Hněvotínská 3, Olomouc CZ-77146 (Czech Republic); Ševčík, Juraj [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic); Chrastina, Jan [Institute of Special Education Studies, Faculty of Education, Palacký University, Žižkovo náměsti 5, Olomouc CZ-77146 (Czech Republic); Maier, Vítězslav, E-mail: vitezslav.maier@upol.cz [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic)

2015-05-18

Highlights: • Synthetic cannabinoids from analytical point of view. • Determination and identification methods of synthetic cannabinoids in different matrices. • Analytical techniques used from thin layer chromatography to high resolution mass spectrometry. • Detailed survey of gas and liquid chromatography methods for synthetic cannabinoids analysis. - Abstract: Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry.

Multi-analytical assessment of iron and steel slag characteristics to estimate the removal of metalloids from contaminated water.

Science.gov (United States)

Mercado-Borrayo, B M; Schouwenaars, R; González-Chávez, J L; Ramírez-Zamora, R M

2013-01-01

A multi-analytical approach was used to develop a mathematical regression model to calculate the residual concentration of borate ions in water present at high initial content, as a function of the main physicochemical, mineralogical and electrokinetic characteristics after adsorption on five different types of iron and steel slag. The analytical techniques applied and slag properties obtained in this work were: X-ray Fluorescence for the identification of the main chemical compounds, X-ray Diffraction to determine crystalline phases, physical adsorption of nitrogen for the quantification of textural properties and zeta-potential for electrokinetic measurements of slag particles. Adsorption tests were carried out using the bottle-point technique and a highly concentrated borate solution (700 mg B/L) at pH 10, with a slag dose of 10 g/L. An excellent correlation between the residual concentration of boron and three independent variables (content of magnesium oxide, zeta potential and specific surface area) was established for the five types of slag tested in this work. This shows that the methodology based on a multi-analytical approach is a very strong and useful tool to estimate the performance of iron and steel slag as adsorbent of metalloids.

An Application of X-ray Fluorescence as Process Analytical Technology (PAT) to Monitor Particle Coating Processes.

Science.gov (United States)

Nakano, Yoshio; Katakuse, Yoshimitsu; Azechi, Yasutaka

2018-03-30

An attempt to apply X-ray Fluorescence (XRF) analysis to evaluate small particle coating process as a Process Analytical Technologies (PAT) was made. The XRF analysis was used to monitor coating level in small particle coating process with at-line manner. The small particle coating process usually consists of multiple coating processes. This study was conducted by a simple coating particles prepared by first coating of a model compound (DL-methionine) and second coating by talc on spherical microcrystalline cellulose cores. The particles with two layered coating are enough to demonstrate the small particle coating process. From the result by the small particle coating process, it was found that the XRF signal played different roles, resulting that XRF signals by first coating (layering) and second coating (mask coating) could demonstrate the extent with different mechanisms for the coating process. Furthermore, the particle coating of the different particle size has also been investigated to evaluate size effect of these coating processes. From these results, it was concluded that the XRF could be used as a PAT in monitoring particle coating processes and become powerful tool in pharmaceutical manufacturing.

Critical Assessment of Analytical Techniques in the Search for Biomarkers on Mars: A Mummified Microbial Mat from Antarctica as a Best-Case Scenario.

Science.gov (United States)

Blanco, Yolanda; Gallardo-Carreño, Ignacio; Ruiz-Bermejo, Marta; Puente-Sánchez, Fernando; Cavalcante-Silva, Erika; Quesada, Antonio; Prieto-Ballesteros, Olga; Parro, Víctor

2017-10-01

The search for biomarkers of present or past life is one of the major challenges for in situ planetary exploration. Multiple constraints limit the performance and sensitivity of remote in situ instrumentation. In addition, the structure, chemical, and mineralogical composition of the sample may complicate the analysis and interpretation of the results. The aim of this work is to highlight the main constraints, performance, and complementarity of several techniques that have already been implemented or are planned to be implemented on Mars for detection of organic and molecular biomarkers on a best-case sample scenario. We analyzed a 1000-year-old desiccated and mummified microbial mat from Antarctica by Raman and IR (infrared) spectroscopies (near- and mid-IR), thermogravimetry (TG), differential thermal analysis, mass spectrometry (MS), and immunological detection with a life detector chip. In spite of the high organic content (ca. 20% wt/wt) of the sample, the Raman spectra only showed the characteristic spectral peaks of the remaining beta-carotene biomarker and faint peaks of phyllosilicates over a strong fluorescence background. IR spectra complemented the mineralogical information from Raman spectra and showed the main molecular vibrations of the humic acid functional groups. The TG-MS system showed the release of several volatile compounds attributed to biopolymers. An antibody microarray for detecting cyanobacteria (CYANOCHIP) detected biomarkers from Chroococcales, Nostocales, and Oscillatoriales orders. The results highlight limitations of each technique and suggest the necessity of complementary approaches in the search for biomarkers because some analytical techniques might be impaired by sample composition, presentation, or processing. Key Words: Planetary exploration-Life detection-Microbial mat-Life detector chip-Thermogravimetry-Raman spectroscopy-NIR-DRIFTS. Astrobiology 17, 984-996.

Voltammetric technique, a panacea for analytical examination of environmental samples

International Nuclear Information System (INIS)

Zahir, E.; Mohiuddin, S.; Naqvi, I.I.

2012-01-01

Voltammetric methods for trace metal analysis in environmental samples of marine origin like mangrove, sediments and shrimps are generally recommended. Three different electro-analytical techniques i.e. polarography, anodic stripping voltammetry (ASV) and adsorptive stripping voltammetry (ADSV) have been used. Cd/sub 2/+, Pb/sub 2/+, Cu/sub 2/+ and Mn/sub 2/+ were determined through ASV, Cr/sub 6/+ was analyzed by ADSV and Fe/sub 2/+, Zn/sub 2/+, Ni/sub 2/+ and Co/sub 2/+ were determined through polarography. Out of which pairs of Fe/sub 2/+Zn/sub 2/+ and Ni/sub 2/+Co/sub 2/+ were determined in two separate runs while Cd/sub 2/+, Pb/sub 2/+, Cu/sub 2/+ were analyzed in single run of ASV. Sensitivity and speciation capabilities of voltammetric methods have been employed. Analysis conditions were optimized that includes selection of supporting electrolyte, pH, working electrodes, sweep rate etc. Stripping voltammetry was adopted for analysis at ultra trace levels. Statistical parameters for analytical method development like selectivity factor, interference, repeatability (0.0065-0.130 macro g/g), reproducibility (0.08125-1.625 macro g/g), detection limits (0.032-5.06 macro g/g), limits of quantification (0.081-12.652 macro g/g), sensitivities (5.636-2.15 nA mL macro g-1) etc. were also determined. The percentage recoveries were found in between 95-105% using certified reference materials. Real samples of complex marine environment from Karachi coastline were also analyzed. The standard addition method was employed where any matrix effect was evidenced. (author)

Fluorescence optical imaging in anticancer drug delivery.

Science.gov (United States)

Etrych, Tomáš; Lucas, Henrike; Janoušková, Olga; Chytil, Petr; Mueller, Thomas; Mäder, Karsten

2016-03-28

In the past several decades, nanosized drug delivery systems with various targeting functions and controlled drug release capabilities inside targeted tissues or cells have been intensively studied. Understanding their pharmacokinetic properties is crucial for the successful transition of this research into clinical practice. Among others, fluorescence imaging has become one of the most commonly used imaging tools in pre-clinical research. The development of increasing numbers of suitable fluorescent dyes excitable in the visible to near-infrared wavelengths of the spectrum has significantly expanded the applicability of fluorescence imaging. This paper focuses on the potential applications and limitations of non-invasive imaging techniques in the field of drug delivery, especially in anticancer therapy. Fluorescent imaging at both the cellular and systemic levels is discussed in detail. Additionally, we explore the possibility for simultaneous treatment and imaging using theranostics and combinations of different imaging techniques, e.g., fluorescence imaging with computed tomography. Copyright © 2016 Elsevier B.V. All rights reserved.

Proficiency Testing by Interlaboratory Comparison Performed in 2010-2015 for Neutron Activation Analysis and Other Analytical Techniques

International Nuclear Information System (INIS)

2017-12-01

The IAEA supports its Member States to increase the utilization of their research reactors. Small and medium sized reactors are mostly used for neutron activation analysis (NAA). Although the markets for NAA laboratories have been identified, demonstration of valid analytical results and organizational quality of the work process are preconditions for expanding the stakeholder community, particularly in commercial routine application of this powerful technique. The IAEA has implemented a new mechanism for supporting NAA laboratories in demonstrating their analytical performance by participation in proficiency testing schemes by interlaboratory comparison. This activity makes possible the identification of deviations and non-conformities, their causes and the process to implement effective approaches to eliminate them. Over 30 laboratories participated between 2010 and 2015 in consecutive proficiency tests organized by the IAEA in conjunction with the Wageningen Evaluating Programmes for Analytical Laboratories (WEPAL) to assess their analytical performances. This publication reports the findings and includes lessons learned of this activity. An attached CD-ROM contains many individual participating laboratory papers sharing their individual results and experience gained through this participation.

Steady state and time-resolved fluorescence spectroscopy of quinine sulfate dication bound to sodium dodecylsulfate micelles: Fluorescent complex formation

Energy Technology Data Exchange (ETDEWEB)

Joshi, Sunita; Pant, Debi D., E-mail: ddpant@pilani.bits-pilani.ac.in

2014-01-15

Interaction of quinine sulfate dication (QSD) with anionic, sodium dodecylsulphate (SDS) surfactant has been studied at different premicellar, micellar and postmicellar concentrations in aqueous phase using steady state, time-resolved fluorescence and fluorescence anisotropy techniques. At premicellar concentrations of SDS, the decrease in absorbance, appearance of an extra fluorescence band at lower wavelengths and tri-exponential decay behavior of fluorescence, are attributed to complex formation between QSD molecules and surfactant monomers. At postmicellar concentrations the red shift in fluorescence spectrum, increase in quantum yield and increase in fluorescence lifetimes are attributed to incorporation of solute molecules to micelles. At lower concentrations of SDS, a large shift in fluorescence is observed on excitation at the red edge of absorption spectrum and this is explained in terms of distribution of ion pairs of different energies in the ground state and the observed fluorescence lifetime behavior corroborates with this model. The temporal fluorescence anisotropy decay of QSD in SDS micelles allowed determination of restriction on the motion of the fluorophore. All the different techniques used in this study reveal that the photophysics of QSD is very sensitive to the microenvironments of SDS micelles and QSD molecules reside at the water-micelle interface. -- Highlights: • Probe molecule is very sensitive to microenvironment of micelles. • Highly fluorescent ion-pair formation has been observed. • Modulated photophysics of probe molecule in micellar solutions has been observed. • Probe molecules strongly bind with micelles and reside at probe–micelle interface.

Ultrafast fluorescence of photosynthetic crystals and light-harvesting complexes

NARCIS (Netherlands)

Oort, van B.F.

2008-01-01

This thesis focuses on the study of photosynthetic pigment protein complexes using time resolved fluorescence techniques. Fluorescence spectroscopy often requires attaching fluorescent labels to the proteins under investigation. With photosynthetic proteins this is not necessary, because these

Determination of fluorine concentrations using wavelength dispersive X-ray fluorescence (WDXRF) spectrometry to analyze fluoride precipitates.

Science.gov (United States)

Lee, H. A.; Lee, J.; Kwon, E.; Kim, D.; Yoon, H. O.

2015-12-01

In recent times, fluorine has been receiving increasing attention due to the possibility for chemical (HF) leakage accidents and its high toxicity to human and environment. In this respect, a novel approach for the determination of fluorine concentrations in water samples using wavelength dispersive X-ray fluorescence (WDXRF) spectrometry was investigated in this study. The main disadvantage of WDXRF technique for fluorine analysis is low analytical sensitivity for light elements with atomic number (Z) less than 15. To overcome this problem, we employed the precipitation reaction which fluoride is reacted with cation such as Al3+ and/or Ca2+ prior to WDXRF analysis because of their high analytical sensitivity. The cation was added in fluoride solutions to form precipitate (AlF3 and/or CaF2) and then the solution was filtered through Whatman filter. After drying at 60 °C for 5 min, the filter was coated with X-ray film and directly analyzed using WDXRF spectrometry. Consequently, we analyzed the cation on filter and subsequently fluorine concentration was calculated inversely based on chemical form of precipitate. This method can improve the analytical sensitivity of WDXRF technique for fluorine analysis and be applicable to various elements that can make precipitate.

Evaluation of available analytical techniques for monitoring the quality of space station potable water