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Sample records for chromatography inductively coupled

  1. Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Douglas C., E-mail: douglas.baxter@alsglobal.com [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Faarinen, Mikko [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Osterlund, Helene; Rodushkin, Ilia [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Division of Geosciences, Lulea University of Technology, 977 87 Lulea (Sweden); Christensen, Morten [ALS Scandinavia AB, Maskinvaegen 2, 183 53 Taeby (Sweden)

    2011-09-09

    Highlights: {center_dot} We determine methylmercury in serum and plasma using isotope dilution calibration. {center_dot} Separation by gas chromatography and detection by inductively coupled plasma mass spectrometry. {center_dot} Data for 50 specimens provides first reference range for methylmercury in serum. {center_dot} Serum samples shown to be stable for 11 months in refrigerator. - Abstract: A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with {sup 198}Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) {mu}g L{sup -1} could be performed with uncertainty amplification factors <2. A limit of quantification of 0.03 {mu}g L{sup -1} was estimated at 10 times the standard deviation of concentrations measured in preparation blanks. Within- and between-run relative standard deviations were <10% at added concentration levels of 0.14 {mu}g L{sup -1}, 0.35 {mu}g L{sup -1} and 2.8 {mu}g L{sup -1}, with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; <0.03-0.19) {mu}g L{sup -1}. This is the first time methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

  2. Determination of multiple human arsenic metabolites employing high performance liquid chromatography inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Stice, Szabina; Liu, Guangliang; Matulis, Shannon; Boise, Lawrence H.; Cai, Yong

    2016-01-01

    During the metabolism of different arsenic-containing compounds in human, a variety of metabolites are produced with significantly varying toxicities. Currently available analytical methods can only detect a limited number of human metabolites in biological samples during one run due to their diverse characteristics. In addition, co-elution of species is often unnoticeable with most detection techniques leading to inaccurate metabolic profiles and assessment of toxicity. A high performance liquid chromatography inductively coupled mass spectrometry (HPLC-ICP-MS) method was developed that can identify thirteen common arsenic metabolites possibly present in human with special attention dedicated to thiolated or thiol conjugated arsenicals. The thirteen species included in this study are arsenite (AsIII), arsino-glutathione (As(GS)3), arsenate (AsV), monomethylarsonous acid (MMAIII), monomethylarsino-glutathione (MMAIII(GS)2), monomethylarsonic acid (MMAV), dimethylarsinous acid (DMAIII (from DMAIIII)), S-(dimethylarsinic)cysteine (DMAIII(Cys)), dimethylarsino-glutathione (DMAIII(GS)), dimethylarsinic acid (DMAV), dimethylmonothioarsinic acid (DMMTAV), dimethyldithioarsinic acid (DMDTAV), dimethylarsinothioyl glutathione (DMMTAV(GS)). The developed method was applied for the analysis of cancer cells that were incubated with Darinaparsin (DMAIII(GS)), a novel chemotherapeutic agent for refractory malignancies, and the arsenic metabolic profile obtained was compared to results using a previously developed method. This method provides a useful analytical tool which is much needed in unequivocally identifying the arsenicals formed during the metabolism of environmental arsenic exposure or therapeutic arsenic administration. PMID:26708625

  3. Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Baxter, Douglas C; Faarinen, Mikko; Österlund, Heléne; Rodushkin, Ilia; Christensen, Morten

    2011-09-01

    A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with (198)Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) μg L(-1) could be performed with uncertainty amplification factors levels of 0.14 μg L(-1), 0.35 μg L(-1) and 2.8 μg L(-1), with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

  4. Speciation of cisplatin in environmental water samples by hydrophilic interaction liquid chromatography coupled to inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Vidmar, Janja; Martinčič, Anže; Milačič, Radmila; Ščančar, Janez

    2015-06-01

    Cisplatin is still widely used for treatment of numerous types of tumours. Different speciation methods have been applied to study behaviour of the intact drug and its individual biotransformation species in various clinical samples. These methods are mainly based on electrophoresis, size exclusion (SEC) or ion chromatography (IC) techniques coupled to inductively coupled plasma mass spectrometry (ICP-MS). Hydrophilic interaction liquid chromatography (HILIC), which is a common technique for separation of polar substances, was rarely applied for separation of cisplatin and its hydrolysed metabolites. There is also a lack of information available on the occurrence of cisplatin and its hydrolysed complexes in the environmental waters. In the present study the concentrations of Pt were determined in hospital wastewaters by ICP-MS. A procedure for separation of cisplatin and its aqueous hydrolysed complexes by the use of HILIC column was optimized. Quantification of separated Pt species was performed by isotope dilution (ID)-ICP-MS procedure. Low limits of detection (LODs) and quantification (LOQs) were obtained for cisplatin and its hydrolysed complexes ranging from 0.0273 to 0.1726 ng Pt/mL and from 0.0909 to 0.5753 ng Pt/mL, respectively. Good repeatability of the procedure with relative standard deviation (RSD) lower than ±2.3% was obtained. The column recoveries, which ranged from 95 to 101%, indicated that the procedure developed enabled quantitative speciation analysis of aqueous cisplatin complexes. The ZIC-HILIC-ID-ICP-MS procedure was successfully applied in speciation of cisplatin in spiked hospital wastewater samples.

  5. Gas and liquid chromatography with inductively coupled plasma mass spectrometry detection for environmental speciation analysis — advances and limitations

    Science.gov (United States)

    Szpunar, Joanna; McSheehy, Shona; Połeć, Kasia; Vacchina, Véronique; Mounicou, Sandra; Rodriguez, Isaac; Łobiński, Ryszard

    2000-07-01

    Recent advances in the coupling of gas chromatography (GC) and high performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP MS) and their role in trace element speciation analysis of environmental materials are presented. The discussion is illustrated with three research examples concerning the following topics: (i) development and coupling of multicapillary microcolumn GC with ICP MS for speciation of organotin in sediment and biological tissue samples; (ii) speciation of arsenic in marine algae by size-exclusion-anion-exchange HPLC-ICP MS; and (iii) speciation of cadmium in plant cell cultures by size-exclusion HPLC-ICP MS. Particular attention is paid to the problem of signal identification in ICP MS chromatograms; the potential of electrospray MS/MS for this purpose is highlighted.

  6. Quantitative Characterization of Gold Nanoparticles by Coupling Thin Layer Chromatography with Laser Ablation Inductively Coupled Plasma Mass Spectrometry.

    Science.gov (United States)

    Yan, Neng; Zhu, Zhenli; Jin, Lanlan; Guo, Wei; Gan, Yiqun; Hu, Shenghong

    2015-06-16

    Metal nanoparticles (NPs) determination has recently attracted considerable attention because of the continuing boom of nanotechnology. In this study, a novel method for separation and quantitative characterization of NPs in aqueous suspension was established by coupling thin layer chromatography (TLC) with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Gold nanoparticles (AuNPs) of various sizes were used as the model system. It was demonstrated that TLC not only allowed separation of gold nanoparticles from ionic gold species by using acetyl acetone/butyl alcohol/triethylamine (6:3:1, v/v) as the mobile phase, but it also achieved the separation of differently sized gold nanoparticles (13, 34, and 47 nm) by using phosphate buffer (0.2 M, pH = 6.8), Triton X-114 (0.4%, w/v), and EDTA (10 mM) as the mobile phase. Various experimental parameters that affecting TLC separation of AuNPs, such as the pH of the phosphate buffer, the coating of AuNPs, the concentrations of EDTA and Triton X-114, were investigated and optimized. It was found that separations of AuNPs by TLC displayed size dependent retention behavior with good reproducibility, and the retardation factors (R(f) value) increased linearly with decreasing nanoparticle size. The analytical performance of the present method was evaluated under optimized conditions. The limits of detection were in the tens of pg range, and repeatability (RSD, n = 7) was 6.3%, 5.9%, and 8.3% for 30 ng of 13 nm AuNPs, 34 nm AuNPs, and 47 nm AuNPs, respectively. The developed TLC-LA-ICP-MS method has also been applied to the analysis of spiked AuNPs in lake water, river water, and tap water samples.

  7. Multicapillary gas chromatography coupled to inductively coupled plasma-time-of-flight mass spectrometry for rapid mercury speciation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jitaru, Petru; Goenaga Infante, Heidi; Adams, Freddy C

    2003-08-11

    A simple, rapid and accurate method on the basis of multicapillary gas chromatography (MCGC) combined with inductively coupled plasma-time-of-flight mass spectrometry (ICP-TOFMS) was developed for speciation analysis of methylmercury (MeHg{sup +}) and inorganic mercury (Hg{sup 2+}). The potential of the ICP-TOFMS for transient multi-isotope detection of very short signals (peak width of 0.4 s at half peak height) was evaluated. Two injection systems (purge-and-trap (PTI) and split (SI) injections) were compared in terms of species separation resolution and transient signal profile. Using purge-and-trap injection, after in situ derivatization of the ionic mercury species with sodium tetraethylborate, a baseline separation of MeHg{sup +} and Hg{sup 2+} was achieved within a chromatographic run of <35 s. To correct for matrix-induced ion signal variation and instrumental drift, propylmercury (PrHg{sup +}) was used as internal standard. Detection limits of 16 and 257 fg g{sup -1} for MeHg{sup +} (as Hg) and Hg{sup 2+}, respectively, were achieved. The analytical precision (R.S.D. (%)) for 10 successive injections of a standard mixture containing 10 pg MeHg{sup +} (as Hg) and Hg{sup 2+} was 1.2% for MeHg{sup +} and 4.1% for Hg{sup 2+}. The method was validated by analysis of two biological certified reference materials (CRM): a dogfish muscle (DORM-2) and a freeze-dried tuna fish (CRM 464)

  8. A Comparison between Ion chromatography and Inductively Coupled Plasma for the Determination of Bromate in Certain Samples of Foodstuffs

    Directory of Open Access Journals (Sweden)

    Alanowd O. Mehder

    2015-06-01

    Full Text Available Ion chromatography (IC and inductively coupled plasma (ICP-MS both were applied for the determination of bromate in some food samples. Attempts were made to establish calibration curves, however in case of IC, an additional abnormal peak was found to overlap with the bromate peak. This renders IC to be unsuccessful in the determination of bromate compared to ICP-MS technique. ICP-MS was found to give accurate results; therefore, it was applied for the determination of bromate in different samples of food stuffs.

  9. Novel applications of high performance ion chromatography-inductively coupled plasma mass spectrometry (HPIC-ICP-MS)

    CERN Document Server

    Hann, S

    2001-01-01

    This work demonstrates the development of highly sensitive and selective analytical methods, which make use of the hyphenation of high performance ion chromatography (HPIC) to inductively coupled plasma sector field mass spectrometry (ICP-SFMS). On-line coupling a chromatographic separation method with an elemental detection method provides two advantages: (1) the components of a possibly interfering matrix can be separated allowing accurate and precise ultra trace analysis of the element of interest and (2) elemental species of an element can be separated and quantified. In this work, matrix separation methods for interference free determination of 232Th, 234U, 235U and 238U in geological matrices were developed and employed. Furthermore HPIC-ICP-SFMS was applied for ultra trace analysis of Pd in environmental and geological matrices. The usefulness of HPIC-ICP-SFMS for speciation studies was demonstrated by investigating the interaction of an anti-cancer drug (cisplatin) with guanosine monophosphates.

  10. Methyl mercury in nail clippings in relation to fish consumption analysis with gas chromatography coupled to inductively coupled plasma mass spectrometry: a first orientation.

    Science.gov (United States)

    Krystek, Petra; Favaro, Paulo; Bode, Peter; Ritsema, Rob

    2012-08-15

    For the identification of human exposure to one of the most toxic compounds, which is methyl mercury (MeHg(+)), fingernail clippings were selected as the matrix of interest. Within this pilot study, six samples from different origins and from people with different food consumption patterns were chosen. Species-analysis of MeHg(+) was performed according to the following procedure: dissolution of the sample material in tetramethylammonium hydroxide (TMAH), derivatisation of MeHg(+) with sodium tetraethylborate (NaBEt(4)), extraction into iso-octane and measurement with gas chromatography hyphenated to inductively coupled plasma mass spectrometry (GC-ICPMS) for the quantification MeHg(+).

  11. Determination of trace mercury species by high performance liquid chromatography-inductively coupled plasma mass spectrometry after cloud point extraction.

    Science.gov (United States)

    Chen, Haiting; Chen, Jianguo; Jin, Xianzhong; Wei, Danyi

    2009-12-30

    A sensitive method for speciation analysis of inorganic mercury (Hg(2+)) and methyl mercury (MeHg(+)) has been developed by using high performance liquid chromatography (HPLC) combined with inductively coupled plasma mass spectrometry (ICP-MS) after cloud point extraction. The analytes were complexed with sodium diethyldithiocarbamate (DDTC) and preconcentrated by a non-ionic surfactant Triton X-114. Mercury species were effectively separated by HPLC in less than 6 min. The enhancement factors for 25 mL sample solution were 42 and 21, and the limits of detection were 4 and 10 ng L(-1) for Hg(2+) and MeHg(+), respectively. The developed method was successfully applied to the determination of trace amount of mercury species in environmental and biological samples.

  12. Comparative oxidation state specific analysis of arsenic species by high-performance liquid chromatography-inductively coupled-mass spectrometry and hydride generation-cryotrapping-atomic absorption spectrometry

    Science.gov (United States)

    The formation of methylarsonous acid (MAsIII) and dimethylarsinous acid (DMAsIII) in the course of inorganic arsenic (iAs) metabolism plays an important role in the adverse effects of chronic exposure to iAs. High-performance liquid chromatography-inductively coupled plasma-mass ...

  13. Determination of Total Arsenic and Speciation in Apple Juice by Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry: An Experiment for the Analytical Chemistry Laboratory

    Science.gov (United States)

    He, Ping; Colon, Luis A.; Aga, Diana S.

    2016-01-01

    A two-part laboratory experiment was designed for upper-level analytical chemistry students to provide hands-on experience in the use of high performance liquid chromatography (HPLC) for separation and inductively coupled plasma mass spectrometry (ICP-MS) for detection. In the first part of the experiment, the students analyze total arsenic in…

  14. Determination of trimethylselenonium ion in urine by ion chromatography and inductively coupled plasma mass spectrometry detection

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jessen, K.D.; Kristensen, F.H.

    2000-01-01

    The selenium species selenite, selenate, selenomethionine (SeMet), and trimethylselenonium iodide (TMSe+) were separated in aqueous solution by ion chromatography. The separation was performed on an Ionpac CS5 cation exchange column by elution with 10 mM oxalic acid and 20 mM potassium sulphate, p...

  15. Arsenic and selenium speciation in coal fly ash extracts by ion chromatography-inductively coupled plasma mass spectrometry

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    Jackson, B.P.; Miller, W.P. [University of Georgia, Aiken, SC (United States). Savannah River Ecology Lab.

    1998-10-01

    Ion chromatography (IC) coupled to inductively coupled plasma mass spectrometry (ICP-MS) was used to determine As(III), As(V), Se(IV), and Se(VI) in aqueous extracts of coal fly ash. Because all species were fully resolved, the resulting chromatograms were obtained by summing signal intensities for m/z 75 + m/z 82. Absolute detection limits of 7.2, 87, 117 and 28 pg for As(III), Se(IV), Se(VI), and As(V) respectively, were obtained corresponding to 0.072, 0.868, 1.174, and 0.284 {mu} gl{sup -1} for 100 {mu} l injection volume. The technique was used to determine the speciation of As and Se in aqueous extracts of 24 coal fly ash samples including NIST SRM 1633 b. The predominant species were As(V) and Se(IV), with As(III) detected in two low pH fly ashes. Extraction of fly ashes at pH 5 altered the concentrations of total soluble As and Se but did not affect the predominant As and Se speciation.

  16. Separation of gold, palladium and platinum in chromite by anion exchange chromatography for inductively coupled plasma atomic emission spectrometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kwang Soon; Lee, Chang Heon; Park, Yeong Jae; Joe, Kih Soo; Kim, Won Ho [KAERI, Taejon (Korea, Republic of)

    2001-08-01

    A study has been carried out on the separation of gold, iridium, palladium, rhodium, ruthenium and platinum in chromite samples and their quantitative determination using inductively coupled plasma atomic emission spectrometry (ICP-AES). The dissolution condition of the minerals by fusion with sodium peroxide was optimized and chromatographic elution behavior of the rare metals was investigated by anion exchange chromatography. Spectral interference of chromium, a matrix of the minerals, was investigated on determination of gold. Chromium interfered on determination of gold at the concentration of 500 mg/L and higher. Gold plus trace amounts of iridium, palladium, rhodium and ruthenium, which must be preconcentrated before ICP-AES was separated by anion exchange chromatography after reducing Cr(VI) to Cr(III) by H{sub 2}O{sub 2}. AuCl{sup -}{sub 4} retained on the resin column was selectively eluted with acetone- HNO{sub 3}-H{sub 2}O as an eluent. In addition, iridium, palladium, rhodium and ruthenium remaining on the resin column were eluted as a group with concentrated HCl. However, platinum was eluted with concentrated HNO{sub 3}. The recovery yield of gold with acetone-HNO{sub 3}-H{sub 2}O was 100.7 {+-} 2.0 % , and the yields of palladium and platinum with concentrated HCl and HNO{sub 3} were 96.1 {+-} 1.8% and 96.6 {+-} 1.3%, respectively. The contents of gold and platinum in a Mongolian chromite sample were 32.6 {+-} 2.2 {mu}g/g and 1.6 {+-} 0.14 {mu}g/g, respectively. Palladium was not detected.

  17. Speciation analysis of mercury in cereals by liquid chromatography chemical vapor generation inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Lin, Liang-Yen; Chang, Lan-Fang; Jiang, Shiuh-Jen

    2008-08-27

    A simple and rapid procedure for the separation and determination of inorganic, methyl, and ethyl mercury compounds was described using liquid chromatography (LC) followed by vapor generation inductively coupled plasma-mass spectrometry (VG-ICP-MS). Well resolved chromatograms were obtained within 5 min by reversed-phase liquid chromatography with a C8 column as the stationary phase and a pH 4.7 solution containing 0.5% v/v 2-mercaptoethanol and 5% v/v methanol as the mobile phase. The separated mercury compounds were converted to mercury vapors by an in situ nebulizer/vapor generation system for their introduction into ICP. The concentrations of NaBH4 and HNO3 required for vapor generation were also optimized. The method was applied for the speciation of mercury in reference materials NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour and also rice flour and wheat flour samples purchased locally. The accuracy of the procedure was verified by analyzing the certified reference material NRCC DOLT-3 Dogfish Liver for methyl mercury. Precision between sample replicates was better than 13% for all the determinations. The detection limits of the mercury compounds studied were in the range 0.003-0.006 ng Hg mL(-1) in the injected solutions, which correspond to 0.02-0.06 ng g(-1) in original flour samples. A microwave-assisted extraction procedure was adopted for the extraction of mercury compounds from rice flour, wheat flour, and fish samples using a mobile phase solution.

  18. Speciation of vanadium in oilsand coke and bacterial culture by high performance liquid chromatography inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, X. Sherry [Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2 (Canada); Le, X. Chris [Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2 (Canada); Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta T6G 2G3 (Canada)], E-mail: xc.le@ualberta.ca

    2007-10-17

    A simple and sensitive method for the speciation of vanadium(III), (IV), and (V) was developed by using high performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICPMS). The EDTA-complexed vanadium species were separated on a strong anion exchange column with an eluent containing 2 mM EDTA, 3% acetonitrile, and 80 mM ammonium bicarbonate at pH 6. Each analysis was complete in 5 min. The detection limits were 0.6, 0.7 and 1.0 {mu}g L{sup -1} for V(III), V(IV), and V(V), respectively. The method was applied to coke pore water samples from an oilsand processing/upgrading site in Fort McMurray, Alberta, Canada and to Shewanella putrefaciens CN32 bacterial cultures incubated with V(V). In the coke pore water samples, V(IV) and V(V) were found to be the major species. For the first time, V(III) was detected in the bacterial cultures incubated with V(V)

  19. High performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry for V and Ni quantification as tetrapyrroles

    Energy Technology Data Exchange (ETDEWEB)

    Duyck, Christiane Beatrice, E-mail: cbduyck@vm.uff.br [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), R. Marques de Sao Vicente, 225, Gavea, Rio de Janeiro, RJ, 22451-900 (Brazil); Universidade Federal Fluminense (UFF), Campus do Valonguinho, Outeiro de Sao Joao Batista, s/no, 24020-150, Niteroi, RJ (Brazil); Saint' Pierre, Tatiana Dillenburg; Miekeley, Norbert [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), R. Marques de Sao Vicente, 225, Gavea, Rio de Janeiro, RJ, 22451-900 (Brazil); Oliveira da Fonseca, Teresa Cristina; Szatmari, Peter [Centro de Pesquisas Leopoldo A. Miguez de Mello da Petrobras (CENPES), Av. Horacio Macedo, 950, Cidade Universitaria, Rio de Janeiro, RJ, 21941-915 (Brazil)

    2011-05-15

    A method was developed for the determination of V and Ni as tetrapyrroles by High Performance Liquid Chromatography hyphenated to Inductively Coupled Plasma Mass Spectrometry (HPLC-ICP-MS) using reversed phase and elution gradient. Chlorinated solvents and tetrahydrofuran were investigated as regard to separation time and ICP-MS detection efficiencies. The final elution gradient program started from pure methanol to a mixture of 20:80 (v/v) chloroform:methanol. External quantification of V and Ni with inorganic standards by flow injection ICP-MS, used online with HPLC, resulted in 95% of recoveries. The Limits of Detection for V during methanol elution and for Ni during the 20% chloroform gradient elution were evaluated by their minimum detectable concentrations, which were, respectively, 5 {mu}g L{sup -1} and 8 {mu}g L{sup -1}. The methodology was applied to polar and resin fractions separated from a Brazilian crude oil and a sediment extract from an oil-polluted area in the Guanabara Bay, Rio de Janeiro, Brazil. Vanadium as tetrapyrroles represented the totality of V content in the polar fraction, whereas Ni was in different polar forms in the resin and sediment extract.

  20. Fingerprinting of complex mixtures with the use of high performance liquid chromatography, inductively coupled plasma atomic emission spectroscopy and chemometrics

    Energy Technology Data Exchange (ETDEWEB)

    Ni Yongnian [Department of Chemistry, Nanchang University, Nanchang, Jiangxi 330047 (China)], E-mail: ynni@ncu.edu.cn; Peng Yunyan [Department of Chemistry, Nanchang University, Nanchang, Jiangxi 330047 (China); Kokot, Serge [Inorganic Materials Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, Queensland 4001 (Australia)

    2008-05-26

    The molecular and metal profile fingerprints were obtained from a complex substance, Atractylis chinensis DC-a traditional Chinese medicine (TCM), with the use of the high performance liquid chromatography (HPLC) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) techniques. This substance was used in this work as an example of a complex biological material, which has found application as a TCM. Such TCM samples are traditionally processed by the Bran, Cut, Fried and Swill methods, and were collected from five provinces in China. The data matrices obtained from the two types of analysis produced two principal component biplots, which showed that the HPLC fingerprint data were discriminated on the basis of the methods for processing the raw TCM, while the metal analysis grouped according to the geographical origin. When the two data matrices were combined into a one two-way matrix, the resulting biplot showed a clear separation on the basis of the HPLC fingerprints. Importantly, within each different grouping the objects separated according to their geographical origin, and they ranked approximately in the same order in each group. This result suggested that by using such an approach, it is possible to derive improved characterisation of the complex TCM materials on the basis of the two kinds of analytical data. In addition, two supervised pattern recognition methods, K-nearest neighbors (KNNs) method, and linear discriminant analysis (LDA), were successfully applied to the individual data matrices-thus, supporting the PCA approach.

  1. High performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry for V and Ni quantification as tetrapyrroles

    Science.gov (United States)

    Duyck, Christiane Béatrice; Saint'Pierre, Tatiana Dillenburg; Miekeley, Norbert; da Fonseca, Teresa Cristina Oliveira; Szatmari, Peter

    2011-05-01

    A method was developed for the determination of V and Ni as tetrapyrroles by High Performance Liquid Chromatography hyphenated to Inductively Coupled Plasma Mass Spectrometry (HPLC-ICP-MS) using reversed phase and elution gradient. Chlorinated solvents and tetrahydrofuran were investigated as regard to separation time and ICP-MS detection efficiencies. The final elution gradient program started from pure methanol to a mixture of 20:80 (v/v) chloroform:methanol. External quantification of V and Ni with inorganic standards by flow injection ICP-MS, used online with HPLC, resulted in 95% of recoveries. The Limits of Detection for V during methanol elution and for Ni during the 20% chloroform gradient elution were evaluated by their minimum detectable concentrations, which were, respectively, 5 μg L - 1 and 8 μg L - 1 . The methodology was applied to polar and resin fractions separated from a Brazilian crude oil and a sediment extract from an oil-polluted area in the Guanabara Bay, Rio de Janeiro, Brazil. Vanadium as tetrapyrroles represented the totality of V content in the polar fraction, whereas Ni was in different polar forms in the resin and sediment extract.

  2. Speciation of gadolinium in surface water samples and plants by hydrophilic interaction chromatography hyphenated with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Lindner, Uwe; Lingott, Jana; Richter, Silke; Jakubowski, Norbert; Panne, Ulrich

    2013-02-01

    Hydrophilic interaction chromatography (HILIC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) was optimized for speciation analysis of gadolinium-based contrast agents in environmental samples, in particular surface river waters and plants. Surface water samples from the Teltow channel, near Berlin, were investigated over a distance of 5 km downstream from the influx of a wastewater treatment plant. The total concentration of gadolinium increased significantly from 50 to 990 ng L(-1) due to the influx of the contrast agents. After complete mixing with the river water, the concentration remained constant over a distance of at least 4 km. Two main substances [Dotarem(®) (Gd-DOTA) and Gadovist(®) (Gd-BT-DO3A)] have been identified in the river water using standards. A gadolinium-based contrast agent, possibly Gd-DOTA (Dotarem(®)), was also detected in water plant samples taken from the Teltow channel. Therefore, uptake of contrast agents [Gadovist(®) (Gd-BTDO3A), Magnevist(®) (Gd-DTPA), Omniscan(®) (Gd-DTPA-BMA), Dotarem(®) (Gd-DOTA), and Multihance(®) (Gd-BOPTA)] by plants was investigated in a model experiment using Lepidium sativum (cress plants). HILIC-ICP-MS was used for identification of different contrast agents, and a first approach for quantification using aqueous standard solutions was tested. For speciation analysis, all investigated contrast agents could be extracted from the plant tissues with a recovery of about 54 % for Multihance(®) (Gd-BOPTA) up to 106 % for Gadovist(®) (Gd-BT-DO3A). These experiments demonstrate that all contrast agents investigated are transported from the roots to the leaves where the highest content was measured.

  3. Evaluation of hydrodynamic chromatography coupled with UV-visible, fluorescence and inductively coupled plasma mass spectrometry detectors for sizing and quantifying colloids in environmental media.

    Directory of Open Access Journals (Sweden)

    Allan Philippe

    Full Text Available In this study, we evaluated hydrodynamic chromatography (HDC coupled with inductively coupled plasma mass spectrometry (ICP-MS for the analysis of nanoparticles in environmental samples. Using two commercially available columns (Polymer Labs-PDSA type 1 and 2, a set of well characterised calibrants and a new external time marking method, we showed that flow rate and eluent composition have few influence on the size resolution and, therefore, can be adapted to the sample particularity. Monitoring the agglomeration of polystyrene nanoparticles over time succeeded without observable disagglomeration suggesting that even weak agglomerates can be measured using HDC. Simultaneous determination of gold colloid concentration and size using ICP-MS detection was validated for elemental concentrations in the ppb range. HDC-ICP-MS was successfully applied to samples containing a high organic and ionic background. Indeed, online combination of UV-visible, fluorescence and ICP-MS detectors allowed distinguishing between organic molecules and inorganic colloids during the analysis of Ag nanoparticles in synthetic surface waters and TiO₂ and ZnO nanoparticles in commercial sunscreens. Taken together, our results demonstrate that HDC-ICP-MS is a flexible, sensitive and reliable method to measure the size and the concentration of inorganic colloids in complex media and suggest that there may be a promising future for the application of HDC in environmental science. Nonetheless the rigorous measurements of agglomerates and of matrices containing natural colloids still need to be studied in detail.

  4. Determination of selenite and selenate in human urine by ion chromatography and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jons, O.

    2000-01-01

    monitored in the inductively coupled plasma mass spectrometry (ICP-MS) detector. When the chromatographic system was applied to analysis of urine samples diluted 1 + 1, the selenomethionine signal appeared in the front together with other unresolved selenium species, while the selenite and selenate signals...

  5. Determination of 20 trace elements and arsenic species for a realgar-containing traditional Chinese medicine Niuhuang Jiedu tablets by direct inductively coupled plasma-mass spectrometry and high performance liquid chromatography-inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Jin, Pengfei; Liang, Xiaoli; Xia, Lufeng; Jahouh, Farid; Wang, Rong; Kuang, Yongmei; Hu, Xin

    2016-01-01

    Niuhuang Jiedu tablet (NHJDT) is a realgar-containing traditional Chinese medicine. A direct inductively coupled plasma-mass spectrometry (ICP-MS) method for the simultaneous determination of 20 trace elements (Mg, K, Ca, Na, Fe, As, Zn, Sr, Ba, Cu, Mn, Ni, Pb, V, Cr, Se, Co, Mo, Cd, Hg) in NHJDT, as well as in water, gastric fluid and intestinal fluid was established. Meanwhile, a high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) method was developed for the determination of arsenite (As(III)), arsenate (As(V)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and for the identification of arsenobetaine (AsB) and arsenocholine (AsC) in these extracts. Both methods were fully validated in the respect of linearity, sensitivity, precision, stability and accuracy. The reliability of the ICP-MS method was further evaluated using a certified standard reference material prepared from dried tomato leaves (NIST, SRM 1572a). The analysis showed that some manufacturers formulated lower amount of realgar than required in the Chinese Pharmacopoeia (ChP) in their preparations. In addition, almost same extraction profiles for total As and inorganic As were found in water and in gastrointestinal fluids, while higher extraction rates for other 19 elements were observed in gastrointestinal fluids. Our findings show that the toxicities of Hg, Cu, Cd and Pb in NHJDP are low, while the real As toxicity in NHJDT should be deeply investigated.

  6. Liquid chromatography-inductively coupled plasma-based metallomic approaches to probe health-relevant interactions between xenobiotics and mammalian organisms.

    Science.gov (United States)

    Gómez-Ariza, José Luis; Jahromi, Elham Zeini; González-Fernández, Macarena; García-Barrera, Tamara; Gailer, Jürgen

    2011-06-01

    In mammals, the transport of essential elements from the gastrointestinal tract to organs is orchestrated by biochemical mechanisms which have evolved over millions of years. The subsequent organ-based assembly of sufficient amounts of metalloproteins is a prerequisite to maintain mammalian health and well-being. The chronic exposure of various human populations to environmentally abundant toxic metals/metalloid compounds and/or the deliberate administration of medicinal drugs, however, can adversely affect these processes which may eventually result in disease. A better understanding of the perturbation of these processes has the potential to advance human health, but their visualization poses a major problem. Nonetheless, liquid chromatography-inductively coupled plasma-based 'metallomics' methods, however, can provide much needed insight. Size-exclusion chromatography-inductively coupled plasma atomic emission spectrometry, for example, can be used to visualize changes that toxic metals/medicinal drugs exert at the metalloprotein level when they are added to plasma in vitro. In addition, size-exclusion chromatography-inductively coupled plasma mass spectrometry can be employed to analyze organs from toxic metal/medicinal drug-exposed organisms for metalloproteins to gain insight into the biochemical changes that are associated with their acute or chronic toxicity. The execution of such studies-from the selection of an appropriate model organism to the generation of accurate analytical data-is littered with potential pitfalls that may result in artifacts. Drawing on recent lessons that were learned by two research groups, this tutorial review is intended to provide relevant information with regard to the experimental design and the practical application of these aforementioned metallomics tools in applied health research.

  7. Separation of silver ions and starch modified silver nanoparticles using high performance liquid chromatography with ultraviolet and inductively coupled mass spectrometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, Traci A.; Saadawi, Ryan; Zhang, Peng; Caruso, Joseph A., E-mail: joseph.caruso@uc.edu; Landero-Figueroa, Julio

    2014-10-01

    The production of commercially available products marketed to contain silver nanoparticles is rapidly increasing. Species-specific toxicity is a phenomenon associated with many elements, including silver, making it imperative to develop a method to identify and quantify the various forms of silver (namely, silver ions vs. silver nanoparticles) possibly present in these products. In this study a method was developed using high performance liquid chromatography (HPLC) with ultraviolet (UV–VIS) and inductively coupled mass spectrometric (ICP-MS) detection to separate starch stabilized silver nanoparticles (AgNPs) and silver ions (Ag{sup +}) by cation exchange chromatography with 0.5 M nitric acid mobile phase. The silver nanoparticles and ions were baseline resolved with an ICP-MS response linear over four orders of magnitude, 0.04 mg kg{sup −1} detection limit, and 90% chromatographic recovery for silver solutions containing ions and starch stabilized silver nanoparticles smaller than 100 nm.

  8. Separation of silver ions and starch modified silver nanoparticles using high performance liquid chromatography with ultraviolet and inductively coupled mass spectrometric detection

    Science.gov (United States)

    Hanley, Traci A.; Saadawi, Ryan; Zhang, Peng; Caruso, Joseph A.; Landero-Figueroa, Julio

    2014-10-01

    The production of commercially available products marketed to contain silver nanoparticles is rapidly increasing. Species-specific toxicity is a phenomenon associated with many elements, including silver, making it imperative to develop a method to identify and quantify the various forms of silver (namely, silver ions vs. silver nanoparticles) possibly present in these products. In this study a method was developed using high performance liquid chromatography (HPLC) with ultraviolet (UV-VIS) and inductively coupled mass spectrometric (ICP-MS) detection to separate starch stabilized silver nanoparticles (AgNPs) and silver ions (Ag+) by cation exchange chromatography with 0.5 M nitric acid mobile phase. The silver nanoparticles and ions were baseline resolved with an ICP-MS response linear over four orders of magnitude, 0.04 mg kg- 1 detection limit, and 90% chromatographic recovery for silver solutions containing ions and starch stabilized silver nanoparticles smaller than 100 nm.

  9. Speciation of eight arsenic compounds in human urine by high performance liquid chromatography with inductively coupled plasma mass spectrometric detection using antimonate for internal chromatographic standardization

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Pritzl, G.; Hansen, S. H.

    1993-01-01

    Four anionic and four cationic arsenic compounds in urine were separated by anion- and cation-exchange high-performance liquid chromatography and detected by inductively coupled plasma mass spectrometry (ICP-MS) at m/z 75. The species were the anions arsenite, arsenate, monomethylarsonate...... and dimethylarsinate and the cations arsenobetaine, trimethylarsine oxide, arsenocholine and the tetramethylarsonium ion. Hexahydroxyantimonate(III) was co-chromatographed with the arsenic anions but detected at m/z 121 and used as an internal standard for their qualitative analysis. Arsenite was prone to oxidation...... to arsenate in urine but was stable after at least 4-fold dilution of the urine with water. Arsenite was unstable in both urine samples and standard mixtures when diluted with the basic (pH 10.3) mobile phase used for anion chromatography. This could not be prevented by adding ascorbic acid as antioxidant...

  10. Survey of inorganic arsenic in marine animals and marine certified reference materials by anion exchange high-performance liquid chromatography-inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt; Julshamn, Kåre

    2005-01-01

    A method for the determination of inorganic arsenic in seafood samples using high-performance liquid chromatography-inductively coupled plasma mass spectrometry is described. The principle of the method relied on microwave-assisted alkaline dissolution of the sample, which at the same time oxidized...... arsenite [As(Ill)] to arsenate [As(V)], whereby inorganic arsenic could be determined as the single species As(V). Anion exchange chromatography using isocratic elution with aqueous ammonium carbonate as the mobile phase was used for the separation of As(V) from other coextracted organoarsenic compounds......, including arsenobetaine. The stability of organoarsenic compounds during the sample pretreatment was investigated, and no degradation/conversion to inorganic arsenic was detected. The method was employed for the determination of inorganic arsenic in a variety of seafood samples including fish, crustaceans...

  11. Towards silicon speciation in light petroleum products using gas chromatography coupled to inductively coupled plasma mass spectrometry equipped with a dynamic reaction cell

    Energy Technology Data Exchange (ETDEWEB)

    Chainet, Fabien, E-mail: fabien.chainet@ifpen.fr [IFP Energies nouvelles, Rond-point de l' échangeur de Solaize, BP 3, 69360 Solaize (France); Lienemann, Charles-Philippe; Ponthus, Jeremie [IFP Energies nouvelles, Rond-point de l' échangeur de Solaize, BP 3, 69360 Solaize (France); Pécheyran, Christophe; Castro, Joaudimir; Tessier, Emmanuel; Donard, Olivier François Xavier [LCABIE-IPREM, UMR 5254, CNRS-UPPA, Helioparc, 2 av. Pr. Angot, 64053 Pau (France)

    2014-07-01

    Silicon speciation has recently gained interest in the oil and gas industry due to the significant poisoning problems caused by silicon on hydrotreatment catalysts. The poisoning effect clearly depends on the structure of the silicon species which must be determined and quantified. The hyphenation of gas chromatography (GC) coupled to inductively coupled plasma mass spectrometry (ICP-MS) allows a specific detection to determine the retention times of all silicon species. The aim of this work is to determine the retention indices of unknown silicon species to allow their characterization by a multi-technical approach in order to access to their chemical structure. The optimization of the dynamic reaction cell (DRC) of the ICP-MS using hydrogen as reactant gas successfully demonstrated the resolution of the interferences ({sup 14}N{sup 14}N{sup +} and {sup 12}C{sup 16}O{sup +}) initially present on {sup 28}Si. The linearity was excellent for silicon compounds and instrumental detection limits ranged from 20 to 140 μg of Si/kg depending on the response of the silicon compounds. A continuous release of silicon in the torch was observed most likely due to the use of a torch and an injector which was made of quartz. A non-universal response for silicon was observed and it was clearly necessary to use response coefficients to quantify silicon compounds. Known silicon compounds such as cyclic siloxanes (D{sub 3}–D{sub 16}) coming from PDMS degradation were confirmed. Furthermore, more than 10 new silicon species never characterized before in petroleum products were highlighted in polydimethylsiloxane (PDMS) degradation samples produced under thermal cracking of hydrocarbons. These silicon species mainly consisted of linear and cyclic structures containing reactive functions such as ethoxy, peroxide and hydroxy groups which can be able to react with the alumina surface and hence, poison the catalyst. This characterization will further allow the development of innovative

  12. Hyphenation of ultra performance liquid chromatography (UPLC) with inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of bromine containing preservatives

    DEFF Research Database (Denmark)

    Bendahl, Lars; Hansen, Steen Honoré; Gammelgaard, Bente

    2006-01-01

    Ultra performance liquid chromatography (UPLC) was coupled to inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of three bromine-containing preservatives, monitoring the 79Br and 81Br isotopes simultaneously. Due to the efficiency of the 1.7 microm column packing material...... at an intermediate and at a high linear velocity. The precision was better than 2.2% R.S.D. and regression analysis showed that a linear response was achieved at both flow rates (R2 > 0.9993, n = 36). The analysis time was less than 4.5 min at a flow rate of 50 microL min(-1) and limits of detection...

  13. Inductively Coupled Augmented Railgun

    CERN Document Server

    Bahder, Thomas B

    2011-01-01

    We derive the non-linear dynamical equations for an augmented electromagnetic railgun, whose augmentation circuit is inductively coupled to the gun circuit. We solve these differential equations numerically using example parameter values. We find a complicated interaction between the augmentation circuit, gun circuit, and mechanical degrees of freedom, leading to a complicated optimization problem. For certain values of parameters, we find that an augmented electromagnetic railgun has an armature kinetic energy that is 42% larger than the same railgun with no augmentation circuit. Optimizing the parameters may lead to further increase in performance.

  14. Development of an analytical method for the determination of polybrominated diphenyl ethers in sewage sludge by the use of gas chromatography coupled to inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Novak, Petra [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, Jamova 39, 1000, Ljubljana (Slovenia); Zuliani, Tea [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana (Slovenia); Milačič, Radmila [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, Jamova 39, 1000, Ljubljana (Slovenia); Ščančar, Janez, E-mail: janez.scancar@ijs.si [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000, Ljubljana (Slovenia); Jožef Stefan International Postgraduate School, Jamova 39, 1000, Ljubljana (Slovenia)

    2016-04-07

    Polybrominated diphenyl ethers (PBDEs) are flame retardants. As a consequence of their widespread use, they have been released into the environment. PBDEs are lipophilic organic contaminants that enter wastewater treatment plants (WWTPs) from urban, agricultural and industrial discharges. Because of their low aqueous solubility and resistance to biodegradation, up to 90% of the PBDEs are accumulated in the sewage sludge during the wastewater treatment. To assess the possibilities for sludge re-use, a reliable determination of the concentrations of these PBDEs is of crucial importance. Six PBDE congeners (BDE 28, BDE 47, BDE 99, BDE 100, BDE 153 and BDE 154) are listed as priority substances under the EU Water Framework Directive. In the present work a simple analytical method with minimal sample-preparation steps was developed for a sensitive and reliable determination of the six PBDEs in sewage sludge by the use of gas chromatography coupled to inductively coupled plasma mass spectrometry (GC-ICP-MS). For this purpose an extraction procedure was optimised. Different extracting agents (methanol (MeOH), acetic acid (AcOH)/MeOH mixture (3:1) and 0.1 mol L{sup −1} hydrochloric acid (HCl) in MeOH) followed by the addition of a Tris-citrate buffer (co-extracting agent) and iso-octane were applied under different modes of extraction (mechanical shaking, microwave- and ultrasound-assisted extraction). Mechanical shaking or the microwave-assisted extraction of sewage sludge with 0.1 mol L{sup −1} HCl in MeOH and the subsequent addition of the Tris-citrate buffer and the iso-octane extracted the PBDEs from the complex sludge matrix most effectively. However, due to easier sample manipulation during the extraction step, mechanical shaking was used. The PBDEs in the organic phase were quantified with GC-ICP-MS by applying a standard addition calibration method. The spike recovery test (recoveries between 95 and 104%) and comparative analyses with the species

  15. Method optimization and quality assurance in speciation analysis using high performance liquid chromatography with detection by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt

    1998-01-01

    operating characteristics of the entire hyphenated system. An isocratic HPLC system, which employs an aqueous mobile phase with organic buffer constituents, is well suited for introduction into the ICP-MS because of the stability of the detector response and high degree of analyte sensitivity attained......Achievement of optimum selectivity, sensitivity and robustness in speciation analysis using high performance liquid chromatography (HPLC) with inductively coupled mass spectrometry (ICP-MS) detection requires that each instrumental component is selected and optimized with a view to the ideal....... Anion and cation exchange HPLC systems, which meet these requirements, were used for the separation of selenium and arsenic species in crude extracts of biological samples. Furthermore, the signal-to-noise ratios obtained for these incompletely ionized elements in the argon ICP were further enhanced...

  16. Arsenic speciation in seafood samples with emphasis on minor constituents. An investigation by high performance liquid chromatography with inductively coupled plasma mass spectrometric detection

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Pritzl, G.; Hansen, S. H.

    1993-01-01

    Extracts of 11 samples of shrimp, crab, fish, fish liver, shellfish and lobster digestive gland (hepatopancreas), including five certified reference materials, were investigated for their contents of arsenic compounds (arsenic speciation). The cation-exchange high performance liquid chromatography...... procedure was optimized to separate six cationic arsenicals present in the samples with internal chromatographic standardization by the trimethylselenonium ion, which was detected a m/z 82 (Se-82), in addition to arsenic at m/z 75, by inductively coupled plasma mass spectrometry. The content of each species...... gland, and another unknown (U2) was present at 0.2-6.4% in all samples. The contents of arsenite and arsenate were 0-1.4%, dimethylarsinate 8.2-29% while monomethylarsonate was detected only in oyster at 0.3% of the total extracted arsenic. Finding tetramethylarsonium ion and arsenocholine in a variety...

  17. Analysis of Organic and Inorganic Arsenic in Waste Water of Agricultural Environment by High Performance Liquid Chromatography and Inductively Coupled Plasma Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    SHAN Hong

    2014-04-01

    Full Text Available A high performance liquid chromatography and inductively coupled plasma mass spectrometric method was established for analyz-ing 4 arsenic speciations in water of agricultural environment, including As(Ⅲ,MMA, DMA and As( V.The results showed that the method had a wide linear range(1~300 μg·L-1and the linear coefficients were more than 0.999 0. The detection limits were very low ( 0.7-0.9μg·L-1.All of the relative standard deviations(RSD were less than 5%. The recoveries were between 94% and 112%. The analysis results showed that As( Vand As(Ⅲwere the main arsenic speciations existed in the waste water of agricultural environment.

  18. A rapid monitoring method for inorganic arsenic in rice flour using reversed phase-high performance liquid chromatography-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Narukawa, Tomohiro; Chiba, Koichi; Sinaviwat, Savarin; Feldmann, Jörg

    2017-01-06

    A new rapid monitoring method by means of high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) following the heat-assisted extraction was developed for measurement of total inorganic arsenic species in rice flour. As(III) and As(V) eluted at the same retention time and completely separated from organoarsenic species by an isocratic elution program on a reversed phase column. Therefore, neither ambiguous oxidation of arsenite to arsenate nor the integration of two peaks were necessary to determine directly the target analyte inorganic arsenic. Rapid injection allowed measuring 3 replicates within 6min and this combined with a quantitative extraction of all arsenic species from rice flour by a 15min HNO3-H2O2 extraction makes this the fastest laboratory based method for inorganic arsenic in rice flour.

  19. Determination of methylmercury in the tuna tissue by High performance liquid chromatography with Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    LV Lei; Jiang Zhi-gang; Li Qun; Zhang Shuai

    2009-01-01

    This study mainly applied one kind oftechnologies to determine the methylmercury in the tuna tissue with high performance liquid chromagraphy-inductively coupled plasma nlass spectrometry.We choosed the optmaum conditiom including that the mobile phase Was water with 5% methanol,2-mercaptoethanol,0.06mol/Lammomum acetate and pH6.8.The sample amount was 1OOuL and the flow rate was 0.4mL/min.The optimum checking conditions is that RF power was 1500W,integral time was 0.3s sampling depth Was 8.0mm,velocity of carrier gas Was 0.75L/min and velocity of auxiliary gas Was 0.40L/min.In this con~tiom.the calibration CUrVe was linear when the concentra tions od methylmercury was in the range of 0-4ug/mL(r=0.9996),the detection limit can achieve 9ng/L,RSD is 8.2%,and the addition recovery is 75%-97%.The results show this method is simple,rapid and sensitive and can be used for the daily analysis of tuna samples.

  20. Speciation of arsenic in different types of nuts by ion chromatography-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Kannamkumarath, Sasi S; Wróbel, Kazimierz; Wróbel, Katarzyna; Caruso, Joseph A

    2004-03-24

    In this work the quantitative determination and analytical speciation of arsenic were undertaken in different types of nuts, randomly purchased from local markets. The hardness of the whole nuts and high lipid content made the preparation of this material difficult for analysis. The lack of sample homogeneity caused irreproducible results. To improve the precision of analysis, arsenic was determined separately in nut oil and in the defatted sample. The lipids were extracted from the ground sample with the two portions of a mixture of chloroform and methanol (2:1). The defatted material was dried and ground again, yielding a fine powder. The nut oil was obtained by combining the two organic extracts and by evaporating the solvents. The two nut fractions were microwave digested, and total arsenic was determined by inductively coupled plasma mass spectrometry (ICP-MS). The results obtained for oils from different types of nuts showed element concentration in the range 2.9-16.9 ng g(-)(1). Lower levels of arsenic were found in defatted material (pine nuts, peanuts, pistachio nuts, and sunflower seeds. The recovery for the speciation procedure was in the range 72.7-90.6%. The primary species found in the oil extracts were As(III) and As(V). The arsenic concentration levels in these two species were 0.7-12.7 and 0.5-4.3 ng g(-)(1), respectively. The contribution of As in DMAs(V) ranged from 0.1 +/- 0.1 ng g(-)(1) in walnuts to 1.3 +/- 0.3 ng g(-)(1) in pine nuts. MMAs(V) was not detected in almonds, peanuts, pine nuts, sunflower seeds, or walnuts, and the highest concentration was found in pistachio nuts (0.5 +/- 0.2 ng g(-)(1)).

  1. Method for the quantification of vanadyl porphyrins in fractions of crude oils by High Performance Liquid Chromatography-Flow Injection-Inductively Coupled Plasma Mass Spectrometry

    Science.gov (United States)

    Wandekoken, Flávia G.; Duyck, Christiane B.; Fonseca, Teresa C. O.; Saint'Pierre, Tatiana D.

    2016-05-01

    High performance liquid chromatography hyphenated by flow injection to inductively coupled plasma mass spectrometry (HPLC-FI-ICP-MS) was used to investigate V linked to porphyrins present in fractions of crude oil. First, the crude oil sample was submitted to fractionation by preparative liquid chromatography with UV detection, at the porphyrin Soret band wavelength (400 nm). The obtained porphyrin fractions were then separated in a 250 mm single column, in the HPLC, and eluted with different mobile phases (methanol or methanol:toluene (80:20; v:v)). The quantification of V-porphyrins in the fractions eluted from HPLC was carried out by online measuring the 51V isotope in the ICP-MS, against vanadyl octaethylporphine standard solutions (VO-OEP), prepared in the same solvent as the mobile phase, and injected post-column directly into the plasma. A 20 μg L- 1 Ge in methanol was used as internal standard for minimizing non-spectral interference, such as short-term variations due to injection. The mathematical treatment of the signal based on Fast Fourier Transform smoothing algorithm was employed to improve the precision. The concentrations of V as V-porphyrins were between 2.7 and 11 mg kg- 1 in the fractions, which were close to the total concentration of V in the porphyrin fractions of the studied crude oil.

  2. Speciation of the bio-available iodine and bromine forms in edible seaweed by high performance liquid chromatography hyphenated with inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Romaris-Hortas, Vanessa; Bermejo-Barrera, Pilar [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n. 15782 - Santiago de Compostela (Spain); Moreda-Pineiro, Jorge [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira, s/n. 15071, A Coruna (Spain); Moreda-Pineiro, Antonio, E-mail: antonio.moreda@usc.es [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n. 15782 - Santiago de Compostela (Spain)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Bioavailable iodine and bromine speciation in edible seaweed were developed. Black-Right-Pointing-Pointer In vitro dialyzability was used to assess the bioavailable fractions. Black-Right-Pointing-Pointer AEC hyphenated with inductively coupled plasma-mass spectrometry was used. Black-Right-Pointing-Pointer Iodide, MIT, DIT, bromide and bromate were found in dialyzates from edible seaweed. Black-Right-Pointing-Pointer Positive correlation between bioavailability and protein contents was found. - Abstract: A bioavailability study based on an in vitro dialyzability approach has been applied to assess the bio-available fractions of iodine and bromine species from edible seaweed. Iodide, iodate, 3-iodo-tyrosine (MIT), 3,5-diiodo-tyrosine (DIT), bromide and bromate were separated by anion exchange chromatography under a gradient elution mode (175 mM ammonium nitrate plus 15% (v/v) methanol, pH 3.8, as a mobile phase, and flow rates within the 0.5-1.5 mL min{sup -1} range). Inductively coupled plasma-mass spectrometry (ICP-MS) was used as a selective detector for iodine ({sup 127}I) and bromine ({sup 79}Br). Low dialyzability ratios (within the 2.0-18% range) were found for iodine species; whereas, moderate dialyzability percentages (from 9.0 to 40%) were obtained for bromine species. Iodide and bromide were the major species found in the dialyzates from seaweed, although MIT and bromate were also found in the dialyzates from most of the seaweed samples analysed. However, DIT was only found in dialyzates from Wakame, Kombu, and NIES 09 (Sargasso) certified reference material; whereas, iodate was not found in any dialyzate. Iodine dialyzability was found to be dependent on the protein content (negative correlation), and on the carbohydrate and dietary fibre levels (positive correlation). However, bromine dialyzability was only dependent on the protein amount in seaweed (negative correlation).

  3. Ion-pair chromatography coupled to inductively coupled plasma-mass spectrometry (IPC-ICP-MS) as a method for thiomolybdate speciation in natural waters.

    Science.gov (United States)

    Lohmayer, Regina; Reithmaier, Gloria Maria Susanne; Bura-Nakić, Elvira; Planer-Friedrich, Britta

    2015-03-17

    Molybdenum precipitates preferentially under reducing conditions; therefore, its occurrence in sediment records is used as an indicator of paleoredox conditions. Although thiomolybdates (MoO4-xSx(2-) with x = 1-4) supposedly are necessary intermediates in the process of molybdenum precipitation under anoxic conditions, there is no information about their abundance in natural environments, because of a lack of element-specific methods with sufficiently low detection limits. Here, we optimized ion-pair chromatographic separation for coupling to an inductively coupled plasma-mass spectrometry detector (IPC-ICP-MS). 2-Propanol (10%-25% gradient) replaced the previously used acetonitrile (25%-75%) as the solvent, to reduce the carbon load into the plasma. In synthetic solutions, formation of thiomolybdates was found to occur spontaneously in the presence of excess sulfide and the degree of thiolation was highest at pH 7. Excess hydroxyl led to a transformation of thiomolybdates to molybdate. Under acidic to neutral conditions, precipitation of molybdenum and hydrolysis of tetrathiomolybdate were observed. Flash-freezing was found to be suitable to stabilize tetrathiomolybdate, with 2 mM) negatively affected the detection of molybdate, which eluted mainly in the dead volume, but had no negative effect on higher thiolated molybdates. Detection limits were ∼10 nM. With the newly developed IPC-ICP-MS method, thiomolybdates were found to form spontaneously in euxinic marine waters after adding a molybdate spike and occur naturally in sulfidic geothermal waters.

  4. Speciation of Selenium in Selenium-Enriched Sunflower Oil by High-Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry/Electrospray-Orbitrap Tandem Mass Spectrometry.

    Science.gov (United States)

    Bierla, Katarzyna; Flis-Borsuk, Anna; Suchocki, Piotr; Szpunar, Joanna; Lobinski, Ryszard

    2016-06-22

    The reaction of sunflower oil with selenite produces a complex mixture of selenitriglycerides with antioxidant and anticancer properties. To obtain insight into the identity and characteristics of the species formed, an analytical approach based on the combination of high-performance liquid chromatography (HPLC) with (78)Se-specific selenium detection by inductively coupled plasma mass spectrometry (ICP MS) and high-resolution (100 000), high mass accuracy (sunflower oil dissolved in isopropanol and methanol extract of the oil containing 65% selenium. HPLC-ICP MS showed 14 peaks, 11 of which could also be detected in the methanol extract. Isotopic patterns corresponding to molecules with one or two selenium atoms could be attributed by Orbitrap MS at the retention times corresponding to the HPLC-ICP MS peak apexes. Structural data for these species were acquired by MS(2) and MS(3) fragmentation of protonated or sodiated ions using high-energy collisional dissociation (HCD). A total of 11 selenium-containing triglycerol derivatives resulting from the oxidation of one or two double bonds of linoleic acid and analogous derivatives of glycerol-mixed linoleate(s)/oleinate(s) have been identified for the first time. The presence of these species was confirmed by the targeted analysis in the total oil isopropanol solution. Their identification corroborated the predicted elution order in reversed-phase chromatography: LLL (glycerol trilinoleate), LLO (glycerol dilinoleate-oleinate), LOO (glycerol linoleate-dioleinate), OOO (glycerol trioleinate), of which the extrapolation allowed for the prediction of the identity [glycerol dioleinate-stearate (OOS) and glycerol oleinate-distearate (OSS)] of the nonpolar species detected by ICP MS in the oil but not detected by electrospray MS.

  5. Speciation of mercury in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Jia, Xiaoyu; Han, Yi; Liu, Xinli; Duan, Taicheng; Chen, Hangting

    2011-01-01

    The dispersive liquid-liquid microextraction (DLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry for the speciation of mercury in water samples was described. Firstly methylmercury (MeHg +) and mercury (Hg 2+) were complexed with sodium diethyldithiocarbamate, and then the complexes were extracted into carbon tetrachloride by using DLLME. Under the optimized conditions, the enrichment factors of 138 and 350 for MeHg + and Hg 2+ were obtained from only 5.00 mL sample solution. The detection limits of the analytes (as Hg) were 0.0076 ng mL -1 for MeHg + and 0.0014 ng mL -1 for Hg 2+, respectively. The relative standard deviations for ten replicate measurements of 0.5 ng mL -1 MeHg + and Hg 2+ were 6.9% and 4.4%, respectively. Standard reference material of seawater (GBW(E)080042) was analyzed to verify the accuracy of the method and the results were in good agreement with the certified values. Finally, the developed method was successfully applied for the speciation of mercury in three environmental water samples.

  6. Arsenic Species in Edible Seaweeds Using In Vitro Biomimetic Digestion Determined by High-Performance Liquid Chromatography Inductively Coupled Plasma Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Yan-Fang Zhao

    2014-01-01

    Full Text Available Arsenite [As (III], arsenate [As (V], methylarsonate (MMA, and dimethylarsinate (DMA in five edible seaweeds (the brown algae Laminaria japonica, red algae Porphyra yezoensis, brown algae Undaria pinnatifida, brown algae Hizikia fusiformis, and green algae Enteromorpha prolifera were analyzed using in vitro digestion method determined by high-performance liquid chromatography inductively coupled plasma mass spectrometry. The results showed that DMA was found in the water extracts of all samples; As (III were detected in L. japonica and U. pinnatifida and about 23.0 and 0.15 mg/kg of As (V were found in H. fusiformis and E. prolifera respectively. However, after the gastrointestinal digestion, As (V was not detected in any of the five seaweeds. About 0.19 and 1.47 mg/kg of As (III was detected in the gastric extracts of L. japonica and H. fusiformis, respectively, and about 0.31 and 0.10 mg/kg of As (III were extracted from the intestinal extracts of Porphyra yezoensis and U. pinnatifida, respectively. The present results successfully reveal the differences of As species and levels in the water and biomimetic extracts of five edible seaweeds. The risk assessment of the inorganic arsenic in the five edible seaweeds based on present data showed almost no hazards to human health.

  7. Speciation of mercury in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jia Xiaoyu; Han Yi; Liu Xinli [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Duan Taicheng, E-mail: tcduan@ciac.jl.cn [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China); Chen Hangting, E-mail: htchen@ciac.jl.cn [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China)

    2011-01-15

    The dispersive liquid-liquid microextraction (DLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry for the speciation of mercury in water samples was described. Firstly methylmercury (MeHg{sup +}) and mercury (Hg{sup 2+}) were complexed with sodium diethyldithiocarbamate, and then the complexes were extracted into carbon tetrachloride by using DLLME. Under the optimized conditions, the enrichment factors of 138 and 350 for MeHg{sup +} and Hg{sup 2+} were obtained from only 5.00 mL sample solution. The detection limits of the analytes (as Hg) were 0.0076 ng mL{sup -1} for MeHg{sup +} and 0.0014 ng mL{sup -1} for Hg{sup 2+}, respectively. The relative standard deviations for ten replicate measurements of 0.5 ng mL{sup -1} MeHg{sup +} and Hg{sup 2+} were 6.9% and 4.4%, respectively. Standard reference material of seawater (GBW(E)080042) was analyzed to verify the accuracy of the method and the results were in good agreement with the certified values. Finally, the developed method was successfully applied for the speciation of mercury in three environmental water samples.

  8. Determination of vanadium species in sediment, mussel and fish muscle tissue samples by liquid chromatography-inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Colina, Marinela [Universidad del Zulia, Facultad de Ciencias, Departamento de Quimica, Laboratorio de Quimica Ambiental, Maracaibo 4011, Zulia (Venezuela)]. E-mail: M.Colina@shu.ac.uk; Gardiner, P.H.E. [Sheffield Hallam University, Howard Street, Sheffield S1 1WB, Sheffield (United Kingdom); Rivas, Zulay [Instituto para la Conservacion del Lago de Maracaibo (ICLAM), Maracaibo, Plaza de las Banderas (Venezuela); Troncone, Federico [Instituto para la Conservacion del Lago de Maracaibo (ICLAM), Maracaibo, Plaza de las Banderas (Venezuela)

    2005-05-04

    Vanadium is introduced into the environment during the extraction of petrochemical products and in the production of steels and insecticides. In this study, a liquid chromatographic method for the separation of V(IV) and V(V) as ethylenediaminetetra acetic acid (EDTA) complexes was developed using reversed-phase ion-pair liquid chromatography with inductively coupled plasma-mass spectrometry detection. A C-8 reversed-phase column, 15 cm long, was used to separate the species. A solution containing ammonium acetate 0.06 M, tetrabutylammonium hydroxide 10 mM, ammonium di-phosphate 10 mM and EDTA 2.5 mM at pH 6 was used as the mobile phase in order to avoid the use of organic solvents that reduce the sensitivity of the determination. To prevent changes in distribution of the vanadium species, samples should be prepared freshly. The method developed was applied to the study the vanadium speciation in sediment, mussel and fish muscle samples collected from Lake Maracaibo, Venezuela. The concentration ranges of V(IV) and V(V) in sediment samples were 0.7-61 and 1.4-2.3 {mu}g g{sup -1}, respectively. The method is simple and has adequate sensitivity for these practical applications.

  9. Development of an ion chromatography-inductively coupled plasma-mass spectrometry method to determine inorganic arsenic in liver from chickens treated with roxarsone.

    Science.gov (United States)

    Conklin, Sean D; Shockey, Nohora; Kubachka, Kevin; Howard, Karyn D; Carson, Mary C

    2012-09-19

    Roxarsone, (4-hydroxy-3-nitrophenyl)arsonic acid, is an arsenic-containing compound that has been approved as a feed additive for poultry and swine since the 1940s; however, little information is available regarding residual arsenic species present in edible tissues. We developed a novel method for the extraction and quantification of arsenic species in chicken liver. A strongly basic solution solubilized the liver, and ultrafiltration removed macromolecules and particulate material. Ion chromatography separated the species [arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, (4-hydroxy-3-aminophenyl)arsonic acid, (4-hydroxy-3-acetaminophenyl)arsonic acid, and roxarsone] in the extracts, which were then detected by inductively coupled plasma-mass spectrometry. The extraction oxidized most arsenite to arsenate. For fortification concentrations at 2 μg kg(-1) and above, recoveries ranged from 70 to 120%, with relative standard deviations from 7 to 34%. We detected roxarsone, its 3-amino and 3-acetamido metabolites, inorganic arsenic, and additional unknown arsenic species in livers from roxarsone-treated chickens. Both the originating laboratory and a second laboratory validated the method.

  10. Speciation analysis of mercury by solid-phase microextraction and multicapillary gas chromatography hyphenated to inductively coupled plasma-time-of-flight-mass spectrometry.

    Science.gov (United States)

    Jitaru, Petru; Adams, Freddy C

    2004-11-05

    This paper reports the development of an analytical approach for speciation analysis of mercury at ultra-trace levels on the basis of solid-phase microextraction and multicapillary gas chromatography hyphenated to inductively coupled plasma-time-of-flight mass spectrometry. Headspace solid-phase microextraction with a carboxen/polydimethylsyloxane fiber is used for extraction/preconcentration of mercury species after derivatization with sodium tetraethylborate and subsequent volatilization. Isothermal separation of methylmercury (MeHg), inorganic mercury (Hg2+) and propylmercury (PrHg) used as internal standard is achieved within a chromatographic run below 45 s without the introduction of spectral skew. Method detection limits (3 x standard deviation criteria) calculated for 10 successive injections of the analytical reagent blank are 0.027 pg g(-1) (as metal) for MeHg and 0.27 pg g(-1) for Hg2+. The repeatability (R.S.D., %) is 3.3% for MeHg and 3.8% for Hg2+ for 10 successive injections of a standard mixture of 10pg. The method accuracy for MeHg and total mercury is validated through the analysis of marine and estuarine sediment reference materials. A comparison of the sediment data with those obtained by a purge-and-trap injection (PTI) method is also addressed. The analytical procedure is illustrated with some results for the ultra-trace level analysis of ice from Antarctica for which the accuracy is assessed by spike recovery experiments.

  11. Determination of mercury compounds in fish by microwave-assisted extraction and liquid chromatography-vapor generation-inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Chiou, Chwei-Sheng; Jiang, Shiuh-Jen; Kumar Danadurai, K. Suresh

    2001-07-01

    A method employing a vapor generation system and LC combined with inductively coupled plasma mass spectrometry (LC-ICP-MS) is presented for the determination of mercury in biological tissues. An open vessel microwave digestion system was used to extract the mercury compounds from the sample matrix. The efficiency of the mobile phase, a mixture of L-cysteine and 2-mercaptoethanol, was evaluated for LC separation of inorganic mercury [Hg(II)], methylmercury (methyl-Hg) and ethylmercury (ethyl-Hg). The sensitivity, detection limits and repeatability of the liquid chromatography (LC) ICP-MS system with a vapor generator were comparable to, or better than, that of an LC-ICP-MS system with conventional pneumatic nebulization, or other sample introduction techniques. The experimental detection limits for various mercury species were in the range of 0.05-0.09 ng ml -1 Hg, based on peak height. The proposed method was successfully applied to the determination of mercury compounds in a swordfish sample purchased from the local market. The accuracy of the method was evaluated by analyzing a marine biological certified reference material (DORM-2, NRCC).

  12. Simultaneous determination of arsenic and mercury species in rice by ion-pairing reversed phase chromatography with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Fang, Yong; Pan, Yushi; Li, Peng; Xue, Mei; Pei, Fei; Yang, Wenjian; Ma, Ning; Hu, Qiuhui

    2016-12-15

    An analytical method using reversed phase chromatography-inductively coupled plasma mass spectrometry for arsenic and mercury speciation analysis was described. The effect of ion-pairing reagent on simultaneous separation of four arsenic (arsenite, arsenate, monomethlyarsonate and dimethylarsinate) and three mercury species (inorganic mercury (Hg(II)), methylmecury and ethylmercury) was investigated. Parameters including concentrations and pH of the mobile phase were optimized. The separation and re-equilibration time was attained within 20min. Meanwhile, a sequential extraction method for arsenic and mercury in rice was tested. Subsequently, 1% HNO3 microwave-assisted extraction was chosen. Calibration curves based on peak area measurements were linear with correlation coefficient greater than 0.9958 for each species in the range studied. The detection limits of the species were in the range of 0.84-2.41μg/L for arsenic and 0.01-0.04μg/L for mercury, respectively. The proposed method was then successfully applied for the simultaneous determination of arsenic and mercury species in rice flour standard material and two kinds of rice from local markets.

  13. Simultaneous pressurized enzymatic hydrolysis extraction and clean up for arsenic speciation in seafood samples before high performance liquid chromatography-inductively coupled plasma-mass spectrometry determination.

    Science.gov (United States)

    Moreda-Piñeiro, Jorge; Alonso-Rodríguez, Elia; Moreda-Piñeiro, Antonio; Moscoso-Pérez, Carmen; Muniategui-Lorenzo, Soledad; López-Mahía, Purificación; Prada-Rodríguez, Darío; Bermejo-Barrera, Pilar

    2010-10-29

    The feasibility of pressurized conditions to assist enzymatic hydrolysis of seafood tissues for arsenic speciation was novelty studied. A simultaneous in situ (in cell) clean-up procedure was also optimized, which speeds up the whole sample treatment. Arsenic species (As(III), MMA, DMA, As(V), AsB and AsC) were released from dried seafood tissues using pepsin as a protease, and the arsenic species were separated/quantified by anion exchange high performance liquid chromatography (HPLC) coupled to inductively coupled plasma-mass spectrometry (ICP-MS). Variables inherent to the enzymatic activity (pH, temperature and ionic strength), the amount of enzyme (pepsin), and factors affecting pressurization (pressure, static time, number of cycles and amount of dispersing agent, C-18) were fully evaluated. Pressurized assisted enzymatic hydrolysis (PAEH) with pepsin can be finished after few minutes (two cycles of 2 min each one plus 3 min to reach the hydrolysis temperature of 50 °C). A total sample solubilisation is not achieved after the procedure, however it is efficient enough for breaking down certain bonds of bio-molecules and for releasing arsenic species. The developed method has been found to be precise (RSDs lower than 6% for As(III), DMA and As(V); and 3% for AsB) and sensitive (LOQs of 18.1, 36.2, 35.7, 28.6, 20.6 and 22.5 ng/g for As(III), MMA, DMA, As(V), AsB and AsC, respectively). The optimized methodology was successfully applied to different certified reference materials (DORM-2 and BCR 627) which offer certified AsB and DMA contents, and also to different seafood products (mollusks, white fishes and cold water fishes).

  14. Determination of (236)U in environmental samples by single extraction chromatography coupled to triple-quadrupole inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-11-09

    In order to measure trace (236)U and (236)U/(238)U in environmental samples with a high matrix effect, a novel and simple method was developed that makes the digestion and purification procedures compatible with advanced triple-quadrupole inductively coupled plasma-mass spectrometry. A total dissolution of sample with HF + HNO3 + HClO4 was followed by chromatographic separation with a single resin column containing normal type DGA resin (N,N,N',N'-tetra-n-octyldiglycolamide) as the extractant system. The analytical accuracy and precision of (236)U/(238)U ratios, measured as (236)U(16)O(+)/(238)U(16)O(+), were examined by using the reference materials IAEA-135, IAEA-385, IAEA-447, and JSAC 0471. The low method detection limit (3.50 × 10(-6) Bq kg(-1)) makes it possible to perform routine monitoring of environmental (236)U due to global fallout combined with the Fukushima Daiichi Nuclear Power Plant accident fallout (>10(-5) Bq kg(-1)). Finally, the developed method was successfully applied to measure (236)U/(238)U ratios and (236)U activities in soil samples contaminated by the accident. The low (236)U/(238)U atom ratios ((1.50-13.5) × 10(-8)) and (236)U activities ((2.25-14.1) × 10(-2) mBq kg(-1)) indicate (236)U contamination was mainly derived from global fallout in the examined samples.

  15. Bead Injection Extraction Chromatography using High-capacity Lab-on-Valve as a Front End to Inductively Coupled Plasma Mass Spectrometry for Rapid Urine Radiobioassay

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per

    2013-01-01

    A novel bead injection (BI) extraction chromatographic microflow system exploiting high-capacity lab-on-valve (LOV) platform coupled with inductively coupled plasma mass spectrometric detection is developed for rapid and automated determination of plutonium in human urine. A microconduit (1 mL) i...

  16. Speciation analysis of arsenic in prenatal and children's dietary supplements using microwave-enhanced extraction and ion chromatography-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Wolle, Mesay M; Rahman, G M Mizanur; Kingston, H M Skip; Pamuku, Matt

    2014-03-25

    A study was conducted to develop a microwave-enhanced extraction method for the determination of arsenic species in prenatal and children's dietary supplements prepared from plant materials. The method was optimized by evaluating the efficiency of various solutions previously used to extract arsenic from the types of plant materials used in the dietary supplement formulations. A multivitamin standard reference material (NIST SRM 3280) and a prenatal supplement sample were analyzed in the method optimization. The identified optimum conditions were 0.25 g of sample, 5 mL of 0.3 mol L(-1) orthophosphoric acid (H3PO4) and microwave heating at 90 °C for 30 min. The extracted arsenic was speciated by cation exchange ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP-MS). The method detection limit (MDL) for the arsenic species was in the range 2-8 ng g(-1). Ten widely consumed prenatal and children's dietary supplements were analyzed using the optimized protocol. The supplements were found to have total arsenic in the concentration range 59-531 ng g(-1). The extraction procedure recovered 61-92% of the arsenic from the supplements. All the supplementary products were found to contain arsenite (As(3+)) and dimethylarsinic acid (DMA). Arsenate (As(5+)) was found in two of the supplements, and an unknown specie of arsenic was detected in one product. The results of the analysis were validated using mass balance by comparing the sum of the extracted and non-extracted arsenic with the total concentration of the element in the corresponding samples.

  17. Method development for the redox speciation analysis of iron by ion chromatography-inductively coupled plasma mass spectrometry and carryover assessment using isotopically labeled analyte analogues.

    Science.gov (United States)

    Wolle, Mesay Mulugeta; Fahrenholz, Timothy; Rahman, G M Mizanur; Pamuku, Matt; Kingston, H M 'Skip'; Browne, Damien

    2014-06-20

    An ion chromatography-inductively coupled plasma mass spectrometry (IC-ICP-MS) method was developed for the redox speciation analysis of iron (Fe) based on in-column complexation of Fe(2+) and Fe(3+) by dipicolinic acid (DPA). The effects of column type, mobile phase composition and molecular ion interference were studied in the method optimization. The carryover of the target species in the IC-ICP-MS method was uniquely and effectively evaluated using isotopically enriched analogues of the analytes ((54)Fe(2+) and (57)Fe(3+)). Standard solutions of the enriched standards were injected into the system following analysis of a sample, and the ratios of the isotopes of iron in the enriched standards were calculated based on the chromatographic peak areas. The concentrations of the analytes carried over from the sample to the enriched standards were determined using the quantitative relationship in isotope dilution mass spectrometry (IDMS). In contrast to the routine way of evaluating carryover effect by injecting a blank solution after sample analysis, the use of isotopically enriched standards identified significant analyte carryover in the present method. Extensive experiments were carried out to systematically identify the source of the carryover and to eliminate the problem; the separation column was found to be the exclusive source. More than 95% of the analyte carryover was eliminated by reducing the length of the column. The detection limit of the IC-ICP-MS method (MDL) for the iron species was 2ngg(-1). The method was used to determine Fe(2+) and Fe(3+) in synthetic aqueous standard solutions and a beverage sample.

  18. Quantitative Metabolite Profiling of an Amino Group Containing Pharmaceutical in Human Plasma via Precolumn Derivatization and High-Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry.

    Science.gov (United States)

    Li, Sanwang; Klencsár, Balázs; Balcaen, Lieve; Cuyckens, Filip; Lynen, Frederic; Vanhaecke, Frank

    2017-02-07

    Quantitative determination of the candidate drug molecule and its metabolites in biofluids and tissues is an inevitable step in the development of new pharmaceuticals. Because of the time-consuming and expensive nature of the current standard technique for quantitative metabolite profiling, i.e., radiolabeling followed by high-performance liquid chromatography (HPLC) with radiodetection, the development of alternative methodologies is of great interest. In this work, a simple, fast, sensitive, and accurate method for the quantitative metabolite profiling of an amino group containing drug (levothyroxine) and its metabolites in human plasma, based on precolumn derivatization followed by HPLC-inductively coupled plasma mass spectrometry (ICPMS), was developed and validated. To introduce a suitable "heteroelement" (defined here as an element that is detectable with ICPMS), an inexpensive and commercially available reagent, tetrabromophthalic anhydride (TBPA) was used for the derivatization of free NH2-groups. The presence of a known number of I atoms in both the drug molecule and its metabolites enabled a cross-validation of the newly developed derivatization procedure and quantification based on monitoring of the introduced Br. The formation of the derivatives was quantitative, providing a 4:1 stoichiometric Br/NH2 ratio. The derivatives were separated via reversed-phase HPLC with gradient elution. Bromine was determined via ICPMS at a mass-to-charge ratio of 79 using H2 as a reaction gas to ensure interference-free detection, and iodine was determined at a mass-to-charge ratio of 127 for cross-validation purposes. The method developed shows a fit-for-purpose accuracy (recovery between 85% and 115%) and precision (repeatability <15% RSD). The limit of quantification (LoQ) for Br was approximately 100 μg/L.

  19. Simultaneous Cu-, Fe-, and Zn-specific detection of metalloproteins contained in rabbit plasma by size-exclusion chromatography-inductively coupled plasma atomic emission spectroscopy.

    Science.gov (United States)

    Manley, Shawn A; Byrns, Simon; Lyon, Andrew W; Brown, Peter; Gailer, Jürgen

    2009-01-01

    Analytical methods which are capable of determining the plasma or serum metalloproteome have inherent diagnostic value for human diseases associated with increased or decreased concentrations of specific plasma metalloproteins. We have therefore systematically developed a method to rapidly determine the major Cu-, Fe-, and Zn-containing metalloproteins in rabbit plasma (0.5 mL) based on size-exclusion chromatography (SEC; stationary phase Superdex 200, mobile phase phosphate-buffered saline pH 7.4) and the simultaneous online detection of Cu, Fe, and Zn in the column effluent by an inductively coupled plasma atomic emission spectrometer (ICP-AES). Whereas most previous studies reported on the analysis of serum, our investigations clearly demonstrated that the analysis of plasma within 30 min of collection results in the detection of one more Cu peak (blood coagulation factor V) than has been previously reported (transcuprein, ceruloplasmin, albumin-bound Cu, and small molecular weight Cu). The average amount of Cu associated with these five proteins corresponded to 21, 18, 21, 30 and 10% of total plasma Cu, respectively. In contrast, only two Fe metalloproteins (ferritin and transferrin, corresponding to an average of 9 and 91% of total plasma Fe) and approximately five Zn metalloproteins (alpha(2)-macroglobulin and albumin-bound Zn, which corresponded to an average of 10 and 57% of total [corrected] plasma Zn) were detected. Metalloproteins were assigned on the basis of the coelution of the corresponding metal and protein identified by immunoassays or activity-based enzyme assays. The SEC-ICP-AES approach developed allowed the determination of approximately 12 Cu, Fe, and Zn metalloproteins in rabbit plasma within approximately 24 min and can be applied to analyze human plasma, which is potentially useful for diagnosing Cu-, Fe-, and Zn-related diseases.

  20. Multielemental fractionation in pine nuts (Pinus pinea) from different geographic origins by size-exclusion chromatography with UV and inductively coupled plasma mass spectrometry detection.

    Science.gov (United States)

    Gómez-Ariza, J L; Arias-Borrego, A; García-Barrera, T

    2006-07-21

    Pine nuts (Pinus pinea) from different geographical origin in Spain and Portugal have been investigated concerning total element content and metal-biomolecules size distribution patterns Mn, Zn, Ni and Cu. All the studied metals were at the highest concentration in pine nuts from Faro and at the lowest from Cataluña. The most abundant element in samples was Mn at concentrations in the range of 26 microg g(-1) (Cataluña) to 559 microg g(-1) (Faro). Zn was also present at high concentration in samples, from 25 microg g(-1) (Cataluña) to 113 microg g(-1) (Faro). To a deeper insight to obtain classification rules for samples, pine nuts were analyzed by size-exclusion chromatography (SEC) with UV detection and inductively coupled plasma mass spectrometry (ICP-MS). Two columns were used covering the molecular weigh range from pine nuts from Huelva. This column allows good discrimination in the range of 2126-1352 Da in which a lot of peaks can be used to differentiate samples. The UV profiles obtained with the high molecular weight (HMW) column allows a poorer differentiation of samples, but pine nuts from Huelva, Castilla and Madrid are clearly distinguished to the others. In relation to fractionation patterns of metals, Mn allows a good discrimination between samples (LMW column), Cu was the only one associated to fractions at MW > 70 kDa in sample from Cádiz, and profiles of Ni and Zn are clearly different in terms of abundance of peaks. All these chromatographic profiles for elements give valuable information about the geographical origin of the studied samples and the differences found are discussed in this work.

  1. High-temperature liquid chromatography inductively coupled plasma atomic emission spectrometry hyphenation for the combined organic and inorganic analysis of foodstuffs.

    Science.gov (United States)

    Terol, Amanda; Paredes, Eduardo; Maestre, Salvador E; Prats, Soledad; Todolí, José L

    2010-10-01

    The coupling of a High-Temperature Liquid Chromatography system (HTLC) with an Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) is reported for the first time. This hyphenation combines the separation efficiency of HTLC with the detection power of a simultaneous ICP-AES system and allows the combined determination of organic compound and metals. The effluents of the column were introduced into the spectrometer and the chromatograms for organic compounds were obtained by plotting the carbon emission signal at a characteristic wavelength versus time. As regards metals, they were determined by injecting a small sample volume between the exit of the column and the spectrometer and taking the emission intensity for each one of the elements simultaneously. Provided that in HTLC the effluents emerged at high temperatures, an aerosol was easily generated at the exit of the column. Therefore, the use of a pneumatic nebulizer as a component of a liquid sample introduction system in the ICP-AES could be avoided, thus reducing the peak dispersion and limits of detection by a factor of two. The fact that a hot liquid stream was nebulized made it necessary to use a thermostated spray chamber so as to avoid the plasma cooling as a cause of the excessive mass of solvent delivered to it. Due to the similarity in sample introduction, an Evaporative Light Scattering Detector (ELSD) was taken as a reference. Comparatively speaking, limits of detection were of the same order for both HTLC-ICP-AES and HTLC-ELSD, although the latter provided better results for some compounds (from 10 to 20 mg L(-1) and 5-10 mg L(-1), respectively). In contrast, the dynamic range for the new hyphenation was about two orders of magnitude wider. More importantly, HTLC-ICP-AES provided information about the content of both organic (glucose, sucrose, maltose and lactose at concentrations from roughly 10 to 400 mg L(-1)) as well as inorganic (magnesium, calcium, sodium, zinc, potassium and

  2. Comparison of an ultrasonic nebulizer with a cross-flow nebulizer for selenium speciation by ion-chromatography and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jons, O.

    2000-01-01

    The purpose of this work was to compare an ultrasonic nebulizer (USN) with a cross-flow nebulizer (CFN) for selenium speciation with inductively coupled plasma mass spectrometry (ICP-MS) detection. The influence of instrumental parameters as well as composition of the solvent on the selenium...

  3. Closed inductively coupled plasma cell

    Science.gov (United States)

    Manning, Thomas J.; Palmer, Byron A.; Hof, Douglas E.

    1990-01-01

    A closed inductively coupled plasma cell generates a relatively high power, low noise plasma for use in spectroscopic studies. A variety of gases can be selected to form the plasma to minimize spectroscopic interference and to provide a electron density and temperature range for the sample to be analyzed. Grounded conductors are placed at the tube ends and axially displaced from the inductive coil, whereby the resulting electromagnetic field acts to elongate the plasma in the tube. Sample materials can be injected in the plasma to be excited for spectroscopy.

  4. Total zinc quantification by inductively coupled plasma-mass spectrometry and its speciation by size exclusion chromatography-inductively coupled plasma-mass spectrometry in human milk and commercial formulas: Importance in infant nutrition.

    Science.gov (United States)

    Fernández-Menéndez, Sonia; Fernández-Sánchez, María L; Fernández-Colomer, Belén; de la Flor St Remy, Rafael R; Cotallo, Gil Daniel Coto; Freire, Aline Soares; Braz, Bernardo Ferreira; Santelli, Ricardo Erthal; Sanz-Medel, Alfredo

    2016-01-01

    This paper summarises results of zinc content and its speciation in human milk from mothers of preterm and full-term infants at different stages of lactation and from synthetic formula milks. Human milk samples (colostrum, 7th, 14th, and 28th day after delivery) from Spanish and Brazilian mothers of preterm and full-term infants (and also formula milks) were collected. After adequate treatment of the sample, total Zn was determined, while speciation analysis of the Zn was accomplished by size exclusion chromatography coupled online with the ICP-MS. It is observed that total zinc content in human milk decreases continuously during the first month of lactation, both for preterm and full term gestations. All infant formulas analysed for total Zn were within the currently legislated levels. For Zn speciation analysis, there were no differences between preterm and full term human milk samples. Moreover Zn species elute mainly associated with immunoglobulins and citrate in human milk whey. Interestingly the speciation in formula milk whey turned out to be completely different as the observed Zn(2+) was bound almost exclusively to low molecular weight ligands (citrate) and only comparatively very low amounts of the metal appeared to be associated with higher mass biomolecules (e.g. proteins).

  5. Rapid determination of {sup 135}Cs and precise {sup 135}Cs/{sup 137}Cs atomic ratio in environmental samples by single-column chromatography coupled to triple-quadrupole inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guosheng [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing 100049 (China); Tazoe, Hirofumi [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan); Yamada, Masatoshi, E-mail: myamada@hirosaki-u.ac.jp [Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564 (Japan)

    2016-02-18

    For source identification, measurement of {sup 135}Cs/{sup 137}Cs atomic ratio not only provides information apart from the detection of {sup 134}Cs and {sup 137}Cs, but it can also overcome the application limit that measurement of the {sup 134}Cs/{sup 137}Cs ratio has due to the short half-life of {sup 134}Cs (2.06 y). With the recent advancement of ICP-MS, it is necessary to improve the corresponding separation method for rapid and precise {sup 135}Cs/{sup 137}Cs atomic ratio analysis. A novel separation and purification technique was developed for the new generation of triple-quadrupole inductively coupled plasma-mass spectrometry (ICP-MS/MS). The simple chemical separation, incorporating ammonium molybdophosphate selective adsorption of Cs and subsequent single cation-exchange chromatography, removes the majority of isobaric and polyatomic interference elements. Subsequently, the ICP-MS/MS removes residual interference elements and eliminates the peak tailing effect of stable {sup 133}Cs, at m/z 134, 135, and 137. The developed analytical method was successfully applied to measure {sup 135}Cs/{sup 137}Cs atomic ratios and {sup 135}Cs activities in environmental samples (soil and sediment) for radiocesium source identification. - Highlights: • A simple {sup 135}Cs/{sup 137}Cs analytical method was developed. • The separation procedure was based on AMP adsorption and one column chromatography. • {sup 135}Cs/{sup 137}Cs was measured by ICP-MS/MS. • Decontamination factors for Ba, Mo, Sb, and Sn were improved. • {sup 135}Cs/{sup 137}Cs atomic ratios of 0.341–0.351 were found in Japanese soil samples.

  6. Determination of glyphosate and AMPA in surface and waste water using high-performance ion chromatography coupled to inductively coupled plasma dynamic reaction cell mass spectrometry (HPIC-ICP-DRC-MS).

    Science.gov (United States)

    Popp, Maximilian; Hann, Stephan; Mentler, Axel; Fuerhacker, Maria; Stingeder, Gerhard; Koellensperger, Gunda

    2008-05-01

    A novel method employing high-performance cation chromatography in combination with inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS) for the simultaneous determination of the herbicide glyphosate (N-phosphonomethylglycine) and its main metabolite aminomethyl phosphonic acid (AMPA) is presented. P was measured as (31)P(16)O(+) using oxygen as reaction gas. For monitoring the stringent target value of 0.1 μg L(-1) for glyphosate, applicable for drinking and surface water within the EU, a two-step enrichment procedure employing Chelex 100 and AG1-X8 resins was applied prior to HPIC-ICP-MS analysis. The presented approach was validated for surface water, revealing concentrations of 0.67 μg L(-1) glyphosate and 2.8 μg L(-1) AMPA in selected Austrian river water samples. Moreover, investigations at three waste water-treatment plants showed that elimination of the compounds at the present concentration levels was not straightforward. On the contrary, all investigated plant effluents showed significant amounts of both compounds. Concentration levels ranged from 0.5-2 μg L(-1) and 4-14 μg L(-1) for glyphosate and AMPA, respectively.

  7. Speciation of manganese binding to biomolecules in pine nuts (Pinus pinea) by two-dimensional liquid chromatography coupled to ultraviolet and inductively coupled plasma mass spectrometry detectors followed by identification by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Arias-Borrego, Ana; García-Barrera, Tamara; Gómez-Ariza, José L

    2008-10-01

    Advances in analytical methodology for speciation of manganese in pine nuts are presented in this work. The approach is based on the use of orthogonal chromatographic systems, namely size-exclusion chromatography (SEC) of the extracts and strong anion exchange (IEC) of the fractions collected by the first column. In both columns, manganese elution is first monitored by a quadrupole inductively coupled plasma mass spectrometry (ICP-MS) instrument equipped with an octopole reaction cell and an ultraviolet (UV) detector. SEC is performed by using two columns covering the molecular weight range from pine nuts samples and the presence of Mn-citrate is confirmed by nanoelectrospray ionization quadrupole time-of-flight mass spectrometry (nESI-QqTOF-MS). In the same fraction, a third Mn-containing peak is detected in the IEC-UV-ICP-MS chromatogram. This peak corresponds to a protein containing Mn that was later submitted to a tryptic digestion and analyzed by nESI-QqTOF. The MS/MS data of a doubly charged peptide are used to obtain the sequence of the protein with the Mascot search engine. The peak turned out to be isocitrate dehydrogenase, a protein commonly associated with Mn.

  8. Fractionation of phosphorus and trace elements species in soybean flour and common white bean seeds by size exclusion chromatography-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Koplík, Richard; Pavelková, Hana; Cincibuchová, Jana; Mestek, Oto; Kvasnicka, Frantisek; Suchánek, Miloslav

    2002-04-25

    Soluble species of phosphorus, sulfur, selenium and eight metals (Mn, Fe, Co, Ni, Cu, Zn, Mo and Cd) in soybean flour and common white bean seeds were investigated by size exclusion chromatography (SEC) and inductively coupled plasma mass spectrometry (ICP-MS). Samples were extracted by 0.02 mol l(-1) Tris-HCI buffer solution (pH 7.5). Fractionation of sample extracts by preparative scale SEC was accomplished using a Fractogel EMD BioSEC column (600 x 16 mm) and 0.02 mol l(-1) Tris-HCl buffer solution (pH 7.5) as mobile phase (flow rate: 2 ml min(-1)). A 2-ml sample was injected. Contents of elements in chromatographic fractions were determined by AAS, ICP-AES and ICP-MS. The elution profiles of P, Fe, Co, Ni, Cu, Zn and Mo in both samples were similar. Main species of Co, Ni, Cu, Zn and Mo were found in the low molecular weight region (2-5 kDa), whereas Fe is predominantly bound to high molecular weight compounds (180 kDa). The dominant phosphorus fraction was detected in the medium molecular weight region (10-30 kDa) and the other fraction in the low molecular weight region. Isotachophoretic analysis of chromatographic fractions revealed that the main phosphorus compound in the medium molecular weight region is phytic acid. SEC on Superdex 75 and Superdex Peptide columns (300 x 10 mm) was performed in on-line hyphenation with ICP-MS. The same mobile phase was used with a flow rate of 0.5 ml min(-1); volume of injected sample was 200 microl. Element specific chromatograms were obtained by continuous nebulization of effluent into ICP-mass spectrometer measuring intensities of 47(PO)+ and 48(SO)+ oxide ions and 55Mn, 57Fe, 59Co, 62Ni, 65Cu, 66Zn, 82Se, 95Mo and 114Cd nuclides. Chromatographic profiles of elements are generally analogous to those obtained with a Fractogel column, but better chromatographic resolution of separated species was achieved so that slight differences between samples were revealed. Estimated molecular weights of major phosphorus species in

  9. Speciation analysis of orthophosphate and myo-inositol hexakisphosphate in soil- and plant-related samples by high-performance ion chromatography combined with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Rugova, Ariana; Puschenreiter, Markus; Santner, Jakob; Fischer, Lisa; Neubauer, Stefan; Koellensperger, Gunda; Hann, Stephan

    2014-07-01

    A novel method based on high-performance ion chromatography inductively coupled plasma mass spectrometry employing strong anion exchange chromatography with HNO3 gradient elution for simultaneous analysis of orthophosphate and myo-inositol hexakisphosphate (IP6 ) in soil solution and plant extracts is presented. As inductively coupled plasma mass spectrometry analysis of phosphorus at m/z 31 is hampered by N-based interferences, (31)P was measured as (31)P(16)O(+) at m/z 47 employing dynamic reaction cell technique with O2 as reaction gas. Orthophosphate and IP6 were separated within a total chromatographic run-time of 12 min revealing a limit of detection of 0.3 μmol/L. The coefficients of determination obtained in a working range of 1-100 and 1-30 μmol/L were 0.9991 for orthophosphate and 0.9968 for IP6, respectively. The method was successfully applied to extracts from three different soils as well as root and shoot extracts of Brassica napus L. The precision of three independently prepared soil extracts was in the range of 4-10% relative standard deviation for PO4 (3-) and 3-8% relative standard deviation for IP6. Soil adsorption/desorption kinetics for IP6/orthophosphate were performed for investigating the sorption behavior of the two P species in the experimental soils.

  10. Report on three aliphatic dimethylarsinoyl compounds as common minor constituents in marine samples. An investigation using high-performance liquid chromatography inductively coupled plasma mass spectrometry and electrospray ionisation tandem mass spectrometry

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt; Julshamn, K.

    2005-01-01

    Three water-soluble aliphatic arsenicals, dimethylarsinoyl acetate (DMAA), dimethylarsinoyl ethanol (DMAE), and dimethylarsinoyl propionate (DMAP), were identified in marine biological samples. Sample extracts in methanol/water (1 + 1) were analysed by cation-exchange high-performance liquid...... chromatography/inductively coupled plasma mass spectrometry (HPLC/ICPMS). Eluate fractions from the HPLC/ICPMS analyses containing the compounds in question were collected and subjected to analysis by electrospray ionisation tandem mass spectrometry (ESI-MS/MS), which provided supportive evidence...... for the structures of the three compounds. The concentrations of the three arsenicals were determined in 37 marine organisms comprising algae, crustaceans, bivalves, fish and mammals by HPLC/ICPMS. The three arsenicals DMAA, DMAE and DMAP, which occurred at mug kg(-1) concentrations, were detected in 25, 23 and 17...

  11. Superconducting Resonant Inductive Power Coupling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed effort will develop a technology to wirelessly and efficiently transfer power over hundreds of meters via resonant inductive coupling. The key...

  12. Determination of aminopolycarboxylic acids at ultra-trace levels by means of online coupling ion exchange chromatography and inductively coupled plasma-mass spectrometry with indirect detection via their Pd²⁺-complexes.

    Science.gov (United States)

    Nette, David; Seubert, Andreas

    2015-07-16

    A new indirect IC-ICP-MS method for the determination of aminopolycarboxylic acids in water samples is described. It is based on the addition of an excess of Pd(II) to water samples. The analytes are forced into very strong and negatively charged palladium complexes, separated by ion exchange chromatography and detected by their palladium content, utilizing an on-line coupled ICP-MS. This method is suitable to determine the concentration of 8 aminopolycarboxylic acids (nitrilotriacetic acid (NTA), (2-carboxyethyl) iminodiacetic acid (β-ADA), methylglycinediacetic acid (MGDA), 2-hydroxyethyl) ethylenediamine triacetic acid (HEDTA), diethylene triamine pentaacetic acid (DTPA), ethylendiamine tetraacetic acid (EDTA), 1,3-diaminopropane tetraacetic acid (1,3-PDTA) and 1,2-diaminopropane tetraacetic acid (1,2-PDTA) at the ng kg(-1) level. The method is faster and easier than the established gas chromatography (GC)-method ISO 16588:2002 and up to two orders of magnitude more sensitive than the ion pair chromatography based method of DIN 38413-8. Analytic performance is superior to ISO 16588:2002 and the comparability is good.

  13. Methodology for monitoring gold nanoparticles and dissolved gold species in culture medium and cells used for nanotoxicity tests by liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    López-Sanz, Sara; Fariñas, Nuria Rodríguez; Vargas, Rosario Serrano; Martín-Doimeadios, Rosa Del Carmen Rodríguez; Ríos, Ángel

    2017-03-01

    An analytical methodology based on coupling reversed-phase liquid chromatography (HPLC) to an inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the characterization and identification of gold nanoparticles (AuNPs) and gold dissolved species (Au(3+)) in culture medium (Dulbecco's Modified Eagle Medium, DMEM) and HeLa cells (a human cervical adenocarcinoma cell line) used in nanotoxicity tests. The influence of the culture medium was also studied and the method applied for nanotoxicity tests. It was also observed that AuNPs can undergo an oxidation process in the supernatants and only a small amount of AuNPs and dissolved Au(3+) was associated with cells. To evaluate the biological impact of AuNPs, a classical viability assay onto HeLa cells was performed using cellular media DMEM in the presence of increasing dosage of 10nm AuNPs. The results showed that 10nm AuNPs exhibit a slight toxic effect.

  14. Effect of nebulizer/spray chamber interfaces on simultaneous, axial view inductively coupled plasma optical emission spectrometry for the direct determination of As and Se species separated by ion exchange high-performance liquid chromatography

    Science.gov (United States)

    Gettar, Raquel T.; Smichowski, Patricia; Garavaglia, Ricardo N.; Farías, Silvia; Batistoni, Daniel A.

    2005-06-01

    Different nebulizer/expansion chamber combinations were evaluated to assess their performance for sample introduction in the direct coupling with an axial view inductively coupled plasma multielement spectrometer for on-line determination of As and Se species previously separated by ion exchange-high performance liquid chromatography. The column effluents were injected into the plasma without prior derivatization. The instrument operation software was adapted for data acquisition and processing to allow multi-wavelength recording of the transient chromatographic peaks. After optimization of the chromatographic operating conditions, separation of mixtures of inorganic As and Se species, and of inorganic and two organic As species (monomethylarsonic and dimethylarsinic acids), was achieved with excellent resolution. Species discrimination from mixtures of As and Se oxyanions was further improved by the simultaneous element detection at specific analytical wavelengths. Three nebulizers and three spray chambers, employed in seven combinations, were tested as interfaces. Concentric nebulizers associated to a glass cyclonic chamber appear most suitable regarding sensitivity and signal to noise ratio. Measured element detection limits (3 σ) were around 10 ng ml - 1 for all the species considered, making the method a viable alternative to similar procedures that employ volatile hydride generation previous to sample injection into the plasma. Analytical recoveries both for inorganic and organic species ranged between 92 and 107%. The method was demonstrated to be apt for the analysis of surface waters potentially subjected to natural contamination with arsenic.

  15. Measurement of elemental speciation by liquid chromatography -- inductively coupled plasma mass spectrometry (LC-ICP-MS) with the direct injection nebulizer (DIN)

    Energy Technology Data Exchange (ETDEWEB)

    Shum, S.

    1993-05-01

    This thesis is divided into 4 parts: elemental speciation, speciation of mercury and lead compounds by microbore column LC-ICP-MS with direct injection nebulization, spatially resolved measurements of size and velocity distributions of aerosol droplets from a direct injection nebulizer, and elemental speciation by anion exchange and size exclusion chromatography with detection by ICP-MS with direct injection nebulization. Tabs, figs, refs.

  16. Speciation of four selenium compounds using high performance liquid chromatography with on-line detection by inductively coupled plasma mass spectrometry or flame atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Pedersen, Gitte Alsing; Larsen, Erik Huusfeldt

    1997-01-01

    spectrometry (ICP-MS). The signal-to-noise ratio of the FAAS detector was optimized using a hydrogen-argon entrained-air flame and a slotted-tube atom trap (STAT) in the flame. The limit of detection (3 sigma) achieved by the HPLC-FAAS system was 1 mg L-1 of selenium (100 mu L injections) for each of the four......An analytical method for the speciation of selenomethionine, selenocystine, selenite and selenate by high performance liquid chromatography (HPLC) with atomic spectrometric detection is presented. An organic polymeric strong anion exchange column was used as the stationary phase in combination...... of 1300 W. The limit of detection achieved under these conditions was 1 mu g L-1 (100 mu L injections). The HPLC-ICP-MS system was used for selenium speciation of selenite and selenate in aqueous solutions during a BCR certification exercise and for selenium speciation in the certified reference material...

  17. Determination of ultra-trace amount methyl-, phenyl- and inorganic mercury in environmental and biological samples by liquid chromatography with inductively coupled plasma mass spectrometry after cloud point extraction preconcentration.

    Science.gov (United States)

    Chen, Jianguo; Chen, Hengwu; Jin, Xianzhong; Chen, Haiting

    2009-02-15

    The cloud point extraction (CPE) preconcentration of ultra-trace amount of mercury species prior to reverse-phase high performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP-MS) detection was studied. Mercury species including methyl-, ethyl-, phenyl- and inorganic mercury were transformed into hydrophobic chelates by reaction with sodium diethyldithiocarbamate, and the hydrophobic chelates were extracted into a surfactant-rich phase of Triton X-114 upon heating in a water bath at 40 degrees C. Ethylmercury was found partially decomposed during the CPE process, and was not included in the developed method. Various experimental conditions affecting the CPE preconcentration, HPLC separation, and ICP-MS determination were optimized. Under the optimized conditions, detection limits of 13, 8 and 6 ng l(-1) (as Hg) were achieved for MeHg(+), PhHg(+) and Hg(2+), respectively. Seven determinations of a standard solution containing the three mercury species each at 0.5 ng ml(-1) level produced relative standard deviations of 5.3, 2.3 and 4.4% for MeHg(+), PhHg(+) and Hg(2+), respectively. The developed method was successfully applied for the determination of the three mercury species in environmental water samples and biological samples of human hair and ocean fish.

  18. Simultaneous determination of Cr(iii) and Cr(vi) using reversed-phased ion-pairing liquid chromatography with dynamic reaction cell inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Wolf, R.E.; Morrison, J.M.; Goldhaber, M.B.

    2007-01-01

    A method for the simultaneous determination of Cr(iii) and Cr(vi) species in waters, soil leachates and synthetic bio-fluids is described. The method uses reversed-phase ion-pairing liquid chromatography to separate the chromium species and a dynamic reaction cell (DRC??) equipped ICP-MS for detection of chromium. Separation of the chromium species is carried out in less than 2 min. Cr(iii) is complexed with ethylenediaminetetraacetic acid (EDTA) prior to separation by mixing samples with the mobile phase containing 2.0 mM tetrabutylammonium hydroxide (TBAOH), 0.5 mM EDTA (dipotassium salt), and 5% (vol/vol) methanol, adjusted to pH 7.6. The interfering 40Ar 12C+ background peak at mass 52 was reduced by over four orders of magnitude to less than 200 cps by using 0.65 mL min-1 ammonia as a reaction gas and an RPq setting on the DRC of 0.75. Method detection limits (MDLs) of 0.09 ??g L-1 for Cr(iii) and 0.06 ??g L-1 for Cr(vi) were obtained based on peak areas at mass 52 for 50 ??L injections of low level spikes. Reproducibility at 2 ??g L-1 was 3% RSD for 5 replicate injections. The tolerance of the method to various levels of common cations and anions found in natural waters and to matrix constituents found in soil leachates and simulated gastric and lung fluids was tested by performing spike recovery calculations for a variety of samples. ?? The Royal Society of Chemistry.

  19. Selenium speciation in radix puerariae using ultrasonic assisted extraction combined with reversed phase high performance liquid chromatography-inductively coupled plasma-mass spectrometry after magnetic solid-phase extraction with 5-sulfosalicylic acid functionalized magnetic nanoparticles

    Science.gov (United States)

    Cao, Yupin; Yan, Lizhen; Huang, Hongli; Deng, Biyang

    2016-08-01

    A new method for determination of selenium species in radix puerariae was described. The method consists of sample enrichment with 5-sulfosalicylic acid (SSA)-functionalized silica-coated magnetic nanoparticles (SMNPs), high performance liquid chromatography (HPLC) separation, and online detection using inductively coupled plasma mass spectrometry (ICP-MS). The selenium species were extracted using ultrasonic extraction system with a mixture of protease K and lipase. The SSA-SMNPs were used to enrich trace amounts of selenite [Se(IV)], selenate [Se(VI)], selenomethionine (SeMet), and selenocystine (SeCys2) from lower selenium containing samples. Under the optimal conditions, the limits of detection (3σ) for SeCys2, Se(IV), SeMet and Se(VI) were observed as 0.0023, 0.0015, 0.0043, and 0.0016 ng mL- 1, respectively. The RSD values (n = 6) of method for intraday were observed between 0.5% and 0.9%. The RSD values of method for interday were less than 1.3%. The linear concentration ranges for SeCys2, Se(IV), SeMet and Se(VI) were 0.008-1000, 0.005-200, 0.015-500 and 0.006-200 ng mL- 1, respectively. The detection limits of this method were improved by 10 times due to the enrichment with the SSA-SMNP extraction. The contents of SeCys2, Se(IV), SeMet, and Se(VI) in radix puerariae were determined as 0.0140, 0.171, 0.0178, and 0.0344 μg g- 1, respectively. The recoveries were in the range of 95.6%-99.4% and the RSDs (n = 6) of recoveries were less than 1.5%.

  20. Direct comparison of capillary electrophoresis and capillary liquid chromatography hyphenated to collision-cell inductively coupled plasma mass spectrometry for the investigation of Cd-, Cu- and Zn-containing metalloproteins.

    Science.gov (United States)

    Montes-Bayon, Maria; Pröfrock, Daniel; Sanz-Medel, Alfredo; Prange, Andreas

    2006-05-05

    Capillary liquid chromatography (cLC) and capillary electrophoresis (CE) have been critically compared for the separation of metalloproteins when using collision-cell inductively coupled plasma mass spectrometry (ICP-CC-MS) as detection system. For cLC separation, the selected column was a C8 (0.3 mm I.D.) and the separation conditions involved a gradient up to 80% methanol in 10mM ammonium acetate buffer (pH 7.4). The low flow rate used (3 microL min(-1)) permitted the utilization of a high methanol content maintaining the sensitivity along the whole chromatographic run. For this purpose, a new low-flow interface has been developed based on a total consumption nebulizer. Similarly, CE has been studied as separation technique using a 75 microm I.D. fused silica capillary and a running buffer of 20 mM Tris-HNO3 (pH 7.4) and working at 30 kV. Metallothionein (mixture of MT-I and -II) and superoxide dismutase (SOD) have been used as protein models in order to evaluate the separation/detection capabilities using the same injection volumes in both systems (20 nL). For both hybrid systems, separation parameters such as retention factor, numbers of theoretical plates, tailing factor and resolution have been critically compared. Also, the analytical performance characteristics of both hybrid systems have been evaluated and tested by analyzing the Cu-, Zn-species present in red blood cell extracts in order to explore more adequate separation methodology for the analysis of metalloproteins in complex matrices.

  1. Multielement characterization of metal-humic substances complexation by size exclusion chromatography, asymmetrical flow field-flow fractionation, ultrafiltration and inductively coupled plasma-mass spectrometry detection: a comparative approach.

    Science.gov (United States)

    Bolea, E; Gorriz, M P; Bouby, M; Laborda, F; Castillo, J R; Geckeis, H

    2006-10-06

    The use of three different separation techniques, ultrafiltration (UF), high performance size exclusion chromatography (HPSEC) and asymmetrical flow field-flow fractionation (AsFlFFF), for the characterization of a compost leachate is described. The possible interaction of about 30 elements with different size fractions of humic substances (HS) has been investigated coupling these separation techniques with UV-vis absorption spectrophotometry and inductively coupled plasma-mass spectrometry (ICP-MS) as detection techniques. The organic matter is constituted by a polydisperse mixture of humic substances ranging from low molecular weights (around 1kDa) to significantly larger entities. Elements can be classified into three main groups with regard to their interaction with HS. The first group is constituted by primarily the monovalent alkaline metal ions and anionic species like B, W, Mo, As existing as oxyanions all being not significantly associated to HS. The second group consists of elements that are at least partly associated to a smaller HS size fraction (such as Ni, Cu, Cr and Co). A third group of mainly tri- and tetravalent metal ions like Al, Fe, the lanthanides, Sn and Th are rather associated to larger-sized HS fractions. The three separation techniques provide a fairly consistent size classification for most of the metal ions, even though slight disagreements were observed. The number-average molecular weight (Mn), the weight-average molecular weight (Mw) and the polydispersity (rho) parameters have been calculated both from AsFlFFF and HPSEC experiments and compared for HS and some metal-HS species. Differences in values can be partly explained by an overloading effect observed in the AsFlFFF experiments induced by electrostatic repulsion effects in the low ionic strength, high pH carrier solution. Size information obtained from ultrafiltration is not as resolved as for the other methods. Molecular weight cut-offs (MWCO) of the individual filter

  2. Inductively coupled radio frequency methane plasma simulation

    Science.gov (United States)

    Bera, K.; Farouk, B.; Vitello, P.

    2001-05-01

    A self-consistent two-dimensional radio frequency inductively coupled glow discharge model has been developed in cylindrical coordinates using a fluid model. The objective of the study is to provide insight into charged species dynamics and investigate their effects on plasma process for a methane discharge. The model includes continuity and energy equations for electrons and continuity, momentum and energy equations for positive and negative ions. An electromagnetic model that considers the electric field due to the space charge within the plasma and due to inductive power coupling is also incorporated. For an inductively coupled methane discharge we expect to find higher fluxes of ions and radicals to the cathode, and hence a higher deposition/etch rate for a high-density plasma. The independent control of ion energy to the cathode in an inductively coupled discharge will facilitate control on film deposition/etch rate and uniformity on the wafer. Swarm data as a function of the electron energy are provided as input to the model. The model predicts the electron density, ion density and their fluxes and energies to the cathode. The radical and neutral densities in the discharge are calculated using a gas phase chemistry model. The diamond-like-carbon thin-film deposition/etch rate is predicted using a surface chemistry model. The gas phase chemistry model considers the diffusion of radicals and neutrals along with creation and loss terms. The surface deposition/etching process involves adsorption-desorption, adsorption layer reaction, ion stitching, direct ion incorporation and carbon sputtering.

  3. Speciation of Volatile Selenium Species in Plants Using Gas Chromatography/Inductively Coupled Plasma Mass Spectrometry%气相色谱/电感耦合等离子体质谱测定植物中挥发性硒化合物

    Institute of Scientific and Technical Information of China (English)

    Juris MEIJA; Maria MONTES-BAY(O)N; Joseph A CARUSO; Danika L LEDUC; Norman TERRY

    2004-01-01

    Gas chromatography/inductively coupled plasma mass spectrometry (GC/ICP-MS) coupled with solid phase micro-extraction can provide a simple, extremely selective and sensitive technique for the analysis of volatile sulfur and selenium compounds in the headspace of growing plants. In this work, the technique was used to evaluate the volatilization of selenium in wild-type and genetically-modified Brassica juncea seedlings. By converting toxic inorganic selenium in the soil to less toxic, volatile organic selenium, B. juncea might be useful in bioremediation of selenium contaminated soil.

  4. A field survey of metal binding to metallothionein and other cytosolic ligands in liver of eels using an on-line isotope dilution method in combination with size exclusion (SE) high pressure liquid chromatography (HPLC) coupled to Inductively Coupled Plasma time-of-flight Mass Spectrometry (ICP-TOFMS).

    Science.gov (United States)

    Van Campenhout, Karen; Goenaga Infante, Heidi; Goemans, Geert; Belpaire, Claude; Adams, Freddy; Blust, Ronny; Bervoets, Lieven

    2008-05-15

    The effect of metal exposure on the accumulation and cytosolic speciation of metals in livers of wild populations of European eel with special emphasis on metallothioneins (MT) was studied. Four sampling sites in Flanders showing different degrees of heavy metal contamination were selected for this purpose. An on-line isotope dilution method in combination with size exclusion (SE) high pressure liquid chromatography (HPLC) coupled to Inductively Coupled Plasma time-of-flight Mass Spectrometry (ICP-TOFMS) was used to study the cytosolic speciation of the metals. The distribution of the metals Cd, Cu, Ni, Pb and Zn among cytosolic fractions displayed strong differences. The cytosolic concentration of Cd, Ni and Pb increased proportionally with the total liver levels. However, the cytosolic concentrations of Cu and Zn only increased above a certain liver tissue threshold level. Cd, Cu and Zn, but not Pb and Ni, were largely associated with the MT pool in correspondence with the environmental exposure and liver tissue concentrations. Most of the Pb and Ni and a considerable fraction of Cu and Zn, but not Cd, were associated to High Molecular Weight (HMW) fractions. The relative importance of the Cu and Zn in the HMW fraction decreased with increasing contamination levels while the MT pool became progressively more important. The close relationship between the cytosolic metal load and the total MT levels or the metals bound on the MT pool indicates that the metals, rather than other stress factors, are the major factor determining MT induction.

  5. Induced lead binding phytochelatins in Brassica juncea and Sesuvium portulacastrum investigated by orthogonal chromatography inductively coupled plasma-mass spectrometry and matrix assisted laser desorption ionization-time of flight-mass spectrometry.

    Science.gov (United States)

    Zaier, H; Mudarra, A; Kutscher, D; Fernández de la Campa, M R; Abdelly, C; Sanz-Medel, A

    2010-06-25

    The accumulation and transport of lead in Brassica juncea and Sesuvium portulacastrum plants and the possible formation of complexes of this element with bioligands such as phytochelatins was studied in roots and shoots of plants exposed to different amounts of Pb(NO(3))(2). Speciation studies on the plant extracts were conducted using size exclusion liquid chromatography and ion pair liquid chromatography coupled to UV and ICP-MS to monitor lead and sulphur. The identification of the species separated by chromatography was performed by MALDI-TOF-MS. In both types of exposed plants it was possible to identify the presence of the phytochelatin isoform PC(3). The results obtained suggest that both types of plants can be useful in studies of phytoremediation but the ability of S. portulacastrum to accumulate and redistribute Pb from root to shoot is more effective than B. juncea.

  6. Mercury speciation in seawater by liquid chromatography-inductively coupled plasma-mass spectrometry following solid phase extraction pre-concentration by using an ionic imprinted polymer based on methyl-mercury-phenobarbital interaction.

    Science.gov (United States)

    Rodríguez-Reino, María Pilar; Rodríguez-Fernández, Roi; Peña-Vázquez, Elena; Domínguez-González, Raquel; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2015-04-24

    Trace levels of inorganic mercury, methyl-mercury and ethyl-mercury have been assessed in seawater by high performance liquid chromatography (HPLC) hyphenated with inductively coupled plasma-mass spectrometry (ICP-MS) after solid phase extraction (SPE) pre-concentration with a novel synthesized ionic imprinted polymer. The adsorbent material was prepared by trapping a non-vinylated chelating ligand (phenobarbital) via imprinting of a ternary mixed ligand complex of the non-vinylated chelating agent, the template (methyl-mercury), and the vinyl ligand (metacrylic acid, MAA). Ethylene dimetacrylate (EDMA) and 2,2'-azobisisobutyronitrile (AIBN) were used as cross-linker and initiator reagents, respectively; and the precipitation polymerization technique was used in a porogen of acetonitrile/water (4:1). The best retention properties for methyl-mercury, inorganic mercury and ethyl-mercury species from seawater were obtained when loading 200 mL of sample adjusted to pH 8.0 and at a flow rate of 2.0 mL min(-1) on a column-packed with 200mg of the material. Quantitative mercury species recoveries were obtained using 4 mL of an eluting solution consisting of 0.8% (v/v) 2-mercaptoethanol and 20% (v/v) methanol (pH adjusted to 4.5) pumped at a flow rate of 2.0 mL min(-1). Mercury species separation was achieved on a Kinetex C18 column working under isocratic conditions (0.4% (v/v) 2-mercaptoethanol, 10% (v/v) methanol, pH 2.5, flow rate 0.7 mL min(-1)). ICP-MS detection was performed by monitoring the mercury mass to charge ratio of 202. The limits of quantification of the method were 11, 6.7, and 12 ng L(-1), for inorganic mercury, methyl-mercury and ethyl-mercury, respectively (pre-concentration factor of 50); whereas, analytical recoveries ranged from 96 to 106%. The developed method was successfully applied to several seawater samples from unpolluted areas.

  7. A Microfabricated Inductively Coupled Plasma Excitation Source

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-Qing; PU Yong-Ni; SUN Rong-Xia; TANG Yu-Jun; CHEN Wen-Jun; LOU Jian-Zhong; MA Wen

    2008-01-01

    A novel miniaturization of inductively coupled plasma(ICP)source based on printed circuit produced using micro-fabrication techniques is presented.The basic parameters of the novel ICP,including its radio frequency,power loss,size,and argon consumption are less than 1% of that for the case of atmospheric pressure ICP source.For example,at 100 Pa of argon gas pressure,the present ICP source can be ignited by using the rf power less than 3.5 W.Potential applications of the ICP is discussed.

  8. Wireless Power Transmission Using Resonance Inductive Coupling

    Directory of Open Access Journals (Sweden)

    Prof. Vishal V. Pande,

    2014-04-01

    Full Text Available In this paper, we present the concept of transmitting power without using wires i.e.transmitting power as Magnetic waves from one place to another is in order to reduce the transmission and distribution losses. This concept is known as Resonance Inductive Coupling (RIC. We also discussed the technological developments in Wireless Power Transmission (WPT. The advantages, disadvantages, biological impacts and applications of WPT are also presented. Wireless power or wireless energy transmission is the transmission of electrical energy from a power source to an electrical load without man-made conductors. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible. the proportion of energy received becomes critical only if it is too low for the signal to be distinguished from the background noise. With wireless power, efficiency is the more significant parameter. A large part of the energy sent out by the generating plant must arrive at the receiver or receivers to make the system economical.The most common form of wireless power transmission is carried out using direct induction followed by resonant magnetic induction. Other methods under consideration are electromagnetic radiation in the form of microwaves or lasers and electrical conduction through natural media

  9. Speciation of arsenic of liquid and gaseous emissions from soil in a microcosmos experiment by liquid and gas chromatography with inductively coupled plasma mass spectrometer (ICP-MS) detection

    Energy Technology Data Exchange (ETDEWEB)

    Prohaska, T.; Stingeder, G. [University of Agricultural Sciences - BOKU Wien (Austria). Inst. of Chemistry; Pfeffer, M.; Tulipan, M.; Mentler, A.; Wenzel, W.W. [Vienna University of Agricultural Sciences - BOKU Wien (Austria). Inst. of Soil Science

    1999-07-01

    Gas chromatography and high-performance liquid chromatography coupled to a double focusing sectorfield ICP-MS as sensitive element specific detector are used for the speciation of arsenic of liquid and gaseous emissions from soil samples, which were equilibrated in a microcosmos experiment. Speciation of liquid samples was performed by HPLC and hydride generation was used as introduction system to ICP-MS. An online prereduction step was introduced to enhance the sensitivity for As(V). A home-built and laboratory-ready transfer line from GC to ICP-MS is presented and quantification of As in gaseous emissions was performed by external calibration via hydride generation. The microcosmos experiment revealed only low production rates of organoarsenic compounds and reflected a limited capability of the biovolatilization experiment for the simulation of natural systems. (orig.) With 5 figs., 5 tabs., 29 refs.

  10. Effect of mutual inductance coupling on superconducting flux qubit decoherence

    Institute of Scientific and Technical Information of China (English)

    Yanyan Jiang; Hualan Xu; Yinghua Ji

    2009-01-01

    In the Born-Markov approximation and two-level approximation, and using the Bloch-Redfield equation, the decoherence property of superconducting quantum circuit with a flux qubit is investigated. The influence on decoherence of the mutual inductance coupling between the circuit components is complicated. The mutual inductance coupling between different loops will decrease the decoherence time. However, the mutual inductance coupling of the same loop, in a certain interval, will increase the decoherence time. Therefore, we can control the decoherence time by changing the mutual inductance parameters such as the strength and direction of coupling.

  11. Protein interactions in hydrophobic charge induction chromatography (HCIC).

    Science.gov (United States)

    Ghose, Sanchayita; Hubbard, Brian; Cramer, Steven M

    2005-01-01

    A quantitative understanding of how proteins interact with hydrophobic charge induction chromatographic resins is provided. Selectivity on this mode of chromatography for monoclonal antibodies as compared to other model proteins is probed by means of a linear retention vs pH plot. The pH-dependent adsorption behavior on this mode of chromatography for a hydrophobic, charged solute is described by taking into account the equilibrium between a hydrophobic, charged solute and an ionizable, heterocyclic ligand. By analogy, an equation that is seen to adequately describe macromolecular retention under linear conditions over a range of pH is developed. A preparative, nonlinear isotherm that can capture both pH and salt concentration dependency for proteins is proposed by using an exponentially modified Langmuir isotherm model. This model is seen to successfully simulate adsorption isotherms for a variety of proteins over a range of pHs and mobile phase salt concentrations. Finally, the widely differing retention characteristics of two monoclonal antibodies are used to derive two different strategies for improving separations on this mode of chromatography. A better understanding of protein binding to this class of resins is seen as an important step to future exploitation of this mode of chromatography for industrial scale purification of proteins.

  12. Rapid determination of ¹³⁵Cs and precise ¹³⁵Cs/¹³⁷Cs atomic ratio in environmental samples by single-column chromatography coupled to triple-quadrupole inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Yang, Guosheng; Tazoe, Hirofumi; Yamada, Masatoshi

    2016-02-18

    For source identification, measurement of (135)Cs/(137)Cs atomic ratio not only provides information apart from the detection of (134)Cs and (137)Cs, but it can also overcome the application limit that measurement of the (134)Cs/(137)Cs ratio has due to the short half-life of (134)Cs (2.06 y). With the recent advancement of ICP-MS, it is necessary to improve the corresponding separation method for rapid and precise (135)Cs/(137)Cs atomic ratio analysis. A novel separation and purification technique was developed for the new generation of triple-quadrupole inductively coupled plasma-mass spectrometry (ICP-MS/MS). The simple chemical separation, incorporating ammonium molybdophosphate selective adsorption of Cs and subsequent single cation-exchange chromatography, removes the majority of isobaric and polyatomic interference elements. Subsequently, the ICP-MS/MS removes residual interference elements and eliminates the peak tailing effect of stable (133)Cs, at m/z 134, 135, and 137. The developed analytical method was successfully applied to measure (135)Cs/(137)Cs atomic ratios and (135)Cs activities in environmental samples (soil and sediment) for radiocesium source identification.

  13. Effect of metal ions on the molecular weight distribution of humic substances derived from municipal compost: ultrafiltration and size exclusion chromatography with spectrophotometric and inductively coupled plasma-MS detection.

    Science.gov (United States)

    Wrobel, Kazimierz; Sadi, Baki B M; Wrobel, Katarzyna; Castillo, Juan R; Caruso, Joseph A

    2003-02-15

    The effect of metal ions (Co, Cu, Ni, Pb, Zn) on the molecular weight distribution of humic substances (HSs) obtained from compost is studied. We believe this is the first of this type of study applied in this way to humic substances. Size exclusion chromatography is coupled with two on-line detection systems (spectrophotometric and ICPMS) to study the binding of metal ions by humic substances leached from compost. ICPMS provided highly specific, sensitive, and multielement analytical information that enabled obtaining direct experimental evidence for the participation of metal ions in molecular size distributions of humic compounds. The compost extract or its high molecular weight fraction (>5,000) was put in contact with EDTA or citrate ions, thereby competing with HSs for binding metals. The experiments were carried out by varying the pH maintained by Tris-HCl or CAPS buffer (pH 8.0 and 10.3) and keeping the ionic strength constant. The elution profile of humic substances using UV/ visible detection was compared with those from ICPMS detection of Co, Cu, Ni, Pb, and Zn in the same chromatographic runs. The results obtained suggested that both bridging between small molecules and complexation/ chelation by individual molecules are involved in metal ion binding to humic substances. The use of ICPMS to study the role of metal ions in aggregation/disassociation of humic substances proposed in this work is promising. Coupling element-specific detection with SEC or other separation systems allows better understanding of the mobility and bioaccessibility of elemental species in the environment and further elucidation of the dissolved humic structure.

  14. Inductive Coupling of Power Converter’s – EMC

    Directory of Open Access Journals (Sweden)

    Irena Kováčová

    2009-07-01

    Full Text Available The paper presents a computer analysis of inductive coupling of theelectromagnetic compatibility (EMC problem. Its focus is on power electronics andelectrical drives and tests performed by a numerical computer simulation that can disclosesuite surprising findings about EMC.

  15. Speciation analysis of cadmium in laver by size exclusion chromatography-high performance liquid chromatography-inductively,coupled plasma mass spectrometry%体积排阻高效液相色谱—电感耦合等离子体质谱法测定紫菜中镉(Cd)的形态

    Institute of Scientific and Technical Information of China (English)

    赵艳芳; 尚德荣; 宁劲松; 翟毓秀; 盛晓风; 张明

    2012-01-01

    运用体积排阻高效液相色谱—电感耦合等离子体质谱联用技术( SEC-HPLC-ICP-MS)分析了紫菜中Cd的存在形态,结果发现,在紫菜水提取液中检测到3种Cd形态,根据其保留时间确定为植物螯合肽( PC)3-Cd、谷胱甘肽(GSH)-Cd和1种未知小分子有机态Cd,结合体外全仿生消化技术,研究了在唾液、胃、肠无机物和有机物(含消化酶)作用下,紫菜中Cd的主要存在形态,分析发现在紫菜胃全仿生提取液中,检测到2种未知小分子有机态Cd,其中以保留时间为24.2 min的Cd形态为主要存在形态.在肠全仿生提取液中检测到2种Cd形态,其中(PC)3-Cd是主要存在形态.有关(PC) 3-Cd在生物体内的代谢规律还需进一步研究.实验确证了Cd在紫菜中的主要有机形态,为紫菜食用安全风险评价提供重要依据.%High content of cadmium in laver has seriously affected the edible safety, export and industry development of seaweed in our country. However, only total cadmium content was detected by present method used worldwide and the total cadmium was used to evaluate the food safety of the laver which may over-estimate the toxicity of the cadmium in laver. Because there are different cadmium forms in laver which have different biological toxicities,the speciation analysis of cadmium in the laver is very urgent. However, studies on the cadmium speciation analysis in seaweed are very scarce at present. In present experiment, we first analyzed the different cadmium forms in laver (Porphyra haitanensis and Porphyra yezoensis) which have high Cd accumulation capability by using size exclusion chromatography-high performance liquid chromatography-inductively coupled plasma mass spectrometry ( SEC-HPLC-ICP-MS). The result showed that three Cd species including Phytochelatins(PC)3-Cd,glutathione(GSH)-Cd and one small molecule Cd species were detected in the deionized water extraction of the laver. In vitro whole-bionic digestion model was used

  16. Progress in antenna coupled kinetic inductance detectors

    NARCIS (Netherlands)

    Baryshev, A.; Baselmans, J.J.A.; Freni, A.; Gerini, G.; Hoevers, H.; Iacono, A.; Neto, A.

    2011-01-01

    This paper describes the combined Dutch efforts toward the development of large wideband focal plane array receivers based on kinetic inductance detectors (KIDs). Taking into account strict electromagnetic and detector sensitivity requirements for future ground and space based observatories, this wo

  17. High-throughput sequential injection method for simultaneous determination of plutonium and neptunium in environmental solids using macroporous anion-exchange chromatography, followed by inductively coupled plasma mass spectrometric detection.

    Science.gov (United States)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2011-01-01

    This paper reports an automated analytical method for rapid and simultaneous determination of plutonium and neptunium in soil, sediment, and seaweed, with detection via inductively coupled plasma mass spectrometry (ICP-MS). A chromatographic column packed with a macroporous anion exchanger (AG MP-1 M) was incorporated in a sequential injection (SI) system for the efficient retrieval of plutonium, along with neptunium, from matrix elements and potential interfering nuclides. The sorption and elution behavior of plutonium and neptunium onto AG MP-1 M resin was compared with a commonly utilized AG 1-gel-type anion exchanger. Experimental results reveal that the pore structure of the anion exchanger plays a pivotal role in ensuring similar separation behavior of plutonium and neptunium along the separation protocol. It is proven that plutonium-242 ((242)Pu) performs well as a tracer for monitoring the chemical yield of neptunium when using AG MP-1 M resin, whereby the difficulties in obtaining a reliable and practicable isotopic neptunium tracer are overcome. An important asset of the SI setup is the feasibility of processing up to 100 g of solid substrates using a small-sized (ca. 2 mL) column with chemical yields of neptunium and plutonium being ≥79%. Analytical results of three certified/standard reference materials and two solid samples from intercomparison exercises are in good agreement with the reference values at the 0.05 significance level. The overall on-column separation can be completed within 3.5 h for 10 g of soil samples. Most importantly, the anion-exchange mini-column suffices to be reused up to 10-fold with satisfactory chemical yields (>70%), as demanded in environmental monitoring and emergency scenarios, making the proposed automated assembly well-suited for unattended and high-throughput analysis.

  18. Arsenic speciation by liquid chromatography coupled with ionspray tandem mass spectrometry

    DEFF Research Database (Denmark)

    Corr, J. J.; Larsen, Erik Huusfeldt

    1996-01-01

    fragmentation patterns showing molecular dissociation through an expected common product ion were obtained for the four arsenosugars, Molecular mode detection was utilized for qualitative verification of speciation analysis by high-performance liquid chromatography coupled to inductively coupled plasma mass......Ionspray mass spectrometry, a well established organic analysis technique, has been coupled to high-performance liquid chromatography for speciation of organic arsenic compounds, The ionspray source and differentially pumped interface of the mass spectrometer were operated in dual modes...... for elemental and molecular analysis, Tandem mass spectrometry was employed to increase selectivity, Dual mode detection was applied to demonstrate the utility of the technique for analysis of nine organoarsenic standards, including four dimethylarsinylriboside derivatives (arsenosugars), Structural...

  19. Analysis of Hydrophilic Mercury-Binding Proteins in Medaka (Oryzias latipes) Using High Performance Liquid Chromatography Coupled with Inductively Coupled Plasma-Mass Spectrometry%高效液相色谱-电感耦合等离子体质谱研究Medaka体内水溶性汞结合蛋白

    Institute of Scientific and Technical Information of China (English)

    李璐; 何滨; 江桂斌

    2011-01-01

    The hydrophilic mercury-binding proteins in the brain and liver extractions of Medaka after methylmercury and inorganic mercury exposure were analyzed by high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry. Size exclusion chromatography was selected in the experiment with a mobile phase of 0. 15 mol/L NHaAc, running at a 0.5 mL/min flow rate. Concentrations of total copper, zinc and mercury in the brain and liver extracts of Medaka were determined by ICP-MS. Detection limits for these three elements were in the range of 0.01 μg/L to 0.05 μg/L, and the spike recoveries ranged from 93. 1%-97. 0%. Compared with the control group, high level of mercury is accumulated in the brain and liver of exposure groups. The distribution patterns of mercury-containing proteins in the brain and liver extracts of Medaka between methylmercury and inorganic mercury exposure group were different. The concentrations of copper and zinc in the brain and liver extractions of both exposure groups were decreased. The studies of the mercurycontaining protein fractions in Medaka are helpful for the understanding of the mechanisms of mercury toxicity.%采用高效液相色谱与电感耦合等离子体质谱联用技术,对不同形态汞暴露后的Medaka肝脏和脑组织中水溶性蛋白进行研究,以体积排阻柱为液相分离柱,流动相为0.15 mol/L NH4Ac,流速为0.5 mL/min.利用电感耦合等离子体质谱对Medaka肝脏和脑组织提取液中铜、锌和汞的含量进行了分析,检出限为0.01~0.05 μg/L,元素的加标回收率为93.1%~97.0%.通过与空白组对比发现,汞暴露后的Medaka鱼体肝脏和脑组织对水体中的汞有一定程度的富集;不同形态汞暴露后,在Medaka肝脏和脑组织中的分布明显不同,并且都会在一定程度上降低Medaka肝脏和脑组织中铜与锌的含量,有利于进一步研究汞在生物体内的毒性机理.

  20. Inductively coupled transducer system for damage detection in composites

    Science.gov (United States)

    Zhong, C. H.; Croxford, A. J.; Wilcox, P. D.

    2012-04-01

    The laminated construction of composite offers the possibility of permanently embedding sensors into structure, for example, ultrasonic transducers which can be used for NDE applications. An attractive and simple solution for probing embedded sensors wirelessly is via inductive coupling. However, before this can be achieved it is necessary to have a full understanding and proper design strategy for the inductively coupled system. This paper presents the developments of both system design procedure and a computer program for one dimensional inductively coupled transducer system mounted on a solid substrate. The design strategy in this paper mainly focuses on issues of localization of transducers, and optimizing the signal to noise level. Starting from a three coil equivalent circuit, this paper also explains how the measured impedance of a bonded piezoelectric disc is implemented into the system model representing a transducer bonded to an arbitrary solid substrate. The computer programme using this model provides immediate predictions of electrical input impedance, acoustic response and pulse-echo response. A series of experiments and calculations have been performed in order to validate the model. This has enabled the degree of accuracy required for various parameters within the model, such as mutual inductance between the coils and self-inductance of coils, to be assessed. Once validated, the model can be used as a tool to predict the effect of physical parameters, such as distance, lateral misalignment between the coils, and the coil geometry on the performance of an inductively coupled system.

  1. Hyphenated techniques in speciation analysis of polyoxometalates: identification of individual [PMo12-xVxO40](-3-x) (x = 1-3) in the reaction mixtures by high performance liquid chromatography and atomic emission spectrometry with inductively coupled plasma.

    Science.gov (United States)

    Shuvaeva, O V; Zhdanov, A A; Romanova, T E; Abramov, P A; Sokolov, M N

    2017-03-14

    Unambiguous identification of polyoxometalate (POM) species generated in self-assembly reactions in solution is rather problematic due to close similarity of their properties such as solubility and spectral characteristics. The situation is made more complex by protonation equilibria (which can change their analytical signals) and the lack of individual compounds to serve as standards for individual members of these mixtures. In the present work a new approach to the study of such POMs has been suggested, taking molybdovanadates [PMo12-xVxO40](-3-x) as a model. The key feature of this approach consists of generation of so-called "conditional model systems" that include most of the expected components of a mixture formed by self-assembly, tracked down by reliable detection techniques, e.g., (51)V NMR-spectroscopy in this particular case. Then the proposed composition of the mixture is verified and corrected by means of high-performance liquid chromatography coupled with inductively coupled plasma atomic emission spectrometry (HPLC-ICP-AES).

  2. Coupling of column liquid chromatography and Fourier transform infrared spectrometry

    NARCIS (Netherlands)

    Somsen, G.W; Gooijer, C; Velthorst, N.H; Brinkman, U.A Th

    1998-01-01

    This paper provides an extensive overview of the literature on the coupling of column liquid chromatography (LC) and Fourier transform infrared spectrometry (FT-IR). Flow-cell-based FT-IR detection and early solvent-elimination interfaces for LC-FT-IR are discussed in brief. A comprehensive descript

  3. Determination of inorganic arsenic in marine products by high performance liquid chromatography and inductively coupled plasma mass spectrometry%高效液相色谱-电感耦合等离子体质谱联用测定海洋产品中无机砷

    Institute of Scientific and Technical Information of China (English)

    庞艳华; 朱鸣鹤; 赵景红; 王秋艳

    2011-01-01

    采用高效液相色谱( HPLC)和电感耦合等离子体质谱(ICP-MS)联用技术测定了海洋产品中的无机砷.动物性和植物性海洋产品试样经过10% H3PO溶液(V/V)提取,阴离子交换色谱分离,ICP-MS测定其中As(Ⅲ)和As(Ⅴ)的含量.实验结果表明As(Ⅲ)和As(Ⅴ)的检出限分别为5.0和8.0 μg/kg,线性范围为5~100 μg/L,相关系数均大于0.9994,加标回收率为81.8%~107.6%,相对标准偏差小于6.7%(n=6).对选取的海洋产品测定结果显示,无机砷的含量均未超出国家卫生标准限量.%A high performance liquid chromatography and inductively coupled plasma mass spectrometric method was established for the determination of inorganic arsenic, including As ( M ) and As ( V ). The animal and vegetative samples were pretreated by phosphoric acid with the concentration of 10% ( V/V) , and inorganic arsenic was separated by anion exchange high performance chromatography and detected by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the linear ranges for As( M) and As( V) were all between 5 and 100 μg/L with correlation coefficients more than 0. 9994, and the detection limits were 5. 0 and 8. 0 μg/kg respectively. The relative standard deviations ( RSDs) were less than 6. 7% and the recoveries were between 81. 8% and 107. 6%. The results indicated that inorganic arsenic in marine products did not exceed national permission limits.

  4. Monitoring microbial metabolites using an inductively coupled resonance circuit

    NARCIS (Netherlands)

    Karnaushenko, Daniil; Baraban, Larysa; Ye, Dan; Uguz, Ilke; Mendes, Rafael G.; Rümmeli, Mark H.; Visser, de Arjan; Schmidt, Oliver G.; Cuniberti, Gianaurelio; Makarov, Denys

    2015-01-01

    We present a new approach to monitor microbial population dynamics in emulsion droplets via changes in metabolite composition, using an inductively coupled LC resonance circuit. The signal measured by such resonance detector provides information on the magnetic field interaction with the bacteria

  5. Design And Construction Of Wireless Charging System Using Inductive Coupling

    Directory of Open Access Journals (Sweden)

    Do Lam Mung

    2015-06-01

    Full Text Available Abstract Wireless charging system described by using the method of inductive coupling. In this project oscillation circuit converts DC energy to AC energytransmitter coil to transmit magnetic field by passing frequency and then induce the receiver coil. The properties of Induction coupling are wavemagnetic field-wideband rangevery shortcm efficiencyhight and operation frequencyLF-bandseveral handred kHz.The project shows as a small charging for 5V battery of phone in this method. The system bases on coupling magnetic field then designed and constructed as two parts. There are transmitter part and receiver part. The transmitter coil transmitter part transmits coupling magnetic field to receiver coil receiver part by passing frequency at about 1.67MHz. The Amperes law Biot-Savart law and Faraday law are used to calculate the inductive coupling between the transmitter coil and the receiver coil. The calculation of this law shows how many power transfer in receiver part when how many distance between the transmitter coil and the receiver coil. The system is safe for users and neighbouring electronic devices. To get more accurate wireless charging system it needs to change the design of the following keywords.

  6. Separation of seven arsenic compounds by high-performance liquid chromatography with on-line detection by hydrogen–argon flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, S. H.; Larsen, E. H.; Pritzl, G.

    1992-01-01

    Seven molecular forms of arsenic were separated by anion- and cation-exchange high-performance liquid chromatography (HPLC) with on-line detection by flame atomic absorption spectrometry (FAAS). The interfacing was established by a vented poly(tetrafluoroethylene) capillary tubing connecting...... the HPLC column to the nebulizer of the atomic absorption spectrometer. Arsenite, arsenate, monomethylarsonate (MMA) and dimethylarsinate (DMA) were separated from each other and from the co-injected cationic arsenic compounds, arsenobetaine (AsB), arsenocholine (AsC) and the tetramethylarsonium ion (TMAs......-to-noise ratio of the on-line AAS detector was optimized. This involved the use of the hydrogen-argon-entrained air flame, a slotted tube atom trap in the flame for signal enhancement, electronic noise damping and a high-intensity light source. The detection limits in mu-g cm-3, using 100 mm3 injections...

  7. Separation of seven arsenic compounds by high performance liquid chromatography with on-line detection by hydrogen-argon flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, S. H.; Larsen, Erik Huusfeldt; Pritzl, G.

    1992-01-01

    Seven molecular forms of arsenic were separated by anion- and cation-exchange high-performance liquid chromatography (HPLC) with on-line detection by flame atomic absorption spectrometry (FAAS). The interfacing was established by a vented poly(tetrafluoroethylene) capillary tubing connecting...... the HPLC column to the nebulizer of the atomic absorption spectrometer. Arsenite, arsenate, monomethylarsonate (MMA) and dimethylarsinate (DMA) were separated from each other and from the co-injected cationic arsenic compounds, arsenobetaine (AsB), arsenocholine (AsC) and the tetramethylarsonium ion (TMAs......-to-noise ratio of the on-line AAS detector was optimized. This involved the use of the hydrogen-argon-entrained air flame, a slotted tube atom trap in the flame for signal enhancement, electronic noise damping and a high-intensity light source. The detection limits in mu-g cm-3, using 100 mm3 injections...

  8. Attachment Instabilities of SF6 Inductively Coupled Plasmas under Different Coupling Intensities

    Institute of Scientific and Technical Information of China (English)

    GAO Wei; SUN Bin; DING Zhen-Feng

    2009-01-01

    Characteristics of attachment instabilities in SF6 inductively coupled plasmas are experimentally studied under different coupling intensities.Experimental results show that the instabilities only occur in H modes operating in positive feedback regions.Both the sudden mode transitions and the instabilities are influenced by the coupling intensities.With increasing absorbed power,weak and middle coupling discharges can sequently undergo sudden mode transitions and attachment instabilities.In strong coupling discharges,the sudden mode transitions disappear and only attachment instabilities exist.The strong and weak coupling discharges are the most stable and unstable,respectively.

  9. Cobalamin Concentrations in Fetal Liver Show Gender Differences: A Result from Using a High-Pressure Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry as an Ultratrace Cobalt Speciation Method.

    Science.gov (United States)

    Bosle, Janine; Goetz, Sven; Raab, Andrea; Krupp, Eva M; Scheckel, Kirk G; Lombi, Enzo; Meharg, Andrew A; Fowler, Paul A; Feldmann, Jörg

    2016-12-20

    Maternal diet and lifestyle choices may affect placental transfer of cobalamin (Cbl) to the fetus. Fetal liver concentration of Cbl reflects nutritional status with regards to vitamin B12, but at these low concentration current Cbl measurement methods lack robustness. An analytical method based on enzymatic extraction with subsequent reversed-phase-high-pressure liquid chromatography (RP-HPLC) separation and parallel ICPMS and electrospray ionization (ESI)-Orbitrap-MS to determine specifically Cbl species in liver samples of only 10-50 mg was developed using 14 pig livers. Subsequently 55 human fetal livers were analyzed. HPLC-ICPMS analysis for cobalt (Co) and Cbl gave detection limits of 0.18 ng/g and 0.88 ng/g d.m. in liver samples, respectively, with a recovery of >95%. Total Co (Cot) concentration did not reflect the amount of Cbl or vitamin B12 in the liver. Cbl bound Co contributes only 45 ± 15% to Cot. XRF mapping and μXANES analysis confirmed the occurrence of non-Cbl cobalt in pig liver hot spots indicating particular Co. No correlations of total cobalt nor Cbl with fetal weight or weeks of gestation were found for the human fetal livers. Although no gender difference could be identified for total Co concentration, female livers were significantly higher in Cbl concentration (24.1 ± 7.8 ng/g) than those from male fetuses (19.8 ± 7.1 ng/g) (p = 0.04). This HPLC-ICPMS method was able to quantify total Cot and Cbl in fetus liver, and it was sensitive and precise enough to identify this gender difference.

  10. Optimization of an anion-exchange high performance liquid chromatography-inductively coupled plasma-mass spectrometric method for the speciation analysis of oxyanion-forming metals and metalloids in leachates from cement-based materials.

    Science.gov (United States)

    Mulugeta, Mesay; Wibetoe, Grethe; Engelsen, Christian J; Lund, Walter

    2010-10-01

    A method was developed for the speciation analysis of the oxyanions of As(III), As(V), Cr(VI), Mo(VI), Sb(III), Sb(V), Se(IV), Se(VI) and V(V) in leachates from cement-based materials, based on anion-exchange HPLC coupled with ICP-MS. The method was optimized in a two-step multivariate approach: the effect of sample pH and mobile phase composition on resolution, peak symmetry and analysis time was studied. Optimum conditions were then identified for the significant experimental factors by studying their interdependence. A mobile phase composition of 20 mM ammonium nitrate, 50 mM ammonium tartrate and pH 9.5 was found to be a compromise optimum for the separation of the target analytes using isocratic elution. The optimum condition provided separation of the analytes in less than 6 min, at a mobile phase flow rate of 1.0 mL/min. The signal intensities of the analytes were improved by adding 1% methanol to the mobile phase. The limit of detection of the method was in the range 0.2-2.2 μg/L for the various species. The effect of sample constituents was studied using spiked concrete leachates. The method was used to determine the target oxyanionic species in leachates generated from a concrete material in the pH range 3.5-12.4; CrO(4)(2-), MoO(4)(2-) and VO(4)(3-) were detected in most of the leachates.

  11. Analysis of the Coupling Coefficient in Inductive Energy Transfer Systems

    Directory of Open Access Journals (Sweden)

    Rafael Mendes Duarte

    2014-01-01

    Full Text Available In wireless energy transfer systems, the energy is transferred from a power source to an electrical load without the need of physical connections. In this scope, inductive links have been widely studied as a way of implementing these systems. Although high efficiency can be achieved when the system is operating in a static state, it can drastically decrease if changes in the relative position and in the coupling coefficient between the coils occur. In this paper, we analyze the coupling coefficient as a function of the distance between two planar and coaxial coils in wireless energy transfer systems. A simple equation is derived from Neumann’s equation for mutual inductance, which is then used to calculate the coupling coefficient. The coupling coefficient is computed using CST Microwave Studio and compared to calculation and experimental results for two coils with an excitation signal of up to 10 MHz. The results showed that the equation presents good accuracy for geometric parameters that do not lead the solution of the elliptic integral of the first kind to infinity.

  12. Investigation of inductively coupled ultrasonic transducer system for NDE.

    Science.gov (United States)

    Zhong, Cheng Huan; Croxford, Anthony J; Wilcox, Paul D

    2013-06-01

    Inductive coupling offers a simple solution to wirelessly probe ultrasonic transducers. This paper investigates the theory and feasibility of such an inductively coupled transducer system in the context of nondestructive evaluation (NDE) applications. The noncontact interface is based on electromagnetic coupling between three coils; one of the coils is physically connected to the transducer, the other two are in a separate probing unit, where they are connected to the transmit and receive channels of the instrumentation. The complete system is modeled as a three-port network with the measured impedance of a bonded piezoelectric ceramic disc representing a sensor attached to an arbitrary solid substrate. The developed transmission line model is a function of the physical parameters of the electromagnetic system, such as the number of turns and diameter of each coil, and their separation. This model provides immediate predictions of electrical input impedance and pulse-echo response. The model has been validated experimentally and a sensitivity analysis of the input parameters performed. This has enabled optimization of the various parameters. Inductively coupled transducer systems have been built for both bulk and guided wave examples. By using chirped excitation and baseline subtraction, inspection distance of up to 700 mm is achieved in single-shot, guided-wave pulse-echo mode measurements with a 5 mm separation between the probing coils and transducer coil on an aluminum plate structure. In the bulk wave example, a delamination in an 8.9-mm-thick carbon fiber composite specimen is successfully identified from the changes in the arrival time of a reflected pulse.

  13. MRI surface-coil pair with strong inductive coupling.

    Science.gov (United States)

    Mett, Richard R; Sidabras, Jason W; Hyde, James S

    2016-12-01

    A novel inductively coupled coil pair was used to obtain magnetic resonance phantom images. Rationale for using such a structure is described in R. R. Mett et al. [Rev. Sci. Instrum. 87, 084703 (2016)]. The original rationale was to increase the Q-value of a small diameter surface coil in order to achieve dominant loading by the sample. A significant improvement in the vector reception field (VRF) is also seen. The coil assembly consists of a 3-turn 10 mm tall meta-metallic self-resonant spiral (SRS) of inner diameter 10.4 mm and outer diameter 15.1 mm and a single-loop equalization coil of 25 mm diameter and 2 mm tall. The low-frequency parallel mode was used in which the rf currents on each coil produce magnetic fields that add constructively. The SRS coil assembly was fabricated and data were collected using a tissue-equivalent 30% polyacrylamide phantom. The large inductive coupling of the coils produces phase-coherency of the rf currents and magnetic fields. Finite-element simulations indicate that the VRF of the coil pair is about 4.4 times larger than for a single-loop coil of 15 mm diameter. The mutual coupling between coils influences the current ratio between the coils, which in turn influences the VRF and the signal-to-noise ratio (SNR). Data on a tissue-equivalent phantom at 9.4 T show a total SNR increase of 8.8 over the 15 mm loop averaged over a 25 mm depth and diameter. The experimental results are shown to be consistent with the magnetic resonance theory of the emf induced by spins in a coil, the theory of inductively coupled resonant circuits, and the superposition principle. The methods are general for magnetic resonance and other types of signal detection and can be used over a wide range of operating frequencies.

  14. 高效液相色谱-电感耦合等离子体质谱同时分析鸡肉中洛克沙生、阿散酸和硝苯胂酸%Simultaneous Determination of Roxarsone,Arsanilic and Nitarsone in Chicken by High Performance Liquid Chromatography/Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    杨丽君; 刘玉敏; 崔凤杰; 郭伟; 徐成钢; 李兆杰

    2011-01-01

    An analytical method was developed to simultaneously determine roxarsone,arsanilic and nitarsone in chicken by high performance liquid chromatography/inductively coupled plasma mass spectrometry(HPLC-ICP-MS).Samples were extracted with methanol/water solution.The chromatographic separation was performed on a Phenomenex Luna C18 using methanol and water(containing 0.05% trifluoroacetic acid) as the mobile phase.Identification and quantification were achieved by using ICP-MS.Good linearity was observed in the range of 1 to 50 μg/kg with correlation coefficients above 0.99.The method was validated at the spike levels of 1,2,10 μg/kg.The validation results indicated that the average recoveries of arsenicum praeparatum ranged from 85.4% to 103.1% with a relative standard deviation of 3.3%-7.2%.The quantification limits of 3 arsenicum praeparatum were 1μg/kg.The method had good reproducibility,high sensitivity and simple pre-treatment.Its performance could meet both domestic and international legislation requirements.This method is applicable for simultaneous determination of arsenicum praeparatum in chicken.%建立一种同时测定鸡肉中洛克沙生、阿散酸和硝苯胂酸等3种有机砷类制剂的高效液相色谱-电感耦合等离子体质谱(high performance liquid chromatography tandem inductively coupled plasma mass spectrometry,HPLC-ICP-MS)分析方法。样品经甲醇溶液提取,采用Phenomenex Luna C18色谱柱,体积分数0.05%的三氟乙酸溶液-甲醇作为流动相进行洗脱,经高效液相色谱分离,电感耦合等离子体质谱进行定性和定量分析。结果表明:1~50μg/kg范围内各砷制剂线性良好,相关系数r2均在0.99以上;在1、2、10μg/kg三个加标水平下进行方法验证,平均回收率为85.4%~103.1%,相对标准偏差为3.3%~7.2%;3种有机砷类制剂的定量限均为1μg/kg。方法重现性好、灵敏度高、前处理简单,各项指标均满足国内外法规要求,适用

  15. Biosynthesis of Cd-bound phytochelatins by Phaeodactylum tricornutum and their speciation by size-exclusion chromatography and ion-pair chromatography coupled to ICP-MS.

    Science.gov (United States)

    Loreti, Valeria; Toncelli, Daniel; Morelli, Elisabetta; Scarano, Gioacchino; Bettmer, Jörg

    2005-10-01

    Cd-bound phytochelatins (Cd-PCs) have been synthesised by incubation of Phaeodactylum tricornutum cell cultures with Cd and purified by size-exclusion chromatography-UV-Vis. These complexes, which were identified in previous work, have now been used as model substances to develop and optimise ion-pair chromatography (IPC) coupled to inductively coupled plasma-mass spectrometry (ICP-MS) for analysis of Cd-PCs. Subsequent analysis of samples taken from Silene vulgaris plants cultivated under heavy metal stress conditions revealed Cd signals but no Cd-PC signals. By use of isotopically enriched (116)Cd-PCs the sample preparation steps were verified to determine the stability of the analytes. We observed species transformation between Cd-PCs and other unidentified Cd complexes. Consequently, the kinetic and thermodynamic lability of Cd-PCs are decisive factors in their detection.

  16. SU-8 etching in inductively coupled oxygen plasma

    DEFF Research Database (Denmark)

    Rasmussen, Kristian Hagsted; Keller, Stephan Sylvest; Jensen, Flemming

    2013-01-01

    Structuring or removal of the epoxy based, photo sensitive polymer SU-8 by inductively coupled plasma reactive ion etching (ICP-RIE) was investigated as a function of plasma chemistry, bias power, temperature, and pressure. In a pure oxygen plasma, surface accumulation of antimony from the photo......-initiator introduced severe roughness and reduced etch rate significantly. Addition of SF6 to the plasma chemistry reduced the antimony surface concentration with lower roughness and higher etch rate as an outcome. Furthermore the etch anisotropy could be tuned by controlling the bias power. Etch rates up to 800 nm...

  17. Quantum Effects of Mesoscopic Inductance and Capacity Coupling Circuits

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Xin; AN Zhan-Yuan; SONG Yong-Hua

    2006-01-01

    Using the quantum theory for a mesoscopic circuit based on the discretenes of electric charges, the finitedifference Schrodinger equation of the non-dissipative mesoscopic inductance and capacity coupling circuit is achieved.The Coulomb blockade effect, which is caused by the discreteness of electric charges, is studied. Appropriately choose the components in the circuits, the finite-difference Schrodinger equation can be divided into two Mathieu equations in p representation. With the WKBJ method, the currents quantum fluctuations in the ground states of the two circuits are calculated. The results show that the currents quantum zero-point fluctuations of the two circuits are exist and correlated.

  18. 体积排阻高效液相色谱-电感耦合等离子体质谱法测定海产贝类中镉的形态%Speciation Analysis of Cadmium in Marine Bivalves by Size Exclusion Chromatography-High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    赵艳芳; 尚德荣; 宁劲松; 翟毓秀

    2012-01-01

    The speciation analysis of cadmium in the scallop (Chlamys farreri, C. farreri) with high Cd accumulation capability and the clam (Ruditapes philippinarum, R. philippivarum) with low Cd accumulation capability was first conducted by size exclusion chromatography-high performance liquid chromatography-inductivcly coupled plasma mass spectrometry (SEC-HPLC-ICP-MS), and in vitro whole-bionic digestion model was used to determine the cadmium speciation in two bivalves under the action of saliva, the acidity of stomach and intestine with inorganic and organic components and diges-tion enzymes. The results showed that the total cadmium content in C. farreri was almost 10 times in R. philippinarum. Three Cd species, metallothionein (MT)-Cd, glutathione (GSH)-Cd and cystein (Cys)-Cd were detected in C. farreri, and two Cd species, MT-Cd and GSH-Cd were detected in R. philippinarum. According to the different peak areas, MT-Cd and GSH-Cd content in C. farreri was about 5. 6 and 2. 0 times of those in R. philippinarum respectively. Using in vitro whole-bionic diges-tion model, one unknown Cd species with small molecule (named Cd-X) was detected in whole-bionic digestion of gastric extracts, and four Cd species (mainly MT-Cd) were detected in the whole-bionic digestion of intestine extracts for C. farreri; however, for R. philippinarum, the unknown Cd-X was the main Cd species in both gastric and intestinal extracts. The experiment also proves that Cd can be separated from MT-Cd, GSH-Cd and Cys-Cd under the effect of the whole-bionic digestion of stomach and intestine.%运用体积排阻高效液相色谱-电感耦合等离子体质谱联用技术(SEC-HPLC-ICP-MS)分析了高镉积累扇贝和低镉积累菲律宾蛤仔中镉的存在形态,并结合体外全仿生消化技术,研究了在唾液、胃、肠无机物和有机物(含消化酶)作用下,扇贝和菲律宾蛤仔中镉的主要存在形态.结果发现:扇贝中Cd总量约为菲律宾蛤仔的10

  19. HPLC-ICP/MS联用同时分析中药材中的多种形态砷%Analysis of arsenic speciation in traditional Chinese medicines by hyphenated technique of high performance liquid chromatography-inductively coupled plasma mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    郝春莉; 赵丽; 庄峙厦

    2011-01-01

    The hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) were applied in the simultaneous determination of six arsenic species including As( Ⅲ ) 、As( Ⅴ ) 、DMA、MMA、AsB and AsC, in traditional Chinese medicines. The arsenic species in Traditional Chinese Medicinal samples were extracted using 1.2 mol/L hydrochloric acid and analyzed by the hyphenated technique of HPLC-ICP-MS with Hamilton PRP-X100 column. The arsenic species were separated well in the 800s,and the detection limits were 0. 2 ~ 0. 6 μg. Arsenate As(Ⅴ) and arsenite As(Ⅲ) were main arsenic species in all samples,and the inorganic arsenic recoveries were 64%. 1% ~91.7%. In addition, a little arsenobetaine (AsB) was found in animal herbs. The method can be applied to the quantitative determination and safety evaluation of inorganic arsenic or six arsenic species in TCMs.%利用高效液相色谱-电感耦合等离子体质谱(HPLC-ICP/MS)对中药材中的6种砷的形态(三价砷(As(Ⅲ))、五价砷(As(Ⅴ))、二甲基砷酸(DMA)、甲基砷酸(MMA)、砷甜菜碱(AsB)和砷胆碱(AsC))进行了同时分析.采用1.2mol/,L HCl浸提,Hamilton PRP-X100阴离子交换色谱柱分离后,根据ICP/MS保留时间的差别跟踪检测砷元素的各种形态.6种砷形态在800s内分离良好,检测限在0.2~0.6μg/L之间;中药材中的砷主要以有毒的无机砷(As(Ⅴ)和As(Ⅲ))形态存在,样品中无机砷的回收率在64.1%~91.7%之间,另外动物药材中还存在微量的AsB等有机砷形态.方法可用于中药材中无机砷或各种砷形态的同时分析.

  20. Microwave Kinetic Inductance Detector with Selective Polarization Coupling

    Science.gov (United States)

    Wollack, Edward; U-yen, Kongpop; Stevenson, Thomas; Brown, Ari; Moseley, Samuel; Hsieh, Wen-Ting

    2013-01-01

    A conventional low-noise detector requires a technique to both absorb incident power and convert it to an electrical signal at cryogenic temperatures. This innovation combines low-noise detector and readout functionality into one device while maintaining high absorption, controlled polarization sensitivity, and broadband detection capability. The resulting far-infrared detectors can be read out with a simple approach, which is compact and minimizes thermal loading. The proposed microwave kinetic inductance detector (MKID) consists of three basic elements. The first is the absorptive section in which the incident power is coupled to a superconducting resonator at far-infrared frequency above its superconducting critical frequency (where superconductor becomes normal conductor). This absorber's shape effectively absorbs signals in the desired polarization state and is resonant at the radio frequency (RF) used for readout of the device. Control over the metal film used in the absorber allows realization of structures with either a 50% broadband or 100% resonance absorptance over a 30% fractional bandwidth. The second element is a microwave resonator - which is realized from the thin metal films used to make the absorber as transmission lines - whose resonance frequency changes due to a variation in its kinetic inductance. The resonator's kinetic inductance is a function of the power absorbed by the device. A low-loss dielectric (mono-crystalline silicon) is used in a parallel-plate transmission line structure to realize the desired superconducting resonators. There is negligible coupling among the adjacent elements used to define the polarization sensitivity of each detector. The final component of the device is a microwave transmission line, which is coupled to the resonator, and allows detection of changes in resonance frequency for each detector in the focal plane array. The spiral shape of the detector's absorber allows incident power with two polarizations to

  1. Physical limitations in ferromagnetic inductively coupled plasma sources

    CERN Document Server

    Bliokh, Yury P; Slutsker, Yakov Z

    2012-01-01

    The Ferromagnetic Inductively Coupled Plasma (FICP) source, which is a version of the common inductively coupled plasma sources, has a number of well known advantages such as high efficiency, high level of ionization, low minimal gas pressure, very low required driver frequency, and even a possibility to be driven by single current pulses. We present an experimental study of such an FICP source which showed that above a certain value of the driving pulse power the properties of this device changed rather drastically. Namely, the plasma became non-stationary and non-uniform contrary to the stationary and uniform plasmas typical for this kind of plasma sources. In this case the plasma appeared as a narrow dense spike which was short compared to the driving pulse. The local plasma density could exceed the neutral atoms density by a few orders of magnitude. When that happened, the afterglow plasma decay time after the end of the pulse was long compared to an ordinary case with no plasma spike. Experiments were pe...

  2. Inductively coupled plasma mass spectrometry for stable isotope metabolic tracer studies of living systems

    Energy Technology Data Exchange (ETDEWEB)

    Luong, Elise [Iowa State Univ., Ames, IA (United States)

    1999-05-10

    This dissertation focuses on the development of methods for stable isotope metabolic tracer studies in living systems using inductively coupled plasma single and dual quadrupole mass spectrometers. Sub-nanogram per gram levels of molybdenum (Mo) from human blood plasma are isolated by the use of anion exchange alumina microcolumns. Million-fold more concentrated spectral and matrix interferences such as sodium, chloride, sulfate, phosphate, etc. in the blood constituents are removed from the analyte. The recovery of Mo from the alumina column is 82 ± 5% (n = 5). Isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) is utilized for the quantitative ultra-trace concentration determination of Mo in bovine and human blood samples. The average Mo concentration in reference bovine serum determined by this method is 10.2 ± 0.4 ng/g, while the certified value is 11.5 ± 1.1 ng/g (95% confidence interval). The Mo concentration of one pool of human blood plasma from two healthy male donors is 0.5 ± 0.1 ng/g. The inductively coupled plasma twin quadrupole mass spectrometer (ICP-TQMS) is used to measure the carbon isotope ratio from non-volatile organic compounds and bio-organic molecules to assess the ability as an alternative analytical method to gas chromatography combustion isotope ratio mass spectrometry (GC-combustion-IRMS). Trytophan, myoglobin, and β-cyclodextrin are chosen for the study, initial observation of spectral interference of 13C+ with 12C 1H+ comes from the incomplete dissociation of myoglobin and/or β-cyclodextrin.

  3. Using Some Coupled Numerical Models in Problems of Designing an Inductive Electrothermal Equipment

    Directory of Open Access Journals (Sweden)

    LEUCA Teodor

    2014-05-01

    Full Text Available This paper focuses on the numerical modeling of coupling the electromagnetic and the thermal field, in the process of inductive heating, for inductive electrothermal equipments. Numerical results are carried out by using a FLUX2D application.

  4. A Tightly Coupled Non-Equilibrium Magneto-Hydrodynamic Model for Inductively Coupled RF Plasmas

    Science.gov (United States)

    2016-02-29

    effects are described based on a hybrid State-to-State (StS) approach. A multi-temperature formulation is used to account for thermal non-equilibrium...for Inductively Coupled Radio-Frequency (RF) Plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State...usually obtained through quantum chemistry calculations51–56 or through phenomenological models providing a simplified descrip- tion of the kinetic

  5. Monitoring microbial metabolites using an inductively coupled resonance circuit

    Science.gov (United States)

    Karnaushenko, Daniil; Baraban, Larysa; Ye, Dan; Uguz, Ilke; Mendes, Rafael G.; Rümmeli, Mark H.; de Visser, J. Arjan G. M.; Schmidt, Oliver G.; Cuniberti, Gianaurelio; Makarov, Denys

    2015-08-01

    We present a new approach to monitor microbial population dynamics in emulsion droplets via changes in metabolite composition, using an inductively coupled LC resonance circuit. The signal measured by such resonance detector provides information on the magnetic field interaction with the bacterial culture, which is complementary to the information accessible by other detection means, based on electric field interaction, i.e. capacitive or resistive, as well as optical techniques. Several charge-related factors, including pH and ammonia concentrations, were identified as possible contributors to the characteristic of resonance detector profile. The setup enables probing the ionic byproducts of microbial metabolic activity at later stages of cell growth, where conventional optical detection methods have no discriminating power.

  6. Effects of driving frequency on properties of inductively coupled plasmas

    Science.gov (United States)

    Godyak, Valery; Kolobov, Vladimir

    2016-10-01

    Inductively coupled plasma (ICP) can be maintained over a wide range of driving frequencies from 50 Hz up to GHz. In this paper, we analyze how the properties of ICP depend on driving frequency ω. With respect to the time of ion transport to the walls, τd and the electron energy relaxation time τɛ three operating regimes are distinguished. The quasi-static regime, ωτd > 1 and the intermediate dynamic regime, 1 /τd helical coil with the plasma current flowing outside the coil, Bc = 0 , while when the plasma current flows inside the coil, Bc ≠ 0 . We show that in the latter case, in the quasi-static regimes, electrons become magnetized over a significant part of the period that may strongly affect the plasma properties. Examples of ICP simulations in different frequency regimes will be demonstrated in this paper.

  7. Quantitative aspects of inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Bulska, Ewa; Wagner, Barbara

    2016-10-01

    Accurate determination of elements in various kinds of samples is essential for many areas, including environmental science, medicine, as well as industry. Inductively coupled plasma mass spectrometry (ICP-MS) is a powerful tool enabling multi-elemental analysis of numerous matrices with high sensitivity and good precision. Various calibration approaches can be used to perform accurate quantitative measurements by ICP-MS. They include the use of pure standards, matrix-matched standards, or relevant certified reference materials, assuring traceability of the reported results. This review critically evaluates the advantages and limitations of different calibration approaches, which are used in quantitative analyses by ICP-MS. Examples of such analyses are provided. This article is part of the themed issue 'Quantitative mass spectrometry'.

  8. Diagnostic studies of ion beam formation in inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Jenee L. [Iowa State Univ., Ames, IA (United States)

    2015-01-01

    This dissertation describes a variety of studies focused on the plasma and the ion beam in inductively coupled plasma mass spectrometry (ICP-MS). The ability to use ICP-MS for measurements of trace elements in samples requires the analytes to be efficiently ionized. Updated ionization efficiency tables are discussed for ionization temperatures of 6500 K and 7000 K with an electron density of 1 x 1015 cm-3. These values are reflective of the current operating parameters of ICP-MS instruments. Calculations are also discussed for doubly charged (M2+) ion formation, neutral metal oxide (MO) ionization, and metal oxide (MO+) ion dissociation for similar plasma temperature values. Ionization efficiency results for neutral MO molecules in the ICP have not been reported previously.

  9. A Review on Inductively Coupled Plasma Mass Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ramyalakshmi G

    2012-12-01

    Full Text Available Inductively coupled plasma mass spectroscopy is routinely used in many diverse research fields such as earth, environmental, life and forensic sciences and in food, material, chemical, semiconductor and nuclear industries. The high ion density and the high temperature in a plasma provide an ideal atomizer and element ionizer for all types of samples and materials introduced by a specialised devices .outstanding properties such as high sensitivity, relative salt tolerance, compound-independent element response and highest quantitation accuracy lead to the unchallenged performance of ICPMS in efficiently detecting, identifying and reliably quantifying trace element. The increasing availability of relevant reference compounds and high separation selectively extend the molecular identification capability of ICPMS hyphenated to species – specific separation techniques

  10. Molecular Nitrogen Vibrational Temperature in an Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    康正德; 蒲以康

    2002-01-01

    Using a technique applied previously to vibrationally excited molecular nitrogen (N*2) in the region of daytime and nighttime aurora, the emission intensity of the N2 second positive band system in an inductively coupled plasma (ICP) has been analysed and the vibrational temperature of nitrogen molecules in the ICP is thus determined. The result shows that the vibrational temperature increases with the increase of the neutral gas pressure from 0.04Pa to 10Pa, then decreases with the further increase of the pressure from 10Pa to 100Pa. Also,this is explained by using the Boltzmann relation between the vibrational temperature and the concentration of the vibrationally excited N*2(X1∑+g ) molecules.

  11. H-mode inductive coupling plasma for PVC surface treatment

    Science.gov (United States)

    Croccolo, F.; Quintini, A.; Barni, R.; Ripamonti, M.; Malgaroli, A.; Riccardi, C.

    2009-08-01

    An inductively coupled plasma machine has been modified to be able to apply working powers in the order of 1 kW, thus switching to the real inductive H-mode. The plasma is generated by applying a 13.56 MHz radio-frequency to a λ/4 antenna outside the plasma chamber in low pressure conditions. The working gas is argon at pressure in the range from 10 to 100 Pa. With this high power source we have been able to perform plasma etching on a poly(vinyl-chloride) (PVC) film. In particular the effect of the plasma is the selective removal of hydrogen and chlorine from the sample surface. The action of the high power plasma on the sample has been proved to be much more effective than that of the low power one. Results similar to those obtained with the low power machine at about 300 W for 120 min, have been obtained with the high power source at about 600 W for 30 min. The superficial generation of a conductive layer of double C=C bonds was obtained. The samples have been investigated by means of ATR spectroscopy, FIB/SEM microscopy and micro-electrical measurements, which revealed the change in charge conductivity.

  12. Matrix effects in inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaoshan [Iowa State Univ., Ames, IA (United States)

    1995-07-07

    The inductively coupled plasma is an electrodeless discharge in a gas (usually Ar) at atmospheric pressure. Radio frequency energy generated by a RF power source is inductively coupled to the plasma gas through a water cooled load coil. In ICP-MS the "Fassel" TAX quartz torch commonly used in emission is mounted horizontally. The sample aerosol is introduced into the central flow, where the gas kinetic temperature is about 5000 K. The aerosol is vaporized, atomized, excited and ionized in the plasma, and the ions are subsequently extracted through two metal apertures (sampler and skimmer) into the mass spectrometer. In ICP-MS, the matrix effects, or non-spectroscopic interferences, can be defined as the type of interferences caused by dissolved concomitant salt ions in the solution. Matrix effects can be divided into two categories: (1) signal drift due to the deposition of solids on the sampling apertures; and/or (2) signal suppression or enhancement by the presence of the dissolved salts. The first category is now reasonably understood. The dissolved salts, especially refractory oxides, tend to deposit on the cool tip of the sampling cone. The clogging of the orifices reduces the ion flow into the ICP-MS, lowers the pressure in the first stage of ICP-MS, and enhances the level of metal oxide ions. Because the extent of the clogging increases with the time, the signal drifts down. Even at the very early stage of the development of ICP-MS, matrix effects had been observed. Houk et al. found out that the ICP-MS was not tolerant to solutions containing significant amounts of dissolved solids.

  13. Phosphorus doped graphene by inductively coupled plasma and triphenylphosphine treatments

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dong-Wook, E-mail: shindong37@skku.edu; Kim, Tae Sung; Yoo, Ji-Beom, E-mail: jbyoo@skku.edu

    2016-10-15

    Highlights: • Substitution doping is a promising method for opening the energy band gap of graphene. • Substitution doping with phosphorus in the graphene lattice has numerous advantage such as high band gap, low formation energy, and high net charge density compared to nitrogen. • V{sub dirac} of Inductively coupled plasma (ICP) and triphenylphosphine (TPP) treated graphene was −57 V, which provided clear evidence of n-type doping. • Substitutional doping of graphene with phosphorus is verified by the XPS spectra of P 2p core level and EELS mapping of phosphorus. • The chemical bonding between P and graphene is very stable for a long time in air (2 months). - Abstract: Graphene is considered a host material for various applications in next-generation electronic devices. However, despite its excellent properties, one of the most important issues to be solved as an electronic material is the creation of an energy band gap. Substitution doping is a promising method for opening the energy band gap of graphene. Herein, we demonstrate the substitutional doping of graphene with phosphorus using inductively coupled plasma (ICP) and triphenylphosphine (TPP) treatments. The electrical transfer characteristics of the phosphorus doped graphene field effect transistor (GFET) have a V{sub dirac} of ∼ − 54 V. The chemical bonding between P and C was clearly observed in XPS spectra, and uniform distribution of phosphorus within graphene domains was confirmed by EELS mapping. The capability for substitutional doping of graphene with phosphorus can significantly promote the development of graphene based electronic devices.

  14. Displacement chromatography of proteins using a retained pH front in a hydrophobic charge induction chromatography column.

    Science.gov (United States)

    Pinto, N D S; Frey, Douglas D

    2015-03-27

    The chromatographic separation of two proteins into a displacement train of two adjoined rectangular bands was accomplished using a novel method for hydrophobic charge induction chromatography (HCIC) which employs a self-sharpening pH front as the displacer. This method exploits the fact that protein elution in HCIC is promoted by a pH change, but is relatively independent of salt effects, so that a retained pH front can be used in place of a traditional displacer in displacement chromatography. The retained pH front was produced using the two adsorbed buffering species tricine and acetic acid. The separation of lysozyme and α-chymotrypsinogen A into adjoined, rectangular bands was accomplished with overall recoveries based on the total mass injected greater than 90 and 70%, respectively. The addition of urea to the buffer system increased the sharpness of the pH front by 36% while the yields of lysozyme and α-chymotrypsinogen A based on the total mass eluted increased from 76% to 99% and from 37% to 85%, respectively, when the purities of both proteins in their product fractions were fixed at 85%. The results demonstrate that the method developed in this study is a useful variant of HCIC and is also a useful alternative to other displacement chromatography methods.

  15. Fractionation analysis of manganese in Turkish hazelnuts (Corylus avellana L.) by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Erdemir, Umran Seven; Gucer, Seref

    2014-11-05

    In this study, an analytical fractionation scheme based on water, diethyl ether, n-hexane, and methanol extractions has been developed to identify manganese-bound fractions. Additionally, in vitro simulated gastric and intestinal digestion, n-octanol extraction, and activated carbon adsorption were used to interpret the manganese-bound structures in hazelnuts in terms of bioaccessibility. The total content of manganese in the samples was determined by inductively coupled plasma-mass spectrometry after microwave-assisted digestion, and additional validation was performed using atomic absorption spectroscopy. Water fractions were further evaluated by high-performance liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry for the identification of water-soluble manganese fractions in hazelnut samples. The limits of detection and quantification were 3.6 and 12.0 μg L(-1), respectively, based on peak height.

  16. Synthesis of Silicon Nanoparticles in Inductively Coupled Plasmas

    Science.gov (United States)

    Markosyan, Aram H.; Le Picard, Romain; Girshick, Steven L.; Kushner, Mark J.

    2016-09-01

    The synthesis of silicon nanoparticles (Si-NPs) is being investigated for their use in photo-emitting electronics, photovoltaics, and biotechnology. The ability to control the size and mono-disperse nature of Si-NPs is important to optimizing these applications. In this paper we discuss results from a computational investigation of Si-NP formation and growth in an inductively coupled plasma (ICP) reactor with the goal of achieving this control. We use a two dimensional numerical model where the algorithms for the kinetics of NP formation are self-consistently coupled with a plasma hydrodynamics simulation. The reactor modeled here resembles a GEC reference cell through which, for the base case, a mixture of Ar/SiH4 = 70/30 flows at 150 sccm at a pressure of 100 mTorr. In continuous wave mode, three coils located on top of the reactor deliver 150 W. The electric plasma potential confines negatively charged particles at the center of the discharge, increasing the residence time of negative NPs, which enables the NPs to potentially grow to large and controllable sizes of many to 100s nm. We discuss methods of controlling NP growth rates by varying the mole fraction and flow rate of SiH4, and using a pulsed plasma by varying the pulse period and duty cycle. Work supported by DOE Office of Fusion Energy Science and National Science Foundation.

  17. Studies of selenium and xenon in inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bricker, T.

    1994-07-27

    Since its development, inductively coupled plasma mass spectrometry (ICP-MS) has been a widely used analytical technique. ICP-MS offers low detection limits, easy determination of isotope ratios, and simple mass spectra from analyte elements. ICP-MS has been successfully employed for many applications including geological, environmental, biological, metallurgical, food, medical, and industrial. One specific application important to many areas of study involves elemental speciation by using ICP-MS as an element specific detector interfaced to liquid chromatography. Elemental speciation information is important and cannot be obtained by atomic spectrometric methods alone which measure only the total concentration of the element present. Part 1 of this study describes the speciation of selenium in human serum by size exclusion chromatography (SEC) and detection by ICP-MS. Although ICP-MS has been widely sued, room for improvement still exists. Difficulties in ICP-MS include noise in the background, matrix effects, clogging of the sampling orifice with deposited solids, and spectral interference caused by polyatomic ions. Previous work has shown that the addition of xenon into the central channel of the ICP decreases polyatomic ion levels. In Part 2 of this work, a fundamental study involving the measurement of the excitation temperature is carried out to further understand xenon`s role in the reduction of polyatomic ions. 155 refs.

  18. Determination of myo-inositol hexakisphosphate (phytate) in urine by inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grases, F.; Perello, J.; Isern, B.; Prieto, R.M

    2004-05-10

    Myo-inositol hexakisphosphate (phytate) is a substance present in urine with an important role in preventing calcium renal calculi development. In spite of this, the use of urinary phytate levels on stone-formers' evaluation and treatment is still notably restricted as a consequence of the enormous difficulty to analyze this substance in urine. In this paper, a simple procedure for routinary urinary phytate determination based on phosphorus determination through inductively coupled plasma atomic emission spectrometry is described. The method only requires a previous separation of phytate from other components by column anion exchange chromatography. The working linear range used was 0-2 mg l{sup -1} phosphorus (0-7 mg l{sup -1} phytate). The limit of detection was 64 {mu}g l{sup -1} of phytate and the limit of quantification was 213 {mu}g l{sup -1}. The relative standard deviation (R.S.D.) for 1.35 mg l{sup -1} phytate was 2.4%. Different urine samples were analyzed using an alternative analytical methodology based on gas chromatography (GC)/mass detection used for inositol determination (phytate was previously hydrolyzed), resulting both methods comparable using as criterion to assess statistical significance P<0.05.

  19. Three dimensional liquid chromatography coupling ion exchange chromatography/hydrophobic interaction chromatography/reverse phase chromatography for effective protein separation in top-down proteomics.

    Science.gov (United States)

    Valeja, Santosh G; Xiu, Lichen; Gregorich, Zachery R; Guner, Huseyin; Jin, Song; Ge, Ying

    2015-01-01

    To address the complexity of the proteome in mass spectrometry (MS)-based top-down proteomics, multidimensional liquid chromatography (MDLC) strategies that can effectively separate proteins with high resolution and automation are highly desirable. Although various MDLC methods that can effectively separate peptides from protein digests exist, very few MDLC strategies, primarily consisting of 2DLC, are available for intact protein separation, which is insufficient to address the complexity of the proteome. We recently demonstrated that hydrophobic interaction chromatography (HIC) utilizing a MS-compatible salt can provide high resolution separation of intact proteins for top-down proteomics. Herein, we have developed a novel 3DLC strategy by coupling HIC with ion exchange chromatography (IEC) and reverse phase chromatography (RPC) for intact protein separation. We demonstrated that a 3D (IEC-HIC-RPC) approach greatly outperformed the conventional 2D IEC-RPC approach. For the same IEC fraction (out of 35 fractions) from a crude HEK 293 cell lysate, a total of 640 proteins were identified in the 3D approach (corresponding to 201 nonredundant proteins) as compared to 47 in the 2D approach, whereas simply prolonging the gradients in RPC in the 2D approach only led to minimal improvement in protein separation and identifications. Therefore, this novel 3DLC method has great potential for effective separation of intact proteins to achieve deep proteome coverage in top-down proteomics.

  20. Investigations on Capacitor Compensation Topologies Effects of Different Inductive Coupling Links Configurations

    Directory of Open Access Journals (Sweden)

    Norezmi Jamal

    2015-06-01

    Full Text Available This paper presents investigations on capacitor compensation topologies with different inductive coupling links for loosely coupled inductive power transfer (IPT system. In general, the main constraint of the loosely coupled IPT system is power losses due to the large leakage inductances. Therefore, to overcome the aforementioned problem, in this work, capacitor compensation is proposed to be used by adding an external capacitor to the system. By using this approach, the resonant inductive coupling can be achieved efficiently and hence the efficiency of the system is also increased significantly. This paper analyzes the performance of two different compensation topologies, which are primary series-secondary series (SS and primary series- secondary parallel (SP topology. The performance of such topologies is evaluated through the experimental results at 1MHz operating frequency for different types of inductive coupling. From the results, SS topology produces a high power transfer but SP topology gives better efficiency.

  1. Uranium quantification in semen by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Todorov, Todor I; Ejnik, John W; Guandalini, Gustavo; Xu, Hanna; Hoover, Dennis; Anderson, Larry; Squibb, Katherine; McDiarmid, Melissa A; Centeno, Jose A

    2013-01-01

    In this study we report uranium analysis for human semen samples. Uranium quantification was performed by inductively coupled plasma mass spectrometry. No additives, such as chymotrypsin or bovine serum albumin, were used for semen liquefaction, as they showed significant uranium content. For method validation we spiked 2g aliquots of pooled control semen at three different levels of uranium: low at 5 pg/g, medium at 50 pg/g, and high at 1000 pg/g. The detection limit was determined to be 0.8 pg/g uranium in human semen. The data reproduced within 1.4-7% RSD and spike recoveries were 97-100%. The uranium level of the unspiked, pooled control semen was 2.9 pg/g of semen (n=10). In addition six semen samples from a cohort of Veterans exposed to depleted uranium (DU) in the 1991 Gulf War were analyzed with no knowledge of their exposure history. Uranium levels in the Veterans' semen samples ranged from undetectable (<0.8 pg/g) to 3350 pg/g. This wide concentration range for uranium in semen is consistent with known differences in current DU body burdens in these individuals, some of whom have retained embedded DU fragments.

  2. AETHER: A simulation platform for inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Turkoz, Emre, E-mail: emre.turkoz@boun.edu.tr; Celik, Murat

    2015-04-01

    An in-house code is developed to simulate the inductively coupled plasma (ICP). The model comprises the fluid, electromagnetic and transformer submodels. Fluid equations are solved to evaluate the plasma flow parameters, including the plasma and neutral densities, ion and neutral velocities, electron flux, electron temperature, and electric potential. The model relies on the ambipolar approximation and offers the evaluation of plasma parameters without solving the sheath region. The electromagnetic model handles the calculation of the electric and magnetic fields using the magnetic vector potential. The transformer model captures the effect of the matching circuit utilized in laboratory experiments for RF power deposition. The continuity and momentum equations are solved using finite volume method. The energy, electric potential, and magnetic vector potential equations are solved using finite difference method. The resulting linear systems of equations are solved with iterative solvers including Jacobi and GMRES. The code is written using the C++ programming language, it works in parallel and has graphical user interface. The model is applied to study ICP characteristics of a plasma confined within a cylindrical chamber with dielectric walls for two different power deposition cases. The results obtained from the developed model are verified using the plasma module of COMSOL Multiphysics. The model is also applied to a plasma source configuration, and it is demonstrated that there is an overall increase in the plasma potential when current is extracted from ICP with a biased wall electrode.

  3. Deposition of Nano-Scaled Coatings Using Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    D H Jung; B Park; J J Lee

    2004-01-01

    Nano-scaled Ti-B-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-B-N coatings were prepared by using a TiB2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP and a bias voltage to the substrate the hardness of the Ti-B-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-B-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

  4. 高效液相色谱-电感耦合等离子体质谱联用技术测定玩具中痕量可迁移Cr(Ⅵ)%Determination of Trace Migratory Chromium(Ⅵ) in Toys by High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    王欣; 幸苑娜; 陈泽勇; 霍巨垣; 陈丽琼

    2013-01-01

    建立了高效液相色谱-电感耦合等离子体质谱联用技术(HPLC-ICP-MS)测定玩具中痕量可迁移Cr(Ⅵ)的方法.采用Dionex AS19分析柱,在流动相为NH4NO3,pH=7A,流速为1.0 mL/min的条件下,可以很好地分离Cr(Ⅲ)和Cr(Ⅵ),且流动相浓度越小,分离度越大.所建立的方法简便、快速、灵敏度高,在色谱进样量为100 μL,质谱采用He碰撞池模式下,对Cr(Ⅵ)的检出限为0.02 μg/L;两个加标水平0.50和5.00 μg/L回收率分别为98.8% ~ 104.2%和96.3% ~ 100.4%,方法精密度优于4.2%,可以满足测定要求.应用本方法测定了玩具可接触部分材料包括涂层、塑料、木料、织物中的可迁移Cr(Ⅵ),分析结果令人满意.%A method for determinating trace migratory chromium(V0 in toys by hyphenated technique of high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) has been developed in this article. The chromium species Cr(HI) and Cr(VO were separated on an Dionex AS19 analysis column using ammonium nitrate as the mobile phase with pH 7. 4 at flow rate 1. 0 mL/min. And the chromatographic separation was increased as the concentration of mobile phase was decreased. This method was easy to operate and with remarkably high sensitivity. The detection limit was found to be 0. 02 μg/L of Cr(VD for 100 μL injection volume in He collision cell mode of mass spectrometry. The spiked recoveries were at the range of 98. 8% -104. 2% and 96. 3% -100. 4% for the spiked levels of 0. 50 μg/L and 5. 00 ug/L respectively, and the RSDs were less than 4. 2% , which met the determination requirements. This method has been used to determine migratory Cr(Ⅵ) in accessible parts of toys, including coating, plastic, wood and textile. The results were satisfactory.

  5. Separation Of Uranium And Plutonium Isotopes For Measurement By Multi Collector Inductively Coupled Plasma Mass Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Martinelli, R E; Hamilton, T F; Williams, R W; Kehl, S R

    2009-03-29

    Uranium (U) and plutonium (Pu) isotopes in coral soils, contaminated by nuclear weapons testing in the northern Marshall Islands, were isolated by ion-exchange chromatography and analyzed by mass spectrometry. The soil samples were spiked with {sup 233}U and {sup 242}Pu tracers, dissolved in minerals acids, and U and Pu isotopes isolated and purified on commercially available ion-exchange columns. The ion-exchange technique employed a TEVA{reg_sign} column coupled to a UTEVA{reg_sign} column. U and Pu isotope fractions were then further isolated using separate elution schemes, and the purified fractions containing U and Pu isotopes analyzed sequentially using multi-collector inductively coupled plasma mass spectrometer (MCICP-MS). High precision measurements of {sup 234}U/{sup 235}U, {sup 238}U/{sup 235}U, {sup 236}U/{sup 235}U, and {sup 240}Pu/{sup 239}Pu in soil samples were attained using the described methodology and instrumentation, and provide a basis for conducting more detailed assessments of the behavior and transfer of uranium and plutonium in the environment.

  6. Three-phase inductive-coupled structures for contactless PHEV charging system

    Science.gov (United States)

    Lee, Jia-You; Shen, Hung-Yu; Li, Cheng-Bin

    2016-07-01

    In this article, a new-type three-phase inductive-coupled structure is proposed for the contactless plug-in hybrid electric vehicle (PHEV) charging system regarding with SAE J-1773. Four possible three-phase core structures are presented and subsequently investigated by the finite element analysis. To study the correlation between the core geometric parameter and the coupling coefficient, the magnetic equivalent circuit model of each structure is also established. In accordance with the simulation results, the low reluctance and the sharing of flux path in the core material are achieved by the proposed inductive-coupled structure with an arc-shape and three-phase symmetrical core material. It results in a compensation of the magnetic flux between each phase and a continuous flow of the output power in the inductive-coupled structure. Higher coupling coefficient between inductive-coupled structures is achieved. A comparison of coupling coefficient, mutual inductance, and self-inductance between theoretical and measured results is also performed to verify the proposed model. A 1 kW laboratory scale prototype of the contactless PHEV charging system with the proposed arc-shape three-phase inductive-coupled structure is implemented and tested. An overall system efficiency of 88% is measured when two series lithium iron phosphate battery packs of 25.6 V/8.4 Ah are charged.

  7. A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Munafò, A., E-mail: munafo@illinois.edu; Alfuhaid, S. A., E-mail: alfuhai2@illinois.edu; Panesi, M., E-mail: mpanesi@illinois.edu [Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Talbot Laboratory, 104 S. Wright St., Urbana, Illinois 61801 (United States); Cambier, J.-L., E-mail: jean-luc.cambier@us.af.mil [Edwards Air Force Base Research Laboratory, 10 E. Saturn Blvd., Edwards AFB, California 93524 (United States)

    2015-10-07

    The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients.

  8. An investigation of algebraic quantum dynamics for mesoscopic coupled electric circuits with mutual inductance

    Energy Technology Data Exchange (ETDEWEB)

    Pahlavani, H., E-mail: h-pahlavani@qom.ac.ir; Kolur, E. Rahmanpour

    2016-08-15

    Based on the electrical charge discreteness, the Hamiltonian operator for the mutual inductance coupled quantum mesoscopic LC circuits has been found. The persistent current on two driven coupled mesoscopic electric pure L circuits (two quantum loops) has been obtained by using algebraic quantum dynamic approach. The influence of the mutual inductance on energy spectrum and quantum fluctuations of the charge and current for two coupled quantum electric mesoscopic LC circuits have been investigated.

  9. Effects of leakage inductances on magnetically-coupled impedance-source networks

    DEFF Research Database (Denmark)

    Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede;

    2014-01-01

    Coupled inductors have lately been used with impedance-source networks for keeping their shoot-through times short, while providing higher voltage boosts. The parameter that is critical to the operation of such impedance network based converter with coupled inductors is the leakage inductances. H....... However, the role of leakage inductances and its effect on the converter performance is often overlooked. This paper analyzes the effects of leakage inductances and demonstrates experimentally how the presence of leakage inductances degrades the performance of the converter....

  10. A novel sputtering technique: Inductively Coupled Impulse Sputtering (ICIS)

    Science.gov (United States)

    Loch, D. A. L.; Ehiasarian, A. P.

    2012-09-01

    Sputtering magnetic materials with magnetron based systems has the disadvantage of field quenching and variation of alloy composition with target erosion. The advantage of eliminating magnetic fields in the chamber is that this enables sputtered particles to move along the electric field more uniformly. Inductively coupled impulse sputtering (ICIS) is a form of high power impulse magnetron sputtering (HIPIMS) without a magnetic field where a high density plasma is produced by a high power radio frequency (RF) coil in order to sputter the target and ionise the metal vapour. In this emerging technology, the effects of power and pressure on the ionisation and deposition process are not known. The setup comprises of a 13.56 MHz pulsed RF coil pulsed with a duty cycle of 25 %. A pulsed DC voltage of 1900 V was applied to the cathode to attract Argon ions and initiate sputtering. Optical emission spectra (OES) for Cu and Ti neutrals and ions at constant pressure show a linear intensity increase for peak RF powers of 500 W - 3400 W and a steep drop of intensity for a power of 4500 W. Argon neutrals show a linear increase for powers of 500 W - 2300 W and a saturation of intensity between 2300 W - 4500 W. The influence of pressure on the process was studied at a constant peak RF power of 2300 W. With increasing pressure the ionisation degree increased. The microstructure of the coatings shows globular growth at 2.95×10-2 mbar and large-grain columnar growth at 1.2×10-1 mbar. Bottom coverage of unbiased vias with a width of 0.360 μm and aspect ratio of 2.5:1 increased from 15 % to 20 % for this pressure range. The current work has shown that the concept of combining a RF powered coil with a magnet-free high voltage pulsed DC powered cathode is feasible and produces very stable plasma. The experiments have shown a significant influence of power and pressure on the plasma and coating microstructure.

  11. Quantum Fluctuation of a Mesoscopic Inductance Coupling Circuit at Finite Temperature

    Institute of Scientific and Technical Information of China (English)

    SONG Tong-Qiang; ZHU Yue-Jin

    2003-01-01

    We study the quantization of mesoscopic inductance coupling circuit and discuss its time evolution. Bymeans of the thermal field dynamics theory we study the quantum fluctuation of the system at finite temperature.

  12. Design of an Improved Type Rotary Inductive Coupling Structure for Rotatable Contactless Power Transfer System

    Directory of Open Access Journals (Sweden)

    Lee Jia-You

    2015-01-01

    Full Text Available This paper is aimed at analyzing the rotary inductive coupling structure of contactless rotary transformer. The main feature of the proposed rotatable contactless power transfer system is which winding is coaxial-interlayered for improving the magnetic coupling capability. There is no ferrite core used in the secondary-side of the rotary inductive coupling structure, this helps to ease the exerted force that is stress by the secondary-side on spindle. In order to verify the feasibility of the proposed contactless power transfer system for rotary applications, an inductive powered rotary machinery and the control system have been integrated. The experimental results show that the maximum power transfer efficiency of the proposed rotary inductive coupling structure is about 94.8%. The maximum output power received in the load end is 1030 W with transmission efficiency of 88%.

  13. Inductively-coupled plasma mass spectrometry in proteomics, metabolomics and metallomics studies.

    Science.gov (United States)

    Mounicou, Sandra; Szpunar, Joanna; Lobinski, Ryszard

    2010-01-01

    The potential of inductively-coupled plasma mass spectrometry (ICP-MS) and its complementarity to soft- ionization MS techniques are discussed in the context of the analysis for biomolecules. ICP-MS offers detection limits in the attomolar range, regardless of the molecular environment of the target element. The sensitivity is hardly affected by the sample matrix, chromatographic mobile phase, or co-eluted compounds. The abundance sensitivity over six decades and the linear dynamic range over nine decades make simultaneous multi-isotopic analysis routinely possible. The manuscript discusses the state-of-the-art of ICP-MS for the detection of proteins in gel electrophoresis and of peptides in 2D high-performance liquid chromatography. The possibilities of quantification to the degree of some post-translational modifications are highlighted. Attention is also paid to the role of ICP-MS in protein quantification via metal-coded labeling and to the use of differentially-labeled antibodies for the multiplexed biomarker analysis. The key role of ICP-MS in the emerging area of metallomics is briefly discussed.

  14. Chromatography.

    Science.gov (United States)

    Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

    This booklet presents some activities on chromatography. Directions for preparing leaf pigment extracts using alcohol are given, and paper chromatography and thin-layer chromatography are described as modifications of the basic principles of chromatography. (KHR)

  15. Analysis of 5 kinds of arsenic species by high performance liquid chromatography and inductively coupled plasma mass spectrometry%高效液相色谱-电感耦合等离子体质谱法测定不同膳食基质中5种砷形态的方法研究

    Institute of Scientific and Technical Information of China (English)

    冯灏; 岳兵; 尚晓虹; 李筱薇; 吴永宁

    2015-01-01

    Objective To establish a method for detection and analysis 5 kinds of arsenic species, including As5+, AsB, As3+, DMA and MMA by using a high performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP-MS) Methods The best extraction and concentration of reagents were determined by comparing the different concentrations of acetic acid, hydrochloric acid, and nitric acid solution under the condition of thermal extract of different dietary matrix (grains, drinks, aquatic products, eggs, beans, fruits and sugar) and the NIST standard reference material of 5 arsenic species in Rice Flour 1568b extraction effect. At the same time, different mobile phase separation effect was compared under different pH, arsenic compounds, the final separation conditions were determined. Results The best extraction method of arsenic speciation analysis in dietary samples was 0.15 mol/L nitric acid soak extract, with a mixture of 20 mmol/L citric acid and 5 mmol/L hexane sulfonic acid sodium solution as mobile phase (pH=4.3), it showed a good linearity within 0~100μg/L concentration of 5 different forms of arsenic (r>0.999), the detection limit was 0.4~1.2μg/L, which had a good precision, the relative standard deviation (RSD) was less than 5%and the standard addition recovery was 80%~113% (iAs), 81%~122% (MMA), 80%~124% (DMA), and 77%~121%(AsB). Using this method for determining the NIST standard reference material Rice Flour 1568 b measured value was consistent with marked value. Conclusion This experiment optimized the arsenic speciation analysis methods of pretreatment and separation conditions, it not only has the time-saving, fast and efficient, but also can ensure the accuracy of determination results.%目的:应用高效液相色谱(HPLC)和电感耦合等离子体质谱(ICP-MS)联用技术优化完善不同膳食基质中五价砷(As5+)、砷甜菜碱(AsB)、三价砷(As3+)、二甲基砷酸(DMA)和一甲基砷酸(MMA)5种砷形态的检测

  16. Low wireless power transfer using Inductive Coupling for mobile phone charger

    Science.gov (United States)

    Fareq, M.; Fitra, M.; Irwanto, M.; Hasan, Syafruddin; Arinal, M.

    2014-04-01

    A wireless power transfer (WPT) using inductive coupling for mobile phone charger is studied. The project is offer to study and fabricate WPT using inductive coupling for mobile phone charger that will give more information about distance is effect for WPT performance and WPT is not much influenced by the presence of hands, books and types of plastics. The components used to build wireless power transfer can be divided into 3 parts components, the transceiver for power transmission, the inductive coils in this case as the antenna, receiver and the rectifier which act convert AC to DC. Experiments have been conducted and the wireless power transfer using inductive coupling is suitable to be implemented for mobile phone charger.

  17. Development of NbTiN-Al direct antenna coupled kinetic inductance detectors

    NARCIS (Netherlands)

    Lankwarden, Y.J.Y.; Endo, A.; Baselmans, J.J.A.; Bruijn, M.P.

    2012-01-01

    We have developed a coplanar waveguide (CPW) Kinetic Inductance Detector consisting of Al and NbTiN, coupled at its shorted end to a planar antenna. To suppress the odd mode due to direct coupling to sky radiation by the KID we have also developed freestanding metal air bridges

  18. Verification of the Model of Inductive Coupling between a Josephson Oscillator and a Stripline

    Science.gov (United States)

    Kudo, Keisuke; Yoshida, Keiji; Enpuku, Keiji; Yamafuji, Kaoru

    1993-01-01

    In order to realize an efficient coupling between a flux-flow-type Josephson oscillator (FFO) and a stripline, we have carried out experiments to verify the mathematical model of the inductive coupling scheme between FFO and a stripline resonator in the frequency range between 50 GHz and 350 GHz. It is shown that the simulation using the proposed equivalent circuit for the inductive coupling scheme well explains the experimental results. The experimentally obtained center frequency and the bandwidth of the matching circuit were as large as 120 GHz and 40 GHz, respectively, which are also in reasonable agreement with those obtained in the simulation.

  19. Application of coupled affinity-sizing chromatography for the detection of proteolyzed HSA-tagged proteins.

    Science.gov (United States)

    London, Anne Serdakowski; Patel, Kunal; Quinn, Lisa; Lemmerer, Martin

    2015-04-01

    Coupled affinity liquid chromatography and size exclusion chromatography (ALC-SEC) is a technique that has been shown to successfully report product quality of proteins during cell expression and prior to the commencement of downstream processing chromatography steps. This method was applied to monitoring the degradation and subsequent partial remediation of a HSA-tagged protein which showed proteolysis, allowing for rapid cell line development to address this product quality dilemma. This paper outlines the novel application of this method for measuring and addressing protease-induced proteolysis.

  20. Delta34S measurements of sulfur by multicollector inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Clough, Robert; Evans, Peter; Catterick, Tim; Evans, E Hywel

    2006-09-01

    An accurate and precise method for the determination of delta34S measurements by multicollector inductively coupled plasma mass spectrometry has been developed. Full uncertainty budgets, taking into consideration all the uncertainties of the measurement process, have been calculated. The technique was evaluated by comparing measured values with a range of isotopically enriched sulfur solutions prepared by gravimetric addition of a 34S spike. The gravimetric and measured results exhibited a correlation of R2 >0.999. Repeat measurements were also made after adding Na (up to 420 microg g(-1)) and Ca (up to 400 microg g(-1)) salts to the sulfur standard. No significant deviations in the delta34S values were observed. The Russell correction expression (Ingle, C.; Sharp, B.; Horstwood, M.; Parrish, R.; Lewis, D. J. J. Anal. At. Spectrom. 2003, 18, 219) was used to correct for mass bias on the 34S/32S isotope amount ratio from the mass bias observed for the 30Si/28Si isotope amount ratio. Consistent compensation for instrumental mass bias was achieved. Resolution of the measured delta34S values was better than 1 per thousand after consideration of all uncertainty components. The technique was evaluated for practical applications by measurement of delta34S for a range of mineral waters by pneumatic nebulization sample introduction and the analysis of genuine and counterfeit pharmaceuticals using both laser ablation sample introduction and liquid chromatography. For the former two cases polyatomic interferences were resolved by operating the MC-ICPMS in medium resolution, while for the chromatographic analyses polyatomic interferences were minimized by the use of a membrane desolvator, allowing the instrument to be operated at a resolution of 400.

  1. Coupling of electromagnetic and thermal codes. Induction heating; Couplage des codes electromagnetique et thermique. Le chauffage par induction

    Energy Technology Data Exchange (ETDEWEB)

    Colombani, M. [CEDRAT, (France)

    1997-12-31

    The development and adjustment of induction heating systems is quite delicate because two different subjects of physics are involved: magnetism (Foucault currents) and thermal engineering. Moreover, the magnetic and electrical properties depends on the temperature and the dissipated power depends on the magnetic and electrical properties and on the electrical excitation sources (geometry, intensity, frequency). The CEDRAT company has been involved since several years in the development of modeling softwares which allow to analyze these kind of problems. The most used is the FLUX2D software, developed by CEDRAT RECHERCHE in collaboration with the LEG (CNRS-INPG) and EdF, and which is used in several domains of applications (electric motors, actuators, high-voltage devices, magnetic recording, induction heating etc..). This software is based on a finite-element calculation method and, in the case of induction heating, it can perform different types of modeling: magnetic, thermal, temperature-dependant properties, weak and strong coupling, coupling with the electric circuit equations etc.. (J.S.)

  2. Discontinuity of mode transition and hysteresis in hydrogen inductively coupled plasma via a fluid model

    Science.gov (United States)

    Xu, Hui-Jing; Zhao, Shu-Xia; Fei, Gao; Yu-Ru, Zhang; Xue-Chun, Li; You-Nian, Wang

    2015-11-01

    A new type of two-dimensional self-consistent fluid model that couples an equivalent circuit module is used to investigate the mode transition characteristics and hysteresis in hydrogen inductively coupled plasmas at different pressures, by varying the series capacitance of the matching box. The variations of the electron density, temperature, and the circuit electrical properties are presented. As cycling the matching capacitance, at high pressure both the discontinuity and hysteresis appear for the plasma parameters and the transferred impedances of both the inductive and capacitive discharge components, while at low pressure only the discontinuity is seen. The simulations predict that the sheath plays a determinative role on the presence of discontinuity and hysteresis at high pressure, by influencing the inductive coupling efficiency of applied power. Moreover, the values of the plasma transferred impedances at different pressures are compared, and the larger plasma inductance at low pressure due to less collision frequency, as analyzed, is the reason why the hysteresis is not seen at low pressure, even with a wider sheath. Besides, the behaviors of the coil voltage and current parameters during the mode transitions are investigated. They both increase (decrease) at the E to H (H to E) mode transition, indicating an improved (worsened) inductive power coupling efficiency. Project supported by the National Natural Science Foundation of China (Grant Nos. 11175034, 11205025, 11305023, and 11075029).

  3. Discontinuity of mode transition and hysteresis in hydrogen inductively coupled plasma via a fluid model

    Institute of Scientific and Technical Information of China (English)

    徐会静; 赵书霞; 高飞; 张钰如; 李雪春; 王友年

    2015-01-01

    A new type of two-dimensional self-consistent fluid model that couples an equivalent circuit module is used to in-vestigate the mode transition characteristics and hysteresis in hydrogen inductively coupled plasmas at different pressures, by varying the series capacitance of the matching box. The variations of the electron density, temperature, and the cir-cuit electrical properties are presented. As cycling the matching capacitance, at high pressure both the discontinuity and hysteresis appear for the plasma parameters and the transferred impedances of both the inductive and capacitive discharge components, while at low pressure only the discontinuity is seen. The simulations predict that the sheath plays a determi-native role on the presence of discontinuity and hysteresis at high pressure, by influencing the inductive coupling efficiency of applied power. Moreover, the values of the plasma transferred impedances at different pressures are compared, and the larger plasma inductance at low pressure due to less collision frequency, as analyzed, is the reason why the hysteresis is not seen at low pressure, even with a wider sheath. Besides, the behaviors of the coil voltage and current parameters during the mode transitions are investigated. They both increase (decrease) at the E to H (H to E) mode transition, indicating an improved (worsened) inductive power coupling efficiency.

  4. Two-dimensional simulation of inductively coupled plasma based on COMSOL and comparison with experimental data

    Institute of Scientific and Technical Information of China (English)

    Cheng Jia; Ji Linhong; Wang Kesheng; Han Chuankun; Shi Yixiang

    2013-01-01

    A two-dimensional axisymmetric inductively coupled plasma (ICP) model,and its implementation in the COMSOL multiphysical software,is described.The simulations are compared with the experimental results of argon discharge from the gaseous electronics conference RF reference cell in the inductively coupled plasma mode.The general trends of the number density and temperature of electrons with radial scanning are approximately correct.Finally,we discuss the reasons why the comparisons are not in agreement,and then propose an improvement in the assumptions of the Maxwellian electron energy distribution function and reaction rate.

  5. Antibody-ligand interactions for hydrophobic charge-induction chromatography: a surface plasmon resonance study.

    Science.gov (United States)

    Cheng, Fang; Li, Ming-Yang; Wang, Han-Qi; Lin, Dong-Qiang; Qu, Jing-Ping

    2015-03-24

    This article describes the use of surface plasmon resonance (SPR) spectroscopy to study antibody-ligand interactions for hydrophobic charge-induction chromatography (HCIC) and its versatility in investigating the surface and solution factors affecting the interactions. Two density model surfaces presenting the HCIC ligand (mercapto-ethyl-pyridine, MEP) were prepared on Au using a self-assembly technique. The surface chemistry and structure, ionization, and protein binding of such model surfaces were characterized by X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure (NEXAFS), contact-angle titration, and SPR, respectively. The influences of the surface and solution factors, e.g., ligand density, salt concentration, and solution pH, on protein adsorption were determined by SPR. Our results showed that ligand density affects both equilibrium and dynamic aspects of the interactions. Specifically, a dense ligand leads to an increase in binding strength, rapid adsorption, slow desorption, and low specificity. In addition, both hydrophobic interactions and hydrogen bonding contribute significantly to the protein adsorption at neutral pH, while the electrostatic repulsion is overwhelmed under acidic conditions. The hydrophobic interaction at a high concentration of lyotropic salt would cause drastic conformational changes in the adsorbed protein. Combined with the self-assembly technique, SPR proves to be a powerful tool for studying the interactions between an antibody and a chromatographic ligand.

  6. The reciprocal relation of mutual inductance in a coupled circuit system

    Science.gov (United States)

    Wang, Dake

    2012-09-01

    The reciprocal relation of mutual inductance in a coupled circuit system is demonstrated theoretically. An alternating-current (AC) analysis is employed to investigate energy conservation in the system, with the only assumption being the steady-state operation of the circuit. This method can be adopted for teaching electromagnetism at the introductory level, provided the students have an adequate background in calculus.

  7. Determination of Arsenic in Sinus Wash and Tap Water by Inductively Coupled Plasma-Mass Spectrometry

    Science.gov (United States)

    Donnell, Anna M.; Nahan, Keaton; Holloway, Dawone; Vonderheide, Anne P.

    2016-01-01

    Arsenic is a toxic element to which humans are primarily exposed through food and water; it occurs as a result of human activities and naturally from the earth's crust. An experiment was developed for a senior level analytical laboratory utilizing an Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) for the analysis of arsenic in household…

  8. Determination of platinum in human subcellular microsamples by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Björn, Erik; Nygren, Yvonne; Nguyen, Tam T. T. N.

    2007-01-01

    A fast and robust method for the determination of platinum in human subcellular microsamples by inductively coupled plasma mass spectrometry was developed, characterized, and validated. Samples of isolated DNA and exosome fractions from human ovarian (2008) and melanoma (T289) cancer cell lines...

  9. High-Q cavity-induced fluxon bunching in inductively coupled Josephson junctions

    DEFF Research Database (Denmark)

    Madsen, S.; Grønbech-Jensen, Niels; Pedersen, Niels Falsig;

    2008-01-01

    We consider fluxon dynamics in a stack of inductively coupled long Josephson junctions connected capacitively to a common resonant cavity at one of the boundaries. We study, through theoretical and numerical analyses, the possibility for the cavity to induce a transition from the energetically...

  10. Improvement of Uniformity of Inductively Coupled Plasma with a Cone Spiral Antenna

    Institute of Scientific and Technical Information of China (English)

    LI Lin-Sen; XU Xu; LIU Feng; ZHOU Qian-Hong; NIE Zong-Fu; LIANG Yi-Zi; LIANG Rong-Qing

    2008-01-01

    Uniformity of inductively coupled plasma (ICP) is improved with a cone spiral antenna in our experiment. Performance of the ICP with a new type of antenna is experimentally investigated, The results indicate that the uniformity of plasma density in the radial direction is obviously improved as compared to the ICP with a planar spiral antenna. Performance of ICP is analysed with the experimental results.

  11. Characterization of inductively coupled plasma generated by a quadruple antenna

    Science.gov (United States)

    Shafir, G.; Zolotukhin, D.; Godyak, V.; Shlapakovski, A.; Gleizer, S.; Slutsker, Ya; Gad, R.; Bernshtam, V.; Ralchenko, Yu; Krasik, Ya E.

    2017-02-01

    The results of the characterization of large-scale RF plasma for studying nonlinear interaction with a high-power (˜400 MW) short duration (˜0.8 ns) microwave (˜10 GHz) beam are presented. The plasma was generated inside a Pyrex tube 80 cm in length and 25 cm in diameter filled by either Ar or He gas at a pressure in the range 1.3-13 Pa using a 2 MHz RF generator with a matching system and a quadruple antenna. Good matching was obtained between the plasma parameters, which were determined using different methods including a movable Langmuir probe, microwave cut-off, interferometry, and optical emission spectroscopy. It was shown that, depending on the gas pressure and RF power delivered to the antenna, the plasma density and electron temperature can be controlled in the range 1 × 1010-5 × 1012 cm-3 and 1-3.5 eV, respectively. The plasma density was found to be uniform in terms of axial (˜60 cm) and radial (˜10 cm) dimensions. Further, it was also shown that the application of the quadruple antenna, with resonating capacitors inserted in its arms, decreases the capacitive coupling of the antenna and the plasma as well as the RF power loss along the antenna. These features make this plasma source suitable for microwave plasma wake field experiments.

  12. Mathematical modeling of intrinsic Josephson junctions with capacitive and inductive couplings

    Science.gov (United States)

    Rahmonov, I. R.; Shukrinov, Yu M.; Zemlyanaya, E. V.; Sarhadov, I.; Andreeva, O.

    2012-11-01

    We investigate the current voltage characteristics (CVC) of intrinsic Josephson junctions (IJJ) with two types of couplings between junctions: capacitive and inductive. The IJJ model is described by a system of coupled sine-Gordon equations which is solved numerically by the 4th order Runge-Kutta method. The method of numerical simulation and numerical results are presented. The magnetic field distribution is calculated as the function of coordinate and time at different values of the bias current. The influence of model parameters on the CVC is studied. The behavior of the IJJ in dependence on coupling parameters is discussed.

  13. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Kaiser, J.; Galiová, M.; Novotný, K.; Červenka, R.; Reale, L.; Novotný, J.; Liška, M.; Samek, O.; Kanický, V.; Hrdlička, A.; Stejskal, K.; Adam, V.; Kizek, R.

    2009-01-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 μm in a up to cm × cm area of sunflower ( Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  14. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, J. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic)], E-mail: kaiser@fme.vutbr.cz; Galiova, M.; Novotny, K.; Cervenka, R. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Reale, L. [Faculty of Sciences, University of L' Aquila, Via Vetoio (Coppito 1), 67010 L' Aquila (Italy); Novotny, J.; Liska, M.; Samek, O. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic); Kanicky, V.; Hrdlicka, A. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Stejskal, K.; Adam, V.; Kizek, R. [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemedelska 1, 613 00 Brno (Czech Republic)

    2009-01-15

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 {mu}m in a up to cm x cm area of sunflower (Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  15. Determination of Nicotine in Smoke Condensate by Ion Chromatography Coupled to Ultraviolet Detection

    Directory of Open Access Journals (Sweden)

    Geiss O

    2014-12-01

    Full Text Available A new method for the determination of the nicotine content of tobacco smoke condensate is described. The smoke condensate of the mainstream smoke was collected in a glass fibre filter trap and dissolved in isopropanol. The nicotine content of an aliquot of this solution was determined by ion chromatography (IC coupled with ultraviolet (UV detection against external calibration and the nicotine content of the whole smoke condensate was calculated. The nicotine content determined in each run by IC was compared with the results obtained by gas chromatography (GC according to the International Standard (ISO method 10315. The present method represents a potential alternative to the GC method. A sensitive and rapid method for the determination of nicotine in smoke condensate using IC with a standard ion chromatography column was developed.

  16. Monitoring of cefepime in human serum and plasma by micellar electrokinetic capillary chromatography: Improvement of sample preparation and validation by liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Šestáková, Nela; Theurillat, Regula; Sendi, Parham; Thormann, Wolfgang

    2017-02-20

    Cefepime monitoring in deproteinized human serum and plasma by micellar electrokinetic capillary chromatography and liquid chromatography coupled to mass spectrometry in presence of other drugs is reported. For micellar electrokinetic capillary chromatography, sample preparation comprised dodecylsulfate protein precipitation at pH 4.5 using an increased buffer concentration compared to that of a previous assay and removal of hydrophobic compounds with dichloromethane. This provided robust conditions for cefepime analysis in the presence of sulfamethoxazole and thus enabled its determination in samples of patients that receive co-trimoxazole. The liquid chromatography assay is based upon use of a column with a pentafluorophenyl-propyl modified and multi-endcapped stationary phase and the coupling to electrospray ionization with a single quadrupole detector. The performances of both assays with multi-level internal calibration were assessed with calibration and control samples and both assays were determined to be robust. Cefepime levels monitored by micellar electrokinetic capillary chromatography in samples from patients that were treated with cefepime only and with cefepime and co-trimoxazole were found to compare well with those obtained by liquid chromatography coupled to mass spectrometry. Cefepime drug levels determined by micellar electrokinetic capillary chromatography could thereby be validated. This article is protected by copyright. All rights reserved.

  17. Quality evaluation of moluodan concentrated pill using high-performance liquid chromatography fingerprinting coupled with chemometrics.

    Science.gov (United States)

    Tao, Lingyan; Zhang, Qing; Wu, Yongjiang; Liu, Xuesong

    2016-12-01

    In this study, a fast and effective high-performance liquid chromatography method was developed to obtain a fingerprint chromatogram and quantitative analysis simultaneously of four indexes including gallic acid, chlorogenic acid, albiflorin and paeoniflorin of the traditional Chinese medicine Moluodan Concentrated Pill. The method was performed by using a Waters X-bridge C18 reversed phase column on an Agilent 1200S high-performance liquid chromatography system coupled with diode array detection. The mobile phase of the high-performance liquid chromatography method was composed of 20 mmol/L phosphate solution and acetonitrile with a 1 mL/min eluent velocity, under a detection temperature of 30°C and a UV detection wavelength of 254 nm. After the methodology validation, 16 batches of Moluodan Concentrated Pill were analyzed by this high-performance liquid chromatography method and both qualitative and quantitative evaluation results were achieved by similarity analysis, principal component analysis and hierarchical cluster analysis. The results of these three chemometrics were in good agreement and all indicated that batch 10 and batch 16 showed significant differences with the other 14 batches. This suggested that the developed high-performance liquid chromatography method could be applied in the quality evaluation of Moluodan Concentrated Pill.

  18. Study of the effect of loop inductance on the RF transmission line to cavity coupling coefficient

    Science.gov (United States)

    Lal, Shankar; Pant, K. K.

    2016-08-01

    Coupling of RF power is an important aspect in the design and development of RF accelerating structures. RF power coupling employing coupler loops has the advantage of tunability of β, the transmission line to cavity coupling coefficient. Analytical expressions available in literature for determination of size of the coupler loop using Faraday's law of induction show reasonably good agreement with experimentally measured values of β below critical coupling (β ≤ 1) but show large deviation with experimentally measured values and predictions by simulations for higher values of β. In actual accelerator application, many RF cavities need to be over-coupled with β > 1 for reasons of beam loading compensation, reduction of cavity filling time, etc. This paper discusses a modified analytical formulation by including the effect of loop inductance in the determination of loop size for any desired coupling coefficient. The analytical formulation shows good agreement with 3D simulations and with experimentally measured values. It has been successfully qualified by the design and development of power coupler loops for two 476 MHz pre-buncher RF cavities, which have successfully been conditioned at rated power levels using these coupler loops.

  19. Study of the effect of loop inductance on the RF transmission line to cavity coupling coefficient.

    Science.gov (United States)

    Lal, Shankar; Pant, K K

    2016-08-01

    Coupling of RF power is an important aspect in the design and development of RF accelerating structures. RF power coupling employing coupler loops has the advantage of tunability of β, the transmission line to cavity coupling coefficient. Analytical expressions available in literature for determination of size of the coupler loop using Faraday's law of induction show reasonably good agreement with experimentally measured values of β below critical coupling (β ≤ 1) but show large deviation with experimentally measured values and predictions by simulations for higher values of β. In actual accelerator application, many RF cavities need to be over-coupled with β > 1 for reasons of beam loading compensation, reduction of cavity filling time, etc. This paper discusses a modified analytical formulation by including the effect of loop inductance in the determination of loop size for any desired coupling coefficient. The analytical formulation shows good agreement with 3D simulations and with experimentally measured values. It has been successfully qualified by the design and development of power coupler loops for two 476 MHz pre-buncher RF cavities, which have successfully been conditioned at rated power levels using these coupler loops.

  20. Mathematical Modeling of the Three Phase Induction Motor Couple to DC Motor in Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Zulkarnain Lubis

    2009-01-01

    Full Text Available Problem statement: With emphasis on a cleaner environment and efficient operation, vehicles today rely more and more heavily on electrical power generation for success. Approach: Mathematical modeling the components of the HEV as the three phase induction motor couple to DC motor in hybrid electric vehicle was introduced. The controller of Induction Motor (IM was designed based on input-output feedback linearization technique. It allowed greater electrical generation capacity and the fuel economy and emissions benefits of hybrid electric automotive propulsion. Results: A typical series hybrid electric vehicle was modeled and investigated. Conclusion: Various tests, such as acceleration traversing ramp and fuel consumption and emission were performed on the proposed model of 3 phase induction motor coupler DC motor in electric hybrid vehicles drive.

  1. Laser sampling system for an inductively-coupled atomic emission spectrometer. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-15

    A laser sampling system was attached to a Perkin Elmer Optima 3000 inductively-coupled plasma, atomic emission spectrometer that was already installed and operating in the Chemistry and Geochemistry Department at the Colorado School of Mines. The use of the spectrometer has been highly successful. Graduate students and faculty from at least four different departments across the CSM campus have used the instrument. The final report to NSF is appended to this final report. Appendices are included which summarize several projects utilizing this instrument: acquisition of an inductively-coupled plasma atomic emission spectrometer for the geochemistry program; hydrogen damage susceptibility assessment for high strength steel weldments through advanced hydrogen content analysis, 1996 and 1997 annual reports; and methods for determination of hydrogen distribution in high strength steel welds.

  2. Study on spatial distribution of plasma parameters in a magnetized inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Hee-Woon; Lee, Woohyun; Kim, Ji-Won; Whang, Ki-Woong, E-mail: kwhang@snu.ac.kr [Plasma Laboratory, Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Hyuk [Samsung Electronics Co., Banwol-dong, Hwaseong 445-701 (Korea, Republic of); Park, Wanjae [Tokyo Electron Miyagi Ltd., Taiwa-cho, Kurokawa-gun, Miyagi 981-3629 (Japan)

    2015-07-15

    Spatial distributions of various plasma parameters such as plasma density, electron temperature, and radical density in an inductively coupled plasma (ICP) and a magnetized inductively coupled plasma (M-ICP) were investigated and compared. Electron temperature in between the rf window and the substrate holder of M-ICP was higher than that of ICP, whereas the one just above the substrate holder of M-ICP was similar to that of ICP when a weak (<8 G) magnetic field was employed. As a result, radical densities in M-ICP were higher than those in ICP and the etch rate of oxide in M-ICP was faster than that in ICP without severe electron charging in 90 nm high aspect ratio contact hole etch.

  3. On frequency optimization of assymetric resonant inductive coupling wireless power transfer links

    OpenAIRE

    2014-01-01

    Resonant Inductive Coupling Wireless Power Transfer (RIC-WPT) is a leading field of research due to the growing number of applications that can benefit from this technology: from biomedical implants to consumer electronics, fractionated spacecraft and electric vehicles amongst others. However, current applications are limited to symetric point-to-point-links. New challenges and applications of RIC-WPT emphasize the necessity to explore, predict and optimize the behavior of these links for dif...

  4. Influence of External Magnetic Field on Anomalous Skin Effects in Inductively Coupled Plasmas

    Institute of Scientific and Technical Information of China (English)

    MAO Ming; WANG You-Nian

    2004-01-01

    @@ Using a one-dimensional slab model, we study the influence of the external static magnetic field on the anomalous skin effects in the inductively coupled plasma. The rf electromagnetic field in the plasma is determined by solving the linearized Boltzmann equation incorporating with the Maxwell equations. The numerical results show that,due to the existence of the external magnetic field, the anomalous skin effects are greatly enhanced and the number of regions with negative absorption is decreased.

  5. Rigorous design of matched wireless power transfer links based on inductive coupling

    Science.gov (United States)

    Monti, G.; Costanzo, A.; Mastri, F.; Mongiardo, M.; Tarricone, L.

    2016-06-01

    This paper focuses on a near-field wireless power transmission link consisting of two magnetically coupled inductances. The case of a resonant coupling realized by adding appropriate compensating capacitances is solved. By using a network formalism, the link is modeled as a two-port network and rigorously analyzed in the case where both the input impedance and the load are specified. In particular, it is demonstrated that there is just one optimum design of the network that allows maximizing both the efficiency and the active power on the load. Closed-form design formulas for the optimum design are presented and validated by circuital simulations.

  6. Geometry Optimization Approaches of Inductively Coupled Printed Spiral Coils for Remote Powering of Implantable Biomedical Sensors

    Directory of Open Access Journals (Sweden)

    Sondos Mehri

    2016-01-01

    Full Text Available Electronic biomedical implantable sensors need power to perform. Among the main reported approaches, inductive link is the most commonly used method for remote powering of such devices. Power efficiency is the most important characteristic to be considered when designing inductive links to transfer energy to implantable biomedical sensors. The maximum power efficiency is obtained for maximum coupling and quality factors of the coils and is generally limited as the coupling between the inductors is usually very small. This paper is dealing with geometry optimization of inductively coupled printed spiral coils for powering a given implantable sensor system. For this aim, Iterative Procedure (IP and Genetic Algorithm (GA analytic based optimization approaches are proposed. Both of these approaches implement simple mathematical models that approximate the coil parameters and the link efficiency values. Using numerical simulations based on Finite Element Method (FEM and with experimental validation, the proposed analytic approaches are shown to have improved accurate performance results in comparison with the obtained performance of a reference design case. The analytical GA and IP optimization methods are also compared to a purely Finite Element Method based on numerical optimization approach (GA-FEM. Numerical and experimental validations confirmed the accuracy and the effectiveness of the analytical optimization approaches to design the optimal coil geometries for the best values of efficiency.

  7. Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez, Raquel [Department of Analytical Chemistry, Nutrition and Food Sciences, P.O. Box 99, 03080, Alicante (Spain); Todolí, José Luis, E-mail: jose.todoli@ua.es [Department of Analytical Chemistry, Nutrition and Food Sciences, P.O. Box 99, 03080, Alicante (Spain); Lienemann, Charles-Philippe [IFP Energies Nouvelles, Rond-point de l' échangeur de Solaize, BP 3, F-69360 Solaize (France); Mermet, Jean-Michel [Spectroscopy Forever, 01390 Tramoyes (France)

    2013-10-01

    The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decomposition. The first one is the most widely employed due to its simplicity. Once the sample has been prepared, an organic matrix is usually present. The performance of the sample introduction system (i.e., nebulizer and spray chamber) depends strongly upon the nature and properties of the solution finally obtained. Many different devices have been assayed and the obtained results are shown. Additionally, samples can be introduced into the plasma by using an electrothermal vaporization (ETV) device or a laser ablation system (LA). The recent results published in the literature showing the feasibility, advantages and drawbacks of latter alternatives are also described. Therefore, the main goal of the review is the discussion of the different approaches developed for the analysis of crude oil and its derivates by inductively coupled plasma (ICP) techniques. - Highlights: • Analysis of petroleum products by inductively coupled plasma techniques is revisited. • Fundamental studies are included together with reports dealing with applications. • Conventional and non-conventional sample introduction methods are considered. • Sample preparation methods are critically compared and described.

  8. Stationary phase modulation in liquid chromatography through the serial coupling of columns: A review.

    Science.gov (United States)

    Alvarez-Segura, T; Torres-Lapasió, J R; Ortiz-Bolsico, C; García-Alvarez-Coque, M C

    2016-06-01

    Liquid chromatography with single columns often does not succeed in the analysis of complex samples, in terms of resolution and analysis time. A relatively simple solution to enhance chromatographic resolution is the modulation of the stationary phase through the serial coupling of columns. This can be implemented with any type of column using compatible elution conditions and conventional instruments. This review describes the key features of column coupling and published procedures, where two or more columns were coupled in series to solve separation problems. In all reports, the authors could not resolve their samples with single columns, whereas significant enhancement in chromatographic performance was obtained when the columns were combined. Particularly interesting is the reduction in the analysis time in the isocratic mode, which alleviates the "general elution problem" of liquid chromatography, and may represent a stimulus for the proposal of new procedures, especially in combination with mass spectrometric, electrochemical and refractometric detection. Developments proposed to make the serial coupling of columns useful in routine and research laboratories are outlined, including optimisation strategies that facilitate the selection of the appropriate column combination and elution conditions (solvent content, flow rate or temperature) in both isocratic and gradient modes. The availability of zero dead volume couplers, able to connect standard columns, and the commercialisation of short columns with multiple lengths, have expanded the possibilities of success.

  9. Complex image method for RF antenna-plasma inductive coupling calculation in planar geometry. Part I: basic concepts

    Science.gov (United States)

    Howling, A. A.; Guittienne, Ph; Jacquier, R.; Furno, I.

    2015-12-01

    The coupling between an inductive source and the plasma determines the power transfer efficiency and the reflected impedance in the primary circuit. Usually, the plasma coupling is analysed by means of a transformer equivalent circuit, where the plasma inductance and resistance are estimated using a global plasma model. This paper shows that, for planar RF antennas, the mutual inductance between the plasma and the primary circuit can be calculated using partial inductances and the complex image method, where the plasma coupling is determined in terms of the plasma skin depth and the distance to the plasma. To introduce the basic concepts, the mutual inductance is calculated here for a linear conductor parallel to the plasma surface. In the accompanying paper part II Guittienne et al (2015 Plasma Sources Sci. Technol. 24 065015), impedance measurements on a RF resonant planar plasma source are modeled using an impedance matrix where the plasma-antenna mutual impedances are calculated using the complex image method presented here.

  10. Equivalent circuit effects on mode transitions in H{sub 2} inductively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hui-Jing; Zhao, Shu-Xia, E-mail: zhaonie@dlut.edu.cn; Zhang, Yu-Ru; Gao, Fei; Li, Xue-Chun; Wang, You-Nian [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2015-04-15

    It is well known experimentally that the circuit matching network plays an important role in the mode transition behavior of inductively coupled plasmas. To date, however, there have been no reports of numerical models being used to study the role of the matching circuit in the transition process. In this paper, a new two-dimensional self-consistent fluid model that couples the components of an equivalent circuit module is developed to investigate the effects of the equivalent circuit on the mode transition characteristics of an inductively coupled, hydrogen plasma. The equivalent circuit consists of a current source, impedance matching network, reactor impedance, and plasma transferred impedance. The nonlinear coupling of the external circuit with the internal plasma is investigated by adjusting the matching capacitance at a fixed input current. The electron density and temperature as well as the electromagnetic fields all change suddenly, and the E to H mode transition occurs abruptly at a certain matching capacitance as the impedance matching of the external circuit is varied. We also analyze the fields and the plasma characteristics during the transition process, especially for the case of the capacitive E mode.

  11. Study on Wireless Power Transmission for Gastrointestinal Microsystems Based on Inductive Coupling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Wireless power transmission based on inductive coupling for remotely implanted micro devices has been considered in this paper. The receiving coil, integrated in microsystems and the external transmitting coil compose a loosely coupled transformer. The coupling coefficient was calculated and measured on spacing misalignments. The geometric size of transmitting coil was analyzed for the target of remotely delivering power. The received power was maximized by choosing appropriate value of frequency, tuning capacitance and the load resistance. A conventional full bridge rectifier circuit was employed to convert ac to dc voltage. The Received dc power was up to 160 mW with a transmitting voltage of 5 Vrms when the receiving coil was placed at the center of the transmitting coil.This may meet the requirement of some microsystems for high power over a long time.

  12. Symmetric Absorber-Coupled Far-Infrared Microwave Kinetic Inductance Detector

    Science.gov (United States)

    U-yen, Kongpop (Inventor); Wollack, Edward J. (Inventor); Brown, Ari D. (Inventor); Stevenson, Thomas R. (Inventor); Patel, Amil A. (Inventor)

    2016-01-01

    The present invention relates to a symmetric absorber-coupled far-infrared microwave kinetic inductance detector including: a membrane having an absorber disposed thereon in a symmetric cross bar pattern; and a microstrip including a plurality of conductor microstrip lines disposed along all edges of the membrane, and separated from a ground plane by the membrane. The conducting microstrip lines are made from niobium, and the pattern is made from a superconducting material with a transition temperature below niobium, including one of aluminum, titanium nitride, or molybdenum nitride. The pattern is disposed on both a top and a bottom of the membrane, and creates a parallel-plate coupled transmission line on the membrane that acts as a half-wavelength resonator at readout frequencies. The parallel-plate coupled transmission line and the conductor microstrip lines form a stepped impedance resonator. The pattern provides identical power absorption for both horizontal and vertical polarization signals.

  13. Numerical Simulations of Low Pressure Inductively Coupled Plasmas in Geometrically Complex Reactors

    Science.gov (United States)

    Yu, Ben; Wu, Hanming; Krishnan, Anantha

    1996-10-01

    A two-dimensional fluid model has been developed for simulation of low pressure inductively coupled plasma (ICP) reactors. The model obtains solutions for the plasma density, electron temperature, and electric field for the given operating conditions. The physical phenomena and processes such as ambipolar diffusion, thermal diffusion, quasi-neutrality, ionization, inductive Joule heating, and excitations are considered in the model. A significant feature of the model is its capability of handling complex geometries that are often encountered in industrial reactors. Complex reactor geometries are modeled by a body-fitted-coordinate (BFC) formulation. A series of numerical experiments have been conducted using the model to study effects of various parameters such as chamber pressure, size of the wafer, position of the inductive coil, and the power input into the plasma. Different reactor geometries such as the GEC ICP reference cell and the belljar reactor have been simulated. The results of the parametric experiments are presented to show certain systematic trends in performance parameters such as uniformity and processing rates. The ICP model has been coupled to a computational fluid dynamics (CFD) code (capable of 3D simulations) that obtains the flow and pressure distribution inside the chamber. The ICP model will use pressure predictions (from the CFD model) to compute the local ionization rates. Chemical source/sink terms from the plasma dissociation model will be used by the CFD code to account for local reactant depletion effects.

  14. Analysis of allergens in tubeimu saponin extracts by using rat basophilic leukemia 2H3 cell-based affinity chromatography coupled to liquid chromatography and mass spectrometry.

    Science.gov (United States)

    Zhang, Tao; Han, Shengli; Liu, Qi; Guo, Ying; He, Langchong

    2014-11-01

    An affinity two-dimensional chromatography method was developed for the recognition, separation, and identification of allergic components from tubeimu saponin extracts, a preparation often injected to treat various conditions as indicated by traditional Chinese medicine. Rat basophilic leukemia-2H3 cell membranes were used as the stationary phase of a membrane affinity chromatography column to capture components with affinity for mast cells that could be involved in a degranulation reaction. The retained components were enriched and analyzed by membrane affinity chromatography with liquid chromatography and mass spectrometry via a port switch valve. Suitability and reliability of the method was investigated using appropriate standards, and then, the method was applied to identify components retained from tubeimu saponin extracts. Tubeimoside A was identified in this way as a potential allergen, and degranulation assays confirmed that tubeimoside A induces RBL-2H3 cell degranulation in a dose-dependent manner. An increase in Ca(2+) influx indicated that degranulation induced by tubeimoside A is likely Ca(2+) dependent. Coupled with the degranulation assay, RBL-2H3 cell-based affinity chromatography coupled with liquid chromatography and mass spectrometry is an effective method for screening and identifying allergic components from tubeimu saponin extracts.

  15. Specific Aspects Regarding Coupled Numerical Modeling of Inverter and Load Equipments in an Induction Heating Installation

    Directory of Open Access Journals (Sweden)

    Claudiu MICH-VANCEA

    2008-05-01

    Full Text Available The most propitious projection of inductiveelectrothermic installation requires a deep study ofcoupled electrothermic and circuits problems; thereforethe present paper follows the same line. Research inspecific literature have emphasized that induction heatinghas a much higher efficiency if the supply of the charge(inductor – piece is done at frequencies other thatindustrial one. [1]. Due to material alter depending ontemperature and, implicitly, the variation of the electricalparameters of the heating installation it is necessary totackle the projection of these inductive electrothermicinstallation projected through coupled numericalmodeling of the inverter circuit and of the heatingthrough induction process. The paper presents thenumerical modeling of the continuous current –alternating current conversion bridge (inverter withelements of static switch – over, the type of commandsignal (PWM of elements of static switch of power, thenumerical modeling of the heating throughelectromagnetic induction process and aspects ofcorrelation regarding the functioning/ working of theinstallation depending on the parameters of the load. Theparameters get modified due to material alter dependingon temperature during the heating process.

  16. Induction

    DEFF Research Database (Denmark)

    Sprogøe, Jonas; Elkjaer, Bente

    2010-01-01

    The purpose of this paper is to explore how induction of newcomers can be understood as both organizational renewal and the maintenance of status quo, and to develop ways of describing this in terms of learning.......The purpose of this paper is to explore how induction of newcomers can be understood as both organizational renewal and the maintenance of status quo, and to develop ways of describing this in terms of learning....

  17. Determination of selenomethionine, selenocysteine, and inorganic selenium in eggs by HPLC-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lipiec, Elzbieta; Siara, Grzegorz [CNRS/UPPA, Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Pau (France); Warsaw University of Technology, Warsaw (Poland); Bierla, Katarzyna; Ouerdane, Laurent; Szpunar, Joanna [CNRS/UPPA, Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Pau (France)

    2010-05-15

    A method for the simultaneous determination of selenomethionine (SeMet), selenocysteine (SeCys), and selenite [Se(IV)] in chicken eggs was developed. A sample preparation protocol including defatting, protein denaturation, and carbamidomethylation was optimized in order to achieve complete protein digestion and to avoid SeCys losses. Quantification was carried out by reversed-phase HPLC-inductively coupled plasma mass spectrometry (ICP MS) after quantitative isolation of the selenium-containing fraction by size-exclusion liquid chromatography. The detection limits were 0.06, 0.003, and 0.01 {mu}g g{sup -1} (dry weight) for SeCys, Se(IV) and SeMet, respectively, and the precision was 5-10%. The end products of carbamidomethylation of the different selenium species were identified for the first time by electrospray QTOF MS after custom-designed 2D HPLC purification. Differences in selenium speciation in egg yolk and white were highlighted, the yolk containing more SeCys and the white more SeMet. An insight into selenium bioaccessibility in eggs was obtained by digestion with simulated gastric and gastrointestinal juices and size-exclusion HPLC-ICP MS. (orig.)

  18. RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

    2010-06-23

    A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

  19. Rapid determination of (237)Np and plutonium isotopes in urine by inductively-coupled plasma mass spectrometry and alpha spectrometry.

    Science.gov (United States)

    Maxwell, Sherrod L; Culligan, Brian K; Jones, Vernon D; Nichols, Sheldon T; Noyes, Gary W; Bernard, Maureen A

    2011-08-01

    A new rapid separation method was developed for the measurement of plutonium and neptunium in urine samples by inductively-coupled plasma mass spectrometry (ICP-MS) and/or alpha spectrometry with enhanced uranium removal. This method allows separation and preconcentration of plutonium and neptunium in urine samples using stacked extraction chromatography cartridges and vacuum box flow rates to facilitate rapid separations. There is an increasing need to develop faster analytical methods for emergency response samples. There is also enormous benefit to having rapid bioassay methods in the event that a nuclear worker has an uptake (puncture wound, etc.) to assess the magnitude of the uptake and guide efforts to mitigate dose (e.g., tissue excision and chelation therapy). This new method focuses only on the rapid separation of plutonium and neptunium with enhanced removal of uranium. For ICP-MS, purified solutions must have low salt content and low concentration of uranium due to spectral interference of (238)U(1)H(+) on m/z 239. Uranium removal using this method is enhanced by loading plutonium and neptunium initially onto TEVA resin, then moving plutonium to DGA resin where additional purification from uranium is performed with a decontamination factor of almost 1×10(5). If UTEVA resin is added to the separation scheme, a decontamination factor of ~3 × 10(6) can be achieved.

  20. Quantitative Characterization of Gold Nanoparticles by Field-Flow Fractionation Coupled Online with Light Scattering Detection and Inductively Coupled Plasma Mass Spectrometry

    DEFF Research Database (Denmark)

    Schmidt, Bjørn; Löschner, Katrin; Hadrup, Niels

    2011-01-01

    An analytical platform coupling asymmetric flow field-flow fractionation (AF4) with multiangle light scattering (MALS), dynamic light scattering (DLS), and inductively coupled plasma mass spectrometry (ICPMS) was established and used for separation and quantitative determination of size and mass ...

  1. Online Coupling of Flow-Field Flow Fractionation and Single Particle Inductively Coupled Plasma-Mass Spectrometry: Characterization of Nanoparticle Surface Coating Thickness and Aggregation State

    Science.gov (United States)

    Surface coating thickness and aggregation state have strong influence on the environmental fate, transport, and toxicity of engineered nanomaterials. In this study, flow-field flow fractionation coupled on-line with single particle inductively coupled plasma-mass spectrometry i...

  2. Thin layer chromatography coupled to paper spray ionization mass spectrometry for cocaine and its adulterants analysis.

    Science.gov (United States)

    De Carvalho, Thays C; Tosato, Flavia; Souza, Lindamara M; Santos, Heloa; Merlo, Bianca B; Ortiz, Rafael S; Rodrigues, Rayza R T; Filgueiras, Paulo R; França, Hildegardo S; Augusti, Rodinei; Romão, Wanderson; Vaz, Boniek G

    2016-05-01

    Thin layer chromatography (TLC) is a simple and inexpensive type of chromatography that is extensively used in forensic laboratories for drugs of abuse analysis. In this work, TLC is optimized to analyze cocaine and its adulterants (caffeine, benzocaine, lidocaine and phenacetin) in which the sensitivity (visual determination of LOD from 0.5 to 14mgmL(-1)) and the selectivity (from the study of three different eluents: CHCl3:CH3OH:HCOOHglacial (75:20:5v%), (C2H5)2O:CHCl3 (50:50v%) and CH3OH:NH4OH (100:1.5v%)) were evaluated. Aiming to improve these figures of merit, the TLC spots were identified and quantified (linearity with R(2)>0.98) by the paper spray ionization mass spectrometry (PS-MS), reaching now lower LOD values (>1.0μgmL(-1)). The method developed in this work open up perspective of enhancing the reliability of traditional and routine TLC analysis employed in the criminal expertise units. Higher sensitivity, selectivity and rapidity can be provided in forensic reports, besides the possibility of quantitative analysis. Due to the great simplicity, the PS(+)-MS technique can also be coupled directly to other separation techniques such as the paper chromatography and can still be used in analyses of LSD blotter, documents and synthetic drugs.

  3. Inductive coupling between overhead power lines and nearby metallic pipelines. A neural network approach

    Directory of Open Access Journals (Sweden)

    Levente Czumbil

    2015-12-01

    Full Text Available The current paper presents an artificial intelligence based technique applied in the investigation of electromagnetic interference problems between high voltage power lines (HVPL and nearby underground metallic pipelines (MP. An artificial neural network (NN solution has been implemented by the authors to evaluate the inductive coupling between HVPL and MP for different constructive geometries of an electromagnetic interference problem considering a multi-layer soil structure. Obtained results are compared to solutions provided by a finite element method (FEM based analysis and considered as reference. The advantage of the proposed method yields in a simplified computation model compared to FEM, and implicitly a lower computational time.

  4. Optimized condition for etching fused-silica phase gratings with inductively coupled plasma technology.

    Science.gov (United States)

    Wang, Shunquan; Zhou, Changhe; Ru, Huayi; Zhang, Yanyan

    2005-07-20

    Polymer deposition is a serious problem associated with the etching of fused silica by use of inductively coupled plasma (ICP) technology, and it usually prevents further etching. We report an optimized etching condition under which no polymer deposition will occur for etching fused silica with ICP technology. Under the optimized etching condition, surfaces of the fabricated fused silica gratings are smooth and clean. Etch rate of fused silica is relatively high, and it demonstrates a linear relation between etched depth and working time. Results of the diffraction of gratings fabricated under the optimized etching condition match theoretical results well.

  5. Electron energy probability function and L-p similarity in low pressure inductively coupled bounded plasma

    OpenAIRE

    Chatterjee, Sanghamitro; Bhattacharjee, Sudeep; Charles, Christine; Boswell, Rod

    2015-01-01

    Particle-In-Cell (PIC) simulations are carried out to investigate the effect of discharge length (L) and pressure (p) on Electron Energy Probability Function (EEPF) in a low pressure radio frequency (rf) inductively coupled plasma (ICP) at 13.56 MHz. It is found that for both cases of varying L (0.1–0.5 m) and p (1–10 mTorr), the EEPF is a bi-Maxwellian with a step in the bounded direction (x) and non-Maxwellian with a hot tail in the symmetric unbounded directions (y, z). The plasma space po...

  6. Inductively Coupled Plasma Optical-Emission Spectroscopy Determination of Major and Minor Elements in Vinegar

    Directory of Open Access Journals (Sweden)

    Arzu AKPINAR-BAYIZIT

    2010-12-01

    Full Text Available This study characterizes the mineral content of vinegar samples. The concentrations of Na, K, Ca, Mg and P (major elements as well as Fe, Mn, Sn, Cu, Ni, Zn, Pb and Cd (minor elements were determined in 35 commercial vinegar samples using inductively coupled plasma optical-emission spectrometry (ICP-OES. The elements with the highest concentrations were K, Na, Ca, Mg and P. The concentrations of heavy metals in the vinegar samples, including Cd, Ni, Sn and Pb, were not considered a health risk.

  7. System Design for Ocean Sensor Data Transmission Based on Inductive Coupling

    Science.gov (United States)

    Xu, Ming; Liu, Fei; Zong, Yuan; Hong, Feng

    Ocean observation is the precondition to explore and utilize ocean. How to acquire ocean data in a precise, efficient and real-time way is the key question of ocean surveillance. Traditionally, there are three types of methods for ocean data transmission: underwater acoustic, GPRS via mobile network and satellite communication. However, none of them can meet the requirements of efficiency, accuracy, real-time and low cost at the same time. In this paper, we propose a new wireless transmission system for underwater sensors, which established on FGR wireless modules, combined with inductive coupling lab and offshore experiments confirmed the feasibility and effectiveness of the proposed wireless transmission system.

  8. Self-consistent Kinetic Description of the Low-Pressure Solenoidal Inductively Coupled Argon Discharge

    Institute of Scientific and Technical Information of China (English)

    毛明; 王友年

    2005-01-01

    Using an one-dimensional slab model, we have studied the electron energy distribution, the anomalous skin effect, and power absorption in the solenoidal-inductively-coupled argon discharge under low pressures (≤1.33 Pa). The electron energy distribution function and rf electromagnetic field in the plasma are determined self-consistently by the linearized Bolztmann equation incorporating with the Maxwell equations. The numerical results show that, at low pressures, the electron energy distribution function exhibits a non-Maxwellian distribution with a long high-energy tail. The anomalous skin effect is greatly enhanced under low pressures and the negative power absorption is also obtained.

  9. [Determination of total sulfur in coal by inductively coupled plasma atomic emission spectrometry].

    Science.gov (United States)

    Liu, Dong-yan; Zhang, Yuan-li

    2002-02-01

    A direct method was reported for the determination of total sulfur in coal by inductively coupled plasma atomic emission spectrometry (ICP-AES). The dissolution conditions of coal samples as well as interference conditions of hydrochloric acid and matrix were studied. The recommended method not only proved to be simple and rapid than traditional gravimetric method but show satisfying precision and accuracy as well. The results of samples are as same as gravimetry. The recoveries are more than 96%, and the relative standard deviation of six samples are less than 3%.

  10. Construction of Larger Area Density-Uniform Plasma with Collisional Inductively Coupled Plasma Cells

    Institute of Scientific and Technical Information of China (English)

    OUYANG Liang; LIU Wandong; BAI Xiaoyan; CHEN Zhipeng; WANG Huihui; LI LUO Chen; JI Liangliang; HU Bei

    2007-01-01

    The plasma density and electron temperature of a multi-source plasma system composed of several collisional inductively coupled plasma (ICP) cells were measured by a double-probe. The discharges of the ICP cells were shown to be independent of each other. Furthermore, the total plasma density at simultaneous multi-cell discharge was observed to be approximately equal to the summation of the plasma density when the cells discharge separately. Based on the linear summation phenomenon, it was shown that a larger area plasma with a uniform density and temperature profile could be constructed with multi-collisional ICP cells.

  11. Solid Carbon Produced in an Inductively Coupled Plasma Torch with a Titan Like Atmosphere

    Directory of Open Access Journals (Sweden)

    D. Vacher

    2013-01-01

    Full Text Available Solid carbon is deposited on the surfaces of an inductively coupled plasma torch operating with a Titan like atmosphere plasma gas. The frame of the initial research is the study of the radiative properties of plasma encountered around a spacecraft during its hypersonic entry in upper layers of planetary atmosphere. Deposition of carbon is observed not only on the quartz tube outside the inductor but also on the ceramic protection of the torch injector. Carbon exhibits two types of morphology more or less dense and it is analyzed by various analytic devices as MEB, SEM, TEM, EDS and Raman spectroscopy. The gathered carbon powder shows the presence of nanostructured particles.

  12. Surface Modification of Nanometre Silicon Carbide Powder with Polystyrene by Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    WEI Gang; MENG Yuedong; ZHONG Shaofeng; LIU Feng; JIANG Zhongqing; SHU Xingsheng; REN Zhaoxing; WANG Xiangke

    2008-01-01

    An investigation was made into polystyrene (PS) grafted onto nanometre sili-con carbide (SIC) particles. In our experiment, the grafting polymerization reaction was in-duced by a radio frequency (RF) inductively coupled plasma (ICP) treatment of the nanome-tre powder. FTIR (Fourier transform infrared spectrum) and XPS (X-ray photoelectron spec-troscopy) results reveal that PS is grafted onto the surface of silicon carbide powder. An analysis is presented on the effectiveness of this approach as a function of plasma operating variables including the plasma treating power, treating time, and grafting reaction temperature and time.

  13. Analysis of tree leaves, bark and wood by sequential inductively coupled argon plasma atomic emission spectrometry

    Science.gov (United States)

    Verbeek, A. A.

    The analysis of extracts from tree leaf, bark and wood samples for Ca, Mg, K, Na, P, Mn, Fe, Al, B, Cu and Zn by inductively coupled argon plasma sequential emission spectrometry is described. Recovery percentages for simulated tree extracts and for spiked tree samples are presented together with typical analysis values for a leaf and a wood sample. The choice of analytical line for each element is discussed and spectral interferences, not listed in the ICP tables of Boumans, of Cu on the 214.9 nm line of P and of Fe on the 249.7 nm line of B are noted.

  14. Langmuir Probe Measurements in an Inductively Coupled GEC Reference Cell Plasma

    Science.gov (United States)

    Ji, J. S.; Kim, J. S.; Cappelli, M. A.; Sharma, S. P.; Arnold, J. O. (Technical Monitor)

    1998-01-01

    Measurements of electron number density, electron temperature, and electron energy distribution function (EEDF) using a compensated Langmuir probe have been performed on an inductively (transformer ) coupled Gaseous Electronics Conference (GEC) reference cell plasma. The plasma source is operated with CH4, CF4, or their mixtures with argon. The effect of independently driving the electrode supporting the wafer on the probe data is studied. In particular, we find that the plasma structure depends on the phase in addition to the magnitude of the power coupled to the electrode relative to that of the transformer coil. The Langmuir probe is translated in a plane parallel to the electrode to investigate the spatial structure of the plasma. The probe data is also compared with fluid model predictions.

  15. Continuous ice-core chemical analyses using inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    McConnell, Joseph R; Lamorey, Gregg W; Lambert, Steven W; Taylor, Kendrick C

    2002-01-01

    Impurities trapped in ice sheets and glaciers have the potential to provide detailed, high temporal resolution proxy information on paleo-environments, atmospheric circulation, and environmental pollution through the use of chemical, isotopic, and elemental tracers. We present a novel approach to ice-core chemical analyses in which an ice-core melter is coupled directly with both an inductively coupled plasma mass spectrometer and a traditional continuous flow analysis system. We demonstrate this new approach using replicated measurements of ice-core samples from Summit, Greenland. With this method, it is possible to readily obtain continuous, exactly coregistered concentration records for a large number of elements and chemical species at ppb and ppt levels and at unprecedented depth resolution. Such very-high depth resolution, multiparameter measurements will significantly expand the use of ice-core records for environmental proxies.

  16. Plasma characteristics in inductively and capacitively coupled hybrid source using single RF power

    Science.gov (United States)

    Kim, Kwan-Yong; Lee, Moo-Young; Kim, Tae-Woo; Kim, Ju-Ho; Chung, Chin-Wook

    2016-09-01

    Parallel combined inductively coupled plasma (ICP) and capacitively coupled plasma (CCP) using single RF generator was proposed to linear control of the plasma density with RF power. In the case of ICP, linear control of the plasma density is difficult because there is a density jump up due to E to H transition. Although the plasma density of CCP changes linearly with power, the density is lower than that of ICP due to high ion energy loss at the substrate. In our hybrid source, the single RF power generator was connected to electrode and antenna, and the variable capacitor was installed between the antenna and the power generator to control the current flowing through the antenna and the electrode. By adjusting the current ratio between the antenna and the electrode, linear characteristic of plasma density with RF power is achieved.

  17. Local thermodynamic equilibrium modeling of ionization of impurities in argon inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Serapinas, Petras, E-mail: serapinas@pfi.l [Institute of Theoretical Physics and Astronomy, Vilnius University, A. Gostauto 12, 01108 Vilnius (Lithuania); Salkauskas, Julius; Ezerinskis, Zilvinas; Acus, Arturas [Institute of Theoretical Physics and Astronomy, Vilnius University, A. Gostauto 12, 01108 Vilnius (Lithuania)

    2010-01-15

    Essentially higher ionization degree of small concentrations of elements in inductively coupled plasma in comparison to the ionization of pure elements is emphasized. This conclusion is used to determine the relative dependence of the sensitivity of the inductively coupled plasma mass spectrometer on the atomic mass. The possibility of evaluation of the ionization temperature and electron density from mass spectrometric signals is proposed. Temperatures about 7000 K and 8000 K were obtained from the ionization ratio dependences on ionization potentials. Electron densities of the order of magnitude 10{sup 15} cm{sup -3}, in excess to the local thermodynamic equilibrium values, follow from the application of the Saha equation to the measurement results and indicate the recombining character of the plasma in the mass spectrometer measurement region. Effects due to additional ionization from matrix were discussed. The effect is largest on minor abundant ionization state components. Matrix effect is restricted to some temperature interval, which depends on the whole matrix composition and the plasma state. The results show that the local thermodynamic equilibrium modeling, if adequately matching the sample composition, can be useful as a quantitative basis for both description of the plasma state and indication of the character of the nonequilibrium effects.

  18. Minimally-invasive Laser Ablation Inductively Coupled Plasma Mass Spectrometry analysis of model ancient copper alloys

    Energy Technology Data Exchange (ETDEWEB)

    Walaszek, Damian [University of Warsaw, Faculty of Chemistry, Biological and Chemical Research Centre, Żwirki i Wigury 101, 02-089 Warszawa (Poland); Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Senn, Marianne; Wichser, Adrian [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Faller, Markus [Laboratory for Jointing Technology and Corrosion, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Wagner, Barbara; Bulska, Ewa [University of Warsaw, Faculty of Chemistry, Biological and Chemical Research Centre, Żwirki i Wigury 101, 02-089 Warszawa (Poland); Ulrich, Andrea [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland)

    2014-09-01

    This work describes an evaluation of a strategy for multi-elemental analysis of typical ancient bronzes (copper, lead bronze and tin bronze) by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS).The samples originating from archeological experiments on ancient metal smelting processes using direct reduction in a ‘bloomery’ furnace as well as historical casting techniques were investigated with the use of the previously proposed analytical procedure, including metallurgical observation and preliminary visual estimation of the homogeneity of the samples. The results of LA-ICPMS analysis were compared to the results of bulk composition obtained by X-ray fluorescence spectrometry (XRF) and by inductively coupled plasma mass spectrometry (ICPMS) after acid digestion. These results were coherent for most of the elements confirming the usefulness of the proposed analytical procedure, however the reliability of the quantitative information about the content of the most heterogeneously distributed elements was also discussed in more detail. - Highlights: • The previously proposed procedure was evaluated by analysis of model copper alloys. • The LA-ICPMS results were comparable to the obtained by means of XRF and ICPMS. • LA-ICPMS results indicated the usefulness of the proposed analytical procedure.

  19. Ion flux and ion distribution function measurements in synchronously pulsed inductively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Brihoum, Melisa; Cunge, Gilles; Darnon, Maxime; Joubert, Olivier [Laboratoire des Technologies de la Microelectronique CNRS, Grenoble Cedex 9, Isere 38054 (France); Gahan, David [Impedans Ltd., Dublin 17 (Ireland); Braithwaite, Nicholas St. J. [Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2013-03-15

    Changes in the ion flux and the time-averaged ion distribution functions are reported for pulsed, inductively coupled RF plasmas (ICPs) operated over a range of duty cycles. For helium and argon plasmas, the ion flux increases rapidly after the start of the RF pulse and after about 50 {mu}s reaches the same steady state value as that in continuous ICPs. Therefore, when the plasma is pulsed at 1 kHz, the ion flux during the pulse has a value that is almost independent of the duty cycle. By contrast, in molecular electronegative chlorine/chlorosilane plasmas, the ion flux during the pulse reaches a steady state value that depends strongly on the duty cycle. This is because both the plasma chemistry and the electronegativity depend on the duty cycle. As a result, the ion flux is 15 times smaller in a pulsed 10% duty cycle plasma than in the continuous wave (CW) plasma. The consequence is that for a given synchronous RF biasing of a wafer-chuck, the ion energy is much higher in the pulsed plasma than it is in the CW plasma of chlorine/chlorosilane. Under these conditions, the wafer is bombarded by a low flux of very energetic ions, very much as it would in a low density, capacitively coupled plasma. Therefore, one can extend the operating range of ICPs through synchronous pulsing of the inductive excitation and capacitive chuck-bias, offering new means by which to control plasma etching.

  20. The optoelectronic properties of silicon films deposited by inductively coupled plasma CVD

    Energy Technology Data Exchange (ETDEWEB)

    Qin Yanli; Yan Hengqing; Li Fei; Qiao Li; Liu Qiming [Department of Physics, Lanzhou University, Lanzhou 730000 (China); He Deyan, E-mail: hedy@lzu.edu.cn [Department of Physics, Lanzhou University, Lanzhou 730000 (China)

    2010-11-15

    Hydrogenated amorphous and microcrystalline silicon films were deposited by inductively coupled plasma chemical vapor deposition (ICP-CVD) at low substrate temperatures using H{sub 2}-diluted SiH{sub 4} as a source gas. High-density plasma generated by inductively coupled excitation facilitates the crystallization of silicon films at low temperatures, and microcrystalline silicon films were obtained at the substrate temperature as low as 180 deg. C. The columnar structure of the films becomes more and more compact with an increase of their crystallinity. The reduction of hydrogen content in the films causes a narrowing of the optical bandgap and an enhancement of the absorption with increasing the substrate temperature. The microcrystalline silicon films show two electronic transport mechanisms: one is related to the density of state distribution in the temperature region near room temperature and the other is the variable range hopping between localized electronic states close to the Fermi level below 170 K. A reasonable explanation is presented for the dependence of the optoelectronic properties on the microstructure of the silicon films. The films prepared at a substrate temperature of 300 deg. C have highly crystalline and compact columnar structure, high optical absorption coefficient and electrical conductivity, and a low hydrogen content of 3.8%.

  1. Inductively coupled corrosion potential sensor for steel reinforced concrete with time domain gating interrogation

    Science.gov (United States)

    Thomson, D. J.; Perveen, K.; Bridges, G. E.; Bhadra, S.

    2012-04-01

    Corrosion is a major problem for civil infrastructure and is one of the leading factors in infrastructure deterioration. Techniques such as half-cell potential can be used to periodically monitor corrosion, but can be difficult to reliably interpret. Wired systems have large installation cost and long-term reliability issues due to wire corrosion. In this paper an embedded inductively coupled coil sensor able to monitor the corrosion potential of reinforcement steel in concrete is presented. The sensor is based on a coil resonator whose resonant frequency changes due to the corrosion potential being applied across a parallel varactor diode. The corrosion potential can be monitored externally using an inductively coupled coil. An accelerated corrosion test shows that it can measure corrosion potentials with a resolution of less than 10 mV. This sensor will detect corrosion at the initiation stage before observable corrosion has taken place. The wireless sensor is passive and simple in design, making it an inexpensive, battery less option for long-term monitoring of the corrosion potential of reinforcing steel.

  2. Development and application of liquid chromatography coupled to isotope ratio mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lijun

    2014-02-19

    Stable isotope analysis has found widespread applications in various disciplines such as archaeology, geochemistry, biology, food authenticity, and forensic science. Coupling chromatography to isotope ratio mass spectrometry for compound-specific isotope analysis (CSIA) is a trend, as it provides several advantages over bulk isotope analysis, e.g., relatively simple sample preparation, the ability to measure individual compounds in a complex mixture in one run, and the reduced sample size required for precise isotope analysis. Gas chromatography coupled to isotope ratio mass spectrometry (GC/IRMS) has been well-established for compound-specific isotope analysis of volatile organic compounds within the last two decades. However, an interface combining liquid chromatography with isotope ratio mass spectrometry (LC/IRMS) was not commercially available until 2004. The current design of the interface requires using a carbon-free eluent in chromatographic separation. This requirement limits the application of the most frequently used reversed-phase liquid chromatography in CSIA, because the elution strength of water at room temperature is too low to serve as mobile phase in reversed-phase separations. In order to increase the elution strength of water, we propose using high temperature water for chromatographic elution. The polarity of water decreases with an increase of temperature, yielding increased elution strength in reversed-phase columns. Therefore, high temperature water can be used as eluent instead of organic solvent for combining reversed-phase liquid chromatography with isotope ratio mass spectrometry (RPLC/IRMS). Additionally, temperature gradients can replace organic solvent gradients to increase chromatographic resolution. This is very important for LC/IRMS analysis, as precise isotope analysis requires baseline separation of analytes. In this thesis, high-temperature reversed-phase liquid chromatography was coupled to, and for the first time carefully

  3. Multielement trace determinations in A1 2O 3 ceramic powders by inductively coupled plasma mass spectrometry with special reference to on-line trace preconcentration

    Science.gov (United States)

    Pollmann, D.; Leis, F.; Tölg, G.; Tschöpel, P.; Broekaert, J. A. C.

    1994-12-01

    The use of inductively coupled plasma mass spectrometry (ICP-MS) for the determination of trace elements in Al 2O 3 powders is reported. Special interest is given to a preconcentration of the trace elements by on-line coupling of chromatography to ICP-MS. This is based on the complexation of Co, Cu, Cr, Fe, Ga, Mn, Ni, V and Zn with hexamethylene-dithiocarbamate (HMDC), their preconcentration on a C18 RP column by reversed phase liquid chromatography and their elution with CH 3OH-H 2O mixtures. A direct coupling of the HPLC system to the ICP-MS has been realized by high pressure pneumatic nebulization using desolvation. With the Chromatographie method developed, removal of the AI by at least 99% was achieved. For the trace elements V, Fe, Ni, Co, Cu and Ga, high and reproducible recoveries (ranging from 96-99%) were reached. The method developed has been shown to considerably enhance the power of detection as compared with direct procedures, namely down to 0.02-0.16 ( μg/g for V and Fe, respectively. The possibilities of the method are shown by the determinations of V, Mn, Fe, Ni, Co, Cu, Zn and Ga at the μg/g level in A1 2O 3 powders. The accuracy of the method at the 0.06 to 9.0 μg/g level for Co and Fe, respectively, is demonstrated by a comparison with results of independent methods from the literature.

  4. A study on plasma parameters in Ar/SF6 inductively coupled plasma

    Science.gov (United States)

    Oh, Seung-Ju; Lee, Hyo-Chang; Chung, Chin-Wook

    2017-01-01

    Sulfur hexafluoride (SF6) gas or Ar/SF6 mixing gas is widely used in plasma processes. However, there are a little experimental studies with various external parameters such as gas pressure and mixing ratio. In this work, a study of the plasma parameters by changing the gas mixing ratio was done in an Ar/SF6 inductively coupled plasma from the measurement of the electron energy distribution function. At a low gas pressure, as the mixing ratio of SF6 gas increased at a fixed inductively coupled plasma (ICP) power, the electron density decreased and the electron temperature increased, while they were not changed drastically. At a high gas pressure, a remarkable increase in the electron temperature was observed with the decrease in the electron density. These variations are due to the electron loss reactions such as the electron attachment. It was also found that at a fixed ICP power, the negative ion creation with the diluted SF6 gas can change the discharge mode transition from an inductive mode to a capacitive mode at the high gas pressure. The electron attachment reactions remove the low energy electrons and change the mean electron energy towards higher energies with diluting SF6 gas at high pressure. The measured results were compared with the simplified global model, and the global model is in relatively good agreement with the measured plasma parameters except for the result in the case of the large portion of SF6 gas at the high pressure and the capacitive mode, which causes strong negative ion formation by the electron attachment reactions.

  5. [Rapid determination of pesticide multiresidues in porphyra by dispersive solid-phase extraction coupled with online gel permeation chromatography-gas chromatography-mass spectrometry].

    Science.gov (United States)

    Sun, Xiaojie; Guo, Mengmeng; Wang, Suyue; Tan, Zhijun; Li, Zhaoxin; Zhai, Yuxiu

    2014-10-01

    A rapid method for the simultaneous identification and quantification of pesticide multiresidues in porphyra was developed using gel permeation chromatography (GPC) coupled to gas chromatography-mass spectrometry (GPC-GC/MS). Nineteen pesticides (organochlorines, organophosphoruses, triazines and pyrethroids) were selected as the target analytes. The pretreatment method was applied consisting of organic solvent extraction followed by dispersive solid-phase extraction with graphitized carbon black (GCB) and primary secondary amine (PSA) adsorbents. GPC was also employed online to remove the large molecules such as pigments and lipids. The quantitative analysis was carried out by external standard method using gas chromatography coupled with mass spectrometry in selective ion monitoring (SIM) mode. Moreover, a large volume of sample was allowed to be injected using the program of GPC programmed-temperature vaporizer of gas chromatography to improve the sensitivity of measurements. The results showed that the calibration curves were linear (r > 0.995) in the range of 10-1,000 μg/L for all the pesticides. The limits of detection (LODs) for the pesticides in porphyra were from 0.005 to 0.03 mg/kg, and the average recoveries were between 70% and 120%. The advantages of the method are simple, sensitive and shorter operation time for analysis of pesticide residues in porphyra samples.

  6. Effective protein separation by coupling hydrophobic interaction and reverse phase chromatography for top-down proteomics.

    Science.gov (United States)

    Xiu, Lichen; Valeja, Santosh G; Alpert, Andrew J; Jin, Song; Ge, Ying

    2014-08-05

    One of the challenges in proteomics is the proteome's complexity, which necessitates the fractionation of proteins prior to the mass spectrometry (MS) analysis. Despite recent advances in top-down proteomics, separation of intact proteins remains challenging. Hydrophobic interaction chromatography (HIC) appears to be a promising method that provides high-resolution separation of intact proteins, but unfortunately the salts conventionally used for HIC are incompatible with MS. In this study, we have identified ammonium tartrate as a MS-compatible salt for HIC with comparable separation performance as the conventionally used ammonium sulfate. Furthermore, we found that the selectivity obtained with ammonium tartrate in the HIC mobile phases is orthogonal to that of reverse phase chromatography (RPC). By coupling HIC and RPC as a novel two-dimensional chromatographic method, we have achieved effective high-resolution intact protein separation as demonstrated with standard protein mixtures and a complex cell lysate. Subsequently, the separated intact proteins were identified by high-resolution top-down MS. For the first time, these results have shown the high potential of HIC as a high-resolution protein separation method for top-down proteomics.

  7. ANALYSIS OF PENTACHLOROPHENOL IN WATER BY PURGE AND TRAP CONCENTRATOR COUPLED TOGAS CHROMATOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    Huixia Lan; Yuancai Chen; Zhonghao Chen

    2004-01-01

    It is convenient and time saving to analyze pentachlorophenol (PCP) in water by purge and trap concentrator coupled to gas chromatography that avoids employing a great deal of organic solvent: In this paper, the appropriate purge and trap conditions of PCP are determined: the trapped sorbent is TenaxGC; the purge gas is pure nitrogen and purge flow is 40ml/min; the purge time is 30min. A series of standard PCP water samples 5, 10, 50, 100, 200,400, 800, 1000ppb are analyzed in order to obtain standard curve, and the linear regressive equation obtained is Y=109.65X-687.72, which correlation coefficient r is 0.9949. The precision of the method is determined with 0.5ppb PCP water sample, and the standard deviation measured is 3%. The detection limit for PCP is 0.2ppb.

  8. ANALYSIS OF PENTACHLOROPHENOL IN WATER BY PURGE AND TRAP CONCENTRATOR COUPLED TO GAS CHROMATOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    HuixiaLan; YuancaiChen; ZhonghaoChen

    2004-01-01

    It is convenient and time saving to analyze pentachlorophenol (PCP) in water by purge and trap concentrator coupled to gas chromatography that avoids employing a great deal of organic solvent. In this paper, the appropriate purge and trap conditions of PCP are determined: the trapped sorbent is TenaxGC; the purge gas is pure nitrogen and purge flow is 40ml/min; the purge time is 30min. A series of standard PCP water samples 5, 10, 50, 100, 200, 400, 800, 1000ppb are analyzed in order to obtain standard curve, and the linear regressive equation obtained is Y=109.65X-687.72, which correlation coefficient r is 0.9949. The precision of the method is determined with 0.5ppb PCP water sample, and the standard deviation measured is 3%. The detection limit for PCP is 0.2ppb.

  9. PDMS Rod-SBSE System Coupled with Gas Chromatography for Determination of PAHs in Aqueous Samples

    Institute of Scientific and Technical Information of China (English)

    CHENG Chuan-xian; PEI Hai-rong; LAN Xiao-zheng

    2011-01-01

    A method for the analysis of trace polycyclic aromatic hydrocarbons(PAHs) in aqueous samples has been established by polydimethylsiloxane(PDMS) rod aided stir bar sorptive extraction(SBSE).The homemade PDMS rod has a size of 30 mm×3 mm o.d.with a volume of ca.200 μL,stable in thermal desorption process.The enriched PAHs by the PDMS rod were released in a homemade thermal desorption system coupled with gas chromatography.Experimental parameters for extraction of six PAHs were optimized including extraction time,pH,ionic strength and temperature of solution.The procedure has good recoveries of 80.0%-100.3% and very low limits of detection of 4.0-33 ng/L.PAHs in rain and river water were analyzed by this method.

  10. Preparation of inulin-type fructooligosaccharides using fast protein liquid chromatography coupled with refractive index detection.

    Science.gov (United States)

    Li, J; Cheong, K L; Zhao, J; Hu, D J; Chen, X Q; Qiao, C F; Zhang, Q W; Chen, Y W; Li, S P

    2013-09-20

    A fast protein liquid chromatography coupled with refractive index detection (FPLC-RID) method was firstly developed for preparation and purification of fructooligosaccharides with different degree of polymerization from burdock, Arctium lappa. After extraction with 60% ethanol and decolorization with MCI gel CHP20P, total fructooligosaccharides were purified on Bio-Gel P-2 column eluted with water at the flow rate of 0.3 ml/min, which was the optimized conditions. The obtained fructooligosaccharides with degree of polymerization of 3-9 were identified based on their methylation analysis, MS and NMR data. This method has the advantages of high automation, good recovery and easy performance, which could be used for preparation of FOS from other sources, as well as other targeted compounds without UV absorbance.

  11. Phytochemical analysis of Hibiscus caesius using high performance liquid chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Ain, Quratul; Naveed, Muhammad Na; Mumtaz, Abdul Samad; Farman, Muhammad; Ahmed, Iftikhar; Khalid, Nauman

    2015-09-01

    Various species in genus Hibiscus are traditionally known for their therapeutic attributes. The present study focused on the phytochemical analysis of a rather unexplored species Hibiscus caesius (H. caesius), using high-pressure liquid chromatography coupled with mass spectrometry (HPLC-MS). The analysis revealed five major compounds in the aqueous extract, viz. vanillic acid, protocatechoic acid, quercetin, quercetin glucoside and apigenin, being reported for the first time in H. caesius. Literature suggests that these compounds have important pharmacological traits such as anti-cancer, anti-inflammatory, anti-bacterial and hepatoprotective etc. however, this requires further pharmacological investigations at in vitro and in vivo scale. The above study concluded the medicinal potential of H. caesius.

  12. Sulfur analysis by inductively coupled plasma-mass spectrometry: A review

    Energy Technology Data Exchange (ETDEWEB)

    Giner Martínez-Sierra, J.; Galilea San Blas, O.; Marchante Gayón, J.M.; García Alonso, J.I., E-mail: jiga@uniovi.es

    2015-06-01

    In recent years the number of applications of sulfur (S) analysis using inductively coupled plasma mass spectrometry (ICP-MS) as detector has increased significantly. In this article we describe in some depth the application of ICP-MS for S analysis with emphasis placed on the sulfur-specific detection by hyphenated techniques such as LC, GC, CE and LA coupled on-line to ICP-MS. The different approaches available for sulfur isotope ratio measurements by ICP-MS are also detailed. Particular attention has been paid to the quantification of peptides/proteins and the analysis of metallopeptides/metalloproteins via sulfur by LC–ICP-MS. Likewise, the speciation analysis of metal-based pharmaceuticals and metallodrugs and non-metal selective detection of pharmaceuticals via S are highlighted. Labeling procedures for metabolic applications are also included. Finally, the measurement of natural variations in S isotope composition with multicollector ICP-MS instruments is also covered in this review. - Highlights: • Emphasis placed on the sulfur-specific detection by chromatographic techniques coupled on-line to ICP-MS. • Different instrumental approaches available for sulfur measurements by ICP-MS. • Quantification of proteins and the analysis of metalloproteins via sulfur by LC-ICP-MS. • Labelling procedures for metabolic applications are also included. • The measurement of natural variations in S isotope composition with multicollector ICP-MS.

  13. Analysis of tungsten carbide coatings by UV laser ablation inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Kanicky, V.; Otruba, V.; Mermet, J.-M.

    2000-06-01

    Tungsten carbide coatings (thickness 0.1-0.2 mm) containing 8.0, 12.2, 17.2 and 22.9% Co were studied with laser ablation inductively coupled plasma atomic emission spectrometry (LA-ICP-AES). Composition of these plasma sprayed deposits on steel disks was determined using X-ray fluorescence spectrometry and electron microprobe energy/wavelength dispersive X-ray spectrometry. The coatings were ablated by means of a Q-switched Nd:YAG laser at 266 nm (10 Hz, 10 mJ per shot) coupled to an ICP echelle-based spectrometer equipped with a segmented charge-coupled device detector. Non-linear dependences of cobalt lines intensities on the Co percentage were observed both at a single spot ablation and at a sample translation. This behaviour could be attributed to a complex phase composition of the system W-C-Co. However, employing tungsten as internal standard the linear calibration was obtained for studied analytical lines Co II 228.616 nm, Co II 230.786 nm, Co II 236.379 nm and Co II 238.892 nm.

  14. Bottom-series coupled quadrature VCO using the inductive gate voltage boosting technique

    Science.gov (United States)

    Jang, Sheng-Lyang; Chou, Li-Te

    2013-09-01

    This article presents a new low-voltage bottom-series coupled quadrature voltage-controlled oscillator (QVCO), which consists of two n-core cross-coupled VCOs with the bottom-series coupling transistors. The low-voltage operation is obtained via an inductive gate voltage boosting technique. The proposed CMOS QVCO has been implemented with the TSMC 0.18 µm CMOS technology and the die area is 0.897 × 0.767 mm2. At the supply voltage of 0.7 V, the total power consumption is 1.5 mW. The free-running frequency of the QVCO is tuneable from 3.77 to 4.12 GHz as the tuning voltage is varied from 0.0 to 0.7 V. The measured phase noise at 1 MHz frequency offset is -123.35 dBc/Hz at the oscillation frequency of 4.12 GHz and the figure of merit of the proposed QVCO is -193.5 dBc/Hz.

  15. Misalignment detection in induction motors with flexible coupling by means of estimated torque analysis and MCSA

    Science.gov (United States)

    Verucchi, Carlos; Bossio, José; Bossio, Guillermo; Acosta, Gerardo

    2016-12-01

    In recent years, progress has been made in developing techniques to detect mechanical faults in actuators driven by induction motors. The latest developments show their capability to detect faults from the analysis of the motor electrical variables. The techniques are based on the analysis of the Motor Current Signature Analysis (MCSA) and the Load Torque Signature Analysis (LTSA), among others. Thus, failures such as misalignment between the motor and load, progressive gear teeth wear, and mass imbalances have been successfully detected. In case of misalignment between the motor and load, both angular and radial misalignment, the results presented in literature do not consider the characteristics of the coupling device. In this work, it is studied a mechanism in which the power transmission between the motor and load is performed by means of different types of couplings, mainly those most frequently used in industry. Results show that the conclusions drawn for a particular coupling are not necessarily applicable to others. Finally, this paper presents data of interest for the development of algorithms or expert systems for fault detection and diagnosis.

  16. Evaluation of micro-parallel liquid chromatography as a method for HTS-coupled actives verification.

    Science.gov (United States)

    Simeonov, Anton; Yasgar, Adam; Klumpp, Carleen; Zheng, Wei; Shafqat, Naeem; Oppermann, Udo; Austin, Christopher P; Inglese, James

    2007-12-01

    The identification of biologically active compounds from high-throughput screening (HTS) can involve considerable postscreening analysis to verify the nature of the sample activity. In this study we evaluated the performance of micro-parallel liquid chromatography (microPLC) as a separation-based enzyme assay platform for follow-up of compound activities found in quantitative HTS of two different targets, a hydrolase and an oxidoreductase. In an effort to couple secondary analysis to primary screening we explored the application of microPLC immediately after a primary screen. In microPLC, up to 24 samples can be loaded and analyzed simultaneously via high-performance liquid chromatography within a specially designed cartridge. In a proof-of-concept experiment for screen-coupled actives verification, we identified, selected, and consolidated the contents of "active" wells from a 1,536-well format HTS experiment into a 384-well plate and subsequently analyzed these samples by a 24-channel microPLC system. The method utilized 0.6% of the original 6-microl 1,536-well assay for the analysis. The analysis revealed several non-biological-based "positive" samples. The main examples included "false" enzyme activators resulting from an increase in well fluorescence due to fluorescent compound or impurity. The microPLC analysis also provided a verification of the activity of two activators of glucocerebrosidase. We discuss the benefits of microPLC and its limitations from the standpoint of ease of use and integration into a seamless postscreen workflow.

  17. Analytical Model and Optimized Design of Power Transmitting Coil for Inductively Coupled Endoscope Robot.

    Science.gov (United States)

    Ke, Quan; Luo, Weijie; Yan, Guozheng; Yang, Kai

    2016-04-01

    A wireless power transfer system based on the weakly inductive coupling makes it possible to provide the endoscope microrobot (EMR) with infinite power. To facilitate the patients' inspection with the EMR system, the diameter of the transmitting coil is enlarged to 69 cm. Due to the large transmitting range, a high quality factor of the Litz-wire transmitting coil is a necessity to ensure the intensity of magnetic field generated efficiently. Thus, this paper builds an analytical model of the transmitting coil, and then, optimizes the parameters of the coil by enlarging the quality factor. The lumped model of the transmitting coil includes three parameters: ac resistance, self-inductance, and stray capacitance. Based on the exact two-dimension solution, the accurate analytical expression of ac resistance is derived. Several transmitting coils of different specifications are utilized to verify this analytical expression, being in good agreements with the measured results except the coils with a large number of strands. Then, the quality factor of transmitting coils can be well predicted with the available analytical expressions of self- inductance and stray capacitance. Owing to the exact estimation of quality factor, the appropriate coil turns of the transmitting coil is set to 18-40 within the restrictions of transmitting circuit and human tissue issues. To supply enough energy for the next generation of the EMR equipped with a Ø9.5×10.1 mm receiving coil, the coil turns of the transmitting coil is optimally set to 28, which can transfer a maximum power of 750 mW with the remarkable delivering efficiency of 3.55%.

  18. Inductively coupled plasma mass spectrometry (ICP-MS)and its application in life sciences

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Inductively-coupled plasma mass spectrometry (ICP-MS) has made much progress since its birth in the late 1990s. This paper will give a rather systematic overview on the use of this technique in new devices and technologies related to plasma source, sample-introducing device and detecting spectrometer etc. In this overview, an emphasis will be put on the evaluation of the ICPMS technique in combination with a series of physical, chemical and biological techniques, such as laser ablation (LA), capillary electrophoresis (CE) and high performance liquid chromatograph (HPLC), along with their representative high accuracy and high sensitivity. Finally, comprehensive and fruitful applications of the ICP-MS and its combinative techniques in the detection of trace metallic elements and isotopes in complex biological and environmental samples will be revealed.

  19. Determination of metals in composite diet samples by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Melnyk, Lisa Jo; Morgan, Jeffrey N; Fernando, Reshan; Pellizzari, Edo D; Akinbo, Olujide

    2003-01-01

    A study was conducted to evaluate the applicability of inductively coupled plasma-mass spectrometry (ICP-MS) techniques for determination of metals in composite diets. Aluminum, cadmium, chromium, copper, lead, manganese, nickel, vanadium, and zinc were determined by this method. Atmospheric pressure microwave digestion was used to solubilize analytes in homogenized composite diet samples, and this procedure was followed by ICP-MS analysis. Recovery of certified elements from standard reference materials ranged from 92 to 119% with relative standard deviations (RSDs) of 0.4-1.9%. Recovery of elements from fortified composite diet samples ranged from 75 to 129% with RSDs of 0-11.3%. Limits of detection ranged from 1 to 1700 ng/g; high values were due to significant amounts of certain elements naturally present in composite diets. Results of this study demonstrate that low-resolution quadrupole-based ICP-MS provides precise and accurate measurements of the elements tested in composite diet samples.

  20. Double layer formation in the expanding region of an inductively coupled electronegative plasma

    CERN Document Server

    Plihon, N; Chabert, P

    2015-01-01

    Double-layers (DLs) were observed in the expanding region of an inductively coupled plasma with $\\text{Ar}/\\text{SF}\\_6$ gas mixtures. No DL was observed in pure argon or $\\text{SF}\\_6$ fractions below few percent. They exist over a wide range of power and pressure although they are only stable for a small window of electronegativity (typically between 8\\% and 13\\% of $\\text{SF}\\_6$ at 1mTorr), becoming unstable at higher electronegativity. They seem to be formed at the boundary between the source tube and the diffusion chamber and act as an internal boundary (the amplitude being roughly 1.5$\\frac{kT\\_e}{e}$)between a high electron density, high electron temperature, low electronegativity plasma upstream (in the source), and a low electron density, low electron temperature, high electronegativity plasma downstream.

  1. Trace elemental composition of curry by inductively coupled plasma optical emission spectrometry (ICP-OES).

    Science.gov (United States)

    Gonzálvez, A; Armenta, S; De La Guardia, M

    2008-01-01

    A methodology based on inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave-assisted acid digestion was developed to determine the content of traces elements in curry samples from the Spanish market. The methodology was validated in terms of accuracy by the analysis of citrus and tomato leaf reference materials achieving comparable results with the certified values. The trace metal content of curry samples was compared with data available from previously published reports concerning Indian samples, especially in terms of heavy metal composition, in order to guarantee the quality of the commercially available spices in the European countries. Values found for the analysis of arsenic, lead and cadmium were significantly lower than the maximum limit allowed by European Union statutory limits for heavy metals and lower than those obtained for Indian curry leaves reported by Indian research teams by using neutron activation and γ-ray analysis.

  2. Horn-coupled, commercially-fabricated aluminum lumped-element kinetic inductance detectors for millimeter wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    McCarrick, H., E-mail: hlm2124@columbia.edu; Flanigan, D.; Jones, G.; Johnson, B. R.; Araujo, D.; Limon, M.; Luu, V.; Miller, A. [Department of Physics, Columbia University, New York, New York 10025 (United States); Ade, P.; Doyle, S.; Tucker, C. [School of Physics and Astronomy, Cardiff University, Cardiff, Wales CF24 3AA (United Kingdom); Bradford, K.; Che, G. [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Cantor, R. [STAR Cryoelectronics, Santa Fe, New Mexico 87508 (United States); Day, P.; Leduc, H. [Jet Propulsion Laboratory, Caltech, Pasadena, California 91109 (United States); Mauskopf, P. [School of Physics and Astronomy, Cardiff University, Cardiff, Wales CF24 3AA (United Kingdom); Department of Physics and School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287 (United States); Mroczkowski, T. [Naval Research Laboratory, Washington DC 20375 (United States); Zmuidzinas, J. [Jet Propulsion Laboratory, Caltech, Pasadena, California 91109 (United States); Department of Physics, Caltech, Pasadena, California 91125 (United States)

    2014-12-15

    We discuss the design, fabrication, and testing of prototype horn-coupled, lumped-element kinetic inductance detectors (LEKIDs) designed for cosmic microwave background studies. The LEKIDs are made from a thin aluminum film deposited on a silicon wafer and patterned using standard photolithographic techniques at STAR Cryoelectronics, a commercial device foundry. We fabricated 20-element arrays, optimized for a spectral band centered on 150 GHz, to test the sensitivity and yield of the devices as well as the multiplexing scheme. We characterized the detectors in two configurations. First, the detectors were tested in a dark environment with the horn apertures covered, and second, the horn apertures were pointed towards a beam-filling cryogenic blackbody load. These tests show that the multiplexing scheme is robust and scalable, the yield across multiple LEKID arrays is 91%, and the measured noise-equivalent temperatures for a 4 K optical load are in the range 26±6 μK√(s)

  3. Inductively Coupled Plasma-Induced Etch Damage of GaN p-n Junctions

    Energy Technology Data Exchange (ETDEWEB)

    SHUL,RANDY J.; ZHANG,LEI; BACA,ALBERT G.; WILLISON,CHRISTI LEE; HAN,JUNG; PEARTON,S.J.; REN,F.

    1999-11-03

    Plasma-induced etch damage can degrade the electrical and optical performance of III-V nitride electronic and photonic devices. We have investigated the etch-induced damage of an Inductively Coupled Plasma (ICP) etch system on the electrical performance of mesa-isolated GaN pn-junction diodes. GaN p-i-n mesa diodes were formed by Cl{sub 2}/BCl{sub 3}/Ar ICP etching under different plasma conditions. The reverse leakage current in the mesa diodes showed a strong relationship to chamber pressure, ion energy, and plasma flux. Plasma induced damage was minimized at moderate flux conditions ({le} 500 W), pressures {ge}2 mTorr, and at ion energies below approximately -275 V.

  4. Low-frequency, self-sustained oscillations in inductively coupled plasmas used for optical pumping

    Energy Technology Data Exchange (ETDEWEB)

    Coffer, J.; Encalada, N.; Huang, M.; Camparo, J. [Physical Sciences Laboratories, The Aerospace Corporation 2310, E. El Segundo Blvd., El Segundo, California 90245 (United States)

    2014-10-28

    We have investigated very low frequency, on the order of one hertz, self-pulsing in alkali-metal inductively-coupled plasmas (i.e., rf-discharge lamps). This self-pulsing has the potential to significantly vary signal-to-noise ratios and (via the ac-Stark shift) resonant frequencies in optically pumped atomic clocks and magnetometers (e.g., the atomic clocks now flying on GPS and Galileo global navigation system satellites). The phenomenon arises from a nonlinear interaction between the atomic physics of radiation trapping and the plasma's electrical nature. To explain the effect, we have developed an evaporation/condensation theory (EC theory) of the self-pulsing phenomenon.

  5. Measurement of neutral gas temperature in a 13.56 MHz inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Jayapalan, Kanesh K.; Chin, Oi Hoong [Plasma Technology Research Centre, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-04-24

    Measuring the temperature of neutrals in inductively coupled plasmas (ICP) is important as heating of neutral particles will influence plasma characteristics such as the spatial distributions of plasma density and electron temperature. Neutral gas temperatures were deduced using a non-invasive technique that combines gas actinometry, optical emission spectroscopy and simulation which is described here. Argon gas temperature in a 13.56 MHz ICP were found to fall within the range of 500 − 800 K for input power of 140 − 200 W and pressure of 0.05 − 0.2 mbar. Comparing spectrometers with 0.2 nm and 0.5 nm resolution, improved fitting sensitivity was observed for the 0.2 nm resolution.

  6. Multielement Analysis of Deep-Sea Sediments by Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIA Ning; WU Zhaohui; GUO Dongfa; YAO De

    2008-01-01

    Marine sediments were dissolved by HNO3-HF-HCIO4 in a sealed container at low pressure; I-IF was evaporated in an open container and salts were dissolved in HCl by heating, then transferred to 2% HNO3 solution. A total of 45 elements, including Li, Be, So, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Cd, In, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, TI, Pb, Bi, Th and U, were measured by inductively coupled plasma mass spectrometry (ICP-MS). Condi-tions and sample experiments showed that this procedure defines a good experimental method which has the advantages of clear interference, easy operation and reliable results. The concentrations of the 45 elements could be used for resource exploration, envi-ronmental assessment and academic research.

  7. Heavy metals in aromatic spices by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Bua, Daniel Giuseppe; Annuario, Giovanni; Albergamo, Ambrogina; Cicero, Nicola; Dugo, Giacomo

    2016-09-01

    Objective of this study was to determine the content of Cd, Hg, As and Pb in common spices traded in the Italian market, using inductively coupled plasma-mass spectrometry (ICP-MS). The results were compared with the maximum limits established by the national Legislative Decree (LD) no. 107 implementing the Council Directive 88/388/EEC and by international organisations, such as Food and Agriculture Organization (FAO) and World Health Organization (WHO). Food safety for spices was assessed considering the tolerable weekly intake (TWI) and the provisional tolerable weekly intake (PTWI), respectively, for Cd and Hg and the 95% lower confidence limit of the benchmark dose of 1% extra risk (BMDL01) for As and Pb. Investigated elements in all samples were within the maximum limits as set by the national and international normative institutions. Nevertheless, the heavy metal content of some spices exceeded the PTWI, TWI and BMDL01, which needs attention when considering consumer's health.

  8. Analysis of iodine in food samples by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Todorov, Todor I; Gray, Patrick J

    2016-01-01

    This work shows a method for the determination of iodine in a variety of food samples and reference materials using inductively coupled plasma-mass spectrometry (ICP-MS) following alkaline extraction. Optimisation of the addition of organic carbon showed that a minimum of 3% 2-propanol was necessary for a constant ratio of iodine to internal standard. The limit of quantification (LOQ), calculated as 30σ for the method, was 36 ng g(-1) in solid food samples. For method validation, seven standard reference materials (SRM) and 21 fortified food samples were used. The precision (%RSD) of the measurements was in the 2-7% range. Accuracies for the SRMs were 85-105%, while the fortified food samples showed 81-119% recoveries, including a number of samples fortified at 50% of the LOQ.

  9. Determination of {sup 233}U by inductively coupled argon plasma - atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Patwardhan, A.B.; Kulkarni, V.T.; Radhakrishnan, K.; Ramanujam, A.; Page, A.G. [Bhabha Atomic Research Centre, Bombay (India)

    1994-09-01

    The paper describes studies carried out for the determination of {sup 233}U at various stages during the recovery and purification of {sup 233}U from {sup 233}U-Al alloy scraps generated during the fabrication of {sup 233}U-Al alloy fuel. Employing a high resolution sequential spectrometer and Inductively Coupled argon Plasma (ICP) as the spectral excitation source, isotope shift for {sup 233}U with respect to {sup 238}U has been resolved and recorded. The shift for the 424.437 nm emission line of {sup 238}U is found to be of the order of 0.040 nm on the lower wavelength side for {sup 233}U and this isotopic effect has been utilised for the quantitative determination of {sup 233}U. The overall precision of the method is 5% RSD with the detection limit of 0.01 {mu}g/ml.

  10. Computational Finite Element Software Assisted Development of a 3D Inductively Coupled Power Transfer System

    Directory of Open Access Journals (Sweden)

    Pratik Raval

    2014-02-01

    Full Text Available To date inductively coupled power transfer (ICPT systems have already found many practical applications including battery charging pads. In fact, current charging platforms tend to largely support only one- or two-dimensional planar movement in load. This paper proposes a new concept of extending the aspect ratios of the operating power transfer volume of ICPT systems to support arbitrary three dimensional load movements with respect to the primary coils. This is done by use of modern finite element method analysis software to propose the primary and secondary magnetic structures of such an ICPT system. Firstly, two primary magnetic structures are proposed based on contrasting modes of operation and different field directions. This includes a single-phase and multi-phase current model. Next, a secondary magnetic structure is customized to be compatible with both primary structures. The resulting system is shown to produce a 3D power transfer volume for battery cell charging applications.

  11. Development of an Inductively Coupled Thermometer for a Cryogenic Half-Wave Plate

    Science.gov (United States)

    Madurowicz, Alexander; Kusaka, Akito

    2017-01-01

    The current state of Cosmic Microwave Background (CMB) research has focused much attention on the measurement of polarization. In an effort to modulate the CMB polarization while also minimizing photon noise due to thermal emission, we are developing a sapphire half-wave plate (HWP) cooled to 50 K rotating at 2 Hz on a superconducting magnetic levitating bearing. In order to measure the temperature of the rotor without making physical contact, we designed an inductively coupled cryogenic thermometer. The complex impedance of the circuit has a resonant peak when driven around 1 MHz. The width of this resonance is dependent on the value of the resistor, which varies with temperature and functions as a thermometer once calibrated. In this talk, we will present results from stationary measurements of this impedance and discuss the temperature accuracy of this thermometer, as well as a preliminary circuit design to measure this impedance during the HWP rotation.

  12. Inductively coupled plasma optical emission spectroscopy determination of trace element composition of argan oil.

    Science.gov (United States)

    Gonzálvez, A; Ghanjaoui, M E; El Rhazi, M; de la Guardia, M

    2010-02-01

    A methodology based on inductively coupled plasma optical emission spectroscopy (ICP-OES) after microwave assisted acid digestion has been developed to determine the trace element content of Moroccan argan oil. Limit of detection values equal or lower than few mg/kg were obtained for all elements under study. To assure the accuracy of the whole procedure, recovery studies were carried out on argan oil samples spiked at different concentration levels from 10 to 200 µg/L. Quantitative average recovery values were obtained for all elements evaluated, demonstrating the suitability of this methodology for the determination of trace elements in argan oil samples. Aluminum, calcium, chromium, iron, potassium, lithium, magnesium, sodium, vanadium and zinc were quantitatively determined in Moroccan argan oils being found that their concentration is different of that found in other edible oils thus offering a way for authentication and for the evaluation of possible adulterations.

  13. Determination of Trace Elements in High Purity Gold by High Resolution Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIE Hualin; HUANG Kelong; NIE Xidu; FU Liang

    2009-01-01

    Trace elements were determined in high purity gold by high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS).Sample were decomposed by aqua regia.To overcome some potentially problematic spectral interference,measurements were acquired in both medium and high resolution modes.The matrix effects due to the presence of excessive HCl and Au were evaluated.The optimum conditions for the determination was tested and discussed.The standard addition method was employed for quantitative analysis.The detection limits range from 0.01 μg/g to 0.28 μg/g depending on the elements.The method is accurate,quick and convenient.It has been applied to the determination of trace elements in high purity gold with satisfactory results.

  14. Nonlinear electromagnetic fields in 0.5 MHz inductively coupled plasmas

    DEFF Research Database (Denmark)

    Ostrikov, K.N.; Tsakadze, E.L.; Xu, S.

    2003-01-01

    Radial profiles of magnetic fields in the electrostatic (E) and electromagnetic (H) modes of low-frequency (similar to500 kHz) inductively coupled plasmas have been measured using miniature magnetic probes. In the low-power (similar to170 W) E-mode, the magnetic field pattern is purely linear......, with the fundamental frequency harmonics only. After transition to higher-power (similar to1130 W) H-mode, the second-harmonic nonlinear azimuthal magnetic field B-phi(2omega) that is in 4-6 times larger than the fundamental frequency component B-phi(omega), has been observed. A simplified plasma fluid model...... explaining the generation of the second harmonics of the azimuthal magnetic field in the plasma source is proposed. The nonlinear second harmonic poloidal (r-z) rf current generating the azimuthal magnetic field B-phi(2omega) is attributed to nonlinear interactions between the fundamental frequency radial...

  15. Determination of trace multi-elements in coal fly ash by inductively coupled plasma mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIE Hua-lin; TANG You-gen; LI Yu-jie; LI Li-bo

    2007-01-01

    The contents of Cr,Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method.The sample digestions were performed in closed microwave vessels with HN03, HClO4 and HF.The optimum conditions for the determination were obtained.The applicability of the proposed method was validated by the analysis of coal fly ash reference material (NIST SRM 1633a). The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode(maximum mass resolution R=9 000).The detection limit is from 0.05 to 0.21μg/g,and the precision is fine with relative standard deviation less than 4.3%.

  16. Three-dimensional discharge simulation of inductively coupled plasma (ICP) etching reactor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    More and more importance has been attached to inductively coupled plasma (ICP) in semiconductor manufacture. For a deep understanding of the plasma discharge process in the etching reactor, this study made a three-dimensional simulation on the Ar plasma discharge process with the commercial software CFD-ACE, which is according to the real experiment conditions and data supplied by North Microelec-tronic Corporation. The error of the simulation results is in the range of ±20% with credibility. The numerical results show that the three-dimentional spatial distribu-tion of electron density is reduced from the chamber center to the wall. The distri-bution of electron density, electron temperature and power deposition is related to the shape and placement of the coil.

  17. Strategies for the analysis of coal by laser ablation inductively coupled plasma mass spectroscopy.

    Science.gov (United States)

    Kleiber, L; Fink, H; Niessner, R; Panne, U

    2002-09-01

    The potential of laser ablation inductively coupled mass spectrometry (LA-ICP-MS) was investigated for the inorganic characterization of different coal samples pressed into pellets. Reference analysis was performed by microwave-assisted digestion of the ground samples followed by ICP-MS analysis of the resulting solutions. Two different laser ablation sampling procedures were compared. For continuous sampling, three sites of the pellet were sampled for approximately one minute, whereas for sequential sampling 15 sites were sampled for two seconds, respectively. The qualitative results of the two procedures were equivalent, but continuous sampling allowed faster analysis and better precision (RSD about 10%) than sequential sampling (RSD 10-20%). Different normalization procedures with internal and extrinsic standards were investigated and allowed a quantitative determination of Al, Ti, Zn, Ni, and V with measurement uncertainties below 10% and Fe, Si, and Sn with measurement uncertainties below 20%.

  18. Strategies for the analysis of coal by laser ablation inductively coupled plasma mass spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kleiber, L.; Fink, H.; Niessner, R.; Panne, U. [Institute of Hydrochemistry, Technical University of Munich, Marchioninistr. 17, 81377 Munich (Germany)

    2002-09-01

    The potential of laser ablation inductively coupled mass spectrometry (LA-ICP-MS) was investigated for the inorganic characterization of different coal samples pressed into pellets. Reference analysis was performed by microwave-assisted digestion of the ground samples followed by ICP-MS analysis of the resulting solutions. Two different laser ablation sampling procedures were compared. For continuous sampling, three sites of the pellet were sampled for approximately one minute, whereas for sequential sampling 15 sites were sampled for two seconds, respectively. The qualitative results of the two procedures were equivalent, but continuous sampling allowed faster analysis and better precision (RSD about 10%) than sequential sampling (RSD 10-20%). Different normalization procedures with internal and extrinsic standards were investigated and allowed a quantitative determination of Al, Ti, Zn, Ni, and V with measurement uncertainties below 10% and Fe, Si, and Sn with measurement uncertainties below 20%. (orig.)

  19. A comprehensive study of different gases in inductively coupled plasma torch operating at one atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Punjabi, Sangeeta B. [Electrical Engineering Department, V. J.T.I, Matunga, Mumbai 400019 (India); Department of Physics, University of Mumbai, Kalina, Santacruz(E) 400098 (India); Joshi, N. K. [Faculty of Engineering and technology, MITS, lakshmangarh, (Sikar), Rajasthan 332311 (India); Mangalvedekar, H. A.; Lande, B. K. [Electrical Engineering Department, V. J.T.I, Matunga, Mumbai 400019 (India); Das, A. K. [Laser and Plasma Technology Division, BARC, Mumbai 400085 (India); Kothari, D. C. [Department of Physics, University of Mumbai, Kalina, Santacruz(E) 400098 (India)

    2012-01-15

    A numerical study is done to understand the possible operating regimes of RF-ICP torch (3 MHz, 50 kW) using different gases for plasma formation at atmospheric pressure. A two dimensional numerical simulation of RF-ICP torch using argon, nitrogen, oxygen, and air as plasma gas has been investigated using computational fluid dynamic (CFD) software fluent{sup (c)}. The operating parameters varied here are central gas flow, sheath gas flow, RF-power dissipated in plasma, and plasma gas. The temperature contours, flow field, axial, and radial velocity profiles were investigated under different operating conditions. The plasma resistance, inductance of the torch, and the heat distribution for various plasma gases have also been investigated. The plasma impedance of ICP torch varies with different operating parameters and plays an important role for RF oscillator design and power coupling. These studies will be useful to decide the design criteria for ICP torches required for different material processing applications.

  20. E→H mode transition density and power in two types of inductively coupled plasma configuration

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian; Du, Yin-chang; Zhang, Xiao; Zheng, Zhe; Liu, Yu; Xu, Liang; Wang, Pi; Cao, Jin-xiang, E-mail: jxcao@ustc.edu.cn [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-07-15

    E → H transition power and density were investigated at various argon pressures in inductively coupled plasma (ICP) in a cylindrical interlaid chamber. The transition power versus the pressure shows a minimum transition power at 4 Pa (ν/ω=1) for argon. Then the transition density hardly changes at low pressures (ν/ω≪1), but it increases clearly when argon pressure exceeds an appropriate value. In addition, both the transition power and transition density are lower in the re-entrant configuration of ICP compared with that in the cylindrical configuration of ICP. The result may be caused from the decrease of stochastic heating in the re-entrant configuration of ICP. This work is useful to understand E → H mode transition and control the transition points in real plasma processes.

  1. Horn-coupled, commercially-fabricated aluminum lumped-element kinetic inductance detectors for millimeter wavelengths.

    Science.gov (United States)

    McCarrick, H; Flanigan, D; Jones, G; Johnson, B R; Ade, P; Araujo, D; Bradford, K; Cantor, R; Che, G; Day, P; Doyle, S; Leduc, H; Limon, M; Luu, V; Mauskopf, P; Miller, A; Mroczkowski, T; Tucker, C; Zmuidzinas, J

    2014-12-01

    We discuss the design, fabrication, and testing of prototype horn-coupled, lumped-element kinetic inductance detectors (LEKIDs) designed for cosmic microwave background studies. The LEKIDs are made from a thin aluminum film deposited on a silicon wafer and patterned using standard photolithographic techniques at STAR Cryoelectronics, a commercial device foundry. We fabricated 20-element arrays, optimized for a spectral band centered on 150 GHz, to test the sensitivity and yield of the devices as well as the multiplexing scheme. We characterized the detectors in two configurations. First, the detectors were tested in a dark environment with the horn apertures covered, and second, the horn apertures were pointed towards a beam-filling cryogenic blackbody load. These tests show that the multiplexing scheme is robust and scalable, the yield across multiple LEKID arrays is 91%, and the measured noise-equivalent temperatures for a 4 K optical load are in the range 26±6 μK√s.

  2. Filterless preconcentration, flow injection analysis and detection by inductively-coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    The influence of interferences in the analysis of elements by inductively-coupled-plasma mass-spectrometry (ICP-MS) may be significantly diminished by utilising a protocol of flow-injection analysis (FIA). The method is based on filterless preconcentration of metallic elements at the walls...... of a knotted reactor that was made of nylon tubings. In the load mode, the preconcentration was accomplished by precipitation of metallic species in alkaline-buffered carriers onto the inner walls of the hydrofilic tube. After a preconcen-tration period of 40-120 seconds using sample volumes of 4-10 m......L, the analyte was transferred by a FIAS 400 system to the ICP-MS detector by dissolving the species in an acidic carrier. The magnitude of the enrichment factor largely depended on the time of preconcentration, on the pH-value of the preconcentration buffer and on the pH-value of the samples. Enrichment factors...

  3. Al-Induced Crystallization Growth of Si Films by Inductively Coupled Plasma Chemical Vapour Deposition

    Institute of Scientific and Technical Information of China (English)

    LI Jun-Shuai; WANG Jin-Xiao; YIN Min; GAO Ping-Qi; HE De-Yan

    2006-01-01

    Polycrystalline Si (poly-Si) films are in situ grown on Al-coated glass substrates by inductively coupled plasma chemical vapour deposition at a temperature as low as 350 C. Compared to the traditional annealing crystallization of amorphous Si/Al-layer structures, no layer exchange is observed and the resultant poly-Si film is much thicker than Al layer. By analysing the depth profiles of the elemental composition, no remains of Al atoms are detected in Si layer within the limit (< 0.01 at. %) of the used evaluations. It is indicated that the poly-Si material obtained by Al-induced crystallization growth has more potential applications than that prepared by annealing the amorphous Si/Al-layer structures.

  4. Numerical Study of a System of Long Josephson Junctions with Inductive and Capacitive Couplings

    Science.gov (United States)

    Rahmonov, I. R.; Shukrinov, Yu. M.; Plecenik, A.; Zemlyanaya, E. V.; Bashashin, M. V.

    2016-02-01

    The phase dynamics of the stacked long Josephson junctions is investigated taking into account the inductive and capacitive couplings between junctions and the diffusion current. The simulation of the current-voltage characteristics is based on the numerical solution of a system of nonlinear partial differential equations by a fourth order Runge-Kutta method and finite-difference approximation. A parallel implementation is based on the MPI technique. The effectiveness of the MPI/C++ code is confirmed by calculations on the multi-processor cluster CICC (LIT JINR, Dubna). We demonstrate the appearance of the charge traveling wave (CTW) at the boundary of the zero field step. Based on this fact, we conclude that the CTW and the fluxons coexist.

  5. Numerical Study of a System of Long Josephson Junctions with Inductive and Capacitive Couplings

    Directory of Open Access Journals (Sweden)

    Rahmonov I. R.

    2016-01-01

    Full Text Available The phase dynamics of the stacked long Josephson junctions is investigated taking into account the inductive and capacitive couplings between junctions and the diffusion current. The simulation of the current–voltage characteristics is based on the numerical solution of a system of nonlinear partial differential equations by a fourth order Runge–Kutta method and finite-difference approximation. A parallel implementation is based on the MPI technique. The effectiveness of the MPI/C++ code is confirmed by calculations on the multi-processor cluster CICC (LIT JINR, Dubna. We demonstrate the appearance of the charge traveling wave (CTW at the boundary of the zero field step. Based on this fact, we conclude that the CTW and the fluxons coexist.

  6. Inductively Coupled Plasma: Fundamental Particle Investigations with Laser Ablation and Applications in Magnetic Sector Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Saetveit, Nathan Joe [Iowa State Univ., Ames, IA (United States)

    2008-01-01

    Particle size effects and elemental fractionation in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) are investigated with nanosecond and femtosecond laser ablation, differential mobility analysis, and magnetic sector ICP-MS. Laser pulse width was found to have a significant influence on the LA particle size distribution and the elemental composition of the aerosol and thus fractionation. Emission from individual particles from solution nebulization, glass, and a pressed powder pellet are observed with high speed digital photography. The presence of intact particles in an ICP is shown to be a likely source of fractionation. A technique for the online detection of stimulated elemental release from neural tissue using magnetic sector ICP-MS is described. Detection limits of 1 μg L-1 or better were found for P, Mn, Fe, Cu, and Zn in a 60 μL injection in a physiological saline matrix.

  7. A cleaning method for reduced graphene oxide by inductively coupled plasma

    Science.gov (United States)

    Shen, Yan; Zhou, Peng; Zhang, David Wei

    2016-10-01

    In this work, we make reduced graphene oxide (rGO) solution via chemical way and use it to fabricate Field-effect transistor (FET) channel by spin coating for investigating the performance of grapheme-based devices. An inductively coupled plasma (ICP) with very low plasma density is applied to etch the surface of rGO. It has been confirmed that residues and contaminations can be removed through etching and proper etching parameters can lead to better electrical properties more like the pristine graphene without creating defects. Considering the application of graphene added to silicon-based electronic devices, such a cleaning method can be used due to its advantages of being a low-temperature, large-area, high-throughput, and Si-compatible process.

  8. RF electric field penetration and power deposition into nonequilibrium planar-type inductively coupled plasmas

    Institute of Scientific and Technical Information of China (English)

    Mao Ming; Wang Shuai; Dai Zhong-Ling; Wang You-Nian

    2007-01-01

    The RF electric field penetration and the power deposition into planar-type inductively coupled plasmas in lowpressure discharges have been studied by means of a self-consistent model which consists of Maxwell equations combined with the kinetic equation of electrons. The Maxwell equations are solved based on the expansion of the Fourier-Bessel series for determining the RF electric field. Numerical results show the influence of a non-Maxwellian electron energy distribution on the RF electric field penetration and the power deposition for different coil currents. Moreover, the two-dimensional spatial profiles of RF electric field and power density are also shown for different numbers of RF coil turns.

  9. OPTIMAL CONTROL OF A NONLINEAR COUPLED ELECTROMAGNETIC INDUCTION HEATING SYSTEM WITH POINTWISE STATE CONSTRAINTS

    Directory of Open Access Journals (Sweden)

    Irwin Yousept

    2010-07-01

    Full Text Available An optimal control problem arising in the context of 3D electromagnetic induction heating is investigated. The state equation is given by a quasilinear stationary heat equation coupled with a semilinear time harmonic eddy current equation. The temperature-dependent electrical conductivity and the presence of pointwise inequality state-constraints represent the main challenge of the paper. In the first part of the paper, the existence and regularity of the state are addressed. The second part of the paper deals with the analysis of the corresponding linearized equation. Some suffcient conditions are presented which guarantee thesolvability of the linearized system. The final part of the paper is concerned with the optimal control. The aim of the optimization is to find the optimal voltage such that a desired temperature can be achieved optimally. The corresponding first-order necessary optimality condition is presented.

  10. Stable isotope dilution analysis of hydrologic samples by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Garbarino, J.R.; Taylor, H.E.

    1987-01-01

    Inductively coupled plasma mass spectrometry is employed in the determination of Ni, Cu, Sr, Cd, Ba, Ti, and Pb in nonsaline, natural water samples by stable isotope dilution analysis. Hydrologic samples were directly analyzed without any unusual pretreatment. Interference effects related to overlapping isobars, formation of metal oxide and multiply charged ions, and matrix composition were identified and suitable methods of correction evaluated. A comparability study snowed that single-element isotope dilution analysis was only marginally better than sequential multielement isotope dilution analysis. Accuracy and precision of the single-element method were determined on the basis of results obtained for standard reference materials. The instrumental technique was shown to be ideally suited for programs associated with certification of standard reference materials.

  11. Development of analytical methods for multiplex bio-assay with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Ornatsky, Olga I; Kinach, Robert; Bandura, Dmitry R; Lou, Xudong; Tanner, Scott D; Baranov, Vladimir I; Nitz, Mark; Winnik, Mitchell A

    2008-01-01

    Advances in the development of highly multiplexed bio-analytical assays with inductively coupled plasma mass spectrometry (ICP-MS) detection are discussed. Use of novel reagents specifically designed for immunological methods utilizing elemental analysis is presented. The major steps of method development, including selection of elements for tags, validation of tagged reagents, and examples of multiplexed assays, are considered in detail. The paper further describes experimental protocols for elemental tagging of antibodies, immunostaining of live and fixed human leukemia cells, and preparation of samples for ICP-MS analysis. Quantitative analysis of surface antigens on model cell lines using a cocktail of seven lanthanide labeled antibodies demonstrated high specificity and concordance with conventional immunophenotyping.

  12. New Applications of Inductively Coupled Plasma-Mass Spectrometry in the Nuclear Industry

    Energy Technology Data Exchange (ETDEWEB)

    Rob Henry; Dagmar Koller; Phil Marriott

    1998-12-31

    Inductively coupled plasma mass spectrometry (ICP-MS) complements the traditional methods of quantitation of radioactive isotopes. Because of the favorable ionization potential of most actinides and their daughter products, the argon plasma provides a rich, stable source of ions, which are introduced through a plasma-mass spectrometer interface into the mass spectrometer for isotopic separation. Samples are normally introduced in solution, although direct solids analysis has also been achieved using laser ablation of the sample into the argon plasma. Since 1983, improvements in ICP-MS sensitivity have resulted in correspondingly lower mass detection capability. This development has in turn expanded the number of isotopes accessible to measurement at the levels required in the nuclear industry.

  13. Inductively Coupling Plasma (ICP) Treatment of Propylene (PP) Surface and Adhesion Improvement

    Science.gov (United States)

    Liu, Yenchun; Fu, Yenpei

    2009-12-01

    Study on increasing the roughness of the polymer substrate surface to enhance the adhesion with the copper layer in an inductively coupling plasma (ICP) process was carried out. The microstructure of the polymer substrate surfaces, which were exposed to different kinds of plasma treatment, was identified by scanning electron microscopy(SEM) analysis, peel strength of the copper coating and water surface contact angle. The adhesion of the substrate was largely enhanced by plasma treatment and the copper deposited coating reached a value of 7.68 kgf/m in verifying the adhesion of the copper coating with polymer material. The quality of the line/space 50/50 μm produced in the laboratory was examined by the pressure cooker test and proved to meet the requirement.

  14. Transport and trapping of dust particles in a potential well created by inductively coupled diffused plasma

    CERN Document Server

    Choudhary, Mangilal; Bandyopadhyay, P

    2016-01-01

    A versatile linear dusty (complex) plasma device is designed to study the transport and dynamical behavior of dust particles in a large volume. Diffused inductively coupled plasma is generated in the background of argon gas. A novel technique is used to introduce the dust particles in the main plasma by striking a secondary direct current (DC) glow discharge. These dust particles are found to get trapped in an electrostatic potential well which is formed due to the combination of the ambipolar electric field caused by diffusive plasma and the field produced by the charged glass wall of the vacuum chamber. According to the requirements, the volume of the dust cloud can be controlled very precisely by tuning the plasma and discharge parameters. The present device can be used to address the underlying physics behind the transport of dust particles, self excited dust acoustic waves and instabilities. The detailed design of this device, plasma production and characterization, trapping and transport of the dust par...

  15. Multi-elemental analysis of aqueous geological samples by inductively coupled plasma-optical emission spectrometry

    Science.gov (United States)

    Todorov, Todor I.; Wolf, Ruth E.; Adams, Monique

    2014-01-01

    Typically, 27 major, minor, and trace elements are determined in natural waters, acid mine drainage, extraction fluids, and leachates of geological and environmental samples by inductively coupled plasma-optical emission spectrometry (ICP-OES). At the discretion of the analyst, additional elements may be determined after suitable method modifications and performance data are established. Samples are preserved in 1–2 percent nitric acid (HNO3) at sample collection or as soon as possible after collection. The aqueous samples are aspirated into the ICP-OES discharge, where the elemental emission signals are measured simultaneously for 27 elements. Calibration is performed with a series of matrix-matched, multi-element solution standards.

  16. Langmuir probe study of an inductively coupled magnetic-pole-enhanced helium plasma

    Science.gov (United States)

    Younus, Maria; Rehman, N. U.; Shafiq, M.; Naeem, M.; Zaka-ul-Islam, M.; Zakaullah, M.

    2017-03-01

    This study reports the effects of RF power and filling gas pressure variation on the plasma parameters, including the electron number density n e , electron temperature T e , plasma potential V p , skin depth δ, and electron energy probability functions (EEPFs) in a low-pressure inductively coupled helium plasma source with magnetic pole enhancement. An RF compensated Langmuir probe is used to measure these plasma parameters. It is observed that the electron number density increases with both the RF power and the filling gas pressure. Conversely, the electron temperature decreases with increasing RF power and gas pressure. It is also noted that, at low RF powers and gas pressures, the EEPFs are non-Maxwellian, while at RF powers of ≥50 W, they evolve into a Maxwellian distribution. The dependences of the skin depth and plasma potential on the RF power are also studied and show a decreasing trend.

  17. Standard practice for alternate actinide calibration for inductively coupled plasma-mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 This practice provides guidance for an alternate linear calibration for the determination of selected actinide isotopes in appropriately prepared aqueous solutions by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This alternate calibration is mass bias adjusted using thorium-232 (232Th) and uranium-238 (238U) standards. One of the benefits of this standard practice is the ability to calibrate for the analysis of highly radioactive actinides using calibration standards at much lower specific activities. Environmental laboratories may find this standard practice useful if facilities are not available to handle the highly radioactive standards of the individual actinides of interest. 1.2 The instrument response for a series of determinations of known concentration of 232Th and 238U defines the mass versus response relationship. For each standard concentration, the slope of the line defined by 232Th and 238U is used to derive linear calibration curves for each mass of interest using interference equ...

  18. Design optimization of transmitting antennas for weakly coupled magnetic induction communication systems

    Science.gov (United States)

    2017-01-01

    This work focuses on the design of transmitting coils in weakly coupled magnetic induction communication systems. We propose several optimization methods that reduce the active, reactive and apparent power consumption of the coil. These problems are formulated as minimization problems, in which the power consumed by the transmitting coil is minimized, under the constraint of providing a required magnetic field at the receiver location. We develop efficient numeric and analytic methods to solve the resulting problems, which are of high dimension, and in certain cases non-convex. For the objective of minimal reactive power an analytic solution for the optimal current distribution in flat disc transmitting coils is provided. This problem is extended to general three-dimensional coils, for which we develop an expression for the optimal current distribution. Considering the objective of minimal apparent power, a method is developed to reduce the computational complexity of the problem by transforming it to an equivalent problem of lower dimension, allowing a quick and accurate numeric solution. These results are verified experimentally by testing a number of coil geometries. The results obtained allow reduced power consumption and increased performances in magnetic induction communication systems. Specifically, for wideband systems, an optimal design of the transmitter coil reduces the peak instantaneous power provided by the transmitter circuitry, and thus reduces its size, complexity and cost. PMID:28192463

  19. Bulk plasma fragmentation in a C4F8 inductively coupled plasma: A hybrid modeling study

    Science.gov (United States)

    Zhao, Shu-Xia; Zhang, Yu-Ru; Gao, Fei; Wang, You-Nian; Bogaerts, Annemie

    2015-06-01

    A hybrid model is used to investigate the fragmentation of C4F8 inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. CxFy (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C4F8 inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C4F8 reaction set used in the model. The C4F8 plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model.

  20. Characterization of stationary and pulsed inductively coupled RF discharges for plasma sterilization

    Science.gov (United States)

    Gans, T.; Osiac, M.; O'Connell, D.; Kadetov, V. A.; Czarnetzki, U.; Schwarz-Selinger, T.; Halfmann, H.; Awakowicz, P.

    2005-05-01

    Sterilization of bio-medical materials using radio frequency (RF) excited inductively coupled plasmas (ICPs) has been investigated. A double ICP has been developed and studied for homogenous treatment of three-dimensional objects. Sterilization is achieved through a combination of ultraviolet light, ion bombardment and radical treatment. For temperature sensitive materials, the process temperature is a crucial parameter. Pulsing of the plasma reduces the time average heat strain and also provides additional control of the various sterilization mechanisms. Certain aspects of pulsed plasmas are, however, not yet fully understood. Phase resolved optical emission spectroscopy and time resolved ion energy analysis illustrate that a pulsed ICP ignites capacitively before reaching a stable inductive mode. Time resolved investigations of the post-discharge, after switching off the RF power, show that the plasma boundary sheath in front of a substrate does not fully collapse for the case of hydrogen discharges. This is explained by electron heating through super-elastic collisions with vibrationally excited hydrogen molecules.

  1. Atlas of Atomic Spectral Lines of Neptunium Emitted by Inductively Coupled Plasma

    Energy Technology Data Exchange (ETDEWEB)

    DeKalb, E.L. and Edelson, M. C.

    1987-08-01

    Optical emission spectra from high-purity Np-237 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 230-700 nm wavelength range are presented along with general commentary on the methodology used in collecting the data. The Ames Laboratory Nuclear Safeguards and Security Program has been charged with the task of developing optical spectroscopic methods to analyze the composition of spent nuclear fuels. Such materials are highly radioactive even after prolonged 'cooling' and are chemically complex. Neptunium (Np) is a highly toxic by-product of nuclear power generation and is found, in low abundance, in spent nuclear fuels. This atlas of the optical emission spectrum of Np, as produced by an inductively coupled plasma (ICP) spectroscopic source, is part of a general survey of the ICP emission spectra of the actinide elements. The ICP emission spectrum of the actinides originates almost exclusively from the electronic relaxation of excited, singly ionized species. Spectral data on the Np ion emission spectrum (i.e., the Np II spectrum) have been reported by Tomkins and Fred [1] and Haaland [2]. Tomkins and Fred excited the Np II spectrum with a Cu spark discharge and identified 114 Np lines in the 265.5 - 436.3 nm spectral range. Haaland, who corrected some spectral line misidentifications in the work of Tomkins and Fred, utilized an enclosed Au spark discharge to excite the Np II spectrum and reported 203 Np lines within the 265.4 - 461.0 nm wavelength range.

  2. Analysis of non-equilibrium phenomena in inductively coupled plasma generators

    Science.gov (United States)

    Zhang, W.; Lani, A.; Panesi, M.

    2016-07-01

    This work addresses the modeling of non-equilibrium phenomena in inductively coupled plasma discharges. In the proposed computational model, the electromagnetic induction equation is solved together with the set of Navier-Stokes equations in order to compute the electromagnetic and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles, with the method of Chapman and Enskog. Particle ambipolar diffusive fluxes are found by solving the Stefan-Maxwell equations with a simple iterative method. Two physico-mathematical formulations are used to model the chemical reaction processes: (1) A Local Thermodynamics Equilibrium (LTE) formulation and (2) a thermo-chemical non-equilibrium (TCNEQ) formulation. In the TCNEQ model, thermal non-equilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules is accounted for. The electronic states of the chemical species are assumed in equilibrium with the vibrational temperature, whereas the rotational energy mode is assumed to be equilibrated with translation. Three different physical models are used to account for the coupling of chemistry and energy transfer processes. Numerical simulations obtained with the LTE and TCNEQ formulations are used to characterize the extent of non-equilibrium of the flow inside the Plasmatron facility at the von Karman Institute. Each model was tested using different kinetic mechanisms to assess the sensitivity of the results to variations in the reaction parameters. A comparison of temperatures and composition profiles at the outlet of the torch demonstrates that the flow is in non-equilibrium for operating conditions characterized by pressures below 30 000 Pa, frequency 0.37 MHz, input power 80 kW, and mass flow 8 g/s.

  3. Multiplex bio-assay with inductively coupled plasma mass spectrometry: Towards a massively multivariate single-cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Tanner, Scott D. [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Room 407, 164 College Street, Toronto, Ontario, M5S 3G9 (Canada)], E-mail: sd.tanner@utoronto.ca; Ornatsky, Olga; Bandura, Dmitry R.; Baranov, Vladimir I. [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Room 407, 164 College Street, Toronto, Ontario, M5S 3G9 (Canada)

    2007-03-15

    Recent progress in the development of massively multiplexed bioanalytical assays using element tags with inductively coupled plasma mass spectrometry detection is reviewed. Feasibility results using commercially available secondary immunolabeling reagents for leukemic cell lines are presented. Multiplex analysis of higher order is shown with first generation tag reagents based on functionalized carriers that bind lanthanide ions. DNA quantification using metallointercalation allows for cell enumeration or mitotic state differentiation. In situ hybridization permits the determination of cellular RNA. The results provide a feasibility basis for the development of a multivariate assay tool for individual cell analysis based on inductively coupled plasma mass spectrometry in a cytometer configuration.

  4. Coupling shell-isolated nanoparticle enhanced Raman spectroscopy with paper chromatography for multi-components on-site analysis.

    Science.gov (United States)

    Zhang, Kun; Qing, Jiang; Gao, Han; Ji, Ji; Liu, Baohong

    2017-01-01

    By coupling shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) with paper chromatography, two birds with one stone method were developed for simultaneous on-site separation and optical detection of multiple components. The established method features high sensitivity of plasmon-enhanced sensing strategies and sufficient temporal and spatial resolution of planar chromatographic techniques.

  5. Multivariate analysis of progressive thermal desorption coupled gas chromatography-mass spectrometry.

    Energy Technology Data Exchange (ETDEWEB)

    Van Benthem, Mark Hilary; Mowry, Curtis Dale; Kotula, Paul Gabriel; Borek, Theodore Thaddeus, III

    2010-09-01

    Thermal decomposition of poly dimethyl siloxane compounds, Sylgard{reg_sign} 184 and 186, were examined using thermal desorption coupled gas chromatography-mass spectrometry (TD/GC-MS) and multivariate analysis. This work describes a method of producing multiway data using a stepped thermal desorption. The technique involves sequentially heating a sample of the material of interest with subsequent analysis in a commercial GC/MS system. The decomposition chromatograms were analyzed using multivariate analysis tools including principal component analysis (PCA), factor rotation employing the varimax criterion, and multivariate curve resolution. The results of the analysis show seven components related to offgassing of various fractions of siloxanes that vary as a function of temperature. Thermal desorption coupled with gas chromatography-mass spectrometry (TD/GC-MS) is a powerful analytical technique for analyzing chemical mixtures. It has great potential in numerous analytic areas including materials analysis, sports medicine, in the detection of designer drugs; and biological research for metabolomics. Data analysis is complicated, far from automated and can result in high false positive or false negative rates. We have demonstrated a step-wise TD/GC-MS technique that removes more volatile compounds from a sample before extracting the less volatile compounds. This creates an additional dimension of separation before the GC column, while simultaneously generating three-way data. Sandia's proven multivariate analysis methods, when applied to these data, have several advantages over current commercial options. It also has demonstrated potential for success in finding and enabling identification of trace compounds. Several challenges remain, however, including understanding the sources of noise in the data, outlier detection, improving the data pretreatment and analysis methods, developing a software tool for ease of use by the chemist, and demonstrating our belief

  6. Species-selective analysis by microcolumn multicapillary gas chromatography with inductively coupled plasma mass spectrometric detection.

    Science.gov (United States)

    Rodriguez, I; Mounicou, S; Lobiński, R; Sidelnikov, V; Patrushev, Y; Yamanaka, M

    1999-10-15

    A glass rod (5-20 cm long, 2 mm o.d.) containing more than 1200 parallel microchannels ( 100 theoretical plates cm-1) GC column by coating the inside of each channel in a way that compensated for the dispersion of the channel inner diameter. The columns were evaluated for the separation of mixtures of several organometallic (Hg, Sn, Pb) compounds prior to on-line sensitive metalselective detection by ICPMS. Chromatographic separation conditions were optimized to enable a rapid (within a maximum 30 s) multielemental speciation analysis. Absolute detection limits were 0.1 pg for Hg, 0.05 pg for Sn, and 0.03 pg for Pb using the carrier gas flows of approximately 200 mL min-1. The microcolumn multicapillary GC/ICPMS developed was applied to the analysis of a number of environmental samples. The results were validated with certified reference materials for tin (BCR477, PACS-2) and mercury (DORM-1, TORT-1).

  7. Inductively coupled plasma-MS in drug development: bioanalytical aspects and applications.

    Science.gov (United States)

    van Heuveln, Fred; Meijering, Henri; Wieling, Jaap

    2012-08-01

    The vast majority of today's modern bioanalytical methods for pharmacokinetic, pharmacodynamic and immunogenicity purposes are based on LC-MS/MS and immunoanalytical approaches. Indeed, these methodologies are suitable for a wide range of molecules from small to large. For a smaller but not insignificant group of compounds, LC-MS/MS is not suitable - or in some cases much less suitable - as a reliable bioanalytical methodology, and inductively coupled plasma (ICP)-MS is a more appropriate methodology. ICP-MS is one of these less widely used techniques in drug development. This methodology is predominantly used for elemental bioanalysis for pharmacokinetics, for imaging purposes, for mass-balance, food-effect and biomarker studies. In addition, in the last couple of years an increasing number of applications has been published, where ICP-MS and its various hyphenations (LC-ICP-MS, CE-ICP-MS) have been used for speciation/metabolism and proteomics studies. Here, the analytical potential, the quantitative bioanalytical aspects, the various modes of operation and the challenges of the application of ICP-MS in life sciences applications are given. This includes an overview of recent applications in this area in scientific literature, the various hyphenation possibilities and their application areas and the analysis of the various sample matrices applicable to these fields. It also provides a brief outlook of where the potential of this technique lies in the future of regulated bioanalysis and drug development.

  8. Measurement of Heavy Metals in Biological and Environmental Matrices Using Microwave Assisted Extraction,Inductively Coupled Plasma Mass Spectrometry and Ion Chromatography for Assessing Potential Risk to Human Health%利用微波辅助萃取、电感耦合等离子体质谱和离子色谱联用方法测定生物和环境样品中的重金属以评价其对人体健康的潜在危害

    Institute of Scientific and Technical Information of China (English)

    Brian Buckley; Willie Johnson; Eric Fischer; 涂强; Mark Heintz

    2003-01-01

    [Objective]To measure metals in both environmental and biological matrices which allows for more accurate assessment of risk to human health as well as monitoring of the pathway from matrix to human incorporation. [ Methods] Microwave assisted extraction for sample preparation, ion chromatography for analyte separation, and inductively coupled plasma/mass spectrometry (ICP/MS) for detection.[ Results ] The microwave assisted extraction demonstrated its utility in removing both inorganic and organic metal species from their matrix without species interconversion. The on - line coupling of IC and ICP/ MS,in conjunction with stable isotope labels, was successfully applied to the determination of metal species (specifically lead, chromium and mercury)in various environmental and biological samples. [Conclusion]The development of methods for more sensitive measurement as well as the determination of the chemical species of the metal analyte can provide critical information in assessing its potential risk to human health.%[目的]测定生物和环境样品中的重金属及其化学形态,从而更准确地评价其对人体健康的潜在危害,并且监测重金属从环境基质到人体的迁移途径.[方法]利用微波辅助萃取进行样品预处理,离子色谱分离重金属不同化学形态,电感耦合等离子体质谱进行检测.[结果]微波辅助萃取能够将重金属的不同无机和有机形态从样品基质中有效分离,分离过程中金属形态不发生变化.将离子色谱和电感耦合等离子体质谱在线联用,辅以稳定性同位素标记,可以准确测定生物和环境样品中的金属(铅、铬和汞)形态.[结论]提高生物和环境样品中重金属检测的灵敏度,并且测定金属的化学形态,可以对评价重金属对人体健康的潜在危害提供重要信息.

  9. A two-dimensional global simulation study of inductive-dynamic magnetosphere-ionosphere coupling

    Science.gov (United States)

    Tu, Jiannan; Song, Paul

    2016-12-01

    We present the numerical methods and results of a global two-dimensional multifluid-collisional-Hall magnetohydrodynamic (MHD) simulation model of the ionosphere-thermosphere system, an extension of our one-dimensional three-fluid MHD model. The model solves, self-consistently, Maxwell's equations, continuity, momentum, and energy equations for multiple ion and neutral species incorporating photochemistry, collisions among the electron, ion and neutral species, and various heating sources in the energy equations. The inductive-dynamic approach (solving self-consistently Faraday's law and retaining inertia terms in the plasma momentum equations) used in the model retains all possible MHD waves, thus providing faithful physical explanation (not merely description) of the magnetosphere-ionosphere/thermosphere (M-IT) coupling. In the present study, we simulate the dawn-dusk cross-polar cap dynamic responses of the ionosphere to imposed magnetospheric convection. It is shown that the convection velocity at the top boundary launches velocity, magnetic, and electric perturbations propagating with the Alfvén speed toward the bottom of the ionosphere. Within the system, the waves experience reflection, penetration, and rereflection because of the inhomogeneity of the plasma conditions. The reflection of the Alfvén waves may cause overshoot (stronger than the imposed magnetospheric convection) of the plasma velocity in some regions. The simulation demonstrates dynamic propagation of the field-aligned currents and ionospheric electric field carried by the Alfvén waves, as well as formation of closure horizontal currents (Pedersen currents in the E region), indicating that in the dynamic stage the M-I coupling is via the Alfvén waves instead of field-aligned currents or electric field mapping as described in convectional M-I coupling models.

  10. Determination of selenoprotein P in human plasma by solid phase extraction and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L.; Sidenius, U.; Gammelgaard, Bente

    2000-01-01

    measured by inductively coupled plasma mass spectrometry (ICP-MS) monitoring the Se-82 isotope. Linear response was observed in the concentration range 0.3-70.8 mu g/l selenium as selenoprotein P with a correlation coefficient of 0.9994. The precision expressed as relative standard deviation was better...

  11. Coupling mechanisms in inductive discharges with RF substrate bias driven at consecutive harmonics with adjustable relative phase

    Science.gov (United States)

    Steinberger, Thomas; Berger, Birk; Schulze, Julian; Schuengel, Edmund; Koepke, Mark

    2016-09-01

    Hybrid combinations of inductive and capacitive RF discharges are commonly used for plasma etching because the inductive coupling ensures a high plasma density, while the capacitive coupling allows the control of the ion bombardment energy at the substrate. We experimentally study the coupling mechanisms between the two driving-voltage sources in such a plasma driven inductively at 13.56 MHz and capacitively at 27.12 MHz in argon and neon at low pressure. We find that the resulting DC self-bias can be controlled via the Electrical Asymmetry Effect by adjusting the relative phase between the two driving harmonics in the E-mode. Langmuir probe measurements and Phase Resolved Optical Emission Spectroscopy (PROES) reveal that the addition of the applied RF-bias in the plasma acts as a catalyst for the transition between E- and H-mode. PROES measurements generally show that the electron power absorption dynamics are affected by the relative phase between the two driving voltage waveforms and by the ratio of the inductive to the capacitive driving powers. Finally, the ion flux-energy distribution function is measured at the RF-powered electrode and found also to be affected by coupling effects.

  12. AC electrokinetic drug delivery in dentistry using an interdigitated electrode assembly powered by inductive coupling.

    Science.gov (United States)

    Ivanoff, Chris S; Wu, Jie Jayne; Mirzajani, Hadi; Cheng, Cheng; Yuan, Quan; Kevorkyan, Stepan; Gaydarova, Radostina; Tomlekova, Desislava

    2016-10-01

    AC electrokinetics (ACEK) has been shown to deliver certain drugs into human teeth more effectively than diffusion. However, using electrical wires to power intraoral ACEK devices poses risks to patients. The study demonstrates a novel interdigitated electrode arrays (IDE) assembly powered by inductive coupling to induce ACEK effects at appropriate frequencies to motivate drugs wirelessly. A signal generator produces the modulating signal, which multiplies with the carrier signal to produce the amplitude modulated (AM) signal. The AM signal goes through the inductive link to appear on the secondary coil, then rectified and filtered to dispose of its carrier signal, and the positive half of the modulating signal appears on the load. After characterizing the device, the device is validated under light microscopy by motivating carboxylate-modified microspheres, tetracycline, acetaminophen, benzocaine, lidocaine and carbamide peroxide particles with induced ACEK effects. The assembly is finally tested in a common dental bleaching application. After applying 35 % carbamide peroxide to human teeth topically or with the IDE at 1200 Hz, 5 Vpp for 20 min, spectrophotometric analysis showed that compared to diffusion, the IDE enhanced whitening in specular optic and specular optic excluded modes by 215 % and 194 % respectively. Carbamide peroxide absorbance by the ACEK group was two times greater than diffusion as measured by colorimetric oxidation-reduction and UV-Vis spectroscopy at 550 nm. The device motivates drugs of variable molecular weight and structure wirelessly. Wireless transport of drugs to intraoral targets under ACEK effects may potentially improve the efficacy and safety of drug delivery in dentistry.

  13. On-line coupled high performance liquid chromatography-gas chromatography for the analysis of contamination by mineral oil. Part 1: method of analysis.

    Science.gov (United States)

    Biedermann, Maurus; Grob, Koni

    2012-09-14

    For the analysis of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH), on-line coupled high performance liquid chromatography-gas chromatography-flame ionization detection (HPLC-GC-FID) offers important advantages: it separates MOSH and MOAH in robust manner, enables direct injection of large aliquots of raw extracts (resulting in a low detection limit), avoids contamination of the sample during preparation and is fully automated. This review starts with an overview of the technology, particularly the fundamentals of introducing large volumes of solvent into GC, and their implementation into various transfer techniques. The main part deals with the concepts of MOSH and MOAH analysis, with a thorough discussion of the choices made. It is followed by a description of the method. Finally auxiliary tools are summarized to remove interfering components, enrich the sample in case of a high fat content and obtain additional information about the MOSH and MOAH composition.

  14. Sequential extraction of inorganic arsenic compounds and methyl arsenate in human urine using mixed-mode monolithic silica spin column coupled with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Namera, Akira; Takeuchi, Akito; Saito, Takeshi; Miyazaki, Shota; Oikawa, Hiroshi; Saruwatari, Tatsuro; Nagao, Masataka

    2012-09-01

    A sequential analytical method was developed for the detection of arsenite, arsenate, and methylarsenate in human urine by gas chromatography-mass spectrometry (GC-MS). The combination of a derivatization of trivalent arsenic compounds by 2,3-dithio-1-propanol (British antilewisite; BAL) and a reduction of pentavalent arsenic compounds (arsenate and methylarsenate) were accomplished to carry out the analysis of arsenic compounds in urine. The arsenic derivatives obtained using BAL were extracted in a stepwise manner using a monolithic spin column and analyzed by GC-MS. A linear curve was observed for concentrations of arsenic compounds of 2.0 to 200 ng/mL, where the correlation coefficients of calibration curves were greater than 0.996 (for a signal-to-noise (S/N) ratio >10). The detection limits were 1 ng/mL (S/N > 3). Recoveries of the targets in urine were in the range 91.9-106.5%, and RSDs of the intra- and interday assay for urine samples containing 5, 50, and 150 ng/mL of arsenic compounds varied between 2.95 and 13.4%. The results from real samples obtained from a patient suspected of having ingested As containing medications using this proposed method were in good agreement with those obtained using high-performance liquid chromatography with inductively coupled plasma mass spectrometry.

  15. Computational hydrodynamics and optical performance of inductively-coupled plasma adaptive lenses

    Energy Technology Data Exchange (ETDEWEB)

    Mortazavi, M.; Urzay, J., E-mail: jurzay@stanford.edu; Mani, A. [Center for Turbulence Research, Stanford University, Stanford, California 94305-3024 (United States)

    2015-06-15

    This study addresses the optical performance of a plasma adaptive lens for aero-optical applications by using both axisymmetric and three-dimensional numerical simulations. Plasma adaptive lenses are based on the effects of free electrons on the phase velocity of incident light, which, in theory, can be used as a phase-conjugation mechanism. A closed cylindrical chamber filled with Argon plasma is used as a model lens into which a beam of light is launched. The plasma is sustained by applying a radio-frequency electric current through a coil that envelops the chamber. Four different operating conditions, ranging from low to high powers and induction frequencies, are employed in the simulations. The numerical simulations reveal complex hydrodynamic phenomena related to buoyant and electromagnetic laminar transport, which generate, respectively, large recirculating cells and wall-normal compression stresses in the form of local stagnation-point flows. In the axisymmetric simulations, the plasma motion is coupled with near-wall axial striations in the electron-density field, some of which propagate in the form of low-frequency traveling disturbances adjacent to vortical quadrupoles that are reminiscent of Taylor-Görtler flow structures in centrifugally unstable flows. Although the refractive-index fields obtained from axisymmetric simulations lead to smooth beam wavefronts, they are found to be unstable to azimuthal disturbances in three of the four three-dimensional cases considered. The azimuthal striations are optically detrimental, since they produce high-order angular aberrations that account for most of the beam wavefront error. A fourth case is computed at high input power and high induction frequency, which displays the best optical properties among all the three-dimensional simulations considered. In particular, the increase in induction frequency prevents local thermalization and leads to an axisymmetric distribution of electrons even after introduction of

  16. Detection of metabolites of trapped humans using ion mobility spectrometry coupled with gas chromatography.

    Science.gov (United States)

    Vautz, Wolfgang; Slodzynski, Rafael; Hariharan, Chandrasekhara; Seifert, Luzia; Nolte, Jürgen; Fobbe, Rita; Sielemann, Stefanie; Lao, Bolan C; Huo, Ran; Thomas, C L Paul; Hildebrand, Lars

    2013-02-19

    For the first time, ion mobility spectrometry coupled with rapid gas chromatography, using multicapillary columns, was applied for the development of a pattern of signs of life for the localization of entrapped victims after disaster events (e.g., earthquake, terroristic attack). During a simulation experiment with entrapped volunteers, 12 human metabolites could be detected in the air of the void with sufficient sensitivity to enable a valid decision on the presence of a living person. Using a basic normalized summation of the measured concentrations, all volunteers involved in the particular experiments could be recognized only few minutes after they entered the simulation void and after less than 3 min of analysis time. An additional independent validation experiment enabled the recognition of a person in a room of ∼25 m(3) after ∼30 min with sufficiently high sensitivity to detect even a person briefly leaving the room. Undoubtedly, additional work must be done on analysis time and weight of the equipment, as well as on validation during real disaster events. However, the enormous potential of the method as a significantly helpful tool for search-and-rescue operations, in addition to trained canines, could be demonstrated.

  17. Characterisation of brewpub beer carbohydrates using high performance anion exchange chromatography coupled with pulsed amperometric detection.

    Science.gov (United States)

    Arfelli, Giuseppe; Sartini, Elisa

    2014-01-01

    High performance anion exchange chromatography (HPAEC) coupled with pulsed amperometric detection (PAD) was optimised in order to quantify mannose, maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose and maltoheptaose content of beer. The method allows the determination of above mentioned oligosaccharides, in a single chromatographic run, without any pre-treatment. Limit of detection and limit of quantification were suitable for beer. Accuracy and repeatability were good for the entire amount considered. Once optimised HPAEC PAD for the specific matrix, the second goal of this research was to verify the possibility to discriminate beers, depending on their style. The carbohydrates content of brewpub commercial beers was very variable, ranging from 19.3 to 1469mg/L (mannose), 34.5 to 2882mg/L (maltose), 141.9 to 20731mg/L (maltotriose), 168.5 to 7650mg/L (maltotetraose), 20.1 to 2537mg/L (maltopentaose), 22.9 to 3295mg/L (maltohexaose), 8.5 to 2492mg/L (maltoeptaose), even in the same style of beer. However, the carbohydrates content was useful, jointed with other compounds amount, to discriminate different styles of beer. As a matter of fact, principal component analysis put in evidence beer differences considering some fermentation conditions and colour.

  18. Liquid chromatography coupled to tandem mass spectrometry for the analysis of acrylamide in typical Spanish products.

    Science.gov (United States)

    Bermudo, E; Moyano, E; Puignou, L; Galceran, M T

    2008-07-15

    This paper describes the use of liquid chromatography coupled to tandem mass spectrometry for the determination of acrylamide in several typical foods produced and consumed in Spain. Christmas sweets, olives, traditionally made potato crisps, pastry products, sweet fritters ("churros") and one of Spain's most famous dishes, Spanish omelette, were selected. Using the mass spectra information provided by an ion trap analyzer in combination with the accurate mass measurements from time-of-flight (TOF) spectrometry a co-extractive interference present in some potato products was identified as valine. A porous graphitic carbon column, which enabled the co-extractive and acrylamide to be separated, and ion trap or triple quadrupole analyzers, depending on the acrylamide concentration, were used to determine this genotoxic compound in foodstuffs. The highest values were found in potato products, sweet fritters, Christmas sweets and pastry products, with values ranging between 70 and 2000 microg/g. Spanish omelette presented relatively low levels, similar to those obtained for dried fruits.

  19. Determination of sulfonamides in beeswax by liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Mitrowska, Kamila; Antczak, Maja

    2015-12-01

    The manuscript presents the development of a new method for the quantification of 16 sulfonamides in beeswax. Different sample preparation techniques were tested and modified to maximise the recovery of the target analytes and minimise the amount of coeluted impurities under conditions that provide reproducible results. The proposed method consisted of melting and dilution of beeswax in a mixture of n-hexane and isopropanol followed by extraction with 2% acetic acid. The extract was cleaned up by solid-phase extraction using strong cation exchange phase. Determination of the sulfonamides was achieved by liquid chromatography coupled to tandem mass spectrometry with the use of a pentafluorophenyl analytical column and applying a gradient elution with acetonitrile and 0.01% acetic acid as mobile phases. The limits of detection and limits of quantification ranged from 1 to 2μg/kg and from 2 to 5μg/kg, respectively. The recoveries varied between 65.2% and 117.8% while coefficient of variation of the method was less than 24.2% under intermediate precision conditions. Finally, the method was applied to the analysis of real samples of beeswax from beekeepers and commercial foundations manufacturers.

  20. Quantitative determination of trisiloxane surfactants in beehive environments based on liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Chen, Jing; Mullin, Christopher A

    2013-08-20

    Organosilicone surfactants are increasingly being applied to agricultural agro-ecosystems as spray adjuvants, and were recently shown to impact the learning ability of honey bees. Here we developed a method for analyzing three trisiloxane surfactants (single polyethoxylate (EO) chain and end-capped with methyl, acetyl, or hydroxyl groups; TSS-CH3, TSS-COCH3, or TSS-H) in beehive matrices based on liquid chromatography coupled to mass spectrometry (LC-MS) and the QuEChERS (quick, easy, cheap, effective, rugged, and safe) approach from less than 2 g of honey, pollen, or beeswax. Recoveries for each oligomer (2-13 EO) were between 66 and 112% in all matrices. Average method detection limits (MDL) were 0.53, 0.60, 0.56 ng/g in honey, 0.63, 0.81, 0.78 ng/g in pollen, and 0.51, 0.69, 0.63 ng/g in beeswax. Five honey, 10 pollen, and 10 beeswax samples were analyzed. Trisiloxane surfactants were detected in every beeswax and 60% of the pollen samples. Total trisiloxane surfactant concentrations were up to 390 and 39 ng/g in wax and pollen. The described method is proved suitable for analyzing trisiloxane surfactants in beehive samples. The presence of trisiloxane surfactants in North American beehives calls for renewed effort to investigate the consequence of these adjuvants to bee health and the ongoing global bee decline.

  1. A new interface for coupling solid phase microextraction with liquid chromatography.

    Science.gov (United States)

    Chen, Yong; Sidisky, Leonard M

    2014-03-19

    A modified Rheodyne 7520 microsample injector was used as a new solid phase microextraction (SPME)-liquid chromatography (LC) interface. The modification was focused on the construction of a new sample rotor, which was built by gluing two sample rotors together. The new sample rotor was further reinforced with 3 pieces of stainless steel tubing. The enlarged central flow passage in the new sample rotor was used as a desorption chamber. SPME fiber desorption occurred in static mode. But all desorption solvent in the desorption chamber was injected into LC system with the interface. The analytical performance of the interface was evaluated by SPME-LC analysis of PAHs in water. At least 90% polycyclic aromatic hydrocarbons (PAHs) were desorbed from a polyacrylonitrile (PAN)/C18 bonded fuse silica fiber in 30s. And injection was completed in 20s. About 10-20% total carryovers were found on the fiber and in the interface. The carryover in the interface was eliminated by flushing the desorption chamber with acetonitrile at 1mL min(-1) for 2min. The repeatability of the method was from 2% to 8%. The limit of detection (LOD) was in the mid pg mL(-1) range. The linear ranges were from 0.1 to 100ng mL(-1). The new SPME-LC interface was reliable for coupling SPME with LC for both qualitative and quantitative analysis.

  2. Determination of Phytochelatins in Rice by Stable Isotope Labeling Coupled with Liquid Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Liu, Ping; Cai, Wen-Jing; Yu, Lei; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-07-01

    A highly sensitive method was developed for the detection of phytochelatins (PCs) in rice by stable isotope labeling coupled with liquid chromatography-electrospray ionization-tandem mass spectrometry (IL-LC-ESI-MS/MS) analysis. A pair of isotope-labeling reagents [ω-bromoacetonylquinolinium bromide (BQB) and BQB-d(7)] were used to label PCs in plant sample and standard PCs, respectively, and then combined prior to LC/MS analysis. The heavy labeled standards were used as the internal standards for quantitation to minimize the matrix and ion suppression effects in MS analysis. In addition, the ionization efficiency of PCs was greatly enhanced through the introduction of a permanent charged moiety of quaternary ammonium of BQB into PCs. The detection sensitivities of PCs upon BQB labeling improved by 14-750-fold, and therefore, PCs can be quantitated using only 5 mg of plant tissue. Furthermore, under cadmium (Cd) stress, we found that the contents of PCs in rice dramatically increased with the increased concentrations and treatment time of Cd. It was worth noting that PC5 was first identified and quantitated in rice tissues under Cd stress in the current study. Taken together, this IL-LC-ESI-MS/MS method demonstrated to be a promising strategy in detection of PCs in plants with high sensitivity and reliability.

  3. Speciation of heavy metals in environmental water by ion chromatography coupled to ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Ammann, A.A. [Swiss Federal Institute for Environmental Science and Technology (EAWAG), Duebendorf (Switzerland)

    2002-02-01

    Biogenic (e.g. phytochelatins, porphyrins, DOM) as well as anthropogenic (e.g. NTA, EDTA, phosphonates) chelators affect the mobility and cycling of heavy metals in environmental waters. Since such chelators can form strongly bound anionic heavy metal complexes that are stable and highly mobile, anion-exchange chromatography coupled to ICP-MS was investigated. A narrow bore HPLC system was connected to a micro concentric nebuliser for in-line sample introduction. A new chromatographic procedure based on a synthetic hydrophilic quaternary ammonium anion exchanger in combination with nitrate as a strong eluent anion, and gradient elution, provided high separation selectivity and a large analytical window. Low detection limits (nmol L{sup -1}) were achieved by on-column matrix removal and sample preconcentration. This allowed the method to be successfully applied to different environmental research areas. In ecotoxicological studies of heavy metal effects on algae low concentrations of metal EDTA complexes were determined in nutrient solutions without interference from high (buffer) salt concentrations. In groundwater, infiltrated by a polluted river, mobile metal EDTA species were observed. In river water of different pollution levels beside CuEDTA other anionic Cu-complexes were found in nmol L{sup -1} concentrations. (orig.)

  4. Headspace in-tube microextraction coupled with micellar electrokinetic chromatography of neutral aromatic compounds.

    Science.gov (United States)

    Cho, Sung Min; Park, Bum Su; Jung, Woo Sung; Lee, Sang Won; Jung, Yunhwan; Chung, Doo Soo

    2016-02-01

    Headspace (HS) extraction can be carried out easily and aptly via single drop microextraction coupled with capillary electrophoresis (CE). However, one drawback is the difficulty of keeping the single drop stably at the capillary tip. To solve this problem, we have recently demonstrated HS in-tube microextraction (ITME) of acidic compounds such as chlrophenols in an acidic sample using a basic run buffer plug in the separation capillary for CE as an acceptor phase. In this report, an organic acceptor plug in a capillary was used to extract neutral organic volatile pollutants such as BTEX (benzene, toluene, ethylbenzene, and m-xylene). After extraction, the analytes enriched in the organic acceptor plug were analyzed with micellar electrokinetic chromatography (MEKC). The enrichment factors for BTEX in a standard solution were up to 350 under an optimal condition of 25°C for 20 min. As an application, BTEX spiked into bottled water were analyzed with HS-ITME-MEKC, and the enrichment factors for BTEX were up to 320. The limits of detections were 1-4 ppb, which are at least 200 times lower than the US Environmental Protection Agency guidelines for drinking water, except benzene. The entire procedure of HS-ITME-MEKC was carried out automatically using a commercial CE instrument.

  5. Determination of xanthohumol in beer based on cloud point extraction coupled with high performance liquid chromatography.

    Science.gov (United States)

    Chen, Ligang; Zhao, Qi; Jin, Haiyan; Zhang, Xiaopan; Xu, Yang; Yu, Aimin; Zhang, Hanqi; Ding, Lan

    2010-04-15

    A method based on coupling of cloud point extraction (CPE) with high performance liquid chromatography separation and ultraviolet detection was developed for determination of xanthohumol in beer. The nonionic surfactant Triton X-114 was chosen as the extraction medium. The parameters affecting the CPE were evaluated and optimized. The highest extraction yield of xanthohumol was obtained with 2.5% of Triton X-114 (v/v) at pH 5.0, 15% of sodium chloride (w/v), 70 degrees C of equilibrium temperature and 10 min of equilibrium time. Under these conditions, the limit of detection of xanthohumol is 0.003 mg L(-1). The intra- and inter-day precisions expressed as relative standard deviations are 4.6% and 6.3%, respectively. The proposed method was successfully applied for determination of xanthohumol in various beer samples. The contents of xanthohumol in these samples are in the range of 0.052-0.628 mg L(-1), and the recoveries ranging from 90.7% to 101.9% were obtained. The developed method was demonstrated to be efficient, green, rapid and inexpensive for extraction and determination of xanthohumol in beer.

  6. Characterization of the limonene oxidation products with liquid chromatography coupled to the tandem mass spectrometry

    Science.gov (United States)

    Witkowski, Bartłomiej; Gierczak, Tomasz

    2017-04-01

    Composition of the secondary organic aerosol (SOA) generated during ozonolysis of limonene was investigated with liquid chromatography coupled to the negative electrospray ionization (ESI), quadrupole tandem mass spectrometry (MS/MS) as well as high resolution Time-of-Flight mass spectrometry. Aerosol was generated in the flow-tube reactor. HR-MS/MS analysis allowed for proposing structures for the several up-to-date unknown limonene oxidation products. In addition to the low MW limonene oxidation products, significant quantities of oligomers characterized by elemental compositions: C19H30O5, C18H28O6, C19H28O7, C19H30O7 and C20H34O9 were detected in the SOA samples. It was concluded that these compounds are most likely esters, aldol reaction products and/or hemiacetals. In addition to detailed study of the limonene oxidation products, the reaction time as well as initial ozone concentration impact on the limonene SOA composition was investigated. The relative intensities of the two esters of the limonic acid and 7-hydroxy limononic acid increased as a result of lowering the initial ozone concentration and shortening the reaction time, indicating that esterification may be an important oligomerization pathway during limonene SOA formation.

  7. Hybrid simulations of solenoidal radio-frequency inductively coupled hydrogen discharges at low pressures

    Science.gov (United States)

    Yang, Wei; Li, Hong; Gao, Fei; Wang, You-Nian

    2016-12-01

    In this article, we have described a radio-frequency (RF) inductively coupled H2 plasma using a hybrid computational model, incorporating the Maxwell equations and the linear part of the electron Boltzmann equation into global model equations. This report focuses on the effects of RF frequency, gas pressure, and coil current on the spatial profiles of the induced electric field and plasma absorption power density. The plasma parameters, i.e., plasma density, electron temperature, density of negative ion, electronegativity, densities of neutral species, and dissociation degree of H2, as a function of absorption power, are evaluated at different gas pressures. The simulation results show that the utilization efficiency of the RF source characterized by the coupling efficiency of the RF electric field and power to the plasma can be significantly improved at the low RF frequency, gas pressure, and coil current, due to a low plasma density in these cases. The densities of vibrational states of H2 first rapidly increase with increasing absorption power and then tend to saturate. This is because the rapidly increased dissociation degree of H2 with increasing absorption power somewhat suppresses the increase of the vibrational states of H2, thus inhibiting the increase of the H-. The effects of absorption power on the utilization efficiency of the RF source and the production of the vibrational states of H2 should be considered when setting a value of the coil current. To validate the model simulations, the calculated electron density and temperature are compared with experimental measurements, and a reasonable agreement is achieved.

  8. Control of electron energy distribution by the power balance of the combined inductively and capacitively coupled RF plasmas

    Science.gov (United States)

    Kim, Jin Seok; Lee, Ho-Jun; Lee, Hae June

    2016-09-01

    The control of electron energy probability function (EEPF) is important to control discharge characteristics in materials processing. For example, O radical density increases by changing the EEPF in O2 plasma, which provides high etching efficiency. The effect of the power balance between the capacitively coupled plasma (CCP) and the inductively coupled plasma (ICP) on the EEPF in Ar and O2 plasmas is investigated with a 1d3v (one-dimensional space and three-dimensional velocity domain) particle-in-cell (PIC) simulation for the combined inductively and capacitively coupled plasmas. The combined effects of the transverse electromagnetic and the longitudinal electrostatic fields are solved in PIC simulation at the same time. In a pressure range of a few mTorr, high energy electrons (>5 eV) are heated by the capacitive power in the sheath while low energy electrons (power in the bulk region. The EEPF has bi-Maxwellian distribution when the CCP power is dominant, but it changes to Maxwellian-like distribution with increasing inductive power. Finally, the EEPF changes to Druyvesteyn-like distribution when the inductive power is dominant.

  9. Accurate determination of silver nanoparticles in animal tissues by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Veverková, Lenka [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Hradilová, Šárka [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Milde, David, E-mail: david.mlde@upol.cz [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Panáček, Aleš [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Skopalová, Jana [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Kvítek, Libor [Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); Petrželová, Kamila [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacky University, 17.listopadu 12, CZ 771 46 Olomouc (Czech Republic); National Reference Laboratory for Chemical Elements, Department of Residues in Kroměříž, State Veterinary Institute Olomouc, Hulínská 2286, CZ 767 60 Kroměříž (Czech Republic); and others

    2014-12-01

    This study examined recoveries of silver determination in animal tissues after wet digestion by inductively coupled plasma mass spectrometry. The composition of the mineralization mixture for microwave assisted digestion was optimized and the best recoveries were obtained for mineralization with HNO{sub 3} and addition of HCl promptly after digestion. The optimization was performed on model samples of chicken meat spiked with silver nanoparticles and a solution of ionic silver. Basic calculations of theoretical distribution of Ag among various silver-containing species were implemented and the results showed that most of the silver is in the form of soluble complexes AgCl{sub 2}{sup −} and AgCl{sub 3}{sup 2−} for the optimized composition of the mineralization mixture. Three animal tissue certified reference materials were then analyzed to verify the trueness and precision of the results. - Highlights: • We performed detailed optimization of microwave assisted digestion procedure of animal tissue used prior to Ag determination by ICP-MS. • We provide basic equilibrium calculations to give theoretical explanation of results from optimization of tested mineralization mixtures. • Results from method validation that was done by analysis of several matrix CRMs are presented.

  10. Laser ablation inductively coupled plasma mass spectrometry imaging of metals in experimental and clinical Wilson's disease.

    Science.gov (United States)

    Boaru, Sorina Georgiana; Merle, Uta; Uerlings, Ricarda; Zimmermann, Astrid; Flechtenmacher, Christa; Willheim, Claudia; Eder, Elisabeth; Ferenci, Peter; Stremmel, Wolfgang; Weiskirchen, Ralf

    2015-04-01

    Wilson's disease is an autosomal recessive disorder in which the liver does not properly release copper into bile, resulting in prominent copper accumulation in various tissues. Affected patients suffer from hepatic disorders and severe neurological defects. Experimental studies in mutant mice in which the copper-transporting ATPase gene (Atp7b) is disrupted revealed a drastic, time-dependent accumulation of hepatic copper that is accompanied by formation of regenerative nodes resembling cirrhosis. Therefore, these mice represent an excellent exploratory model for Wilson's disease. However, the precise time course in hepatic copper accumulation and its impact on other trace metals within the liver is yet poorly understood. We have recently established novel laser ablation inductively coupled plasma mass spectrometry protocols allowing quantitative metal imaging in human and murine liver tissue with high sensitivity, spatial resolution, specificity and quantification ability. By use of these techniques, we here aimed to comparatively analyse hepatic metal content in wild-type and Atp7b deficient mice during ageing. We demonstrate that the age-dependent accumulation of hepatic copper is strictly associated with a simultaneous increase in iron and zinc, while the intrahepatic concentration and distribution of other metals or metalloids is not affected. The same findings were obtained in well-defined human liver samples that were obtained from patients suffering from Wilson's disease. We conclude that in Wilson's disease the imbalances of hepatic copper during ageing are closely correlated with alterations in intrahepatic iron and zinc content.

  11. Bioimaging of metals by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).

    Science.gov (United States)

    Becker, J Sabine; Zoriy, Miroslav; Matusch, Andreas; Wu, Bei; Salber, Dagmar; Palm, Christoph; Becker, J Susanne

    2010-01-01

    The distribution analysis of (essential, beneficial, or toxic) metals (e.g., Cu, Fe, Zn, Pb, and others), metalloids, and non-metals in biological tissues is of key interest in life science. Over the past few years, the development and application of several imaging mass spectrometric techniques has been rapidly growing in biology and medicine. Especially, in brain research metalloproteins are in the focus of targeted therapy approaches of neurodegenerative diseases such as Alzheimer's and Parkinson's disease, or stroke, or tumor growth. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) using double-focusing sector field (LA-ICP-SFMS) or quadrupole-based mass spectrometers (LA-ICP-QMS) has been successfully applied as a powerful imaging (mapping) technique to produce quantitative images of detailed regionally specific element distributions in thin tissue sections of human or rodent brain. Imaging LA-ICP-QMS was also applied to investigate metal distributions in plant and animal sections to study, for example, the uptake and transport of nutrient and toxic elements or environmental contamination. The combination of imaging LA-ICP-MS of metals with proteomic studies using biomolecular mass spectrometry identifies metal-containing proteins and also phosphoproteins. Metal-containing proteins were imaged in a two-dimensional gel after electrophoretic separation of proteins (SDS or Blue Native PAGE). Recent progress in LA-ICP-MS imaging as a stand-alone technique and in combination with MALDI/ESI-MS for selected life science applications is summarized.

  12. Measuring atomic oxygen densities and electron properties in an Inductively Coupled Plasma for thin film deposition

    Science.gov (United States)

    Meehan, David; Gibson, Andrew; Booth, Jean-Paul; Wagenaars, Erik

    2016-09-01

    Plasma Enhanced Pulsed Laser Deposition (PE-PLD) is an advanced way of depositing thin films of oxide materials by using a laser to ablate a target, and passing the resulting plasma plume through a background Inductively-Coupled Plasma (ICP), instead of a background gas as is done in traditional PLD. The main advantage of PE-PLD is the control of film stoichiometry via the direct control of the reactive oxygen species in the ICP instead of relying on a neutral gas background. The aim is to deposit zinc oxide films from a zinc metal target and an oxygen ICP. In this work, we characterise the range of compositions of the reactive oxygen species achievable in ICPs; in particular the atomic oxygen density. The density of atomic oxygen has been determined within two ICPs of two different geometries over a range of plasma powers and pressures with the use of Energy Resolved Actinometry (ERA). ERA is a robust diagnostic technique with determines both the dissociation degree and average electron energy by comparing the excitation ratios of two oxygen and one argon transition. Alongside this the electron densities have been determined with the use of a hairpin probe. This work received financial support from the EPSRC, and York-Paris CIRC.

  13. A control-oriented self-consistent model of an inductively-coupled plasma

    Science.gov (United States)

    Keville, Bernard; Turner, Miles

    2009-10-01

    An essential first step in the design of real time control algorithms for plasma processes is to determine dynamical relationships between actuator quantities such as gas flow rate set points and plasma states such electron density. An ideal first principles-based, control-oriented model should exhibit the simplicity and computational requirements of an empirical model and, in addition, despite sacrificing first principles detail, capture enough of the essential physics and chemistry of the process in order to provide reasonably accurate qualitative predictions. This presentation describes a control-oriented model of a cylindrical low pressure planar inductive discharge with a stove top antenna. The model consists of equivalent circuit coupled to a global model of the plasma chemistry to produce a self-consistent zero-dimensional model of the discharge. The non-local plasma conductivity and the fields in the plasma are determined from the wave equation and the two-term solution of the Boltzmann equation. Expressions for the antenna impedance and the parameters of the transformer equivalent circuit in terms of the isotropic electron distribution and the geometry of the chamber are presented.

  14. Horn-Coupled, Commercially-Fabricated Aluminum Lumped-Element Kinetic Inductance Detectors for Millimeter Wavelengths

    CERN Document Server

    McCarrick, H; Jones, G; Johnson, B R; Ade, P; Araujo, D; Bradford, K; Cantor, R; Che, G; Day, P; Doyle, S; Leduc, H; Limon, M; Luu, V; Mauskopf, P; Miller, A; Mroczkowski, T; Tucker, C; Zmuidzinas, J

    2014-01-01

    We discuss the design, fabrication, and testing of prototype horn-coupled, lumped-element kinetic inductance detectors (LEKIDs) designed for cosmic microwave background (CMB) studies. The LEKIDs are made from a thin aluminum film deposited on a silicon wafer and patterned using standard photolithographic techniques at STAR Cryoelectronics, a commercial device foundry. We fabricated twenty-element arrays, optimized for a spectral band centered on 150 GHz, to test the sensitivity and yield of the devices as well as the multiplexing scheme. We characterized the detectors in two configurations. First, the detectors were tested in a dark environment with the horn apertures covered, and second, the horn apertures were pointed towards a beam-filling cryogenic blackbody load. These tests show that the multiplexing scheme is robust and scalable, the yield across multiple LEKID arrays is 91%, and the noise-equivalent temperatures (NET) for a 4 K optical load are in the range 26$\\thinspace\\pm6 \\thinspace \\mu \\mbox{K} \\s...

  15. Langmuir Probe Measurements of Inductively Coupled Plasmas in CF4/Ar/O2 Mixtures

    Science.gov (United States)

    Rao, M. V. V. S.; Cruden, Brett; Sharma, Surendra; Meyyappan, Meyya

    2001-01-01

    Inductively coupled plasmas of CF4:Ar:O2, which have been of importance to material processing, were studied in the GEC cell at 80:10:10, 60:20:20, and 40:30:30 mixture ratios. Radial distributions of plasma potential (V(sub p)), electron and ion number densities (n(sub e) and n(sub i), electron temperature (T(sub e)), and electron energy distribution functions (EEDFs) were measured in the mid-plane of plasma across the electrodes in the pressure range of 10-50 mTorr, and RF (radio frequency) power of 200 and 300 W. V(sub p), n(sub e) and n(sub i), which peak in the center of the plasma, increase with decrease of pressure. T(sub e) also increases with pressure but peaks toward the electrode edge. Both V(sub p) and T(sub e) remain nearly independent of RF power, whereas n(sub e) and n(sub i) increase with power. In all conditions the EEDFs exhibit non-Maxwellian shape and are more like Druyvesteyn form at higher energies. They exhibit a broad dip in the energy range 0-10 eV suggesting an electron loss mechanism, which could be due to via resonance electron attachment processes producing negative ions in this rich electronegative gas mixture. This behavior is more prominent towards the electrode edge.

  16. Langmuir Probe Distortions and Probe Compensation in an Inductively Coupled Plasma

    Science.gov (United States)

    Ji, J. S.; Cappelli, M. A.; Kim, J. S.; Rao, M. V. V. S.; Sharma, S. P.

    1999-01-01

    In many RF discharges, Langmuir probe measurements are usually made against a background of sinusoidal (and not so sinusoidal) fluctuations in the plasma parameters such as the plasma potential (Vp), the electron number density (ne), and the electron temperature (Te). The compensation of sinusoidal fluctuations in Vp has been extensively studied and is relatively well understood. Less attention has been paid to the possible distortions introduced by small fluctuations in plasma density and/or plasma temperature, which may arise in the sheath and pre-sheath regions of RF discharges. Here, we present the results of a model simulation of probe characteristics subject to fluctuations in both Vp and ne. The modeling of probe distortion due to possible fluctuations in Te is less straightforward. A comparison is presented of calculations with experimental measurements using a compensated and uncompensated Langmuir probe in an inductively coupled GEC reference cell plasma, operating on Ar and Ar/CF4 mixtures. The plasma parameters determined from the compensated probe characteristics are compared to previous measurements of others made in similar discharges, and to our own measurements of the average electron density derived from electrical impedance measurements.

  17. Langmuir Probe Measurements in an Inductively Coupled Ar/CF4 Plasmas

    Science.gov (United States)

    Rao, M. V. V. S.; Meyyappan, M.; Sharma, S. P.; Arnold, James O. (Technical Monitor)

    2000-01-01

    Technological advancement in the microelectronics industry requires an understanding of the physical and chemical processes occurring in plasmas of fluorocarbon gases, such as carbon tetrafluoride (CF4) which is commonly used as an etchant, and their mixtures to optimize various operating parameters. In this paper we report data on electron number density (ne), electron temperature'(Te), electron energy distribution function (EEDF), mean electron energy, ion number density (ni), and plasma potential (Vp) measured by using Langmuir probe in an inductively coupled 13.56 MHz radio frequency plasmas generated in 50%Ar:50%CF4 mixture in the GEC cell. The probe data were recorded at various radial positions providing radial profiles of these plasma parameters at 10-50 mTorr pressures and 200 W and 300 W of RF power. Present measurements indicate that the electron and ion number densities increase with increase in pressure and power. Whereas the plasma potential and electron temperature decrease with increase in pressure, and they weakly depend on RF power. The radial profiles exhibit that the electron and ion number densities and the plasma potential peak at the center of the plasma with an exponential fall away from it, while the electron temperature has a minimum at the center and it increases steadily towards the electrode edge. The EEDFs have a characteristic drop near the low energy end at all pressures and pressures and their shapes represent non-Maxwellian plasma and exhibit more like Druyvesteyn energy distribution.v

  18. Trace Elements Analysis of Geological Samples by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper describes recent work applying a taser ablation system (LSX-200) hyphenated with POEMS Ⅲ inductively coupled plasma mass spectrometry (LA-ICP-MS) for the in situ analysis of 22 trace elements of solid geological materials. It demonstrates the potential of LA-ICP-MS for the determination of geochemically important trace and ultra-trace elements following XRF routine sample preparation. Signal drift, difference in transport efficiency and sampling yield are well corrected with NIST SRM 612 as external calibration standard and Ca as internal standard. The obtained results agree to the recommended values with relative error better than 15 % and RSD less than 15 % for most determined trace elemems. LOD ranges from 0.021 × 10-6 to 0. 23 × 10-6 and less than 0.10 × 10-6 for majority trace elements determined. In addition, home-made macro functions including filter and calculator compiled by VBA language under Excel software greatly enhanced off-line data reduction efficiency.``

  19. Determination of additives in PVC material by UV laser ablation inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Hemmerlin, M.; Mermet, J. M.; Bertucci, M.; Zydowicz, P.

    1997-04-01

    UV laser ablation inductively coupled plasma atomic emission spectrometry (LA-ICP-AES) has been applied to the direct determination of additives in solid poly(vinyl chloride) materials. A Nd:YAG laser, operating at its fourth harmonic (266 nm), was used with a beam masking device, in the most reproducible conditions, to introduce solid particles into the plasma torch of a simultaneous ICP-AES system. Emphasis was placed on both precision and accuracy in the analysis of PVC materials by LA-ICP-AES. A series of six in-house PVC reference materials was prepared by incorporating several additives in increasing concentrations. Three alternative methods were evaluated to certify the amount of incorporated elements: ICP-AES with sample dissolution, NAA and XRF. Satisfactory results and good agreement were obtained for seven elements (Al, Ca, Cd, Mg, Sb, Sn and Ti) among the ten incorporated. Sample homogeneity appeared to be satisfactory, and calibration graphs obtained by LA-ICP-AES for several elements are presented. Finally, the performance of the technique in terms of repeatability (1.6-5%), reproducibility (2-5%), and limits of detection was investigated.

  20. Depleted uranium analysis in blood by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Todorov, T.I.; Xu, H.; Ejnik, J.W.; Mullick, F.G.; Squibb, K.; McDiarmid, M.A.; Centeno, J.A.

    2009-01-01

    In this study we report depleted uranium (DU) analysis in whole blood samples. Internal exposure to DU causes increased uranium levels as well as change in the uranium isotopic composition in blood specimen. For identification of DU exposure we used the 235U/238U ratio in blood samples, which ranges from 0.00725 for natural uranium to 0.002 for depleted uranium. Uranium quantification and isotopic composition analysis were performed by inductively coupled plasma mass spectrometry. For method validation we used eight spiked blood samples with known uranium concentrations and isotopic composition. The detection limit for quantification was determined to be 4 ng L-1 uranium in whole blood. The data reproduced within 1-5% RSD and an accuracy of 1-4%. In order to achieve a 235U/238U ratio range of 0.00698-0.00752% with 99.7% confidence limit a minimum whole blood uranium concentration of 60 ng L??1 was required. An additional 10 samples from a cohort of veterans exposed to DU in Gulf War I were analyzed with no knowledge of their medical history. The measured 235U/ 238U ratios in the blood samples were used to identify the presence or absence of DU exposure within this patient group. ?? 2009 The Royal Society of Chemistry.

  1. The Kalman filter approach to inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Van Veen, E. H.; Bosch, S.; De Loos-Vollebregt, M. T. C.

    1994-07-01

    This article is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta Part B (SAB). The hardcopy text, comprising the main article and two appendices, is accompanied by a disk containing the compiled program, a reference manual and data files. The work deals with data handling in inductively coupled plasma atomic emission spectrometry (ICP-AES). With this technique, the analyte signal is superimposed on a background signal. When separating the signals by manual or automated three-point background correction, there are many instances in which the data reduction fails. Based on scans recorded in a fast-scanning mode and on a library of pure-component scans, the Kaiman filter approach models the emission in the spectral window (about 100 pm) of the analyte and mathematically solves the problem of background correction. By using a criterion-based algorithm to correct for optical instability, the uncertainty in the determination of the interferent line signal is eliminated. Therefore, the present filter implementation yields more accurate and precise results, especially in the case of line overlap. The Kalman filter Approach to Atomic Spectrometry (KAAS) software automatically processes Perkin-Elmer Plasma 1000/2000 text files, but can also handle ASCII data files. Practical and comprehensive examples are given to evoke the "Kalman filter feeling" in the crucial step of creating the emission model.

  2. Transient plasma potential in pulsed dual frequency inductively coupled plasmas and effect of substrate biasing

    Science.gov (United States)

    Mishra, Anurag; Yeom, Geun Young

    2016-09-01

    An electron emitting probe in saturated floating potential mode has been used to investigate the temporal evolution of plasma potential and the effect of substrate RF biasing on it for pulsed dual frequency (2 MHz/13.56 MHz) inductively coupled plasma (ICP) source. The low frequency power (P2MHz) has been pulsed at 1 KHz and a duty ratio of 50%, while high frequency power (P13.56MHz) has been used in continuous mode. The substrate has been biased with a separate bias power at (P12.56MHz) Argon has been used as a discharge gas. During the ICP power pulsing, three distinct regions in a typical plasma potential profile, have been identified as `initial overshoot', pulse `on-phase' and pulse `off-phase'. It has been found out that the RF biasing of the substrate significantly modulates the temporal evolution of the plasma potential. During the initial overshoot, plasma potential decreases with increasing RF biasing of the substrate, however it increases with increasing substrate biasing for pulse `on-phase' and `off-phase'. An interesting structure in plasma potential profile has also been observed when the substrate bias is applied and its evolution depends upon the magnitude of bias power. The reason of the evolution of this structure may be the ambipolar diffusion of electron and its dependence on bias power.

  3. Electron heating during E-H transition in inductively coupled RF plasmas

    Science.gov (United States)

    Wegner, Th; Küllig, C.; Meichsner, J.

    2015-08-01

    A planar inductively coupled RF discharge (13.56 MHz) in argon and oxygen was exemplarily studied using space and phase resolved optical emission spectroscopy. The characteristic excitation rate pattern due to the electron heating during the sheath expansion was found for both gases in the E-mode. Furthermore, an intensive pattern in oxygen appears during the sheath collapse. This is associated with the electron heating caused by electric field reversal due to the strong electronegativity. The transition from the E- to the H-mode may be stepwise or continuous, depending on the gas type and total gas pressure. In the H-mode, significant differences in the excitation rate patterns exist. A broad and weakly modulated pattern is found over the RF cycle in argon, whereas in oxygen two separated patterns appear representing the electron heating for each half cycle. The reason may be the different excitation processes of the investigated resonant states and the influence of metastable argon atoms as well as attachment/detachment processes and dissociative recombination in oxygen. The E-H transition in oxygen at 5 Pa develops continuously and was studied in detail through the excitation rate. During the transition, the E- and H-mode are present and a hybrid mode was observed.

  4. Profiling metals in Cordyceps sinensis by using inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Wei, Xin; Hu, Hankun; Zheng, Baogeng; Arslan, Zikri; Huang, Hung-Chung; Mao, Weidong; Liu, Yi-Ming

    2017-01-28

    Cordyceps sinensis (C. sinensis) is a natural product that has diverse nutritional and medicinal values. Since the availability of natural C. sinensis becomes limited its authentication and quality control is of high significance. Herein we report on profiling of metals in C. sinensis by using inductively coupled plasma mass spectrometry (ICP-MS). The analysis reveals that C. sinensis contains a wide array of essential elements, including P, Mg, Zn, Cu, Fe, etc. Toxic metals detected are Cd, Pb, and As. In all five samples analyzed Pb contents are below 2.0 ppm. Arsenic level in C. sinensis caterpillar is significantly higher than that in its mycelium and varies from 3.0 to 32 ppm likely due to soil contamination. It's for the first time demonstrated in this work that clustering analysis on the proposed metal profiles consisting of 24 elements is very useful to identify "abnormal" C. sinensis samples, thus adding another dimension to the effective means for authentication and quality assessment of this highly demanded previous natural product.

  5. [Analysis of Trace Inorganic Elements in Castor Oil by Inductively Coupled Plasma Mass Spectrometry].

    Science.gov (United States)

    Li, Tan-ping; Xie, Hua-lin; Nie, Xi-du

    2015-10-01

    A method for the determination of Na, Mg, Si, P, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Hg and Pb in castor oil after direct dilution with ethanol by inductively coupled plasma mass spectrometry (ICP-MS) was established. The sample was diluted by ethanol before ICP-MS determination. The condensation and deposition of high concentrations of carbon in mass cone interface and ion lens, which will decrease the sensitivity of element analysis, were avoided effectively by introducing O2 to plasma. The mass spectral interferences were eliminated by octopole reaction system (ORS). The matrix effects were calibrated to using Sc, Ge, Rh and Ir as internal standard elements. Au standard solution, which could form amalgam alloy with Hg, was dropped to eliminate the memory effect of Hg. The results show that the correlation coefficient for analyte is no less than 0.999 5, the detection limits is in the range of 0.06 - 20.1 ng x L(-1), the recovery is in the range of 990.4% - 110.2%, and the RSD is less than 4.8%. This method was very fast, simple and accurate to simultaneously analyze multi-elements in castor oil.

  6. Laser ablation - inductively coupled plasma mass spectrometry (LA-ICP-MS): Novel applications for coal research

    Energy Technology Data Exchange (ETDEWEB)

    Booth, C.A.; Spears, D.A.

    1999-07-01

    Laser Ablation - Inductively Coupled Plasma - Mass Spectrometry (LA-ICP-MS) has enormous potential in coal research. Element concentrations are determined with limits of detection currently in the parts per billion range, whilst spatial resolution as low as 10 microns can be achieved using the CETAC Technologies LSX-100 laser ablation system. Calibration of the LA-ICP-MS systems is notoriously difficult but in this paper the authors review two different techniques used in Sheffield, which allow trace element concentrations of whole coals (bituminous) and minerals and macerals within the coal to be determined. The first technique involves calibrating the system with PF grade coal samples in order that trace element concentrations can directly be determined after ablation of a solid coal or pressed coal sample. Using this technique, potentially hazardous trace elements such as As, Cd, Pb and Hg can be detected and measured even in the low parts per billion concentration (mg/Kg) range. The second application utilizes the spatial resolution of the laser to measure element concentrations in individual coal components. In this paper the results from ablating pyrite framboids in polished sections of the coal are discussed. Elemental information is obtained throughout the ablation procedure and this is then calibrated against the Fe content in order to establish the concentration of an element per 1% pyritic iron.

  7. Identification of organically associated trace elements in wood and coal by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Richaud, R.; Lazaro, M.J.; Lachas, H.; Miller, B.B.; Herod, A.A.; Dugwell, D.R.; Kandiyoti, R. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Dept. of Chemical Engineering and Chemical Technology

    2000-07-01

    1-Methyl-2-pyrrolidinone (NMP) was used to extract samples of wood (forest residue) and coal; the extracts were analysed by inductively coupled plasma mass spectrometry (ICP-MS) using two different sample preparation methods, in order to identify trace elements associated with the organic part of the samples. A sample of fly ash was similarly extracted and analysed. Size exclusion chromatograms of the extracts indicated the presence of significant amounts of large molecular mass materials ({gt} 1000 {mu}) in the biomass and coal extracts but not in the ash extract. Trace element analyses were carried out using ICP-MS on the acid digests prepared by 'wet ashing' and microwave extraction. Sixteen elements (As, Ba, Be, Cd, Co, Cr, Cu, Ga, Mn, Mo, Ni, pH, Sb, Se, V and Zn) were quantified, in the samples before extraction, in the extracts and in the residues. Concentrations of trace elements in the original biomass samples were lower than in the coal sample while the concentrations in the ash sample were the highest. The major trace elements in the NMP extracts were Ba, Cu, Mn and Zn from the forest residue; Ba, Cu, Mn, Pb and Zn from the coal; Cu and Zn from the ash. These elements are believed to be associated with the organic extracts from the forest residue and coal, and also from the ash.

  8. Wireless thin film transistor based on micro magnetic induction coupling antenna

    Science.gov (United States)

    Jun, Byoung Ok; Lee, Gwang Jun; Kang, Jong Gu; Kim, Seunguk; Choi, Ji-Woong; Cha, Seung Nam; Sohn, Jung Inn; Jang, Jae Eun

    2015-12-01

    A wireless thin film transistor (TFT) structure in which a source/drain or a gate is connected directly to a micro antenna to receive or transmit signals or power can be an important building block, acting as an electrical switch, a rectifier or an amplifier, for various electronics as well as microelectronics, since it allows simple connection with other devices, unlike conventional wire connections. An amorphous indium gallium zinc oxide (α-IGZO) TFT with magnetic antenna structure was fabricated and studied for this purpose. To enhance the induction coupling efficiency while maintaining the same small antenna size, a magnetic core structure consisting of Ni and nanowires was formed under the antenna. With the micro-antenna connected to a source/drain or a gate of the TFT, working electrical signals were well controlled. The results demonstrated the device as an alternative solution to existing wire connections which cause a number of problems in various fields such as flexible/wearable devices, body implanted devices, micro/nano robots, and sensors for the ‘internet of things’ (IoT).

  9. Determination of trace elements in refined gold samples by inductively coupled plasma atomic emission spectrometry

    Directory of Open Access Journals (Sweden)

    Steharnik Mirjana

    2013-01-01

    Full Text Available This paper presents a method for determination the trace contents of silver, copper, iron, palladium, zinc and platinum in refined gold samples. Simultaneous inductively coupled plasma atomic emission spectrometer with radial torch position and cross flow nebulizer was used for determination. In order to compare the different calibration strategies, two sets of calibration standards were prepared. The first set was based on matrix matched calibration standards and the second was prepared without the addition of matrix material. Detection limits for matrix matching calibrations were higher for some elements than those without matrix matching. In addition, the internal standardization method was applied and experiments indicated that indium was the best option as internal standard. The obtained results for gold sample by matrix matching and matrix free calibrations were compared with the obtained results by standard addition method. The accuracy of the methods was tested performing recovery test. Recoveries for spiked sample were in the range of 90-115 %. The accuracy of the methods was also tested by analysis of certified reference material of high pure goldAuGHP1. The best results were achieved by matrix free calibration and standard addition method using indium as internal standard at wavelength of 230 nm. [Projekat Ministarstva nauke Republike Srbije, br. 34024: Development of Technologies for Recycling of Precious, Rare and Associated Metals from Solid Waste in Serbia to High Purity Products

  10. Analytic Couple Modeling Introducing Device Design Factor, Fin Factor, Thermal Diffusivity Factor, and Inductance Factor

    Science.gov (United States)

    Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred

    2014-01-01

    A set of convenient thermoelectric device solutions have been derived in order to capture a number of factors which are previously only resolved with numerical techniques. The concise conversion efficiency equations derived from governing equations provide intuitive and straight-forward design guidelines. These guidelines allow for better device design without requiring detailed numerical modeling. The analytical modeling accounts for factors such as i) variable temperature boundary conditions, ii) lateral heat transfer, iii) temperature variable material properties, and iv) transient operation. New dimensionless parameters, similar to the figure of merit, are introduced including the device design factor, fin factor, thermal diffusivity factor, and inductance factor. These new device factors allow for the straight-forward description of phenomenon generally only captured with numerical work otherwise. As an example a device design factor of 0.38, which accounts for thermal resistance of the hot and cold shoes, can be used to calculate a conversion efficiency of 2.28 while the ideal conversion efficiency based on figure of merit alone would be 6.15. Likewise an ideal couple with efficiency of 6.15 will be reduced to 5.33 when lateral heat is accounted for with a fin factor of 1.0.

  11. High sensitivity ultra-broad-band absorption spectroscopy of inductively coupled chlorine plasma

    Science.gov (United States)

    Marinov, Daniil; Foucher, Mickaël; Campbell, Ewen; Brouard, Mark; Chabert, Pascal; Booth, Jean-Paul

    2016-06-01

    We propose a method to measure the densities of vibrationally excited Cl2(v) molecules in levels up to v  =  3 in pure chlorine inductively coupled plasmas (ICPs). The absorption continuum of Cl2 in the 250-450 nm spectral range is deconvoluted into the individual components originating from the different vibrational levels of the ground state, using a set of ab initio absorption cross sections. It is shown that gas heating at constant pressure is the major depletion mechanism of the Cl2 feedstock in the plasma. In these line-integrated absorption measurements, the absorption by the hot (and therefore rarefied) Cl2 gas in the reactor centre is masked by the cooler (and therefore denser) Cl2 near the walls. These radial gradients in temperature and density make it difficult to assess the degree of vibrational excitation in the centre of the reactor. The observed line-averaged vibrational distributions, when analyzed taking into account the radial temperature gradient, suggest that vibrational and translational degrees of freedom in the plasma are close to local equilibrium. This can be explained by efficient vibrational-translational (VT) relaxation between Cl2 and Cl atoms. Besides the Cl2(v) absorption band, a weak continuum absorption is observed at shorter wavelengths, and is attributed to photodetachment of Cl- negative ions. Thus, line-integrated densities of negative ions in chlorine plasmas can be directly measured using broad-band absorption spectroscopy.

  12. Determination of impurity elements in MnZn ferrites by inductively coupled plasma mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    张萍; 符靓; 马俊才; 唐有根

    2015-01-01

    An inductively coupled plasma mass spectrometry (ICP-MS) method was developed for the determination of Na, Mg, Al, K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water, then the above 16 impurity elements in the solution were analyzed directly by ICP-MS. The impurity elements were introduced by the helium gas or hydrogen gas into the octopole reaction system (ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effect was minimized through matrix matching, and Be, Y and Rh were used as internal standard elements. The working parameters of the instrument were optimized. The results show that the method has good precision and high accuracy. The detection limits for the investigated elements are in the range of 0.9−37.5 ng/L, the relative standard deviation of each element is within 1.1%−4.8%, and the recovery of each element is 90%−108%.

  13. Fundamental and methodological investigations for the improvement of elemental analysis by inductively coupled plasma mass soectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Christopher Hysjulien [Ames Lab., Ames, IA (United States)

    2012-01-01

    This dissertation describes a variety of studies meant to improve the analytical performance of inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation (LA) ICP-MS. The emission behavior of individual droplets and LA generated particles in an ICP is studied using a high-speed, high frame rate digital camera. Phenomena are observed during the ablation of silicate glass that would cause elemental fractionation during analysis by ICP-MS. Preliminary work for ICP torch developments specifically tailored for the improvement of LA sample introduction are presented. An abnormal scarcity of metal-argon polyatomic ions (MAr{sup +}) is observed during ICP-MS analysis. Evidence shows that MAr{sup +} ions are dissociated by collisions with background gas in a shockwave near the tip of the skimmer cone. Method development towards the improvement of LA-ICP-MS for environmental monitoring is described. A method is developed to trap small particles in a collodion matrix and analyze each particle individually by LA-ICP-MS.

  14. Unique applications of solvent removal in inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Minnich, M.

    1997-01-10

    Inductively coupled plasma mass spectrometry (ICP-MS) is the technique of choice for rapid, high precision, semiquantitative elemental and isotopic analysis for over 70 elements. Less than 20 years after the first mass spectrum was obtained by ICP-MS, this technique has applications in clinical chemistry, geochemistry, the semiconductor industry, the nuclear industry, environmental chemistry, and forensic chemistry. The determination of many elements, though, by ICP-MS is complicated by spectral interferences from background species, interelement spectral overlaps, and polyatomic ions of matrix elements. The emphasis of this thesis is the unique applications of solvent removal using cryogenic and membrane desolvation. Chapter 1 is a general introduction providing background information concerning the need for these methods and some information about the methods themselves. Chapter 5 discusses general conclusions and general observations pertaining to this work. Chapters 2, 3, and 4 have been processed separately for inclusion on the database. Chapter 2 describes a method to screen urine samples for vanadium using cryogenic desolvation. Chapter 3 compares solvent removal by cryogenic and membrane desolvation. Chapter 4 describes the use of cool plasma conditions for the determination of potassium in the presence of excess sodium by ICP-MS.

  15. Macro-loading Effects in Inductively Coupled Plasma Etched Mercury Cadmium Telluride

    Science.gov (United States)

    Apte, Palash; Rybnicek, Kimon; Stoltz, Andrew

    2016-09-01

    This paper reports the effect of macro-loading on mercury cadmium telluride (Hg1- x Cd x Te) and Photoresist (PR) etched in an inductively coupled plasma (ICP). A significant macro-loading effect is observed, which affects the etch rates of both PR and Hg1- x Cd x Te. It is observed that the exposed silicon area has a significant effect on the PR etch rate, but not on the Hg1- x Cd x Te etch rate. It is also observed that the exposed Hg1- x Cd x Te area has a significant effect on the etch rate of the PR, but the exposed PR area does not seem to have an effect on the Hg1- x Cd x Te etch rate. Further, the exposed Hg1- x Cd x Te area is shown to affect the etch rate of the Hg1- x Cd x Te, but there does not seem to be a similar effect for the exposed PR area on the etch rate of the PR. Since the macro-loading affects the selectivity significantly, this effect can cause significant problems in the etching of deep trenches. A few techniques to reduce the effect of macro-loading on the etch rates of the PR and Hg1- x Cd x Te are listed, herein.

  16. Inductively coupled plasma emission spectroscopic and flame photometric analysis of goat epididymal fluid

    Institute of Scientific and Technical Information of China (English)

    MeenakshiGaur; VikasPruthi; RamasarePrasad; BenM.J.Pereira

    2000-01-01

    Aim: The elemental composition of the epididymal luminal fluid (ELF) in adult goat (Capra indica) was investigated. Methods: ELF was collected by micropuncture from twelve sites along the epididymal duct. The elemental contents was analyzed with inductively coupled plasma (ICP) emission spectroscopy, a microanalytical technique that can simultaneously measure many elements in minute volumes of sample. The Na and K concentrations were determined by flame photometry. Results: ICP spectroscopy showed the presence of copper, calcium, nickel, iron, magnesium, chromium, titanium and zinc in ELF, with fluctuating levels at different sites along the length of the epididymis.Cadmium, cobalt, lead and manganese were not found. The Na+/K+ ratio was seen to be higher at the initial segments of the epididymis and lower at the distal. Conclusion: It is proposed that the observed characteristic distribution of elements in ELF may have far reaching implications in sperm maturation and storage known to occur in the epididymis. (Asian J Androl 2000 Dec;2:288-292)

  17. Inductively coupled plasma mass spectrometer with laser ablation metal ions release detection in the human mouth

    Science.gov (United States)

    Kueerova, Hana; Dostalova, Tatjana; Prochazkova, J.

    2002-06-01

    Presence of more dental alloys in oral cavity often causes pathological symptoms. Due to various and multi-faced symptomatology, they tend to be a source of significant problems not only for the patient but also for the dentist. Metal ions released from alloys can cause subjective and objective symptoms in mouth. The aim of this study was detection of metal elements presence in saliva. There were 4 groups of examined persons: with intact teeth (15 individuals) with metallic restorations, pathological currents 5-30 (mu) A, multi-faced subjective symptomatology and uncharacteristic objective diagnosis (32 patients), with metallic restorations and no subjective symptoms (14 persons) and with metallic restorations, without pathological currents and with problems related to galvanism (13 patients). Presence of 14 metal elements was checked by inductively coupled plasma mass spectrometer with laser ablation. Nd:YAG laser detector was used. There were significant differences in content of silver, gold and mercury between persons with intact teeth and other three groups. There were no differences found between subjects with and without galvanic currents, and presence of subjective and objective symptoms.

  18. Characterization of microconcentric nebulizer uptake rates for capillary electrophoresis inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Yanes, Enrique G.; Miller-Ihli, Nancy J.

    2003-05-01

    There is demonstrated interest in combining capillary electrophoresis (CE) with inductively coupled plasma mass spectrometry (ICP-MS) for speciation determinations. When self-aspirating nebulizers are used for this application, it is important to offset the suction effect to avoid degradation of the separation. In this study, sample uptake rates for three microconcentric nebulizers of the same model, in combination with a cyclonic spray chamber, were characterized and compared for future utilization in CE-ICP-MS interfaces. The specific model studied was a MicroMist with a nominal uptake rate of 100 μl/min at 1 l/min argon gas flow rate per the manufacturer's specifications. Sample uptake rates at various nebulizer gas flows were measured by aspirating water from a weighed container and calculating the uptake rate in microliter per minute. The nebulizers studied provided good reproducibility from day to day, but a comparison of the different nebulizers reflected a significant difference in performance. A characteristic observed during the study was that uptake rates decreased with increasing nebulizer gas flow. This can be used for sample introduction for CE-ICP-MS. Interestingly, very different performance was observed when comparing the three different nebulizers of the same model. Uptake rates showed strong dependence on argon gas flow rates and the dimensions of the sample uptake tubing.

  19. Rapidly removing grinding damage layer on fused silica by inductively coupled plasma processing

    Science.gov (United States)

    Chen, Heng; Zhou, Lin; Xie, Xuhui; Shi, Baolu; Xiong, Haobin

    2016-10-01

    During the conventional optical shaping process of fused silica, lapping is generally used to remove grinding damage layer. But this process is of low efficiency, it cannot meet the demand of large aperture optical components. Therefore, Inductively Coupled Plasma Processing (ICPP) was proposed to remove grinding damage layer instead of lapping. ICPP is a non-contact, deterministic figuring technology performed at atmospheric pressure. The process benefits from its ability to simultaneously remove sub-surface damage (SSD) while imparting the desired figure to the surface with high material remove rate. The removing damage capability of ICPP has preliminarily been confirmed on medium size optical surfaces made of fused silica, meanwhile serious edge warping was found. This paper focused on edge effect and a technique has been designed to compensate for these difficulties. Then it was demonstrated on a large aperture fused silica mirror (Long320mm×Wide370mm×High50mm), the removal depth was 30.2μm and removal rate got 6.6mm3/min. The results indicate that ICPP can rapidly remove damage layer on the fused silica induced by the previous grinding process and edge effect is effective controlled.

  20. Unexpected properties of the inductively coupled plasma induced defect in germanium

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, S.M.M., E-mail: sergio@up.ac.za; Auret, F.D.; Janse van Rensburg, P.J.; Nel, J.M.

    2014-04-15

    Inductively coupled plasma (ICP) etching of germanium introduces a single defect, the E{sub 0.31} electron trap, for a large range of argon partial pressures from 4×10{sup –3} to 6.5×10{sup –4} mbar that correspond to ion energies of 8 to 60 eV. Ge of three crystallographic orientations, (1 0 0), (1 1 0) and (1 1 1), treated with 20 and 60 eV ICP had defect concentration profiles that were similar in appearance, with a maximum concentration of 10{sup 14} cm{sup −3} extending more than a µm into the material, approximately three orders of magnitude deeper than what TRIM simulations predicted. All profiles were measured using Laplace deep level transient spectroscopy (L-DLTS), a technique that is sensitive to defect concentrations as low as 10{sup 11} cm{sup −3}. Isochronal annealing of samples showed concentration curves broadening after a 400 K anneal and decreasing to the 10{sup 13} cm{sup −3} level after a 450 K anneal. Unannealed samples measured after a year exhibited similar decreases in defect concentration without broadening of their profiles. A 550 K anneal lowered the defect concentration to levels below the L-DLTS detection limit. Thereafter additional plasma treatment of the surface failed to reintroduce this defect indicating that the structure required for the formation of E{sub 0.31} was no longer present in the region under observation.

  1. On the heating of inductively coupled resonators (stents) during MRI examinations.

    Science.gov (United States)

    Busch, Martin; Vollmann, Wolfgang; Bertsch, Thomas; Wetzler, Rainer; Bornstedt, Axel; Schnackenburg, Bernhard; Schnorr, Jörg; Kivelitz, Dietmar; Taupitz, Matthias; Grönemeyer, Dietrich

    2005-10-01

    Stents that have been implanted to preserve the results of vascular dilatation are frequently affected by in-stent restenosis, which ideally should be followed up by a noninvasive diagnostic modality. Active MRI stents can enable this kind of follow-up, while normal metallic stents can not. The prototype stents investigated in this study were designed as electric resonating circuits without a direct connection to the MR imager, and function as inductively coupled transmit coils. The model of a long solenoid coil is used to describe the additional power loss caused by such resonators. The theoretically estimated temperature increase is verified by measurements for different resonators and discussed for worst-case conditions. The RF power absorption of an active resonator is negligible compared to the total power absorbed during MRI. The local temperature increase observed for prototypes embedded in phantoms is in a range that excludes direct tissue damage. However, ruptures in the conducting structure of a resonator can cause hot spots, which may establish a high local temperature. This hazard can be reduced by designing resonators with a low quality (Q) factor or by setting the circuit slightly off resonance; however, this would lower the nominal amplification for which the resonator was designed.

  2. [Determination of relative elements of hard metal in workplace air and urine by inductive coupled plama].

    Science.gov (United States)

    Li, X X; Jiao, Y N; Luo, Y N; Chen, Y X; Tian, D; Lou, F; Li, H D; Li, W; Chen, J D; Yan, Y J

    2016-11-20

    Objective: To establish a rapid detection method regarding the air conditions of workplace and the workers' urine included Tungsten, Cobalt, Nickel, Titanium, Cadmium, Manganese, Lead and its compounds based on inductively coupled plasma mass spectrometry (ICP-MS) . Methods: The experiment adopts ICP-MS to deter-mine those metals in workshop air and workers urine, evaluate the detection's limitation, the precision and accuracy of the method. Using the membrane filter and urine freeze - dried metal standard material to verify this method. Results: Each element of correlation coefficient was greater than 0.999. The recovery rate of air samples was 91.6%~104.6%, within-batch RSD precision was 1.41%~3.50%, between-run precision was 1.28%~4.31%, urine samples recovery rate was 93.0%~102.6%, within - batch RSD precision was 1.25%~3.56%, between - run precision was 1.58%~4.67%, According to the method every element was within the scope of the standard reference, it was also showed that the established method is accurate and reliable. Conclusion: ICP-MS is an effective and feasible method to detect the workshop air and the workers' urine which included Tungsten, Cobalt, Nickel, Titanium, Cadmium, Manganese, Lead and its compounds.

  3. Oxygen bomb combustion of biological samples for inductively coupled plasma optical emission spectrometry

    Science.gov (United States)

    Souza, Gilberto B.; Carrilho, Elma Neide V. M.; Oliveira, Camila V.; Nogueira, Ana Rita A.; Nóbrega, Joaquim A.

    2002-12-01

    A rapid sample preparation method is proposed for decomposition of milk powder, corn bran, bovine and fish tissues, containing certified contents of the analytes. The procedure involves sample combustion in a commercial stainless steel oxygen bomb operating at 25 bar. Most of the samples were decomposed within 5 min. Diluted nitric acid or water-soluble tertiary amines 10% v/v were used as absorption solutions. Calcium, Cu, K, Mg, Na, P, S and Zn were recovered with the bomb washings and determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Ethanol mixed with paraffin was used as a combustion aid to allow complete combustion. A cooling step prior releasing of the bomb valve was employed to increase the efficiency of sample combustion. Iodine was also determined in milk samples spiked with potassium iodide to evaluate the volatilization and collection of iodine in amine CFA-C medium and the feasibility of its determination by ICP-OES with axial view configuration. Most of the element recoveries in the samples were between 91 and 105% and the certified and found contents exhibited a fair agreement at a 95% confidence level.

  4. On-line elemental analysis of fossil fuel process streams by inductively coupled plasma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, W.P.

    1995-06-01

    METC is continuing development of a real-time, multi-element plasma based spectrometer system for application to high temperature and high pressure fossil fuel process streams. Two versions are under consideration for development. One is an Inductively Coupled Plasma system that has been described previously, and the other is a high power microwave system. The ICP torch operates on a mixture of argon and helium with a conventional annular swirl flow plasma gas, no auxiliary gas, and a conventional sample stream injection through the base of the plasma plume. A new, demountable torch design comprising three ceramic sections allows bolts passing the length of the torch to compress a double O-ring seal. This improves the reliability of the torch. The microwave system will use the same data acquisition and reduction components as the ICP system; only the plasma source itself is different. It will operate with a 750-Watt, 2.45 gigahertz microwave generator. The plasma discharge will be contained within a narrow quartz tube one quarter wavelength from a shorted waveguide termination. The plasma source will be observed via fiber optics and a battery of computer controlled monochromators. To extract more information from the raw spectral data, a neural net computer program is being developed. This program will calculate analyte concentrations from data that includes analyte and interferant spectral emission intensity. Matrix effects and spectral overlaps can be treated more effectively by this method than by conventional spectral analysis.

  5. Inductively coupled plasma mass spectrometry in the analysis of biological samples and pharmaceutical drugs

    Science.gov (United States)

    Ossipov, K.; Seregina, I. F.; Bolshov, M. A.

    2016-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in the analysis of biological samples (whole blood, serum, blood plasma, urine, tissues, etc.) and pharmaceutical drugs. The shortcomings of this method related to spectral and non-spectral interferences are manifested in full measure in determination of the target analytes in these complex samples strongly differing in composition. The spectral interferences are caused by similarity of masses of the target component and sample matrix components. Non-spectral interferences are related to the influence of sample matrix components on the physicochemical processes taking place during formation and transportation of liquid sample aerosols into the plasma, on the value and spatial distribution of plasma temperature and on the transmission of the ion beam from the interface to mass spectrometer detector. The review is devoted to analysis of different mechanisms of appearance of non-spectral interferences and to ways for their minimization or elimination. Special attention is paid to the techniques of biological sample preparation, which largely determine the mechanisms of the influence of sample composition on the results of element determination. The ways of lowering non-spectral interferences by instrumental parameter tuning and application of internal standards are considered. The bibliography includes 189 references.

  6. Methods for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry

    Science.gov (United States)

    Chan, George C. Y.; Hieftje, Gary M.

    2010-08-03

    A method for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry (ICP-AES). ICP-AES analysis is performed across a plurality of selected locations in the plasma on an unknown sample, collecting the light intensity at one or more selected wavelengths of one or more sought-for analytes, creating a first dataset. The first dataset is then calibrated with a calibration dataset creating a calibrated first dataset curve. If the calibrated first dataset curve has a variability along the location within the plasma for a selected wavelength, errors are present. Plasma-related errors are then corrected by diluting the unknown sample and performing the same ICP-AES analysis on the diluted unknown sample creating a calibrated second dataset curve (accounting for the dilution) for the one or more sought-for analytes. The cross-over point of the calibrated dataset curves yields the corrected value (free from plasma related errors) for each sought-for analyte.

  7. Design of a Wideband Inductively Coupled Loop Feed Patch Antenna for UHF RFID Tag

    Directory of Open Access Journals (Sweden)

    M. S. R. Bashri

    2015-04-01

    Full Text Available A planar wideband patch antenna for ultra-high frequency (UHF radio frequency identification (RFID tag for metallic applications is presented in this research work. Three different shape patches are inductively coupled to a triangle loop to form wide impedance bandwidth for universal application UHF (860-960 MHz RFID. The structure of proposed antenna exhibits planar profile to provide ease of fabrication for cost reduction well suited for mass production. The simulation of the antenna was carried out using Finite Element Method (FEM based software, Ansoft HFSS v13. The simulated and measured impedance bandwidth of 113 MHz and 117 MHz (Return Loss≥6 dB were achieved to cover the entire UHF RFID operating frequency band worldwide. The simulated and measured radiation patterns at the operating frequency of 915 MHz are in good agreement. Moreover the simulated minimum antenna gain at the bore sight direction in free space and when mounted on 200 x 200 mm2 metal plate are -15 dBi and -14dBi respectively which is enough to provide reasonable read range over the entire UHF RFID system operating band.

  8. High Resolution Studies of the Origins of Polyatomic Ions in Inductively Coupled Plasma-Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, Jill Wisnewski [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    The inductively coupled plasma (ICP) is an atmospheric pressure ionization source. Traditionally, the plasma is sampled via a sampler cone. A supersonic jet develops behind the sampler, and this region is pumped down to a pressure of approximately one Torr. A skimmer cone is located inside this zone of silence to transmit ions into the mass spectrometer. The position of the sampler and skimmer cones relative to the initial radiation and normal analytical zones of the plasma is key to optimizing the useful analytical signal [1]. The ICP both atomizes and ionizes the sample. Polyatomic ions form through ion-molecule interactions either in the ICP or during ion extraction [l]. Common polyatomic ions that inhibit analysis include metal oxides (MO+), adducts with argon, the gas most commonly used to make up the plasma, and hydride species. While high resolution devices can separate many analytes from common interferences, this is done at great cost in ion transmission efficiency--a loss of 99% when using high versus low resolution on the same instrument [2]. Simple quadrupole devices, which make up the bulk of ICP-MS instruments in existence, do not present this option. Therefore, if the source of polyatomic interferences can be determined and then manipulated, this could potentially improve the figures of merit on all ICP-MS devices, not just the high resolution devices often utilized to study polyatomic interferences.

  9. Langmuir Probe Measurements of Inductively Coupled Plasma in CF4/AR/O2 Mixtures

    Science.gov (United States)

    Rao, M. V. V. S.; Cruden, Brett; Sharma, Surendra; Meyyappan, Meyya

    2001-01-01

    Inductively coupled plasmas of CF4:Ar:O2, which have been of importance to material processing, were studied in the GEC cell at 80:10:10, 60:20:20, and 40:30:30 mixture ratios. Radial distributions of plasma potential (V(sub p)), electron and ion number densities (n(sub e) and n(sub i)), electron temperature (T(sub e)), and electron energy distribution functions (EEDFs) were measured in the mid-plane of plasma across the electrodes in the pressure range of 10-50 mTorr, and RF power of 200 and 300 W. V(sub p), n(sub e) and n(sub i), which peak in the center of the plasma, increase with decrease of pressure. T(sub e) also increases with pressure but peaks toward the electrode edge. Both V(sub p) and T(sub e) remain nearly independent of RF power, whereas n(sub e) and n(sub i) increase with power. In all conditions the EEDFs exhibit non-Maxwellian shape and are more like Druyvesteyn form at higher energies. They exhibit a broad lip in the energy range 0-10 eV suggesting an electron loss mechanism, which could be due to via resonance electron attachment processes producing negative ions in this rich electronegative gas mixture. This behavior is more prominent towards the electrode edge.

  10. Isotope ratio analysis of individual sub-micrometer plutonium particles with inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Esaka, Fumitaka; Magara, Masaaki; Suzuki, Daisuke; Miyamoto, Yutaka; Lee, Chi-Gyu; Kimura, Takaumi

    2010-12-15

    Information on plutonium isotope ratios in individual particles is of great importance for nuclear safeguards, nuclear forensics and so on. Although secondary ion mass spectrometry (SIMS) is successfully utilized for the analysis of individual uranium particles, the isobaric interference of americium-241 to plutonium-241 makes difficult to obtain accurate isotope ratios in individual plutonium particles. In the present work, an analytical technique by a combination of chemical separation and inductively coupled plasma mass spectrometry (ICP-MS) is developed and applied to isotope ratio analysis of individual sub-micrometer plutonium particles. The ICP-MS results for individual plutonium particles prepared from a standard reference material (NBL SRM-947) indicate that the use of a desolvation system for sample introduction improves the precision of isotope ratios. In addition, the accuracy of the (241)Pu/(239)Pu isotope ratio is much improved, owing to the chemical separation of plutonium and americium. In conclusion, the performance of the proposed ICP-MS technique is sufficient for the analysis of individual plutonium particles.

  11. Inductively coupled plasma--atomic emission spectrometry: trace elements in oil matrices

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, C. A.

    1977-12-01

    The simultaneous determination of up to 20 trace elements in various oil matrices by inductively coupled plasma-atomic emission spectrometry is reported. The oil matrices investigated were lubricating oils (for wear metals), fuel oil, centrifuged coal liquefaction product, crude soybean oil, and commercial edible oils. The samples were diluted with appropriate organic solvents and injected into the plasma as an aerosol generated by a pneumatic nebulization technique. Detection limits of the 28 elements studied ranged from 0.0006 to 9 ..mu..g/g with the majority falling in the 0.01 to 0.1 ..mu..g/g range. Analytical calibration curves were linear over at least two orders of magnitude and for some elements this linearity extended over 4.5 orders of magnitude. Relevant data on precision and accuracy are included. Because metals often occur as particles in lubricating oil and coal liquefaction products, the effect of particles on the analytical results was examined. Wear metal particles in used oil did not appear to affect the analytical results. However, incomplete recovery relative to organometallic reference solutions was obtained for iron particles with a nominal mean diameter of 3.0 ..mu..m suspended in oil. It was shown that the following factors contributed to incomplete recovery for the particles: settling of the suspended particles in the flask, a difference in nebulization efficiency between particle suspensions and organometallic solutions, and indications of incomplete vaporization of the larger particles in the plasma.

  12. Comparison of femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for uranium isotopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Havrilla, George Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McIntosh, Kathryn Gallagher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Judge, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dirmyer, Matthew R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Campbell, Keri [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gonzalez, Jhanis J. [Applied Spectra Inc., Fremont, CA (United States)

    2016-10-20

    Feasibility tests were conducted using femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry for rapid uranium isotopic measurements. The samples used in this study consisted of a range of pg quantities of known 235/238 U solutions as dried spot residues of 300 pL drops on silicon substrates. The samples spanned the following enrichments of 235U: 0.5, 1.5, 2, 3, and 15.1%. In this direct comparison using these particular samples both pulse durations demonstrated near equivalent data can be produced on either system with respect to accuracy and precision. There is no question that either LA-ICP-MS method offers the potential for rapid, accurate and precise isotopic measurements of U10Mo materials whether DU, LEU or HEU. The LA-ICP-MS equipment used for this work is commercially available. The program is in the process of validating this work for large samples using center samples strips from Y-12 MP-1 LEU-Mo Casting #1.

  13. Experimental and numerical studies of neutral gas depletion in an inductively coupled plasma

    Science.gov (United States)

    Shimada, Masashi

    the neutral pressure is reduced due the balance of total pressure with plasma pressure (mainly electron pressure). Neutral gas heating is due to the elastic scattering and charge exchange collisions with ions, which are accelerated by the bulk plasma ambi-polar electrostatic field. The excellent agreement between experiment and simulation, and parametric study reveal that gas heating and pressure balance are the main mechanisms of gas depletion in an inductively coupled plasma. Coupling between plasma and neutral gas was observed by both experiment and simulation. The resulting gas depletion enhances the plasma transport to the surrounding wall, increases the particle loss, and decreases the plasma density.

  14. RAPID DETERMINATION OF ACTINIDES IN URINE BY INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY: A HYBRID APPROACH

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Jones, V.

    2009-05-27

    A new rapid separation method that allows separation and preconcentration of actinides in urine samples was developed for the measurement of longer lived actinides by inductively coupled plasma mass spectrometry (ICP-MS) and short-lived actinides by alpha spectrometry; a hybrid approach. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration, if required, is performed using a streamlined calcium phosphate precipitation. Similar technology has been applied to separate actinides prior to measurement by alpha spectrometry, but this new method has been developed with elution reagents now compatible with ICP-MS as well. Purified solutions are split between ICP-MS and alpha spectrometry so that long- and short-lived actinide isotopes can be measured successfully. The method allows for simultaneous extraction of 24 samples (including QC samples) in less than 3 h. Simultaneous sample preparation can offer significant time savings over sequential sample preparation. For example, sequential sample preparation of 24 samples taking just 15 min each requires 6 h to complete. The simplicity and speed of this new method makes it attractive for radiological emergency response. If preconcentration is applied, the method is applicable to larger sample aliquots for occupational exposures as well. The chemical recoveries are typically greater than 90%, in contrast to other reported methods using flow injection separation techniques for urine samples where plutonium yields were 70-80%. This method allows measurement of both long-lived and short-lived actinide isotopes. 239Pu, 242Pu, 237Np, 243Am, 234U, 235U and 238U were measured by ICP-MS, while 236Pu, 238Pu, 239Pu, 241Am, 243Am and 244Cm were measured by alpha spectrometry. The method can also be adapted so that the separation of uranium isotopes for assay is not required, if uranium assay by direct dilution of the urine sample is preferred instead

  15. Review: Current applications and challenges for liquid chromatography coupled to isotope ratio mass spectrometry (LC/IRMS).

    Science.gov (United States)

    Godin, Jean-Philippe; McCullagh, James S O

    2011-10-30

    High-precision isotope analysis is recognized as an essential research tool in many fields of study. Until recently, continuous flow isotope ratio mass spectrometry (CF-IRMS) was available via an elemental analyzer or a gas chromatography inlet system for compound-specific analysis of light stable isotopes. In 2004, however, an interface that coupled liquid chromatography with IRMS (LC/IRMS) became commercially available for the first time. This brought the capability for new areas of application, in particular enabling compound-specific δ(13)C analysis of non-volatile, aqueous soluble, compounds from complex mixtures. The interface design brought with it several analytical constraints, however, in particular a lack of compatibility with certain types of chromatography as well as limited flow rates and mobile phase compositions. Routine LC/IRMS methods have, however, been established for measuring the δ(13)C isotopic ratios of underivatized individual compounds for application in archeology, nutrition and physiology, geochemistry, hydrology, soil science and food authenticity. Seven years after its introduction, we review the technical advances and constraints, methodological developments and new applications of liquid chromatography coupled to isotope ratio mass spectrometry.

  16. Liquid chromatography-mass spectrometry coupling by the intermediary of a liquid micro chromatography-electro spray interface; Couplage chromatographie liquide-spectrometrie de masse par l`intermediaire d`une interface electrospray-microchromatographie liquide

    Energy Technology Data Exchange (ETDEWEB)

    Gillard Factor, C.

    1996-12-06

    The objective of this work is to realize a liquid chromatography- mass spectrometry coupling by the intermediary of an electro spray interface and the evaluation of performances of tis analytical tool to study pollutants in water, and more particularly pesticides whom maximum admissible concentration in a table water is 0.1{mu}g/l. This study has allowed to bring to the fore the interest of the ionization mode by electro spray in a LC/MS coupling to identify and quantify pesticides in the state of traces without treating the sample. Then, it was demonstrated the usefulness of this analytical tool to detect high molecular masses molecules. (N.C.)

  17. Comprehensive multidimensional gas chromatography coupled to low resolution quadrupole mass spectrometry for the analysis of PCDDs, PCDFs and PCBs

    Energy Technology Data Exchange (ETDEWEB)

    Costa, J.P. [Universitat de Barcelona (Spain). Facultat de Quimica, Dept. de Quimica Analitica; Korytar, P.; Boer, J. de [Netherlands Institutes for Fisheries Research, Ijmuiden (Netherlands); Leonards, P. [Instituto Quimico de Sarria, Barcelona (Spain)

    2004-09-15

    Because of the high persistency and extreme toxicity of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and so-called dioxin-like polychlorinated biphenyls (PCBs), their trace level determination is a topic of much interest. The typical concentrations of this compounds, sub-ng/kg, makes that they have to be clearly separated from other, less toxic, congeners present in the samples and from the matrix and the use of sensitive techniques is required for the quantification. The analyses of the compounds are usually done by high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC-HRMS). Recently, alternative novel techniques have been developed which are improving the chromatographic separation, e.g. comprehensive multidimensional gas chromatography (GC x GC), for the analysis of the compounds. The aim of this work is to evaluate GC x GC coupled to a low resolution quadrupole mass spectrometer for the quantification of PCDDs, PCDFs and dioxin like PCBs.

  18. Determination and characterization of phytochelatins by liquid chromatography coupled with on line chemical vapour generation and atomic fluorescence spectrometric detection.

    Science.gov (United States)

    Bramanti, Emilia; Toncelli, Daniel; Morelli, Elisabetta; Lampugnani, Leonardo; Zamboni, Roberto; Miller, Keith E; Zemetra, Joseph; D'Ulivo, Alessandro

    2006-11-10

    Liquid chromatography (LC) coupled on line with UV/visible diode array detector (DAD) and cold vapour generation atomic fluorescence spectrometry (CVGAFS) has been developed for the speciation, determination and characterization of phytochelatins (PCs). The method is based on a bidimensional approach, e.g. on the analysis of synthetic PC solutions (apo-PCs and Cd(2+)-complexed PCs) (i) by size exclusion chromatography coupled to UV diode array detector (SEC-DAD); (ii) by the derivatization of PC -SH groups in SEC fractions by p-hydroxymercurybenzoate (PHMB) and the indirect detection of PC-PHMB complexes by reversed phase liquid chromatography coupled to atomic fluorescence detector (RPLC-CVGAFS). MALDI-TOF/MS (matrix assisted laser desorption ionization time of flight mass spectrometry) analysis of underivatized synthetic PC samples was performed in order have a qualitative information of their composition. Quantitative analysis of synthetic PC solutions has been performed on the basis of peak area of PC-PHMB complexes of the mercury specific chromatogram and calibration curve of standard solution of glutathione (GSH) complexed to PHMB (GS-PHMB). The limit of quantitation (LOQ) in terms of GS-PHMB complex was 90 nM (CV 5%) with an injection volume of 35 microL, corresponding to 3.2 pmol (0.97 ng) of GSH. The method has been applied to analysis of extracts of cell cultures from Phaeodactylum tricornutum grown in Cd-containing nutrient solutions, analysed by SEC-DAD-CVGAFS and RPLC-DAD-CVGAFS.

  19. Preparation of thin Si:H films in an inductively coupled plasma reactor and analysis of their surface roughness

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Wenfeng [School of Physics and Telecommunication Engineering, Laboratory of Quantum Information Technology, South China Normal University, Guangzhou 510006 (China); College of Engineering, South China Agricultural University, Guangzhou 510642 (China); Chen Junfang, E-mail: chenjf@scnu.edu.cn [School of Physics and Telecommunication Engineering, Laboratory of Quantum Information Technology, South China Normal University, Guangzhou 510006 (China); Meng Ran; Wang Yang; Wang Hui; Guo Chaofeng; Xue Yongqi [School of Physics and Telecommunication Engineering, Laboratory of Quantum Information Technology, South China Normal University, Guangzhou 510006 (China)

    2010-01-15

    An important concern in the deposition of Si:H films is to obtain smooth surfaces. Herein, we deposit the thin Si:H films using Ar-diluted SiH{sub 4} as feedstock gas in an inductively coupled plasma reactor. And we carry a real-time monitor on the deposition process by using optical emission spectrum technology in the vicinity of substrate and diagnose the Ar plasma radial distribution by Langmuir probe. Surface detecting by AFM and surface profilometry in large scale shows that the thin Si:H films have small surface roughness. Distributions of both the ion density and the electron temperature are homogeneous at h = 0.5 cm. Based on these experimental results, it can be proposed inductively coupled plasma reactor is fit to deposit the thin film in large scale. Also, Ar can affect the reaction process and improve the thin Si:H films characteristics.

  20. Documenting utility of paddlefish otoliths for quantification of metals using inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Long, James M.; Schaffler, James J.

    2013-01-01

    RATIONALE The otoliths of the inner ear of fishes record the environment of their surrounding water throughout their life. For paddlefish (Polyodon spathula), otoliths have not been routinely used by scientists since their detriments were outlined in the early 1940s. We sought to determine if paddlefish otoliths were useful for resolving elemental information contained within. METHODS Adult paddlefish were collected from two wild, self-sustaining populations in Oklahoma reservoirs in the Arkansas River basin. Juveniles were obtained from a hatchery in the Red River basin of Oklahoma. Otoliths were removed and laser ablation, inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify eight elements (Li, Mg, Mn, Rb, Sr, Y, Ba, and Pb) along the core and edge portions, which were analyzed for differences between otolith regions and among paddlefish sources. RESULTS Differences were found among samples for six of the eight elements examined. Otoliths from Red River basin paddlefish born in a hatchery had significantly lower amounts of Mg and Mn, but higher levels of Rb than otoliths from wild paddlefish in the Arkansas River basin. Concentrations of Y, Sr, and Ba were reduced on the edges of adult paddlefish from both reservoirs compared with the cores. CONCLUSIONS This research shows the utility of using an ICP-MS analysis of paddlefish otoliths. Future research that seeks to determine sources of paddlefish production, such as which reservoir tributaries are most important for reproduction or what proportion of the population is composed of wild versus hatchery-produced individuals, appears promising. Published in 2013. This article is a U.S. Government work and is in the public domain in the USA.

  1. Investigation of pyrolysis gas chemistry in an inductively coupled plasma facility

    Science.gov (United States)

    Tillson, Corey C.

    The pyrolysis mechanics of Phenolic Impregnated Carbon Ablators (PICA) makes it a valued material for use in thermal protection systems for spacecraft atmospheric re-entry. The present study of the interaction of pyrolysis gases and char with plasma gases in the boundary layer over PICA and its substrate, FiberForm, extends previous work on this topic that has been done in the UVM 30 kW Inductively Coupled Plasma (ICP) Torch Facility. Exposure of these material samples separately to argon, nitrogen, oxygen, air, and carbon dioxide plasmas, and combinations of said test gases provides insight into the evolution of the pyrolysis gases as they react with the different environments. Measurements done to date include time-resolved absolute emission spectroscopy, location-based temperature response, flow characterization of temperature, enthalpy, and enthalpy flux, and more recently, spatially resolved and high-resolution emission spectroscopy, all of which provide measure of the characteristics of the pyrolysis chemistry and material response. Flow characterization tests construct an general knowledge of the test condition temperature, composition, and enthalpy. Tests with relatively inert argon plasmas established a baseline for the pyrolysis gases that leave the material. Key pyrolysis species such as CN Violet bands, NH, OH and Hydrogen Alpha (Hα) lines were seen with relative repeatability in temporal, spectral, and intensity values. Tests with incremental addition, and static mixtures, of reactive plasmas provided a preliminary image of how the gases interacted with atmospheric flows and other pyrolysis gases. Evidence of a temporal relationship between NH and Hα relating to nitrogen addition is seen, as well as a similar relationship between OH and Hα in oxygen based environments. Temperature analysis highlighted the reaction of the material to various flow conditions and displayed the in depth material response to argon and air/argon plasmas. The development

  2. Analysis of liquid samples using dried-droplet laser ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Do, Trong-Mui; Hsieh, Hui-Fang; Chang, Wei-Ciang [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013 Taiwan (China); Chang, E.-E. [Department of Biochemistry, Taipei Medical University, Taipei City, 11031 Taiwan (China); Wang, Chu-Fang, E-mail: cfwang@mx.nthu.edu.tw [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, 30013 Taiwan (China); Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2011-08-15

    In this study we developed a dried-droplet method for laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The proposed method provides accurate and precise results when building calibration curves and determining elements of interest in real liquid samples. After placing just 1 {mu}L of a liquid standard solution or a real sample onto the filter surface and then converting the solution into a very small, thin dry spot, the sample could be applied as an analytical subject for LA. To demonstrate the feasibility of this proposed method, we used LA-ICP-MS and conventional ICP-MS to determine the levels of 13 elements (Li, V, Mn, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, Tl, and Pb) in five water samples. The correlation coefficients obtained from the various calibration curves ranged from 0.9920 ({sup 205}Tl) to 0.9998 ({sup 51}V), sufficient to allow the determination of a wide range of elements in the samples. We also investigated the effects of Methylene Blue (MB) and the NaCl concentration on the elemental analyses. MB could be used as an indicator during the ablation process; its presence in the samples only negligibly influenced the intensities of the signals of most of the tested elements. Notably, high NaCl contents led to signal suppression for some of the elements. In comparison with the established sample introduction by nebulization, our developed technique abrogates the need for time-consuming sample preparation and reduces the possibility of sample contamination.

  3. Determination of minor elements in steelmaking flue dusts using laser ablation inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Coedo, A G; Padilla, I; Dorado, M T

    2005-07-15

    Element determination in solid waste products from the steel industry usually involves the time-consuming step of preparing a solution of the solid. Laser ablation (LA) inductively coupled plasma mass spectrometry (ICP-MS) has been applied to the analysis of Cr, Ni, Cu, As, Cd and Sn, elements of importance from the point of view of their impact on the environment, in electric arc furnace flue dust (EAFD). A simple method of sample preparation as pressed pellets using a mixture of cellulose and paraffin as binder material was applied. Calibration standards were prepared spiking multielement solution standards to a 1:1 ZnO+Fe(2)O(3) synthetic matrix. The wet powder was dried and mechanically homogenised. Quantitative analysis were based on external calibration using a set of matrix matched calibration standards with Rh as a internal standard. Results obtained using only one-point for calibration without matrix matched, needing less time for standardization and data processing, are also presented. Data are calculated for flue dust reference materials: CRM 876-1 (EAFD), AG-6203 (EAFD), AG-6201 (cupola dust) and AG-SX3705 (coke ashes), and for two representative electrical arc furnace flue dusts samples from Spanish steelmaking companies: MS-1 and MS-2. For the reference materials, an acceptable agreement with certificate values was achieved, and the results for the MS samples matched with those obtained from conventional nebulization solutions (CN). The analytical precision was found to be better than 7% R.S.D. both within a single pellet and between several pellets of the same sample for all the elements.

  4. Langmuir Probe and Mass Spectroscopic Measurements in Inductively Coupled CF4 Plasmas

    Science.gov (United States)

    Rao, M. V. V. S.; Sharma, Surendra; Cruden, B. A.; Meyyappan, M.

    2001-01-01

    Abstract Electron and ion energy distribution functions and other plasma parameters such as plasma potential (V(sub p)) , electron temperature (T(sub e)), and electron and ion number densities (n (sub e) and n(sub i)) in low pressure CF4 plasmas have been measured. The experiments were conducted in a GEC cell using an inductively coupled plasma (ICP) device powered by a 13.56 MHz radio-frequency (rf) power source. The measurements were made at 300 W of input rf power at 10, 30 and 50 mTorr gas pressures. Langmuir probe measurements suggest that n(sub e), n(sub i) and V(sub p) remain constant over 60% of the central electrode area, beyond which they decrease. Within the limits of experimental error (+/- 0.25 eV), T(sub e) remains nearly constant over the electrode area. T(sub e) and V(sub p) increase with a decrease in pressure. n(sub e) and n(sub i) are not affected as significantly as T(sub e) or V(sub p) by variation in the gas pressure. The electron energy distribution function (EEDF) measurements indicate a highly non-Maxwellian plasma. CF3+ is the most dominant ion product of the plasma, followed by CF2+ and CF+. The concentrations of CF2+ and CF+ are much larger than that is possible from direct electron impact ionization of the parent gas. The cross-section data suggest that the direct electron impact ionization of fragment neutrals and negative ion production by electron attachment may be responsible for increase of the minor ions.

  5. Photochemical vapor generation of lead for inductively coupled plasma mass spectrometric detection

    Science.gov (United States)

    Duan, Hualing; Zhang, Ningning; Gong, Zhenbin; Li, Weifeng; Hang, Wei

    2016-06-01

    Photochemical vapor generation (PCVG) of lead was successfully achieved with a simplified and convenient system, in which only low molecular weight organic acid and a high-efficiency photochemical reactor were needed. The reactor was used to generate lead volatile species when a solution of lead containing a small amount of low molecular weight organic acid was pumped through. Several factors, including the concentration of acetic acid, the concentration of hydrochloride acid, and the irradiation time of UV light were optimized. Under the optimal conditions, including the addition of 0.90% (v/v) acetic acid and 0.03% (v/v) hydrochloride acid, and irradiation time of 28 s, intense and repeatable signal of lead volatile species was successfully obtained and identified with inductively coupled plasma mass spectrometry (ICPMS). In addition, the effects from inorganic anions and transition metal ions, including Cl-, NO3-, SO42 -, Cu2 +, Fe3 +, Co2 + and Ni2 +, were investigated, which suggests that their suppression to the PCVG of lead was in the order of Cl- anions and Ni2 +, Co2 + < Fe3 + < Cu2 + for transition metal ions. Under optimized conditions, relative standard derivation (RSD) of 4.4% was achieved from replicate measurements (n = 5) of a standard solution of 0.1 μg L- 1 lead. And, the limit of quantitation (LOQ, 10σ) of 0.012 μg L- 1 lead was obtained using this method and the method blank could be easily controlled down to 0.023 μg L- 1. To validate applicability of this method, it was also employed for the determination of lead in tap water, rain water and lake water.

  6. Determination of total tin in canned food using inductively coupled plasma atomic emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Perring, Loic; Basic-Dvorzak, Marija [Department of Quality and Safety Assurance, Nestle Research Centre, P.O. Box 44, Vers chez-les-Blanc, 1000, Lausanne (Switzerland)

    2002-09-01

    Tin is considered to be a priority contaminant by the Codex Alimentarius Commission. Tin can enter foods either from natural sources, environmental pollution, packaging material or pesticides. Higher concentrations are found in processed food and canned foods. Dissolution of the tinplate depends on the of food matrix, acidity, presence of oxidising reagents (anthocyanin, nitrate, iron and copper) presence of air (oxygen) in the headspace, time and storage temperature. To reduce corrosion and dissolution of tin, nowadays cans are usually lacquered, which gives a marked reduction of tin migration into the food product. Due to the lack of modern validated published methods for food products, an ICP-AES (Inductively coupled plasma-atomic emission spectroscopy) method has been developed and evaluated. This technique is available in many laboratories in the food industry and is more sensitive than atomic absorption. Conditions of sample preparation and spectroscopic parameters for tin measurement by axial ICP-AES were investigated for their ruggedness. Two methods of preparation involving high-pressure ashing or microwave digestion in volumetric flasks were evaluated. They gave complete recovery of tin with similar accuracy and precision. Recoveries of tin from spiked products with two levels of tin were in the range 99{+-}5%. Robust relative repeatabilities and intermediate reproducibilities were <5% for different food matrices containing >30 mg/kg of tin. Internal standard correction (indium or strontium) did not improve the method performance. Three emission lines for tin were tested (189.927, 283.998 and 235.485 nm) but only 189.927 nm was found to be robust enough with respect to interferences, especially at low tin concentrations. The LOQ (limit of quantification) was around 0.8 mg/kg at 189.927 nm. A survey of tin content in a range of canned foods is given. (orig.)

  7. Gunshot residue testing in suicides: Part II: Analysis by inductive coupled plasma-atomic emission spectrometry.

    Science.gov (United States)

    Molina, D Kimberley; Castorena, Joe L; Martinez, Michael; Garcia, James; DiMaio, Vincent J M

    2007-09-01

    Several different methods can be employed to test for gunshot residue (GSR) on a decedent's hands, including scanning electron microscopy with energy dispersive x-ray (SEM/EDX) and inductive coupled plasma-atomic emission spectrometry (ICP-AES). In part I of this 2-part series, GSR results performed by SEM/EDX in undisputed cases of suicidal handgun wounds were studied. In part II, the same population was studied, deceased persons with undisputed suicidal handgun wounds, but GSR testing was performed using ICP-AES. A total of 102 cases were studied and analyzed for caliber of weapon, proximity of wound, and the results of the GSR testing. This study found that 50% of cases where the deceased was known to have fired a handgun immediately prior to death had positive GSR results by ICP/AES, which did not differ from the results of GSR testing by SEM/EDX. Since only 50% of cases where the person is known to have fired a weapon were positive for GSR by either method, this test should not be relied upon to determine whether someone has discharged a firearm and is not useful as a determining factor of whether or not a wound is self-inflicted or non-self-inflicted. While a positive GSR result may be of use, a negative result is not helpful in the medical examiner setting as a negative result indicates that either a person fired a weapon prior to death or a person did not fire a weapon prior to death.

  8. Determination of ammonium and organic bound nitrogen by inductively coupled plasma emission spectroscopy.

    Science.gov (United States)

    Jaber, A M Y; Mehanna, N A; Sultan, S M

    2009-06-15

    The continuous flow sample introduction technique with a hydride generator system in conjunction with an inductively coupled plasma emission spectrometer (ICP-AES-HG), is used in this study for quantitative determination of ammonium and organic bound nitrogen in aqueous and solid samples. Ammonia vapor released from ammonium salt after treatment with concentrated NaOH is transferred by argon to plasma for detection at 174.273 nm using axial argon plasma mode. The calibration curves were linear within a range of 25-1000 mg L(-1)N as ammonium molybdate with correlation coefficients of better than 0.99 and limits of detection of about 10-25mg L(-1)N. The percent recovery of N (25-500 mg L(-1)N) in soft (distilled) water and high salt content (1.7 mol L(-1) NaCl) matrices was found to be in the range of about 97-102% with %RSD in the range of 4.6-0.62. The sensitivity, limit of detection, and blank contribution from the atmospheric nitrogen, were tremendously improved in this method compared with the available ICP-AES spray chamber counterpart. Furthermore, the ICP-AES-HG method gave results for real samples (soil, fertilizer, waste water) containing about 50-1800 mg L(-1)N in good agreement with those obtained by the standard Kjeldahl method. No statistical differences at the 95% confidence level on applying the t-test were observed between the values obtained by the two methods. Thus, the ICP-AES-HG method is reliable and faster than the conventional tedious Kjeldahl method, superior to the ICP-AES spray chamber method, and almost free from matrix interference which is usually a critical factor in atomic emission spectroscopic techniques.

  9. Determination of iodine and bromine compounds in foodstuffs by CE-inductively coupled plasma MS.

    Science.gov (United States)

    Chen, Jing-Huan; Wang, Kai-en; Jiang, Shiuh-Jen

    2007-11-01

    A CE-inductively coupled plasma mass spectrometric (CE-ICP-MS) method for iodine and bromine speciation analysis is described. Samples containing ionic iodine (I(-) and IO(3)(-)) and bromine (Br(-) and BrO(3)(-)) species are subjected to electrophoretic separation before injection into the microconcentric nebulizer (CEI-100). The separation has been achieved in a 50 cm length x 75 microm id fused-silica capillary. The electrophoretic buffer used is 10 mmol/L Tris (pH 8.0), while the applied voltage is set at -8 kV. Detection limits are 1 and 20-50 ng/mL for various I and Br compounds, respectively, based on peak height. The RSD of the peak areas for seven injections of 0.1 microg/mL I(-), IO(3)(-) and 1 microg/mL Br(-), BrO(3)(-) mixture is in the range of 3-5%. This method has been applied to determine various iodine and bromine species in NIST SRM 1573a Tomato Leaves reference material and a salt and seaweed samples obtained locally. A microwave-assisted extraction method is used for the extraction of these compounds. Over 87% of the total iodine and 83% of the total bromine are extracted using a 10% m/v tetramethylammonium hydroxide (TMAH) solution in a focused microwave field within a period of 10 min. The spike recoveries are in the range of 94-105% for all the determinations. The major species of iodine and bromine in tomato leaves, salt, and seaweed are Br(-), IO(3)(-), I(-), and Br(-), respectively.

  10. Ultracentrifugation and inductively coupled plasma mass spectrometry for metal-protein equilibrium studies

    Science.gov (United States)

    Arnquist, Isaac J.; Holcombe, James A.

    2012-10-01

    The coupling of separation by preparative ultracentrifugation and metal detection by inductively coupled plasma mass spectrometry (ICP-MS) has been explored for metal-protein equilibrium determinations. This study characterizes the stoichiometry as well as apparent (Kapp) and intrinsic (Kint) binding affinities of the metal-protein association for a model protein. In particular, the affinity of Cu2 + for the high affinity binding site in bovine serum albumin (BSA) is determined. Once equilibrium is established between Cu2 + and BSA, preparative ultracentrifugation moves the metalloprotein away from the meniscus, leaving unbound equilibrium copper in the protein free solution. Since the initial (total) concentrations of purified BSA and Cu2 + can be determined, the free copper concentration at equilibrium can also be determined by taking a small aliquot above the sedimenting boundary for analysis using ICP-MS. This analysis allows for the determination of free Cu2 + ion, which is identical to the equilibrium concentration prior to ultracentrifugation. From these data Kapp and Kint were determined at two different conditions, 100 mM Tris(hydroxymethyl)aminomethane (Tris) at pH 9.53 and pH 7.93. log Kapp values of 17.6 and 14.6 were determined at pH 9.53 and pH 7.93, respectively. Furthermore, pH-independent log Kint values of - 1.43 and - 1.04 were determined at pH 9.53 and 7.93, respectively. While the log Kint at pH 9.53 was in good agreement with literature values obtained from alternative methods, Kint at pH 7.93 was about 2.5 × larger than previously reported. BSA undergoes a structural rearrangement between pH 7-9, and the generally accepted pH-dependency of protein tertiary structure may be responsible for the variations in the "intrinsic" binding constant. The Cu-BSA binding affinity was also monitored in 100 mM Tris 0.1% sodium dodecyl sulfate (SDS) solution at pH 7.93 in order to determine the effect of a denaturant on metal binding. Results for both log

  11. Relationship between the discharge mode and the spatial oxygen plasma distribution in a large size ferrite inductively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jun [Department of Electrical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); R and D Center for PSK-INC Corporation, Hwaseong-si 445-170 (Korea, Republic of); Hwang, Hye Ju; Cho, Jeong Hee; Chae, Hee Sun [R and D Center for PSK-INC Corporation, Hwaseong-si 445-170 (Korea, Republic of); Kim, Dong Hwan [Department of Nanoscale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Chung, Chin-Wook, E-mail: joykang@hanyang.ac.kr [Department of Electrical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2015-04-15

    The electrical characteristics and the spatial distribution of oxygen plasma according to the number of turns in ferrite inductively coupled plasmas (ferrite ICPs) are investigated. Through a new ICP model, which includes the capacitive coupling and the power loss of the ferrite material with the conventional ICP model, the variation of the oxygen discharge characteristics depending on the number of turns is simply understood by the electrical measurement, such as the antenna voltages and the currents. As the number of the turns increases, the capacitive coupling dominantly affects the spatial plasma distribution. This capacitive coupling results in a center focused density profile along the radial direction. In spite of the same discharge conditions (discharge chamber, neutral gas, and pressure), the spatial plasma distribution over 450 mm has drastic changes by increasing number of the turns. In addition, the effect of the negative species to the density profile is compared with the argon discharge characteristics at the same discharge configuration.

  12. Improved Cd determination in glasses by laser ablation inductively coupled plasma mass spectrometry using nitrogen as a matrix modifier

    Institute of Scientific and Technical Information of China (English)

    Qian Ni; Zhao Chu Hu; Zheng Yu Bao; Ya Feng Zhang

    2009-01-01

    The addition of 5-10 mL min-1 nitrogen to the central channel of plasma in Laser ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) increases the sensitivities of Cd by a factor of 3 and decreases oxide interferences by one order of magnitude, which allows the direct analysis of trace levels of Cd in glass samples. This simple method shows a great potential for the direct determination of Cd in various kinds of samples.

  13. Application of inductively coupled plasma quadrupole mass spectrometry for the determination of monazite ages by lead isotope ratios

    OpenAIRE

    Godoy,José Marcus; Godoy,Maria Luiza D. P; Aronne,Cláudia C.

    2007-01-01

    In order to evaluate the applicability of inductively coupled plasma quadrupole mass spectrometry to the determination of Pb/Pb, U/Pb and Th/Pb ages of monazite, studies were carried out initially applying lead atom ratio reference standards (NIST SRM 981 and 982). Further, the optimized methodology was applied to monazite sands from three different sites, Sugar Loaf Hill (Rio de Janeiro city), Buena (Rio de Janeiro state) and Black Sands Beach (Guarapari, Espirito Santo state); the obtained ...

  14. Elemental analysis using instrumental neutron activation analysis and inductively coupled plasma atomic emission spectrometry: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Choi, Kwang Soon; Moon, Jong Hwa; Kim, Sun Ha; Lim, Jong Myoung; Kim, Young Jin [KAERI, Taejon (Korea, Republic of); Quraishi, Shamshad Begum [Bangladesh Atomic Energy Commission, Dhaka (Bangladesh)

    2003-05-01

    Elemental analyses for certified reference materials were carried out using instrumental neutron activation analysis and inductively coupled plasma-atomic emission spectrometry. Five Certified Reference Materials (CRM) were selected for the study on comparative analysis of environmental samples. The CRM are Soil (NIST SRM 2709), Coal fly ash (NIST SRM 1633a), urban dust (NIST SRM 1649a) and air particulate on filter media (NIST SRM 2783 and human hair (GBW 09101)

  15. Thermal effect and energy-level transition rule for a mesoscopic LC circuit with inductance-capacitance coupling

    Institute of Scientific and Technical Information of China (English)

    Su Jie; Wang Ji-Suo; Liang Bao-Long; Zhang Xiao-Yan

    2009-01-01

    This paper reports that the mesoscopic inductance and capacitance coupling LC circuit is quantized by means of the canonical quantization method. Using the 'invariant eigen-operator' method, it deduces the energy-level transition rule when the system is disturbed by an external electromagnetic field. At the same time, the quantum fluctuations for the system at finite temperature are examined by virtue of the generalized Hellmann-Feynman theorem.

  16. Simultaneous determination of iridoid glycosides, phenethylalcohol glycosides and furfural derivatives in Rehmanniae Radix by high performance liquid chromatography coupled with triple-quadrupole mass spectrometry

    DEFF Research Database (Denmark)

    Xu, Jun; Wu, Jie; Zhu, Ling-Ying

    2012-01-01

    In this study, a sensitive and selective method for simultaneously quantifying eight major components (four iridoid glycosides, three phenethylalcohol glycosides and one furfural derivative) of Rehmanniae Radix by high performance liquid chromatography coupled with triple-quadrupole mass...

  17. Evaluating misoprostol content in pregnant women with hourly oral administration during labor induction by microElution solid phase extraction combined with liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Hung, Cheng-Han; Cheng, Shi-Yann; Chan, Tzu-Min; Lee, Maw-Rong

    2015-09-01

    Misoprostol is a widely used alternative of prostaglandin for labor induction. Based on previous studies, we envision that small and frequent oral dosage of misoprostol is an effective method for labor induction. To monitor the misoprostol content during labor induction, a rapid, sensitive, and selective microElution solid phase extraction (μElution SPE) combined with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. Using μElution SPE could minimize the sample consumption and elution volume in order to maximize the sample enrichment and throughput. The misoprostol acid, a metabolite of misoprostol, was gradient separated in a Bidentate C18 column, then quantified by highly-selective reaction monitoring (H-SRM) in a total run time of 6min. The developed method was optimized and validated in human plasma, and showed linear range of 0.01-10ng/mL. The limit of detection (LOD) was 0.001ng/mL. The recovery ranged from 89.0 to 96.0%, and no significant matrix effect or carryover was observed. The precision, accuracy and stability were met with the criteria of U.S. FDA guidance. The developed method was successfully applied to evaluate misoprostol concentration during labor induction in pregnant women. The concentration-time profiles approves that hourly oral administration of misoprostol is a safe and effective method without drug accumulation for labor induction.

  18. Coupling of a gas chromatograph to a simultaneous-detection inductively coupled plasma mass spectrograph for speciation of organohalide and organometallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, James H.; Schilling, G; Sperline, Roger; Denton, M Bonner B.; Young, Erick T.; Barinaga, Charles J.; Koppenaal, David W.; Hieftje, Gary M.

    2004-06-01

    A gas chromatograph (GC) has been coupled to an inductively coupled plasma Mattauch-Herzog geometry mass spectrograph (ICP-MHMS) equipped with a novel detector array. In its current state of development the detector array, termed the focal plan camera (FPC), permits the simultaneous monitoring of up to 15 m/z values. A heated line was used to transfer the capillary-column effluent from the GC to the ICP torch, though due to instrument operating conditions, the transfer line was terminated 50 mm ahead of the ICP torch. Minimal tailing was observed, with the most severe effect seen for high-boiling analytes. With the coupling, absolute limits of detection are in the tens to hundreds of femtogram regime for organometallic species and in the single pictogram regime for halogenated hydrocarbons.

  19. VACUUM DISTILLATION COUPLED WITH GAS CHROMATOGRAPHY/MASS SPECTROMETRY FOR THE ANALYSIS OF ENVIRONMENTAL SAMPLES

    Science.gov (United States)

    A procedure is presented that uses a vacuum distillation/gas chromatography/mass spectrometry system for analysis of problematic matrices of volatile organic compounds. The procedure compensates for matrix effects and provides both analytical results and confidence intervals from...

  20. Comparative analysis of steroidal saponins in four Dioscoreae herbs by high performance liquid chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Guo, Long; Zeng, Su-Ling; Zhang, Yu; Li, Ping; Liu, E-Hu

    2016-01-01

    Steroidal saponins, which exhibit multiple pharmacological effects, are the major bioactive constituents in herbal medicines from Dioscoreae species. In this study, a sensitive method based on high performance liquid chromatography-mass spectrometry (HPLC-MS) was established and validated for qualitative and quantitative analysis of steroidal saponins in four Dioscoreae herbs including Dioscoreae Nipponica Rhizome (DNR) and Dioscoreae Hypoglaucae Rhizome (DHR), Dioscoreae Spongiosae Rhizome (DSR) and Dioscoreae Rhizome (DR). A total of eleven steroidal saponins were identified by high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF/MS). Furthermore, seven major steroidal saponins was simultaneous quantified using a high performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-QQQ/MS). The qualitative and quantitative analysis results indicated that the chemical composition of DNR, DHR and DSR samples exhibited a high level of global similarity, while the ingredients in DR varied greatly from the other three herbs. Moreover, principal component analysis (PCA) and hierarchical clustering analysis (HCA) were performed to compare and discriminate the Dioscoreae herbs based on the quantitative data. The results demonstrated the qualitative and quantitative analysis of steroidal saponins based on HPLC-MS is a feasible method for quality control of Dioscoreae herbs.

  1. Relative Quantification of Sites of Peptide and Protein Modification Using Size Exclusion Chromatography Coupled with Electron Transfer Dissociation

    Science.gov (United States)

    Xie, Boer; Sharp, Joshua S.

    2016-08-01

    One difficult problem in the analysis of peptide modifications is quantifying isomeric modifications that differ by the position of the amino acid modified. HPLC separation using C18 reverse phase chromatography coupled with electron transfer dissociation (ETD) in tandem mass spectrometry has recently been shown to be able to relatively quantify how much of a given modification occurs at each amino acid position for isomeric mixtures; however, the resolution of reverse phase chromatography greatly complicates quantification of isomeric modifications by ETD because of the chromatographic separation of peptides with identical modifications at different sequence positions. Using peptide oxidation as a model system, we investigated the use of size exclusion chromatography coupled with ETD fragmentation to separate peptide sequences. This approach allows for the benefits of chromatographic separation of peptide sequences while ensuring co-elution of modification isomers for accurate relative quantification of modifications using standard data-dependent acquisitions. Using this method, the relative amount of modification at each amino acid can be accurately measured from single ETD MS/MS spectra in a standard data-dependent acquisition experiment.

  2. Systematic comparison of sensitivity between hydrophilic interaction liquid chromatography and reversed phase liquid chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Periat, Aurélie; Boccard, Julien; Veuthey, Jean-Luc; Rudaz, Serge; Guillarme, Davy

    2013-10-18

    Hydrophilic interaction liquid chromatography (HILIC) appears as a promising strategy to increase sensitivity with electrospray ionization source (ESI/MS). In the present study, peak heights, background noises and signal-to-noise ratios (S/N) obtained with HILIC-MS/MS and RPLC-MS/MS conditions were systematically compared using a dataset of 56 basic drugs possessing diverse physico-chemical properties. Various mobile phase conditions were investigated, including different pH (3 and 6 in HILIC; 3, 6 and 9 in RPLC) and flow rates (300, 600 and 1000μL/min). The average gain in sensitivity obtained between HILIC and RPLC was equal to 7 and 10 at pH 3 and 6, respectively. However, this value was not reliable, since it was altered by a few compounds possessing an "extreme" behaviour (gain in sensitivity from 100-fold to >8000-fold better). Then, the median gain in sensitivity, equal to 4 in our case, whatever the pH, should be considered. For about 90% of the tested compounds and analytical conditions, the best S/N was systematically attained under HILIC mode. Thanks to PCA representation, it was shown that the basic compounds with pKa between 6 and 8 generally had the best sensitivity in HILIC at pH 6, while the best sensitivity for basic analytes possessing pKa higher than 8 was usually obtained in HILIC at pH 3. As previously reported, the sensitivity gain in HILIC vs. RPLC was explained by the difference in acetonitrile concentration at elution (in average 29% ACN in RPLC and 82% ACN in HILIC at pH 6) leading to better analytes' desolvation. However, it seems that this high proportion of solvent also favourably influenced the ionization by modifying pH and pKa. Indeed the weakest bases of our training set of compounds (pKa between 2 and 5) showed an unexpectedly strong gain in sensitivity, between 20 and 100-fold in comparison to RPLC. These results prove that the ionic character of analytes in solution (i.e., pKa and pH) and the ionization mechanism (i.e., proton

  3. Offline coupling of high-speed counter-current chromatography and gas chromatography/mass spectrometry generates a two-dimensional plot of toxaphene components.

    Science.gov (United States)

    Kapp, Thomas; Vetter, Walter

    2009-11-20

    High-speed counter-current chromatography (HSCCC), a separation technique based solely on the partitioning of solutes between two immiscible liquid phases, was applied for the fractionation of technical toxaphene, an organochlorine pesticide which consists of a complex mixture of structurally closely related compounds. A solvent system (n-hexane/methanol/water 34:24:1, v/v/v) was developed which allowed to separate compounds of technical toxaphene (CTTs) with excellent retention of the stationary phase (S(f) = 88%). Subsequent analysis of all HSCCC fractions by gas chromatography coupled to electron-capture negative ion mass spectrometry (GC/ECNI-MS) provided a wealth of information regarding separation characteristics of HSCCC and the composition of technical toxaphene. The visualization of the large amount of data obtained from the offline two-dimensional HSCCC-GC/ECNI-MS experiment was facilitated by the creation of a two-dimensional (2D) contour plot. The contour plot not only provided an excellent overview of the HSCCC separation progress, it also illustrated the differences in selectivity between HSCCC and GC. The results of this proof-of-concept study showed that the 2D chromatographic approach involving HSCCC facilitated the separation of CTTs that coelute in unidimensional GC. Furthermore, the creation of 2D contour plots may provide a useful means of enhancing data visualization for other offline two-dimensional separations.

  4. Elucidation of the aroma compositions of Zhenjiang aromatic vinegar using comprehensive two dimensional gas chromatography coupled to time-of-flight mass spectrometry and gas chromatography-olfactometry.

    Science.gov (United States)

    Zhou, Zhilei; Liu, Shuangping; Kong, Xiangwei; Ji, Zhongwei; Han, Xiao; Wu, Jianfeng; Mao, Jian

    2017-03-03

    In this work, a method to characterize the aroma compounds of Zhenjiang aromatic vinegar (ZAV) was developed using comprehensive two dimensional gas chromatography (GC×GC) coupled with time-of-flight mass spectrometry (TOFMS) and gas chromatography olfactometry (GC-O). The column combination was optimized and good separation was achieved. Structured chromatograms of furans and pyrazines were obtained and discussed. A total of 360 compounds were tentatively identified based on mass spectrum match factors, structured chromatogram and linear retention indices comparison. The most abundant class in number was ketones. A large number of esters, furans and derivatives, aldehydes and alcohols were also detected. The odor-active components were identified by comparison of the reported odor of the identified compounds with the odor of corresponding GC-O region. The odorants of methanethiol, 2-methyl-propanal, 2-methyl-butanal/3-methyl-butanal, octanal, 1-octen-3-one, dimethyl trisulfide, trimethyl-pyrazine, acetic acid, 3-(methylthio)-propanal, furfural, benzeneacetaldehyde, 3-methyl-butanoic acid/2-methyl-butanoic acid and phenethyl acetate were suspected to be the most potent. About half of them were identified as significant aroma constituents in ZAV for the first time. Their contribution to specific sensory attribute of ZAJ was also studied. The results indicated that the presented method is suitable for characterization of ZAV aroma constituents. This study also enriches our knowledge on the components and aroma of ZAV.

  5. Rapid recognition of irradiated dry-cured ham by on-line coupling of reversed-phase liquid chromatography with gas chromatography and mass spectrometry.

    Science.gov (United States)

    Martínez, R M; Barba, C; Calvo, M M; Santa-María, G; Herraiz, M

    2011-06-01

    The use of on-line coupling of reversed-phase liquid chromatography and gas chromatography (RPLC-GC) with the through oven transfer adsorption desorption (TOTAD) interface and mass spectrometry (MS) was proposed for testing different types of commercial Spanish dry-cured ham for irradiation treatment at various doses (0, 1.5, 2, and 4 kGy). The qualitative analysis of radiation-specific compounds (e.g., n-pentadecane, 1-hexadecene, 1,7-hexadecadiene, n-heptadecane, 8-heptadecene, and 2-dodecylcyclobutanone) can be simultaneously established in a single run with samples that have or have not been irradiated. The overall analysis, which takes less than 100 min, includes a rapid extraction step using a small amount of dichloromethane-methanol (1:1, vol/vol) and anhydrous sodium sulfate, the subsequent fractionation of the sample in the first dimension of the system (RPLC), the transfer of the target fraction to the second dimension, the GC separation, and the MS detection. The calculated limits of detection in ham were lower than 22 ng/g. Repeatability studies provided relative standard deviation values of 0.8 to 13.5%.

  6. Antioxidant activity guided separation of major polyphenols of marjoram (Origanum majorana L.) using flash chromatography and their identification by liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Hossain, Mohammad B; Camphuis, Gabriel; Aguiló-Aguayo, Ingrid; Gangopadhyay, Nirupama; Rai, Dilip K

    2014-11-01

    Marjoram extracts have been separated into polar and nonpolar parts using liquid-liquid extraction. Both polar and nonpolar parts of the extracts were further fractionated by flash chromatography. The obtained fractions (90 polar and 45 nonpolar fractions) were investigated for their antioxidant activities by 2,2-diphenylpicrylhydrazyl and ferric ion reducing antioxidant power assays. A direct, positive, and linear relationship between antioxidant activity and total phenolic content of the fractions was observed. Based on antioxidant and total phenolic content data, the three fractions with the high antioxidant activities from polar and nonpolar part of the extract were analyzed for their constituent polyphenols by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Compounds were identified by matching the mass spectral data and retention time with those of authentic standards. Identification of the compounds for which there were no "in-house" standards available was carried out by accurate mass measurement of the precursor ions and product ions generated from collision-induced dissociation. Rosmarinic acid was found to be the strongest antioxidant polyphenol conferring the highest antioxidant activity to fractions 47 and 17 of polar and nonpolar part of the extract, respectively. The identification of the rosmarinic acid was further confirmed by (1) H NMR spectroscopy.

  7. Evaluation of the analytical capability of NIR femtosecond laser ablation-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Hirata, Takafumi; Kon, Yoshiaki

    2008-03-01

    A laser ablation-inductively coupled plasma-mass spectrometric (LA-ICPMS) technique utilizing a titanium-sapphire (TiS) femtosecond laser (fs-laser) has been developed for elemental and isotopic analysis. The signal intensity profile, depth of the ablation pit and level of elemental fractionation were investigated in order to evaluate the analytical capability of the present fs-laser ablation-ICPMS technique. The signal intensity profile of (57)Fe, obtained from iron sulfide (FeS(2)), demonstrated that the resulting signal intensity of (57)Fe achieved by the fs-laser ablation was almost 4-times higher than that obtained by ArF excimer laser ablation under a similar energy fluence (5 J/cm(2)). In fs-laser ablation, there is no significant difference in a depth of the ablation pit between glass and zircon material, while in ArF laser ablation, the resulting crater depth on the zircon crystal was almost half the level than that obtained for glass material. Both the thermal-induced and particle size-related elemental fractionations, which have been thought to be main sources of analytical error in the LA-ICPMS analysis, were measured on a Harvard 91500 zircon crystal. The resulting fractionation indexes on the (206)Pb/(238)U (f(Pb/U)) and (238)U/(232)Th (f(U/Th)) ratios obtained by the present fs-laser ablation system were significantly smaller than those obtained by a conventional ArF excimer laser ablation system, demonstrative of smaller elemental fractionation. Using the present fs-laser ablation technique, the time profile of the signal intensity of (56)Fe and the isotopic ratios ((57)Fe/(54)Fe and (56)Fe/(54)Fe) have been measured on a natural pyrite (FeS(2)) sample. Repeatability in signal intensity of (56)Fe achieved by the fs-laser ablation system was significantly better than that obtained by ArF excimer laser ablation. Moreover, the resulting precision in (57)Fe/(54)Fe and (56)Fe/(54)Fe ratio measurements could be improved by the fs-laser ablation system

  8. Deactivation of lipopolysaccharide by Ar and H2 inductively coupled low-pressure plasma

    Science.gov (United States)

    Bartis, E. A. J.; Barrett, C.; Chung, T.-Y.; Ning, N.; Chu, J.-W.; Graves, D. B.; Seog, J.; Oehrlein, G. S.

    2014-01-01

    Using an inductively coupled plasma system, we study the effects of direct plasma, plasma-generated high-energy photons in the ultraviolet and vacuum ultraviolet (UV/VUV), and radical treatments on lipopolysaccharide (LPS). LPS is a biomolecule found in the outer membrane of Gram-negative bacteria and a potent stimulator of the immune system composed of polysaccharide and lipid A, which contains six aliphatic chains. LPS film thickness spun on silicon was monitored by ellipsometry while the surface chemistry was characterized before and after treatments by x-ray photoelectron spectroscopy (XPS). Additionally, biological activity was measured using an enzyme-linked immunosorbent assay under (a) a sensitive regime (sub-µM concentrations of LPS) and (b) a bulk regime (above µM concentrations of LPS) after plasma treatments. Direct plasma treatment causes rapid etching and deactivation of LPS in both Ar and H2 feed gases. To examine the effect of UV/VUV photons, a long-pass filter with a cut-off wavelength of 112 nm was placed over the sample. H2 UV/VUV treatment causes material removal and deactivation due to atomic and molecular UV/VUV emission while Ar UV/VUV treatment shows minimal effects as Ar plasma does not emit UV/VUV photons in the transmitted wavelength range explored. Interestingly, radical treatments remove negligible material but cause deactivation. Based on the amphiphilic structure of LPS, we expect a lipid A rich surface layer to form at the air-water interface during sample preparation with polysaccharide layers underneath. XPS shows that H2 plasma treatment under direct and UV/VUV conditions causes oxygen depletion through removal of C-O and O-C = O bonds in the films, which does not occur in Ar treatments. Damage to these groups can remove aliphatic chains that contribute to the pyrogenicity of LPS. Radical treatments from both Ar and H2 plasmas remove aliphatic carbon from the near-surface, demonstrating the important role of neutral species.

  9. Investigation of a measure of robustness in inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Makonnen, Yoseif; Beauchemin, Diane

    2015-01-01

    In industrial/commercial settings where operators often have minimal expertise in inductively coupled plasma (ICP) mass spectrometry (MS), there is a prevalent need for a response factor indicating robust plasma conditions, which is analogous to the Mg II/Mg I ratio in ICP optical emission spectrometry (OES), whereby a Mg II/Mg I ratio of 10 constitutes robust conditions. While minimizing the oxide ratio usually corresponds to robust conditions, there is no specific target value that is widely accepted as indicating robust conditions. Furthermore, tuning for low oxide ratios does not necessarily guarantee minimal matrix effects, as they really address polyatomic interferences. From experiments, conducted in parallel for both MS and OES, there were some element pairs of similar mass and very different ionization potential that were exploited for such a purpose, the rationale being that, if these elements were ionized to the same extent, then that could be indicative of a robust plasma. The Be II/Li I intensity ratio was directly related to the Mg II/Mg I ratio in OES. Moreover, the 9Be+/7Li+ ratio was inversely related to the CeO+/Ce+ and LaO+/La+ oxide ratios in MS. The effects of different matrices (i.e. 0.01-0.1 M Na) were also investigated and compared to a conventional argon plasma optimized for maximum sensitivity. The suppression effect of these matrices was significantly reduced, if not eliminated in the case of 0.01 M Na, when the 9Be+/7Li+ ratio was around 0.30 on the Varian 820 MS instrument. Moreover, a very similar ratio (0.28) increased robustness to the same extent on a completely different ICP-MS instrument (PerkinElmer NEXION). Much greater robustness was achieved using a mixed-gas plasma with nitrogen in the outer gas and either nitrogen or hydrogen as a sheathing gas, as the 9Be+/7Li+ ratio was then around 1.70. To the best of our knowledge, this is the first report on using a simple analyte intensity ratio, 9Be+/7Li+, to gauge plasma robustness.

  10. Inductive couple plasma reactive ion etching characteristics of TiO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Garay, Adrian Adalberto; Hwang, Su Min; Chung, Chee Won, E-mail: cwchung@inha.ac.kr

    2015-07-31

    Changes in the inductively coupled plasma reactive ion etching characteristics of TiO{sub 2} thin films in response to the addition of HBr, Cl{sub 2} and C{sub 2}F{sub 6} to Ar gas were investigated. As the HBr, Cl{sub 2} and C{sub 2}F{sub 6} concentration increased, the etch rate increased; however, the etch profile degree of anisotropy followed a different trend. As HBr concentration increased, the greatest anisotropic etch profile was obtained at 100% HBr, while the greatest anisotropic etch profile was obtained at concentrations of 25% when etching was conducted under C{sub 2}F{sub 6} and Cl{sub 2}. Field emission scanning electron microscopy revealed that 25% C{sub 2}F{sub 6} generated the greatest vertical etch profile; hence, etch parameters were varied at this concentration. The effects of rf power, dc-bias voltage and gas pressure on the etch rate and etch profile were also investigated. The etch rate and degree of anisotropy in the etch profile increased with increasing rf power and dc-bias voltage and decreasing gas pressure. X-ray photoelectron spectroscopy analysis of the films etched under a C{sub 2}F{sub 6}/Ar gas mixture revealed the existence of etch byproducts containing F (i.e. TiF{sub x}) over the film. C{sub x}F{sub y} compounds were not detected on the film surface, probably due to contamination with atmospheric carbon. - Highlights: • Reactive ion etching of TiO{sub 2} films under HBr, C{sub 2}F{sub 6}, and Cl{sub 2} gases was studied. • Etch rate and etch profile of TiO{sub 2} films were investigated under each gas chemistry. • The highest degree of anisotropy was achieved at 25% C{sub 2}F{sub 6}/Ar. • Strong etch conditions at 25% C{sub 2}F{sub 6}/Ar increased etch rate and degree of anisotropy. • X-ray photoelectron spectroscopy revealed the existence of F-containing etch residues.

  11. Laser ablation inductively coupled plasma optical emission spectrometry for analysis of pellets of plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Marcos S. [Departamento de Química, Universidade Federal de São Carlos, Rod. Washington Luís, km 235, 13565-905 São Carlos, SP (Brazil); Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Schenk, Emily R. [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States); Santos, Dário [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Rua Professor Arthur Riedel 275, Diadema, SP (Brazil); Krug, Francisco José [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Almirall, José R., E-mail: almirall@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States)

    2014-04-01

    An evaluation of laser ablation inductively coupled plasma optical emission spectroscopy (LAICP OES) for the direct analysis of pelleted plant material is reported. Ground leaves of orange citrus, soy and sugarcane were comminuted using a high-speed ball mill, pressed into pellets and sampled directly with laser ablation and analyzed by ICP OES. The limits of detection (LODs) for the method ranged from as low as 0.1 mg kg{sup −1} for Zn to as high as 94 mg kg{sup −1} for K but were generally below 6 mg kg{sup −1} for most of the elements of interest. A certified reference material consisting of a similar matrix (NIST SRM 1547 peach leaves) was used to check the accuracy of the calibration and the reported method resulted in an average bias of ∼ 5% for all the elements of interest. The precision for the reported method ranged from as low as 4% relative standard deviation (RSD) for Mn to as high as 17% RSD for Zn but averaged ∼ 6.5% RSD for all the elements (n = 10). The proposed method was tested for the determination of Ca, Mg, P, K, Fe, Mn, Zn and B, and the results were in good agreement with those obtained for the corresponding acid digests by ICP-OES, no differences being observed by applying a paired t-test at the 95% confidence level. The reported direct solid sampling method provides a fast alternative to acid digestion that results in similar and appropriate analytical figures of merit with regard to sensitivity, accuracy and precision for plant material analysis. - Highlights: • An evaluation of LA-ICP-OES for the direct analysis of pelleted plant material is reported. • Orange citrus, soy and sugarcane plants were pressed into pellets and sampled directly. • The element menu consisted of Ca, Mg, P, K, Fe, Mn, Zn and B. • LODs for the method ranged from 0.1 mg kg{sup −1} for Zn to 94 mg kg{sup −1} for K. • The precision ranged from 4% RSD for Mn to 17% RSD for Zn (∼ 6.5% RSD average)

  12. Identification of organically associated trace elements in wood and coal by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Richaud, R; Lazaro, M J; Lachas, H; Miller, B B; Herod, A A; Dugwell, D R; Kandiyoti, R

    2000-01-01

    1-Methyl-2-pyrrolidinone (NMP) was used to extract samples of wood (forest residue) and coal; the extracts were analysed by inductively coupled plasma mass spectrometry (ICP-MS) using two different sample preparation methods, in order to identify trace elements associated with the organic part of the samples. A sample of fly ash was similarly extracted and analysed in order to assess the behaviour of the mineral matter contained within the wood and coal samples. 32% of the biomass was extracted at the higher temperature and 12% at room temperature while only 12% of the coal was extracted at the higher temperature and 3% at room temperature. Less than 2% of the ash dissolved at the higher temperature. Size exclusion chromatograms of the extracts indicated the presence of significant amounts of large molecular mass materials (>1000 mu) in the biomass and coal extracts but not in the ash extract. Trace element analyses were carried out using ICP-MS on the acid digests prepared by 'wet ashing' and microwave extraction. Sixteen elements (As, Ba, Be, Cd, Co, Cr, Cu, Ga, Mn, Mo, Ni, Pb, Sb, Se, V and Zn) were quantified, in the samples before extraction, in the extracts and in the residues. Concentrations of trace elements in the original biomass sample were lower than in the coal sample while the concentrations in the ash sample were the highest. The major trace elements in the NMP extracts were Ba, Cu, Mn and Zn from the forest residue; Ba, Cu, Mn, Pb and Zn from the coal; Cu and Zn from the ash. These elements are believed to be associated with the organic extracts from the forest residue and coal, and also from the ash. Be and Sb were not quantified in the extracts because they were present at too low concentrations; up to 40% of Mn was extracted from the biomass sample at 202 degrees C, while Se was totally extracted from the ash sample. For the forest residue, approximately 7% (at room temperature) and 45% (at 202 degrees C) of the total trace elements studied were

  13. Depolymerization of the waste polymers in municipal solid waste streams using induction-coupled plasma technology

    Science.gov (United States)

    Guddeti, Ravikishan Reddy

    2000-10-01

    A significant, valuable percentage of today's municipal solid waste stream consists of polymeric materials, for which almost no economic recycling technology currently exists. This polymeric waste is incinerated, landfilled or recycled via downgraded usage. Thermal plasma treatment is a potentially viable means of recycling these materials by converting them back into monomers or into other useful compounds. The technical, laboratory scale, feasibility of using an induction-coupled RF plasma [ICP] heated reactor for this purpose has been demonstrated in the present study. Polyethylene [PE], polypropylene [PP] and polyethylene terephthalate [PET], the model polymers chosen for the study, were injected axially through the center of an ICP torch. 68% of PE, 78% of PP and 75% of PET were converted into gaseous products. Ethylene and propylene were the primary gaseous products of decomposition of the former two polymers and acetylene was the primary product of the depolymerization of PET. The amount of propylene obtained in PE depolymerization was significantly higher than anticipated and was believed to be due to beta-scission reactions occurring at the high plasma temperatures. Statistical design of experiments was used to determine the influence of individual variables. Analysis of results showed that plasma plate power, central gas flow rate, probe gas flow rate, powder feed rate and the interaction between the quench gas flow rate and power input were the key process parameters affecting the yield of monomer in the product gas stream. Depolymerization of a PE + PP mixture yielded concentrations of propylene and ethylene close to those predicted from weighting the concentrations of products from the individual polymers. 75.5 wt.% of the mixture was converted into monomers. TEM analysis of the carbon residues collected from different locations of the reactor indicated the formation of some novel carbon structures, including carbon nanotubes. The presence of these

  14. Investigation of lanthanum-strontium-cobalt ferrites using laser ablation inductively coupled plasma-mass spectrometry

    Science.gov (United States)

    Óvári, Mihály; Tarsoly, Gergely; Németh, Zoltán; Mihucz, Victor G.; Záray, Gyula

    2017-01-01

    In the present study, suitability of laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for characterization of the purity and homogeneity of lanthanum-strontium-cobalt ferrite (LSCF) ceramic microsamples with general formula La1 - xSrxFe0.025Co0.975O3 (0.00 ≤ x ≤ 0.50) was studied through determination of their Sr:La ratios as well as Sr content either in depth or line profiling mode. The Sr content of the LSCF samples expressed as weight percent ranged between 5.8% and 9.7% in the case of wet chemical ICP-MS analysis, while theoretical values varied from 5.5% to 9.4%. In the case of LA-ICP-MS, relative standard deviation of the La-normalized Sr intensities was sufficient to characterize the homogeneity of the studied samples. Major and trace element (Mn, Ni, Cu, Mg, Al, Ba) concentrations could be detected at medium resolution of the applied sector field ICP-MS instrument after microwave-assisted acid digestion. For depth and line profiling, a successful approach consisted of the normalization of intensities of Sr, Fe and Co with the corresponding La counts. For the determination of the elemental ratios of La and Sr, the methods involving LA were in good agreement with theoretical values by standardization to an in-house standard corresponding to the LSCF sample having the highest x value (i.e., 0.50) checked by wet chemical ICP-MS measurements. Thus, assessment of fine scale doping of synthesized perovskite type of microsamples could be achieved by the proposed LA-ICP-MS based on a novel calibration approach applying an in-house perovskite standard. Therefore, LA-ICP-MS can be recommended for quality control of perovskite-based products. In memoriam Attila Vértes (1934-2011), full professor of the Institute of Chemistry, Eötvös Loránd University, Budapest, Hungary.

  15. Separation of Oligosaccharides from Lotus Seeds via Medium-pressure Liquid Chromatography Coupled with ELSD and DAD

    Science.gov (United States)

    Lu, Xu; Zheng, Zhichang; Miao, Song; Li, Huang; Guo, Zebin; Zhang, Yi; Zheng, Yafeng; Zheng, Baodong; Xiao, Jianbo

    2017-03-01

    Lotus seeds were identified by the Ministry of Public Health of China as both food and medicine. One general function of lotus seeds is to improve intestinal health. However, to date, studies evaluating the relationship between bioactive compounds in lotus seeds and the physiological activity of the intestine are limited. In the present study, by using medium pressure liquid chromatography coupled with evaporative light-scattering detector and diode-array detector, five oligosaccharides were isolated and their structures were further characterized by electrospray ionization-mass spectrometry and gas chromatography-mass spectrometry. In vitro testing determined that LOS3-1 and LOS4 elicited relatively good proliferative effects on Lactobacillus delbrueckii subsp. bulgaricus. These results indicated a structure-function relationship between the physiological activity of oligosaccharides in lotus seeds and the number of probiotics applied, thus providing room for improvement of this particular feature. Intestinal probiotics may potentially become a new effective drug target for the regulation of immunity.

  16. Optimization of the operating conditions of solid sampling electrothermal vaporization coupled to inductively coupled plasma optical emission spectrometry for the sensitive direct analysis of powdered rice.

    Science.gov (United States)

    Sadiq, Nausheen; Beauchemin, Diane

    2014-12-03

    Two different approaches were used to improve the capabilities of solid sampling (SS) electrothermal vaporization (ETV) coupled to inductively coupled plasma optical emission spectrometry (ICP-OES) for the direct analysis of powdered rice. Firstly, a cooling step immediately before and after the vaporization step in the ETV temperature program resulted in a much sharper analyte signal peak. Secondly, point-by-point internal standardization with an Ar emission line significantly improved the linearity of calibration curves obtained with an increasing amount of rice flour certified reference material (CRM). Under the optimized conditions, detection limits ranged from 0.01 to 6ngg(-1) in the solid, depending on the element and wavelength selected. The method was validated through the quantitative analysis of corn bran and wheat flour CRMs. Application of the method to the multi-elemental analysis of 4-mg aliquots of real organic long grain rice (white and brown) also gave results for Al, As, Co, Cu, Fe, Mg, Se, Pb and Zn in agreement with those obtained by inductively coupled plasma mass spectrometry following acid digestion of 0.2-g aliquots. As the analysis takes roughly 5min per sample (2.5min for grinding, 0.5-1min for weighing a 4-mg aliquot and 87s for the ETV program), this approach shows great promise for fast screening of food samples.

  17. Ultracentrifugation and inductively coupled plasma mass spectrometry for metal-protein equilibrium studies

    Energy Technology Data Exchange (ETDEWEB)

    Arnquist, Isaac J.; Holcombe, James A., E-mail: holcombe@mail.utexas.edu

    2012-10-15

    The coupling of separation by preparative ultracentrifugation and metal detection by inductively coupled plasma mass spectrometry (ICP-MS) has been explored for metal-protein equilibrium determinations. This study characterizes the stoichiometry as well as apparent (K{sub app}) and intrinsic (K{sub int}) binding affinities of the metal-protein association for a model protein. In particular, the affinity of Cu{sup 2+} for the high affinity binding site in bovine serum albumin (BSA) is determined. Once equilibrium is established between Cu{sup 2+} and BSA, preparative ultracentrifugation moves the metalloprotein away from the meniscus, leaving unbound equilibrium copper in the protein free solution. Since the initial (total) concentrations of purified BSA and Cu{sup 2+} can be determined, the free copper concentration at equilibrium can also be determined by taking a small aliquot above the sedimenting boundary for analysis using ICP-MS. This analysis allows for the determination of free Cu{sup 2+} ion, which is identical to the equilibrium concentration prior to ultracentrifugation. From these data K{sub app} and K{sub int} were determined at two different conditions, 100 mM Tris(hydroxymethyl)aminomethane (Tris) at pH 9.53 and pH 7.93. log K{sub app} values of 17.6 and 14.6 were determined at pH 9.53 and pH 7.93, respectively. Furthermore, pH-independent log K{sub int} values of - 1.43 and - 1.04 were determined at pH 9.53 and 7.93, respectively. While the log K{sub int} at pH 9.53 was in good agreement with literature values obtained from alternative methods, K{sub int} at pH 7.93 was about 2.5 Multiplication-Sign larger than previously reported. BSA undergoes a structural rearrangement between pH 7-9, and the generally accepted pH-dependency of protein tertiary structure may be responsible for the variations in the 'intrinsic' binding constant. The Cu-BSA binding affinity was also monitored in 100 mM Tris 0.1% sodium dodecyl sulfate (SDS) solution at p

  18. 汞结合金属硫蛋白的色谱-质谱表征方法%Characterization of Mercurial-bound Metallothioneins in Tissues of Rat Kidney by Chromatography Coupled With ICP-MS and ESI-MS

    Institute of Scientific and Technical Information of China (English)

    黄志勇; 沈金灿; 庄峙厦; 王小如; 黎先春

    2004-01-01

    Mercurial-bound metallothioneins (MTs) induced in kidney of rat after oral intake of HgCl2 were characterized with the developed hyphenated techniques including reverse phase chromatography (RPC) coupled with inductively coupled plasma mass spectrometry (ICPMS) and electrospray ionization mass spectrometry(ESIMS). After being purified with size-exclusion column (Sephadex G-75) and dialysis (M<1000 Da), the extracts was separated with a narrow-bore reverse phase column and eluted by increasing methanol at gradient mode. The MT polymorphism with different binding-metal (including Hg, Cu and Zn) species was interpreted by the measured masses at the vicinity of apexes in total ion current (TIC) of ESIMS and the reference data of apo-MTs reported.The results indicated that many Hg-binding MT species existed in the polluted rat kidney.

  19. Arsenic speciation in edible alga samples by microwave-assisted extraction and high performance liquid chromatography coupled to atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Salgado, S. [Departamento de Ingenieria Civil: Tecnologia Hidraulica y Energetica, Escuela Universitaria de Ingenieria Tecnica de Obras Publicas, Universidad Politecnica de Madrid, Alfonso XII 3 y 5, 28014 Madrid (Spain); Quijano, M.A., E-mail: marian.quijano@upm.es [Departamento de Ingenieria Civil: Tecnologia Hidraulica y Energetica, Escuela Universitaria de Ingenieria Tecnica de Obras Publicas, Universidad Politecnica de Madrid, Alfonso XII 3 y 5, 28014 Madrid (Spain); Bonilla, M.M. [Departamento de Ingenieria Civil: Tecnologia Hidraulica y Energetica, Escuela Universitaria de Ingenieria Tecnica de Obras Publicas, Universidad Politecnica de Madrid, Alfonso XII 3 y 5, 28014 Madrid (Spain)

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer Total As and As species were analyzed in edible marine algae. Black-Right-Pointing-Pointer A microwave-assisted extraction method with deionized water was applied. Black-Right-Pointing-Pointer As compounds identified comprised DMA, As(V) and four arsenosugars Black-Right-Pointing-Pointer Considerably high As(V) concentrations were found in the most of the algae studied. - Abstract: Twelve commercially available edible marine algae from France, Japan and Spain and the certified reference material (CRM) NIES No. 9 Sargassum fulvellum were analyzed for total arsenic and arsenic species. Total arsenic concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) after microwave digestion and ranged from 23 to 126 {mu}g g{sup -1}. Arsenic species in alga samples were extracted with deionized water by microwave-assisted extraction and showed extraction efficiencies from 49 to 98%, in terms of total arsenic. The presence of eleven arsenic species was studied by high performance liquid chromatography-ultraviolet photo-oxidation-hydride generation atomic-fluorescence spectrometry (HPLC-(UV)-HG-AFS) developed methods, using both anion and cation exchange chromatography. Glycerol and phosphate sugars were found in all alga samples analyzed, at concentrations between 0.11 and 22 {mu}g g{sup -1}, whereas sulfonate and sulfate sugars were only detected in three of them (0.6-7.2 {mu}g g{sup -1}). Regarding arsenic toxic species, low concentration levels of dimethylarsinic acid (DMA) (<0.9 {mu}g g{sup -1}) and generally high arsenate (As(V)) concentrations (up to 77 {mu}g g{sup -1}) were found in most of the algae studied. The results obtained are of interest to highlight the need to perform speciation analysis and to introduce appropriate legislation to limit toxic arsenic species content in these food products.

  20. Flow-field differences and electromagnetic-field properties of air and N2 inductively coupled plasmas

    Science.gov (United States)

    Yu, Minghao; Yamada, Kazuhiko; Takahashi, Yusuke; Liu, Kai; Zhao, Tong

    2016-12-01

    A numerical model for simulating air and nitrogen inductively coupled plasmas (ICPs) was developed considering thermochemical nonequilibrium and the third-order electron transport properties. A modified far-field electromagnetic model was introduced and tightly coupled with the flow field equations to describe the Joule heating and inductive discharge phenomena. In total, 11 species and 49 chemical reactions of air, which include 5 species and 8 chemical reactions of nitrogen, were employed to model the chemical reaction process. The internal energy transfers among translational, vibrational, rotational, and electronic energy modes of chemical species were taken into account to study thermal nonequilibrium effects. The low-Reynolds number Abe-Kondoh-Nagano k-ɛ turbulence model was employed to consider the turbulent heat transfer. In this study, the fundamental characteristics of an ICP flow, such as the weak ionization, high temperature but low velocity in the torch, and wide area of the plasma plume, were reproduced by the developed numerical model. The flow field differences between the air and nitrogen ICP flows inside the 10-kW ICP wind tunnel were made clear. The interactions between the electromagnetic and flow fields were also revealed for an inductive discharge.

  1. Plasma lipid analysis by hydrophilic interaction liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Sonomura, Kazuhiro; Kudoh, Shinobu; Sato, Taka-Aki; Matsuda, Fumihiko

    2015-06-01

    A novel method for the analysis of endogenous lipids and related compounds was developed employing hydrophilic interaction liquid chromatography with electrospray ionization tandem mass spectrometry. A hydrophilic interaction liquid chromatography with carbamoyl stationary phase achieved clear separation of phosphatidylcholine, lysophosphatidylcholine, sphingomyelin, ceramide, and mono-hexsosyl ceramide groups with good peak area repeatability (RSD% 0.99). The established method was applied to human plasma assays and a total of 117 endogenous lipids were successfully detected and reproducibly identified. In addition, we investigated the simultaneous detection of small polar metabolites such as amino and organic acids co-existing in the same biological samples processed in a single analytical run with lipids. Our results show that hydrophilic interaction liquid chromatography is a useful tool for human plasma lipidome analysis and offers more comprehensive metabolome coverage.

  2. Fabrication and application of a wireless inductance-capacitance coupling microsensor with electroplated high permeability material NiFe

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y H; Chang, I N [Ph. D. Program in Electrical and Communications Engineering, Feng-Chia University, Taichung 40724, Taiwan (China); Chang, H C; Lai, C C, E-mail: hcchang@fcu.edu.tw [Department of Automatic Control Engineering, Feng-Chia University, Taichung 40724, Taiwan (China)

    2011-01-01

    A fully integrated wireless inductance-capacitance (LC) coupling microsensor was designed and fabricated by MEMS technology. The sensing loop was formed by connecting a deformable parallel-plated capacitor and a planar spiral inductor with a Ni(80)Fe(20) core. Polyimide and PMMA were used to isolate and package the devices. Typical dimension of the sensors was 5 x 5 mm{sup 2} x 0.77 mm. Different electroplated inductive coils (30, 40, and 60 turns) were fabricated to connect with a 4 x 4 mm{sup 2} plate capacitor in series. The LC sensing module for measuring liquid-level induced frequency responses was setup. Experimental results show that frequency response decreased as liquid level increased and sensitivity is about 7.01 kHz/cm with deviation less than 2%. Developed planar spiral inductor with high permeability magnetic core can provide a wide range of frequency variation in LC sensing applications.

  3. Influence of Discharge Parameters on Tuned Substrate Self-Bias in an Radio-Frequency Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    Ding Zhenfeng; Sun Jingchao; Wang Younian

    2005-01-01

    The tuned substrate self-bias in an rf inductively coupled plasma source is controlled by means of varying the impedance of an external LC network inserted between the substrate and the ground. The influencing parameters such as the substrate axial position, different coupling coils and inserted resistance are experimentally studied. To get a better understanding of the experimental results, the axial distributions of the plasma density, electron temperature and plasma potential are measured with an rf compensated Langmuir probe; the coil rf peak-to-peak voltage is measured with a high voltage probe. As in the case of changing discharge power, it is found that continuity, instability and bi-stability of the tuned substrate bias can be obtained by means of changing the substrate axial position in the plasma source or the inserted resistance. Additionally,continuity can not transit directly into bi-stability, but evolves via instability. The inductance of the coupling coil has a substantial effect on the magnitude and the property of the tuned substrate bias.

  4. TRACE ANALYSIS OF FLUORESCEIN-DERIVATIZED PHENOXY ACID HERBICIDES BY MICELLAR ELECTROKINETIC CHROMATOGRAPHY WITH LASER-INDUCTED FLUORESCENCE DETECTION

    Science.gov (United States)

    Micellar electrokinetic chromatography (MEKC) with laser-induced fluorescence (LIF) detection was used for the trace analysis of phenoxy acid herbicides. Capillary electrophoresis (CE) with LIF detection, which has not previously been used for pesticide analysis, overcomes the po...

  5. Coupling of electrokinetic chromatography and mass spectrometry for profiling of drugs

    NARCIS (Netherlands)

    Mol, R.

    2007-01-01

    In this thesis the potential of electrokinetic chromatography (EKC) – mass spectrometry (MS) has been evaluated, including its applicability to the impurity profiling of drugs. Over the past years, capillary zone electrophoresis (CZE) and EKC have gained acceptance as separation techniques next to l

  6. Analysis of therapeutic proteins and peptides using multiangle light scattering coupled to ultra high performance liquid chromatography.

    Science.gov (United States)

    Espinosa-de la Garza, Carlos E; Miranda-Hernández, Mariana P; Acosta-Flores, Lilia; Pérez, Néstor O; Flores-Ortiz, Luis F; Medina-Rivero, Emilio

    2015-05-01

    Analysis of the physical properties of biotherapeutic proteins is crucial throughout all the stages of their lifecycle. Herein, we used size-exclusion ultra high performance liquid chromatography coupled to multiangle light scattering and refractive index detection systems to determine the molar mass, mass-average molar mass, molar-mass dispersity and hydrodynamic radius of two monoclonal antibodies (rituximab and trastuzumab), a fusion protein (etanercept), and a synthetic copolymer (glatiramer acetate) employed as models. A customized instrument configuration was set to diminish band-broadening effects and enhance sensitivity throughout detectors. The customized configuration showed a performance improvement with respect to the high-performance liquid chromatography standard configuration, as observed by a 3 h column conditioning and a higher resolution analysis in 20 min. Analysis of the two monoclonal antibodies showed averaged values of 148.0 kDa for mass-average molar mass and 5.4 nm for hydrodynamic radius, whereas for etanercept these values were 124.2 kDa and 6.9 nm, respectively. Molar-mass dispersity was 1.000 on average for these proteins. Regarding glatiramer acetate, a molar mass range from 3 to 45 kDa and a molar-mass dispersity of 1.304 were consistent with its intrinsic peptide diversity, and its mass-average molar mass was 10.4 kDa. Overall, this method demonstrated an accurate determination of molar mass, overcoming the difficulties of size-exclusion chromatography.

  7. [Quantification of acrylamide in foods by gas chromatography-mass spectrometry coupled with pro-column derivatization].

    Science.gov (United States)

    Yang, Sichao; Zhang, Hui; Wang, Junhan; Chen, Fang

    2011-05-01

    The quantification of acrylamide in foods was investigated by gas chromatography-mass spectrometry (GC-MS). In this method, (13)C3-acrylamide was used as an internal standard. The samples were homogenized, defatted with hexane and extracted with ethyl acetate for twice. The derivatization of acrylamide into 2-bromopropenamide (2-BPA) was done using potassium bromide/potassium bromate at 4 degrees C for 90 min. Selective ion monitoring mode was chosen to monitor objective chromatography. This method had a good linearity between 0.05-2.00 mg/kg (r2 = 0.9995), and the limits of detection and quantification were 3 microg/kg and 7 microg/kg, respectively. The recoveries of acrylamide were in the range of 62.7%-65.5%. In order to confirm this GC-MS method, the acrylamide in foods was also determined by high performance liquid chromatography coupled to quadrupole tandem mass spectrometry (HPLC-MS/MS), which had been proved in our laboratory. The concentrations of acrylamide in the samples quantified by GC-MS were slightly higher than those detected by HPLC-MS/MS. This method can be used to quantify acrylamide in normal foods.

  8. Femtosecond laser ablation: Experimental study of the repetition rate influence on inductively coupled plasma mass spectrometry performance

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Jhanis J. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Fernandez, Alberto [Centro de Fisicoquimica. Escuela de Quimica, Universidad Central de Venezuela, Caracas 1020-A (Venezuela); Oropeza, Dayana; Mao Xianglei [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Russo, Richard E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)], E-mail: RERusso@lbl.gov

    2008-02-15

    This paper demonstrates the feasibility of performing bulk chemical analysis based on laser ablation for good lateral resolution with only nominal mass ablated per pulse. The influence of repetition rate (1-1000 Hz) and scan speed (1-200 {mu}m/s) using a low energy (30 {mu}J) and a small spot size ({approx} 10 {mu}m) UV-femtosecond laser beam was evaluated for chemical analysis of silica glass samples, based on laser ablation sampling and inductively coupled plasma mass spectrometry (ICP-MS). Accuracy to approximately 14% and precision of 6% relative standard deviation (RSD) were measured.

  9. Uncertainty Estimation of Metals and Semimetals Determination in Wastewater by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES)

    Science.gov (United States)

    Marques, J. R.; Villa-Soares, S. M.; Stellato, T. B.; Silva, T. B. S. C.; Faustino, M. G.; Monteiro, L. R.; Pires, M. A. F.; Cotrim, M. E. B.

    2016-07-01

    The measurement uncertainty is a parameter that represents the dispersion of the results obtained by a method of analysis. The estimation of measurement uncertainty in the determination of metals and semimetals is important to compare the results with limits defined by environmental legislation and conclude if the analytes are meeting the requirements. Therefore, the aim of this paper is present all the steps followed to estimate the uncertainty of the determination of amount of metals and semimetals in wastewater by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Measurement uncertainty obtained was between 4.6 and 12.2% in the concentration range of mg.L-1.

  10. Magneto-structural Coupling Field Analysis on the End Winding of a Multi-phase Induction Machine

    Directory of Open Access Journals (Sweden)

    Liu Hailong

    2012-09-01

    Full Text Available In order to study the steady-state electromagnetic forces acting on the stator end-winding in a multi-phase induction machine during the operation, we conducted a 3-D electromagnetic and mechanical sequential coupling analysis to analyze the stress and the deformation. Both of them are done by the finite-element method. Meanwhile, the geometry of the nose portion is modified for the limited computer resources. The result shows the nose part of the coil ends experiences larger displacement, but von Mises stresses are larger in the straight part.

  11. Differentiation of colloidal and dissolved silica: Analytical separation using spectrophotometry and inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Lewis-Russ, A.; Ranville, J.; Kashuba, A.T.

    1991-01-01

    A method is described that differentiates between solutions containing silica-dominated colloids and solutions that are essentially free of colloids. Suspensions of tuff particles were treated to remove colloids by centrifugation, filtration or both. Agreement of silica concentrations determined by inductively coupled plasma atomic emission spectrometry and by a spectrophotometric method was taken as an indication of colloid-free solutions. For two tuffs, centrifugation was effective for removing colloids. For the third, highly altered tuff, filtration was more effective for removing colloids.

  12. Inductively coupled plasma-atomic emission spectroscopy: a computer controlled, scanning monochromator system for the rapid determination of the elements

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, M.A.

    1980-03-01

    A computer controlled, scanning monochromator system specifically designed for the rapid, sequential determination of the elements is described. The monochromator is combined with an inductively coupled plasma excitation source so that elements at major, minor, trace, and ultratrace levels may be determined, in sequence, without changing experimental parameters other than the spectral line observed. A number of distinctive features not found in previously described versions are incorporated into the system here described. Performance characteristics of the entire system and several analytical applications are discussed.

  13. A low-power ASK demodulator for inductively coupled implantable electronics

    DEFF Research Database (Denmark)

    Gudnason, Gunnar

    2000-01-01

    An amplitude shift keying (ASK) demodulator is presented which is suitable for implantable electronic devices that are powered through an inductive link. The demodulator has been tested with carrier frequencies in the range 1-15 MHz, covering most commonly used frequencies. Data rates up to several...

  14. A Maximum Efficiency Point Tracking Control Scheme Based on Different Cross Coupling of Dual-Receiver Inductive Power Transfer System

    Directory of Open Access Journals (Sweden)

    Ruikun Mai

    2017-02-01

    Full Text Available One of the most promising inductive power transfer applications is the wireless power supply for locomotives which may cancel the need for pantographs. In order to meet the dynamic and high power demands of wireless power supplies for locomotives, a relatively long transmitter track and multiple receivers are usually adopted. However, during the dynamic charging, the mutual inductances between the transmitter and receivers vary and the load of the locomotives also changes randomly, which dramatically affects the system efficiency. A maximum efficiency point tracking control scheme is proposed to improve the system efficiency against the variation of the load and the mutual inductances between the transmitter and receivers while considering the cross coupling between receivers. Firstly, a detailed theoretical analysis on dual receivers is carried out. Then a control scheme with three control loops is proposed to regulate the receiver currents to be the same, to regulate the output voltage and to search for the maximum efficiency point. Finally, a 2 kW prototype is established to validate the performance of the proposed method. The overall system efficiency (DC-DC efficiency reaches 90.6% at rated power and is improved by 5.8% with the proposed method under light load compared with the traditional constant output voltage control method.

  15. Contactless vector network analysis using diversity calibration with capacitive and inductive coupled probes

    Directory of Open Access Journals (Sweden)

    T. Zelder

    2007-06-01

    Full Text Available Contactless vector network analysis based on a diversity calibration is investigated for the measurement of embedded devices in planar circuits. Conventional contactless measurement systems based on two probes for each measurement port have the disadvantage that the signal-to-noise system dynamics strongly depends on the distance between the contactless probes.

    In order to avoid a decrease in system dynamics a diversity based measurement system is presented. The measurement setup uses one inductive and two capacitive probes. As an inductive probe a half magnetic loop in combination with a broadband balun is introduced. In order to eliminate systematic errors from the measurement results a diversity calibration algorithm is presented. Simulation and measurement results for a one-port configuration are shown.

  16. Radionuclide Determination In Surface Water Samples By Inductively Coupled Plasma With Sector Field Mass Spectrometry (ICP-SFMS

    Directory of Open Access Journals (Sweden)

    E. T. Romero-Guzmán

    2016-08-01

    Full Text Available The determination of naturally occurring radionuclides in the environment by inductively coupled plasma mass spectrometry of high resolution (ICP-SFMS has gained recognition over the last fifteen years, relative to the radiometric techniques, as the result of improvement in instrumental performance, sample introduction equipment and sample preparation. With the increase in instrumental sensitivity, it is now possible to measure ultratrace levels of many radioisotopes. The aim of this work was to determined the natural radionuclides (232Th, 234U, 235U and 238U in surface water using Inductively Coupled PlasmaSector Field Mass Spectrometry (ICP-SFMS. The samples were sampling from Lerma river, State of Mexico at february to april 2015. The process of treatment of sample consisted in perform an acid digestion according to the 3015A USEPA method followed of the direct measurement in ICP-SFMS. Results obtained were: a identify the presence of 232Th, 234U, 235U and 238U isotopes in water, b isotopic ratios were for 234U/238U=1.133 ± 0.016. ICPSFMS has gained popularity in the field of radiochemistry, particularly as a method of detection for long lived-actinides.

  17. Measuring Inductive-Heating Coupling Coefficients and Thermal Loss Characteristics as a Function of Crucible Geometry and Material Selection

    Science.gov (United States)

    Gomes, Jay

    A power measurement system has been designed for an ultra-high temperature inductively heated molten oxide electrolysis (MOE) reactor. The work presented in this research contributes to three different aspects of the induction heated MOE reactor facility: mathematical modeling of coil-to-workpiece power transfer, numerical modeling of heat transfer within the reactor, and experiments to measure the total hemispherical emittance of potential crucible materials. Facility-specific coupling coefficients for various samples have been experimentally determined for the MOE reactor facility. An analytical model coupling the predicted power input with heat transfer software was developed using COMSOL Multiphysics, and validated with experimental measurements of the steady state temperature gradient inside the reactor. These models were used to support the design of an experiment to measure the total hemispherical emissivity (epsilon) of conductive samples using a transient calorimetric technique. Results of epsilon are presented over a wide range of temperatures for copper, nickel, graphite and molybdenum. Furthermore, an investigation into optimizing the reactor system for heating will be discussed.

  18. Multi-elemental analysis of aqueous geochemical samples by quadrupole inductively coupled plasma-mass spectrometry (ICP-MS)

    Science.gov (United States)

    Wolf, Ruth E.; Adams, Monique

    2015-01-01

    Typically, quadrupole inductively coupled plasma-mass spectrometry (ICP-MS) is used to determine as many as 57 major, minor, and trace elements in aqueous geochemical samples, including natural surface water and groundwater, acid mine drainage water, and extracts or leachates from geological samples. The sample solution is aspirated into the inductively coupled plasma (ICP) which is an electrodeless discharge of ionized argon gas at a temperature of approximately 6,000 degrees Celsius. The elements in the sample solution are subsequently volatilized, atomized, and ionized by the ICP. The ions generated are then focused and introduced into a quadrupole mass filter which only allows one mass to reach the detector at a given moment in time. As the settings of the mass analyzer change, subsequent masses are allowed to impact the detector. Although the typical quadrupole ICP-MS system is a sequential scanning instrument (determining each mass separately), the scan speed of modern instruments is on the order of several thousand masses per second. Consequently, typical total sample analysis times of 2–3 minutes are readily achievable for up to 57 elements.

  19. Modeling RP-1 Fuel Advanced Distillation Data using Comprehensive Two-Dimensional Gas Chromatography Coupled with Time-of-Flight Mass Spectrometry and Partial Least Squares Analysis

    Science.gov (United States)

    2014-05-07

    Advanced Distillation Data using Comprehensive Two- Dimensional Gas Chromatography coupled with Time-of-Flight Mass Spectrometry and Partial Least Squares...that included comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GC × GC –TOFMS) to analyze RP-1 fuels...each RP-1 fuel with good precision and accuracy. The predictive power of the overall method via PLS modeling was assessed using leave -one-out cross

  20. Investigations into the origins of polyatomic ions in inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Sally M. [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    An inductively coupled plasma-mass spectrometer (ICP-MS) is an elemental analytical instrument capable of determining nearly all elements in the periodic table at limits of detection in the parts per quadrillion and with a linear analytical range over 8-10 orders of magnitude. Three concentric quartz tubes make up the plasma torch. Argon gas is spiraled through the outer tube and generates the plasma powered by a looped load coil operating at 27.1 or 40.6 MHz. The argon flow of the middle channel is used to keep the plasma above the innermost tube through which solid or aqueous sample is carried in a third argon stream. A sample is progressively desolvated, atomized and ionized. The torch is operated at atmospheric pressure. To reach the reduced pressures of mass spectrometers, ions are extracted through a series of two, approximately one millimeter wide, circular apertures set in water cooled metal cones. The space between the cones is evacuated to approximately one torr. The space behind the second cone is pumped down to, or near to, the pressure needed for the mass spectrometer (MS). The first cone, called the sampler, is placed directly in the plasma plume and its position is adjusted to the point where atomic ions are most abundant. The hot plasma gas expands through the sampler orifice and in this expansion is placed the second cone, called the skimmer. After the skimmer traditional MS designs are employed, i.e. quadrupoles, magnetic sectors, time-of-flight. ICP-MS is the leading trace element analysis technique. One of its weaknesses are polyatomic ions. This dissertation has added to the fundamental understanding of some of these polyatomic ions, their origins and behavior. Although mainly continuing the work of others, certain novel approaches have been introduced here. Chapter 2 includes the first reported efforts to include high temperature corrections to the partition functions of the polyatomic ions in ICP-MS. This and other objections to preceeding

  1. Investigations into the origins of polyatomic ions in inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Sally M. [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    An inductively coupled plasma-mass spectrometer (ICP-MS) is an elemental analytical instrument capable of determining nearly all elements in the periodic table at limits of detection in the parts per quadrillion and with a linear analytical range over 8-10 orders of magnitude. Three concentric quartz tubes make up the plasma torch. Argon gas is spiraled through the outer tube and generates the plasma powered by a looped load coil operating at 27.1 or 40.6 MHz. The argon flow of the middle channel is used to keep the plasma above the innermost tube through which solid or aqueous sample is carried in a third argon stream. A sample is progressively desolvated, atomized and ionized. The torch is operated at atmospheric pressure. To reach the reduced pressures of mass spectrometers, ions are extracted through a series of two, approximately one millimeter wide, circular apertures set in water cooled metal cones. The space between the cones is evacuated to approximately one torr. The space behind the second cone is pumped down to, or near to, the pressure needed for the mass spectrometer (MS). The first cone, called the sampler, is placed directly in the plasma plume and its position is adjusted to the point where atomic ions are most abundant. The hot plasma gas expands through the sampler orifice and in this expansion is placed the second cone, called the skimmer. After the skimmer traditional MS designs are employed, i.e. quadrupoles, magnetic sectors, time-of-flight. ICP-MS is the leading trace element analysis technique. One of its weaknesses are polyatomic ions. This dissertation has added to the fundamental understanding of some of these polyatomic ions, their origins and behavior. Although mainly continuing the work of others, certain novel approaches have been introduced here. Chapter 2 includes the first reported efforts to include high temperature corrections to the partition functions of the polyatomic ions in ICP-MS. This and other objections to preceeding

  2. Improving accuracy in the quantitation of overlapping, asymmetric, chromatographie peaks by deconvolution: theory and application to coupled gas chromatography atomic absorption spectrometry

    Science.gov (United States)

    Johansson, M.; Berglund, M.; Baxter, D. C.

    1993-09-01

    Systematic errors in the measurement of overlapping asymmetric, Chromatographic peaks are observed using the perpendicular-drop and tangent-skimming algorithms incorporated in commercial integrators. The magnitude of such errors increases with the degree of tailing and differences in peak size, and was found to be as great as 80% for peak-area and 100% for peak-height measurements made on the smaller, second component of simulated, noise-free chromatograms containing peaks at a size ratio of 10 to 1. Initial deconvolution of overlapping peaks, by mathematical correction for asymmetry, leads to significant improvements in the accuracy of both peak-area and height measurements using the simple, perpendicular-drop algorithm. A comparison of analytical data for the separation and determination of three organolead species by coupled gas chromatography atomic absorption spectrometry using peak-height and area measurements also demonstrates the improved accuracy obtained following deconvolution. It is concluded that the deconvolution method described could be beneficial in a variety of Chromatographic applications where overlapping, asymmetric peaks are observed.

  3. Potential of ion chromatography coupled to isotope ratio mass spectrometry via a liquid interface for beverages authentication.

    Science.gov (United States)

    Guyon, Francois; Gaillard, Laetitia; Brault, Audrey; Gaultier, Nicolas; Salagoïty, Marie-Hélène; Médina, Bernard

    2013-12-27

    New tools for the determination of characteristic parameters for food authentication are requested to prevent food adulteration from which health concerns, unfair competition could follow. A new coupling in the area of compound-specific carbon 13 isotope ratio (δ(13)C) analysis was developed to simultaneously quantify δ(13)C values of sugars and organic acids. The coupling of ion chromatography (IC) together with isotope ratio mass spectrometry (IRMS) can be achieved using a liquid interface allowing a chemical oxidation (co) of organic matter. Synthetic solutions containing 1 polyol (glycerol), 3 carbohydrates (sucrose, glucose and fructose) and 12 organic acids (gluconic, lactic, malic, tartaric, oxalic, fumaric, citric and isocitric) were used to optimize chromatographic conditions (concentration gradient and 3 types of column) and the studied isotopic range (-32.28 to -10.65‰) corresponds to the values found in food products. Optimum chromatographic conditions are found using an IonPac AS15, an elution flow rate of 0.3mLmin(-1) and a linear concentration gradient from 2 to 76mM (rate 21mMmin(-1)). Comparison between δ(13)C value individually obtained for each compound with the coupling IRMS and elemental analyzer, EA-IRMS, and the ones measured on the mixture of compounds by IC-co-IRMS does not reveal any isotope fractionation. Thus, under these experimental conditions, IC-co-IRMS results are accurate and reproducible. This new coupling was tested on two food matrices, an orange juice and a sweet wine. Some optimization is necessary as the concentration range between sugars and organic acids is too large: an increase in the filament intensity of the IRMS is necessary to simultaneously detect the two compound families. These first attempts confirm the good results obtained on synthetic solutions and the strong potential of the coupling IC-co-IRMS in food authentication area.

  4. Pesticide analysis at ppt concentration levels: coupling nano-liquid chromatography with dielectric barrier discharge ionization-mass spectrometry.

    Science.gov (United States)

    Mirabelli, Mario F; Wolf, Jan-Christoph; Zenobi, Renato

    2016-05-01

    We report the coupling of nano-liquid chromatography (nano-LC) with an ambient dielectric barrier discharge ionization (DBDI)-based source. Detection and quantification were carried out by high-resolution mass spectrometry (MS), using an LTQ-Orbitrap in full scan mode. Despite the fact that nano-LC systems are rarely used in food analysis, this coupling was demonstrated to deliver extremely high sensitivity in pesticide analysis, with limits of detection (LODs) as low as 10 pg/mL. In all cases, the limits of quantification (LOQs) were compliant with the current EU regulation. An excellent signal linearity over up to four orders of magnitude was also observed. Therefore, this method can easily compete with conventional GC-(EI)-MS or LC-ESI-MS/MS methods and in some cases outperform them. The method was successfully tested for food sample analysis, with apples and baby food, extracted using the QuEChERS approach. Our results demonstrate an outstanding sensitivity (at femtogram level) and reproducibility of the nano-LC-DBDI coupling, capable of improving routine pesticide analysis. To the best of our knowledge, this is the most sensitive and reproducible plasma-MS-based method for pesticide analysis reported to date.

  5. Direct determination of melamine in dairy products by gas chromatography/mass spectrometry with coupled column separation

    Energy Technology Data Exchange (ETDEWEB)

    Xu Xiaomin [Department of Chemistry, Xixi Campus, Zhejiang University, Hangzhou, 310028 (China); Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051 (China); Ren Yiping [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051 (China); Zhu Yun [Xinjiang Uygur Autonomous Region Center for Disease Control and Prevention, Urumchi, 830002 (China); Cai Zengxuan; Han Jianlong; Huang Baifen [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, 310051 (China); Zhu Yan, E-mail: zhuyan@zju.edu.cn [Department of Chemistry, Xixi Campus, Zhejiang University, Hangzhou, 310028 (China)

    2009-09-14

    A coupled capillary column system was developed for the qualitative and quantitative determination of melamine with isotope internal standard in dairy products by gas chromatography/mass spectrometry (GC/MS) without derivatization. A 30 m of DB-5ms ((5%-phenyl)-methylpolysiloxane, 0.25 mm i.d., 0.25 {mu}m df) coupled with a 1.5 m of Innowax (polyethylene glycol, 0.32 mm i.d., 0.25 {mu}m df) by a quartz capillary column connector was introduced as separation column. Three advantages were discussed for the coupled system. The sample was fortified with a ring-labeled {sup 13}C{sub 3}{sup 15}N{sub 3}-melamine as an isotope internal standard and extracted by 1% of trichloroacetic acid aqueous solution. 2.2% of lead acetate solution was then added to deposit protein in the sample matrix. After purification by cation exchange cartridge, the sample solution was directly injected and detected by GC/MS. A six-point calibration curve ranging from 0.05 to 2 mg kg{sup -1} of melamine in sample was used to establish instrument response. The recovery was 93.9-102% with relative standard deviation from 3.1 to 8.7% when isotope internal standard used. The calculated method detection limit was 0.01 mg kg{sup -1}.

  6. On-line coupling of an ion chromatograph to the ICP-MS: Separations with a cation exchange chromatography column

    Energy Technology Data Exchange (ETDEWEB)

    Roellin, Stefan [Studsvik Nuclear AB, Nykoeping (Sweden)

    1999-12-01

    An ion chromatography system was coupled on-line to the ICP-MS. All separations were made with a cation exchange chromatography column. Fundamental laws about elution parameters affecting individual retention times and elution forms are explained by applying a proper ion exchange mechanism for the isocratic elution (separations with constant eluent concentration) of mono-, di-, tri-, and tetravalent cations and the actinide species MO{sub 2}{sup +} and MO{sub 2}{sup 2+}. A separation method with two eluents has been investigated to separate mono- from divalent ions in order to separate isobaric overlaps of Rb/Sr and Cs/Ba. The ions normally formed by actinides in aqueous solutions in the oxidation states III to VI are M{sup 3+}, M{sup 4+}, MO{sub 2}{sup +} and MO{sub 2}{sup 2+} respectively. Elution parameters were investigated to separate all four actinide species from each other in order to separate isobaric overlaps of the actinides Np, Pu, U and Am. A major question of concern over the possible release of actinides to the environment is the speciation of actinides within their four possible oxidation states. To check the possibility of speciation analysis with ion chromatography, a separation method was investigated to separate U{sup 4+} and UO{sub 2}{sup 2+} without changing the redox species composition during the separation. First results of Pu speciation analysis showed that Pu could be eluted as three different species. Pu(VI) was always eluting at the same time as Np(V). This was surprising as Pu(VI) is expected to have the same chemical characteristics as U(VI) and thus was expected to elute at the same time as U(VI)

  7. Study on the Characteristics of Loosely Coupled Transformer in Inductive Power Transfer System

    Directory of Open Access Journals (Sweden)

    Ruizhen Li

    2013-06-01

    Full Text Available A new kind of non-contact loosely coupled transformer of transmission method was proposed based on the principle of electromagnetic, thus to solve the problems of signal transmission in boring machine processing non-cylinder piston pin hole system. In this study, the factors that influence loosely coupled transformer characteristics are discussed, including coil position and air gap. Then, their influences are detailed presented by means of ANSYS simulation. Furthermore, choose appropriate coil position structure and air gap provides the reliable theory basis for non-contact power transfer system transmission.

  8. High performance liquid chromatography coupled with resonance Rayleigh scattering for the detection of three fluoroquinolones and mechanism study

    Science.gov (United States)

    Zhou, Mingqiong; Peng, Jingdong; He, Rongxing; He, Yuting; Zhang, Jing; Li, Aiping

    2015-02-01

    A reliable and versatile high performance liquid chromatography coupled with resonance Rayleigh scattering method was established for the determination of three fluoroquinolones, including levofloxacin, norfloxacin and enrofloxacin in water sample and human urine sample. In pH 4.4-4.6 Britton-Robinson buffer medium, the fluoroquinolones separated by high performance liquid chromatography could react with erythrosine to form 1:1 ion-association complexes, which could make contributions to the great enhancement of RRS. The resonance Rayleigh scattering signal was recorded at λex = λem = 330 nm. The resonance Rayleigh scattering spectral characteristics of the drugs and the experimental conditions such as pH, detection wavelength, erythrosine concentration, flow rate, the length of reaction tube were studied. Quantum chemistry calculation, Fourier transform infrared spectroscopy and absorption spectroscopy were used to discuss the reaction mechanism. The recoveries of samples added standard ranged from 97.53% to 102.00%, and the relative standard deviation was below 4.64%. The limit of detection (S/N = 3) of 0.05-0.12 μg mL-1 was reached, and the linear regression coefficients were all above 0.999. The proposed method was proved as a simple, low cost and high sensitivity method.

  9. Analysis of neonicotinoids by gas chromatography coupled to nuclide {sup 63}Ni - Electron Capture Detector - GC/ECD

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Priscila O.; Leao, Claudio; Redigolo, Marcelo M.; Crepaldi, Caike; Bustillos, Oscar V., E-mail: priscilaoamaral@gmail.com, E-mail: claudio.leao@usp.br, E-mail: marceloredigolo@gmail.com, E-mail: caike1995@gmail.com, E-mail: ovega@ipen.bremails [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Recently, several reports have been published discussing reduction in bee population which polymerizes cultures around the world this phenomenon is known as Colony Collapse Disorder (CCD). The phenomenon describes the lack of worker honeybees in the colony despite having pups and food. The causes of this problem are unknown but there are studies that claim that reduction of population of bees is linked to poisoning through insecticides specifically neonicotinoids. Among this type of pesticide are imidacloprid (C{sub 9}H{sub 10}ClN{sub 5}O{sub 2}), clothianidin (C{sub 6}H{sub 8}ClN{sub 5}O{sub 2}S) and thiamethoxam (C{sub 8}H{sub 10}ClN{sub 5}O{sub 3}S). This paper presents the analysis of neonicotinoids - clothianidin, imidacloprid and thiamethoxam - by the technique of gas chromatography coupled to nuclide {sup 63}Ni electron capture detector (GC/ECD). The electron capture detector (ECD) is a gas chromatography detector that has been used for the detection of organic halogens, nitriles, nitrates and organometallic compounds. The ECD detector ionizes the analytes by the beta particles from the nuclide sources {sup 63}Ni within carrier gas N{sub 2}. The electrons produced in this process are collected and create a current that are amplified and generates a chromatographic peak. Methodology and details of the analysis are present in this work. (author)

  10. Enrichment and Analysis of Nonenzymatically Glycated Peptides: Boronate Affinity Chromatography Coupled with Electron-Transfer Dissociation Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qibin; Tang, Ning; Brock, Jonathan W.; Mottaz, Heather M.; Ames, Jennifer M.; Baynes, John; Smith, Richard D.; Metz, Thomas O.

    2007-06-01

    Non-enzymatic glycation of peptides and proteins by D-glucose has important implications in the pathogenesis of diabetes mellitus, particularly in the development of diabetic complications. However, no effective high-throughput methods exist for identifying proteins containing this low abundance post-translational modification in bottom-up proteomic studies. In this report, phenylboronate affinity chromatography was used in a two-step enrichment scheme to selectively isolate first glycated proteins and then glycated, tryptic peptides from human serum glycated in vitro. Enriched peptides were subsequently analyzed by alternating electron transfer dissociation (ETD) and collision induced dissociation (CID) tandem mass spectrometry. It was observed that ETD fragmentation mode resulted in a significantly higher number of glycated peptide identifications (87.6% of all identified peptides) versus CID mode (17.0% of all identified peptides), when utilizing dual glycation enrichment on both the protein and peptide level. This study illustrates that phenylboronate affinity chromatography coupled with LC-MS/MS with ETD as the fragmentation mode is an efficient approach for analyses of glycated proteins and can have broad applications in studies of diabetes mellitus.

  11. Simultaneous determination of capsaicin and dihydrocapsaicin for vegetable oil adulteration by immunoaffinity chromatography cleanup coupled with LC-MS/MS.

    Science.gov (United States)

    Ma, Fei; Yang, Qingqing; Matthäus, Bertrand; Li, Peiwu; Zhang, Qi; Zhang, Liangxiao

    2016-05-15

    Capsaicin and dihydrocapsaicin were selected as adulteration markers to authenticate vegetable oils. In this study, a method of immunoaffinity chromatography (IAC) combined with liquid chromatography-tandem mass spectrometry was established for the determination of capsaicin and dihydrocapsaicin in vegetable oils. In this method, immunosorbents were obtained by covalently coupling highly specific capsaicinoid polyclonal antibodieswith CNBr-activated Sepharose 4B, and then packed into a polyethylene column. In this paper, the major parameters affecting IAC extraction efficiency, including loading, washing and eluting conditions, were also investigated. The IAC column displayed high selectivity for capsaicin and dihydrocapsaicin with the maximum capacity of 240ng. The limit of detection (LOD) and limit of quantification (LOQ) for capsaicin were calculated as 0.02 and 0.08μgkg(-1), and for dihydrocapsaicin were 0.03 and 0.10μgkg(-1). The recoveries of capsaicin and dihydrocapsaicin in oil samples were in the range of 87.3-95.2% with the relative standard deviation (RSD) of less than 6.1%. The results indicated that capsaicinoid compounds could not be found in edible vegetable oils. Therefore, the proposed method is simple, reliable and adequate for routine monitoring of capsaicinoid compounds in vegetable oils and has an excellent potential for detection of adulteration with inedible waste oil.

  12. Congener specific determination of toxaphene residues in fish liver oil using gas chromatography coupled to ion trap MS/MS.

    Science.gov (United States)

    Bernardo, F J Guzmán; Fernández, M A; González, M J

    2005-10-01

    A new approach to the determination of six toxaphene congeners in edible stuff has been accomplished. The analytical procedure presented in this paper involves a single-step cleanup process prior to the analysis. A solution containing three (13)C labelled polychlorinated biphenyls was used as internal standard and tetrachloronaphtalene was used as injection standard. The analytical technique used was gas chromatography coupled to ion trap mass spectrometry detector in MS/MS mode. The parameters affecting the successive fragmentations were discussed and optimized. The limits of detection ranged from 2 to 49pg microl(-1). The toxaphene congeners were determined in two different fish liver oil pills sold in Spain as a supplementary vitamin support.

  13. A metabonomic analysis of serum from rats treated with ricinine using ultra performance liquid chromatography coupled with mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Jing Peng

    Full Text Available A metabonomic approach based on ultra performance liquid chromatography coupled with mass spectrometry (UPLC/MS was used to study the hepatotoxicity of ricinine in rats. Potential biomarkers of ricinine toxicity and toxicological mechanism were analyzed by serum metabonomic method. The significant differences in the metabolic profiling of the control and treated rats were clear by using the principal components analysis (PCA of the chromatographic data. Significant changes of metabolite biomarkers like phenylalanine, tryptophan, cholic acid, LPC and PC were detected in the serum. These biochemical changes were related to the metabolic disorders in amino acids and phospholipids. This research indicates that UPLC/MS-based metabonomic analysis of serum samples can be used to predict the hepatotoxicity and further understand the toxicological mechanism induced by ricinine. This work shows that metabonomics method is a valuable tool in drug mechanism study.

  14. Determination of the macromolecular dimensions of hydrophobically modified polymers by micellar size exclusion chromatography coupled with multiangle light scattering.

    Science.gov (United States)

    Dupuis, Guillaume; Rigolini, Julien; Clisson, Gérald; Rousseau, David; Tabary, René; Grassl, Bruno

    2009-11-01

    The present work demonstrates that the use of a nonionic surfactant in the mobile phase together with light scattering coupled to size exclusion chromatography (SEC) provides an accurate determination of macromolecular dimensions of hydrophobically modified water-soluble polymer and polyelectrolyte, i.e., weight-average molar mass M(w) and polydispersity I(p). This method, called micellar SEC, is based on the dissociation of the aggregates in aqueous solution and the formation of mixed micelles between the surfactant and the polymer hydrophobic groups. The methodology and its application are presented for synthetic sulfonated polyacrylamides (5 and 20 mol %) modified with three hydrophobic alkyl side groups (C8, C12, and C18) and with Triton X-100 as a nonionic surfactant and are discussed according to the associativity of polymers. The results are compared to those obtained by classical SEC in 0.1 M NaNO(3) and by static light scattering in formamide solution.

  15. Magnetic mixed hemimicelles solid-phase extraction of xanthohumol in beer coupled with high-performance liquid chromatography determination.

    Science.gov (United States)

    Ding, Jie; Zhao, Qi; Sun, Lei; Ding, Lan; Ren, Nanqi

    2011-06-01

    In this study, silica-coated magnetic nanoparticles (Fe(3)O(4)/SiO(2) NPs) modified by cetyltrimethylammonium bromide (CTAB) were synthesized. They were successfully applied for extraction of xanthohumol in beer based on magnetic mixed hemimicelles solid-phase extraction (MMHSPE) coupled with high-performance liquid chromatography-ultraviolet determination. The main factors influencing the extraction efficiency including the surfactant amount, the beer pH, the extraction time, the desorption condition and the maximum extraction beer volume were optimized. Under the optimized conditions, a concentration factor of 60 was achieved by extracting 120 mL beer sample using MMHSPE and the detection limit of xanthohumol is 0.0006 mg/L. The proposed method was successfully applied for determination of xanthohumol in various beer samples with the xanthohumol contents in the range of 0.031-0.567 mg/L. The satisfactory recoveries (90-103%) were obtained in analyzing spiked beer samples.

  16. Battery-powered pulsed high density inductively coupled plasma source for pre-ionization in laboratory astrophysics experiments.

    Science.gov (United States)

    Chaplin, Vernon H; Bellan, Paul M

    2015-07-01

    An electrically floating radiofrequency (RF) pre-ionization plasma source has been developed to enable neutral gas breakdown at lower pressures and to access new experimental regimes in the Caltech laboratory astrophysics experiments. The source uses a customized 13.56 MHz class D RF power amplifier that is powered by AA batteries, allowing it to safely float at 3-6 kV with the electrodes of the high voltage pulsed power experiments. The amplifier, which is capable of 3 kW output power in pulsed (<1 ms) operation, couples electrical energy to the plasma through an antenna external to the 1.1 cm radius discharge tube. By comparing the predictions of a global equilibrium discharge model with the measured scalings of plasma density with RF power input and axial magnetic field strength, we demonstrate that inductive coupling (rather than capacitive coupling or wave damping) is the dominant energy transfer mechanism. Peak ion densities exceeding 5 × 10(19) m(-3) in argon gas at 30 mTorr have been achieved with and without a background field. Installation of the pre-ionization source on a magnetohydrodynamically driven jet experiment reduced the breakdown time and jitter and allowed for the creation of hotter, faster argon plasma jets than was previously possible.

  17. Mutually coupled circuits. A method for induction systems calculation; Metodo dos circuitos mutuamente acoplados. Um metodo para calcular sistemas de inducao

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Maysa Nunes [UNESP, Guaratingueta, SP (Brazil). Dept. de Engenharia Eletrica

    1997-12-31

    This paper deals with a numerical method based on the couples equivalent circuit for the calculation of axially symmetric induction heating systems. Using a procedure for the calculation of the self and mutual inductances , it is possible to calculate the currents, even in the case of complex configurations and with no limits on the choice of the subdivision elements. (author) 6 refs., 5 figs.; e-mail: maysa at feg.unesp.br

  18. Trace metal analysis in arctic aerosols by an inductively coupled plasma-time of flight-mass spectrometer combined with an inductively heated vaporizer

    Energy Technology Data Exchange (ETDEWEB)

    Luedke, Christian [ISAS - Institute for Analytical Sciences, Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany)]. E-mail: luedke@ansci.de; Skole, Jochen [ISAS - Institute for Analytical Sciences, Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Taubner, Kerstin [ISAS - Institute for Analytical Sciences, Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Kriews, Michael [Alfred Wegener Institute for Polar- and Marine Research, Am Handelshafen 12, 27570 Bremerhaven (Germany)

    2005-11-15

    Two newly developed instruments were combined to analyze the trace metal content in size separated arctic aerosols during the measurement campaign ASTAR 2004 (Arctic Study of Tropospheric Aerosols, Clouds and Radiation 2004) at Spitsbergen in May-June 2004. The aim of this extensive aerosol measurement campaign was to obtain a database for model-calculations of arctic aerosol, which play an important role in the global climate change. The ASTAR project was centered on two aircraft measurement campaigns, scheduled from 2004 to 2005, addressing both aerosol and cloud measurements, combined with ground-based and satellite observations. In the present paper one example for the analysis of ground-based aerosol particles is described. The sampling of aerosol particles was performed in a well-known manner by impaction of the particles on cleaned graphite targets. By means of a cascade impactor eight size classes between 0.35 and 16.6 {mu}m aerodynamic diameters were separated. To analyze the metal content in the aerosol particles the targets were rapidly heated up to 2700 deg. C in an inductively heated vaporizer system (IHVS). An argon flow transports the vaporized sample material into the inductively coupled plasma (ICP) used as ionization source for the time of flight-mass spectrometer (TOF-MS). The simultaneous extraction of the ions from the plasma, as realized in the TOF instrument, allows to obtain the full mass spectrum of the sample during the vaporization pulse without any limitation in the number of elements detected. With optimized experimental parameters the element content in arctic aerosol particles was determined in a mass range between {sup 7}Li and {sup 209}Bi. Comparing the size distribution of the elemental content of the aerosol particles, two different meteorological situations were verified. For calibration acidified reference solutions were placed on the cleaned target inside the IHVS. The limits of detection (LOD) for the element mass on the

  19. Method validation for high resolution sector field inductively coupled plasma mass spectrometry determination of the emerging contaminants in the open ocean: Rare earth elements as a case study

    Science.gov (United States)

    Wysocka, Irena; Vassileva, Emilia

    2017-02-01

    Analytical procedure for the determination of fourteen rare earth elements (REEs) in the seawater samples has been developed and validated. The elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) at ultra-trace level were measured by high resolution sector field inductively coupled plasma mass spectrometry (HR ICP-SFMS) after off-line analytes pre-concentration and matrix separation. The sample pre-treatment was carried out by commercially available automated system seaFAST-pico™, which is a low-pressure ion chromatography technique, based on solid phase extraction principles. Efficient elimination of seawater matrix and up to 50-fold pre-concentration of REEs enabled their accurate and precise quantification at ng L- 1 level. A validation approach in line with the requirements of ISO/IEC 17025 standard and Eurachem guidelines were followed. With this in mind, selectivity, working range, linearity, recovery (from 92% to 102%), repeatability (1%-4%), intermediate precision (2%-6%), limits of detection (0.001-0.08 ng L- 1) were systematically assessed. The total uncertainty associated to each result was estimated and the main sources of uncertainty sorted out. All major contributions to the combined uncertainty of the obtained results were identified and propagated together, following the ISO/GUM guidelines. The relative expanded uncertainty was estimated at range from 10.4% to 11.6% (k = 2). Demonstration of traceability of measurement results was also presented. Due to the low limits of detection, this method enables the determination of ultra-low levels of REEs in the open seawater as well as small variations in their concentrations. The potential of the proposed analytical procedure, based on combination of seaFAST-pico™ for sample preparation and HR ICP-SFMS, was demonstrated by direct analysis of seawater form different regions of the world.

  20. Analysis of N-nitrosodiethylamine by ion chromatography coupled with UV photolysis pretreatment

    Directory of Open Access Journals (Sweden)

    Xueli Li

    2016-04-01

    Full Text Available Nitrosamines such as N-nitrosodiethylamine (NDEA are commonly detected by spectrophotometry after photolysis and Griess reaction (PG in food industries for lower cost. Results of this research indicate that NDEA decays rapidly under UV irradiation, and concentrations of the generated NO2− and NO3− ions vary with photolysis conditions. Thus, the measurement of the PG method may be inconsistent because it is based on the amount of photoproduced NO2−. In addition, more errors may be present in the PG method since NO3− cannot be measured colorimetrically using Griess reagent. In this work, the sum of the concentrations of photoproduced NO2− and NO3− was found to be equivalent to the initial NDEA before photolysis, and a photolysis–ion chromatography method was validated, which may serve as a feasible and accurate method to determine nitrosamines.

  1. Quantification of six bioactive compounds in Zhenqi Fuzheng preparation by high-performance liquid chromatography couple

    Institute of Scientific and Technical Information of China (English)

    Yi-Kai Shi; Fang Cui; Fang-Di Hu; Ying-Yan Bi; Yu-Feng Ma; Shi-Lan Feng

    2011-01-01

    A simple and accurate high-performance liquid chromatography(HPLC)coupled with diode array detector(DAD)and evaporative light scattering detector(ELSD)was established for the determination of six bioactive compounds in Zhenqi Fuzheng preparation(ZFP).The

  2. Measurement of the 135Cs half-life with accelerator mass spectrometry and inductively coupled plasma mass spectrometry

    Science.gov (United States)

    MacDonald, C. M.; Cornett, R. J.; Charles, C. R. J.; Zhao, X. L.; Kieser, W. E.

    2016-01-01

    The isotope 135Cs is quoted as having a half-life of 2.3 Myr. However, there are three published values ranging from 1.8 to 3 Myr. This research reviews previous measurements and reports a new measurement of the half-life using newly developed accelerator mass spectrometry (AMS) and inductively coupled plasma mass spectrometry (ICPMS) techniques along with β and γ radiometric analysis. The half-life was determined to be (1.6 ±0.6 ) ×106 yr by AMS and (1.3 ±0.2 ) ×106 yr by ICPMS with 95% confidence. The two values agree with each other but differ from the accepted value by ˜40 % .

  3. Direct Determination of Trace Impurities in High Purity Zinc Oxide by High Resolution Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIE Hualin; NIE Xidu; LI Libo; SONG Chuhua

    2006-01-01

    The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) was investigated. To overcome some potentially problematic spectral interference, measurements were acquired in both middle and high resolution modes. The matrix effects due to the presence of excess HCl and zinc were evaluated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits ranged from 0.02 μg/g to 6 μg/g depending on the elements.The experimental results for the determination of Na, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Sb and Pb in several high purity zinc oxide powders were presented.

  4. Modeling Approach and Analysis of the Structural Parameters of an Inductively Coupled Plasma Etcher Based on a Regression Orthogonal Design

    Institute of Scientific and Technical Information of China (English)

    CHENG Jia; ZHU Yu; JI Linhong

    2012-01-01

    The geometry of an inductively coupled plasma (ICP) etcher is usually considered to be an important factor for determining both plasma and process uniformity over a large wafer. During the past few decades, these parameters were determined by the "trial and error" method, resulting in wastes of time and funds. In this paper, a new approach of regression orthogonal design with plasma simulation experiments is proposed to investigate the sensitivity of the structural parameters on the uniformity of plasma characteristics. The tool for simulating plasma is CFD-ACE+, which is commercial multi-physical modeling software that has been proven to be accurate for plasma simulation. The simulated experimental results are analyzed to get a regression equation on three structural parameters. Through this equation, engineers can compute the uniformity of the electron number density rapidly without modeling by CFD-ACE+. An optimization performed at the end produces good results.

  5. Fundamental study on filter effect of confronting divergent magnetic fields applied to low-pressure inductively coupled plasmas

    Science.gov (United States)

    Sugawara, Hirotake; Ogino, So

    2016-07-01

    The electron motion under confronting divergent magnetic fields (CDMFs) applied to inductively coupled plasmas was simulated using a Monte Carlo method. The CDMFs induced by two coaxial dc coils confined electrons in one side of the separatrix of the CDMFs. However, electrons diffused across the separatrix mainly in two ways. One was the displacement of their gyrocenters due to scattering near the outer part of the separatrix. This process tended to occur for high-energy electrons with correspondingly large gyroradii. The other was passage through the weak magnetic field around the center. This process was allowed for low-energy electrons. The position-dependent selectivity about the electron energy was pointed out as a seed property for applications of the separatrix as a magnetic filter or shutter. The mechanism by which the functions of the separatrix emerge was explained from a viewpoint of electron motion under the CDMFs.

  6. Determination of Silicon in Gasoline by Directly Measuring under Organic Phase Using Inductively Coupled Plasma Optical Emission Spectroscopy.

    Science.gov (United States)

    Zhang, Wen-mei; Wen, Huan; Lü, Huan-ming; Liu, Hui-qin; Lin, Zhi-sheng; Wang, Rong-hua

    2015-03-01

    A simple and accurate method was developed for determining silicon in gasoline using inductively coupled plasma optical emission spectroscopy (ICP-OES). For sample inroduction a Burgener nubulizer and a Cyclonic spray chamber were used. A gasoline sample was diluted with isooctane and then introduced into the cooled spray chamber of the ICP-OES. Good linearity was achieved in the silicon concentration range 0.1 - 10.0 mg x kg(-1), and the correlation coefficient was 0.999 96. The detection limit for silicon was 0.012 mg x kg(-1) and the silicon recoveries from gasoline samples were 95.8% - 98.4%, with relative standard deviations of less than 3.0% The method was proved to be simple, reliable and highly sensitive, and suitable for determining silicon in samples of motor gasoline, ethanol-gasoline and methanol-gasoline fuel mixtures those containing not more than 15% (V/V) oxygenates.

  7. Inductively-coupled-plasma reactive ion etching of single-crystal β-Ga2O3

    Science.gov (United States)

    Zhang, Liheng; Verma, Amit; (Grace Xing, Huili; Jena, Debdeep

    2017-03-01

    Dry etching behavior of unintentionally-doped (\\bar{2}01) β-Ga2O3 has been studied in a BCl3/Ar chemistry using inductively-coupled-plasma reactive ion etching (ICP-RIE). The effects of various etch parameters like ICP and RIE powers, BCl3/Ar gas ratio and chamber pressure on etch rate are studied systematically. Higher ICP, RIE powers and lower pressure conditions are found to enhance the etch rate. A synergic etching mechanism between chemical and physical components is proposed and used to obtain fast Ga2O3 etch rates more than 160 nm/min, nearly-vertical sidewalls and smooth etched surfaces. The findings of this work will enable Ga2O3 vertical devices for power electronics.

  8. Online Determination of Sm, Eu and Yb in Environmental Samples by Inductively Coupled Plasma – Optical Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    J. Dilip Kumar

    2007-01-01

    Full Text Available A procedure was developed for the determination of Sm, Eu and Yb in water samples by inductively coupled plasma-optical emission spectrometry (ICP-OES after preconcentration on synthesized 5-(4-pyridyl azo-8-quinolinol supported by Borassus flabellifer inflorescence (BFI. The sorbed element was subsequently eluted with 0.4 M HNO3 and the acid eluates were analyzed by ICP-OES. Under the optimal conditions, Sm, Eu and Yb in aqueous samples were concentrated 100-fold. Recoveries were obtained by the proposed method in the range of 98.6 -99.8%. This method was also applied for the analysis of spiked and natural water samples. The results provide strong evidence to support the hypothesis of an adsorption mechanism.

  9. Evaluation of arsenic and selenium in Brazilian soluble coffee by inductively coupled plasma atomic emission spectrometry with hydride generation

    Directory of Open Access Journals (Sweden)

    Santos Éder José dos

    2001-01-01

    Full Text Available A method for the evaluation of arsenic and selenium in soluble coffee by inductively coupled plasma atomic emission spectrometry with continuous hydride generation to attend the Brazilian food legislation is described. Samples were digested with nitric acid and hydrogen peroxide in a focused microwave system. Slow heating eliminated nitric acid and selenium (VI was reduced to selenium (IV by addition of 6 mol/L hydrochloric acid and heating at 90° C under a reflux system. The influence of sample acidity on sensitivity was investigated. Hydrochloric acid 6 mol/L was the most suitable reaction medium. Practical detection limits of 2.0mug/L for As and 1.0mu g/L for Se were achieved and attended the Brazilian food legislation. The results of recoveries on spiked samples demonstrate the reliability and accuracy of the procedure.

  10. Comparison of ultraviolet femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry analysis in glass, monazite, and zircon.

    Science.gov (United States)

    Poitrasson, Franck; Mao, Xianglei; Mao, Samuel S; Freydier, Rémi; Russo, Richard E

    2003-11-15

    We compared the analytical performance of ultraviolet femtosecond and nanosecond laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). The benefit of ultrafast lasers was evaluated regarding thermal-induced chemical fractionation, that is otherwise well known to limit LA-ICPMS. Both lasers had a Gaussian beam energy profile and were tested using the same ablation system and ICPMS analyzer. Resulting crater morphologies and analytical signals showed more straightforward femtosecond laser ablation processes, with minimal thermal effects. Despite a less stable energy output, the ultrafast laser yielded elemental (Pb/U, Pb/Th) and Pb isotopic ratios that were more precise, repeatable, and accurate, even when compared to the best analytical conditions for the nanosecond laser. Measurements on NIST glasses, monazites, and zircon also showed that femtosecond LA-ICPMS calibration was less matrix-matched dependent and therefore more versatile.

  11. Aluminium content of some processed foods, raw materials and food additives in China by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Deng, Gui-Fang; Li, Ke; Ma, Jing; Liu, Fen; Dai, Jing-Jing; Li, Hua-Bin

    2011-01-01

    The level of aluminium in 178 processed food samples from Shenzhen city in China was evaluated using inductively coupled plasma-mass spectrometry. Some processed foods contained a concentration of up to 1226 mg/kg, which is about 12 times the Chinese food standard. To establish the main source in these foods, Al levels in the raw materials were determined. However, aluminium concentrations in raw materials were low (0.10-451.5 mg/kg). Therefore, aluminium levels in food additives used in these foods was determined and it was found that some food additives contained a high concentration of aluminium (0.005-57.4 g/kg). The results suggested that, in the interest of public health, food additives containing high concentrations of aluminium should be replaced by those containing less. This study has provided new information on aluminium levels in Chinese processed foods, raw materials and a selection of food additives.

  12. Properties and etching rates of negative ions in inductively coupled plasmas and dc discharges produced in Ar/SF6

    DEFF Research Database (Denmark)

    Draghici, Mihai; Stamate, Eugen

    2010-01-01

    Negative ion production is investigated in a chamber with transversal magnetic filter operated in dc or inductively coupled plasma (ICP) modes in Ar/SF6 gas mixtures. Plasma parameters are evaluated by mass spectrometry and Langmuir probe for different discharge conditions. The density ratio...... of negative ion to electron exceeded 300 in dc mode while it was below 100 in the ICP mode. The possibility to apply a large positive bias to an electrode without affecting the plasma potential and the transition from a negative sheath to anodic glow are also investigated. The etching rates by positive...... and negative ions are evaluated on silicon substrate for different Ar/SF6 gas ratios. The etching rate by negative ions was with less than 5% smaller than that by positive ions....

  13. Determination of cadmium, mercury and lead in coal fly ash by slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.C.; Jiang, S.J. [National Sun Yat Sen University, Kaohsiung (Taiwan). Dept. of Chemistry

    1999-08-09

    Ultrasonic slurry sampling electrothermal vaporization isotope dilution inductively coupled plasma mass spectrometry (USS-ETV-ID-ICP-MS) was used to the determine Cd, Hg and Pb in coal fly ash samples. Thioacetamide (TAC) was the modifier. Since the sensitivities of the elements studied in coal fly ash slurry and aqueous solution were quite different, isotope dilution method was used for the determination of Cd, Hg and Pb in the coal fly ash samples. The isotope ratios of each element were calculated from the peak areas of each injection peak. This method was applied to the determination of Cd, Hg and Pb in NIST SRM 1633a coal fly ash reference material and a coal fly ash sample collected from Kaohsiung area. Detection limits estimated from standard addition curves were in the range of 24-58, 6-28 and 108-110 ng g{sup -1} for Cd, Hg and Pb, respectively.

  14. Plasma sterilization of Geobacillus Stearothermophilus by O{mathsf2}:N{mathsf2} RF inductively coupled plasma

    Science.gov (United States)

    Kylián, O.; Sasaki, T.; Rossi, F.

    2006-05-01

    The aim of this work is to identify the main process responsible for sterilization of Geobacillus Stearothermophilus spores in O{2}:N{2} RF inductively coupled plasma. In order to meet this objective the sterilization efficiencies of discharges in mixtures differing in the initial O{2}/N{2} ratios are compared with plasma properties and with scanning electron microscopy images of treated spores. According to the obtained results it can be concluded that under our experimental conditions the time needed to reach complete sterilization is more related to O atom density than UV radiation intensity, i.e. complete sterilization is not related only to DNA damage as in UV sterilization but more likely to the etching of the spore.

  15. Multi-elemental analysis of brain tissue from healthy Wistar rats using sector field inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Mitchell C. [Molecular Structure and Detection Group, School of Environmental and Life Sciences, University of Newcastle, University Drive, Callaghan NSW 2308 (Australia); Parsons, Carl H. [School of Biomedical Science, University of Newcastle, Callaghan NSW 2308 (Australia); Calford, Mike B. [School of Biomedical Science, University of Newcastle, Callaghan NSW 2308 (Australia); Nagy-Felsobuki, Ellak I. von [Molecular Structure and Detection Group, School of Environmental and Life Sciences, University of Newcastle, University Drive, Callaghan NSW 2308 (Australia)]. E-mail: ellak@newcastle.edu.au

    2004-09-20

    The normal distribution of a range of elements in the brain tissue of healthy Wistar rats was established using sector field inductively coupled plasma mass spectrometry. A protocol was developed to determine concentrations of Ag, Cd, Hg, Pb, Bi, U, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As and Se in specific brain regions. The concentrations of these elements were determined in the range of 2{+-}1 (e.g. Cr in diencephalon) to 7558{+-}450 ng ml{sup -1} (e.g. Fe in olfactory bulb). The detection limits of the sixteen elements ranged between 5 and 300 pg ml{sup -1}, with U yielding the lowest and Fe the highest value. The validity of the protocol was assessed by the analysis of SRM 1577B Bovine Liver and brain tissue spike recoveries. A principal component analysis was used to reveal elemental patterns of the brain regions.

  16. Determination of Rare Earth Elements in Green River Shale By Inductively Coupled Plasma Mass Spectrometry Using a Desolvating Nebulizer System

    Science.gov (United States)

    Smith, F.; Clarke, D.; Moody, S.

    2014-12-01

    In this work, inductively coupled plasma mass spectrometry (ICP-MS) is applied to a geological sample for the determination of rare earth elements (REEs) using a specialized nebulizer system. The low flow desolvating nebulizer has been shown to decrease metal oxide formation which leads to a reduction in mass spectral interferences. Traditional nebulizers and spray chambers may be suitable for similar sample types, but reduction of water vapor loading to the plasma can improve REE detection limits for quadrupole-based ICP-MS. The Green River formation holds the largest oil shale deposits in the world and understanding the elemental composition of these samples is important in its study. A certified reference material, USGS Green River Shale (SGR-1), was microwave digested prior to analysis, and recoveries of REEs compared to historical values are discussed.

  17. Room temperature inductively coupled plasma etching of InAs/InSb in BCl 3/Cl 2/Ar

    KAUST Repository

    Sun, Jian

    2012-10-01

    Inductively coupled plasma (ICP) etching of InAs and InSb at room temperature has been investigated using BCl 3/Cl 2/Ar plasma. Specifically, the etch rate and post-etching surface morphology were investigated as functions of the gas composition, ICP power, process pressure, and RF chuck power. An optimized process has been developed, yielding anisotropic etching and very smooth surfaces with roughnesses of 0.25 nm for InAs, and 0.57 nm for InSb, which is comparable with the surface of epi-ready polished wafers. The process provides moderate etching rates of 820 /min for InAs and 2800 /min for InSb, and the micro-masking effect is largely avoided. © 2012 Elsevier B.V. All rights reserved.

  18. The effects of analyte mass and collision gases on ion beam formation in an inductively coupled plasma mass spectrometer

    Science.gov (United States)

    Larsen, Jessica J.; Edmund, Alisa J.; Farnsworth, Paul B.

    2016-11-01

    Planar laser induced fluorescence (PLIF) was used to evaluate the effect of matrix components on the formation and focusing of a Ba ion beam in a commercial inductively coupled plasma mass spectrometer. Cross sections of the ion beams were taken in the second vacuum stage, in front of the entrance to the mass analyzer. Under normal operating conditions, the addition of Pb shifted the position of the Ba ion beam to the right. PLIF was also used to evaluate the effect of a collision reaction interface (CRI) on Ca and Ba ion beams. A wider velocity distribution of ions and a decrease in overall intensity were observed for the CRI images. The fluorescence and mass spectrometer signals decreased with increased CRI flow rates. These effects were most obvious for Ca ions with He gas.

  19. Use of dried blood spots and inductively coupled plasma mass spectrometry for multi-element determination in blood.

    Science.gov (United States)

    Vacchina, Véronique; Huin, Vincent; Hulo, Sébastien; Cuny, Damien; Broly, Franck; Renom, Gilles; Perini, Jean-Marc

    2014-07-01

    The paper describes the development of an inductively coupled plasma mass spectrometry (ICP MS) method for multitrace element determination in dried blood spots (DBSs). The analytical conditions were optimized using Seronorm™ L-3 and L-1 Certified Reference Materials. The best results were obtained by sampling blood drops on a decontaminated PVDF filter membrane. After drying under metal-free conditions, the DBSs underwent acidic digestion and were analyzed with ICP MS. The method was then validated for As, Cd, Cu, Pb, Mo, Se and Zn. Using a matrix-matched calibration curve, the recovery levels ranged from 96% to 117%. The repeatability and reproducibility were generally below 15%. Limits of quantification ranging from 0.5 to 50 μg/L. In order to investigate the analytical procedure under real sampling conditions, the results obtained from DBSs and liquid blood aliquots (less subject to contamination) from two adult subjects were compared.

  20. A ground-based radio frequency inductively coupled plasma apparatus for atomic oxygen simulation in low Earth orbit.

    Science.gov (United States)

    Huang, Yongxian; Tian, Xiubo; Yang, Shiqin; Chu, Paul K

    2007-10-01

    A radio frequency (rf) inductively coupled plasma apparatus has been developed to simulate the atomic oxygen environment encountered in low Earth orbit (LEO). Basing on the novel design, the apparatus can achieve stable, long lasting operation, pure and high density oxygen plasma beam. Furthermore, the effective atomic oxygen flux can be regulated. The equivalent effective atomic oxygen flux may reach (2.289-2.984) x 10(16) at.cm(2) s at an oxygen pressure of 1.5 Pa and rf power of 400 W. The equivalent atomic oxygen flux is about 100 times than that in the LEO environment. The mass loss measured from the polyimide sample changes linearly with the exposure time, while the density of the eroded holes becomes smaller. The erosion mechanism of the polymeric materials by atomic oxygen is complex and involves initial reactions at the gas-surface interface as well as steady-state material removal.

  1. Analysis and Optimization of Spiral Circular Inductive Coupling Link for Bio-Implanted Applications on Air and within Human Tissue

    Directory of Open Access Journals (Sweden)

    Saad Mutashar

    2014-06-01

    Full Text Available The use of wireless communication using inductive links to transfer data and power to implantable microsystems to stimulate and monitor nerves and muscles is increasing. This paper deals with the development of the theoretical analysis and optimization of an inductive link based on coupling and on spiral circular coil geometry. The coil dimensions offer 22 mm of mutual distance in air. However, at 6 mm of distance, the coils offer a power transmission efficiency of 80% in the optimum case and 73% in the worst case via low input impedance, whereas, transmission efficiency is 45% and 32%, respectively, via high input impedance. The simulations were performed in air and with two types of simulated human biological tissues such as dry and wet-skin using a depth of 6 mm. The performance results expound that the combined magnitude of the electric field components surrounding the external coil is approximately 98% of that in air, and for an internal coil, it is approximately 50%, respectively. It can be seen that the gain surrounding coils is almost constant and confirms the omnidirectional pattern associated with such loop antennas which reduces the effect of non-alignment between the two coils. The results also show that the specific absorption rate (SAR and power loss within the tissue are lower than that of the standard level. Thus, the tissue will not be damaged anymore.

  2. Bulk plasma fragmentation in a C{sub 4}F{sub 8} inductively coupled plasma: A hybrid modeling study

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shu-Xia; Zhang, Yu-Ru [School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China); Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium); Gao, Fei; Wang, You-Nian [School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China); Bogaerts, Annemie [Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium)

    2015-06-28

    A hybrid model is used to investigate the fragmentation of C{sub 4}F{sub 8} inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. C{sub x}F{sub y} (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C{sub 4}F{sub 8} inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C{sub 4}F{sub 8} reaction set used in the model. The C{sub 4}F{sub 8} plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model.

  3. Ultra-sensitive quantification of lysozyme based on element chelate labeling and capillary electrophoresis–inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, MingWei [Key Laboratory of Analysis and Detection for Food Safety of Ministry of Education, Fujian Provincial Key Lab of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, Fujian (China); Department of Chemistry, Florida International University, Miami, FL 33199 (United States); Wu, WeiHua; Ruan, YaJuan; Huang, LiMei [Key Laboratory of Analysis and Detection for Food Safety of Ministry of Education, Fujian Provincial Key Lab of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, Fujian (China); Wu, Zujian [Department of Plant Protection, Fujian Agriculture and Forest University, Fuzhou 350002, Fujian (China); Cai, Yong [Department of Chemistry, Florida International University, Miami, FL 33199 (United States); Fu, FengFu, E-mail: fengfu@fzu.edu.cn [Key Laboratory of Analysis and Detection for Food Safety of Ministry of Education, Fujian Provincial Key Lab of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, Fujian (China); Department of Plant Protection, Fujian Agriculture and Forest University, Fuzhou 350002, Fujian (China)

    2014-02-17

    Graphical abstract: An ultra-sensitive method for the determination of lysozyme was developed based on the Gd{sup 3+} chelate labeling and CE–ICP–MS. The proposed method has an extremely low detection limit of 3.89 attomole and has been successfully used to detect lysozyme in saliva sample, showing excellent reliability. The success of the present method provides a new possibility for biological assays and clinical diagnoses. -- Highlights: •An ultra-sensitive method for detecting lysozyme based on CE–ICP–MS was described. •The proposed method has an extremely low detection limit of 3.89 attomole. •It can be used to detect trace lysozyme in saliva sample with a satisfied recovery. •The method provides a new potential for sensitive detection of low-abundant proteins. -- Abstract: In this study, an ultra-sensitive method for the quantification of lysozyme based on the Gd{sup 3+} diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid labeling and capillary electrophoresis–inductively coupled plasma mass spectrometry (CE–ICP–MS) was described. The Gd{sup 3+}-tagged lysozyme was effectively separated by capillary electrophoresis (CE) and sensitively determined by inductively coupled plasma mass spectrometry (ICP–MS). Based on the gadolinium-tagging and CE–ICP–MS, the lysozyme was determined within 12 min with an extremely low detection limit of 3.89 attomole (3.89 × 10{sup −11} mol L{sup −1} for 100 nL of sample injection) and a RSD < 6% (n = 5). The proposed method has been successfully used to detect lysozyme in saliva samples with a recovery of 91–106%, suggesting that our method is sensitive and reliable. The success of the present method provides a new potential for the biological assays and sensitive detection of low-abundant proteins.

  4. Development of a direct hydride generation nebulizer for the determination of selenium by inductively coupled plasma optical emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Carrion, Nereida E-mail: ncarrion@strix.ciens.ucv.ve; Murillo, Miguel; Montiel, Edie; Diaz, Dorfe

    2003-08-15

    A study was conducted to evaluate the performance of a new direct hydride generation nebulizer system for determination of hydride forming elements by inductively coupled plasma optical emission spectroscopy. This system was designed and optimized to obtain the highest sensitivity. Several experimental designs were used for these purposes. To optimize the individual parameters of the system, and to study the interaction between these parameters for both direct hydride generation nebulizers, a central composite orthogonal design with eight factors was set up. Significant behavioral differences were observed in the two direct hydride generation nebulizers studied. Finally, a 70 {mu}m gas orifice nebulizer exhibits a better detection limit than the 120 {mu}m nebulizer. Generally, for determination of selenium, this new direct hydride generation nebulizer system exhibits a linear dynamic range and detection limit (3{sigma}b) of 3 orders of magnitude and 0.2 {mu}g l{sup -1} for selenium, respectively. This new hydride generator is much simpler system that conventional hydride generation systems, which does not need to be changed to work in normal mode with the inductively coupled plasma, since this system may be used for hydride forming elements and those that do not form them. It produces a rapid response with low memory effect. It reduces the interference level of Ni, Co and Cu to 600, 500 and 5 mg l{sup -1}, respectively. The accuracy of the system was verified by the determination of selenium in several standard reference materials of ambient, food and clinical sample matrices. No statistically significant differences (95 confidence level) were obtained between our method and the reference values.

  5. Simultaneous determination of macronutrients, micronutrients and trace elements in mineral fertilizers by inductively coupled plasma optical emission spectrometry

    Science.gov (United States)

    de Oliveira Souza, Sidnei; da Costa, Silvânio Silvério Lopes; Santos, Dayane Melo; dos Santos Pinto, Jéssica; Garcia, Carlos Alexandre Borges; Alves, José do Patrocínio Hora; Araujo, Rennan Geovanny Oliveira

    2014-06-01

    An analytical method for simultaneous determination of macronutrients (Ca, Mg, Na and P), micronutrients (Cu, Fe, Mn and Zn) and trace elements (Al, As, Cd, Pb and V) in mineral fertilizers was optimized. Two-level full factorial design was applied to evaluate the optimal proportions of reagents used in the sample digestion on hot plate. A Doehlert design for two variables was used to evaluate the operating conditions of the inductively coupled plasma optical emission spectrometer in order to accomplish the simultaneous determination of the analyte concentrations. The limits of quantification (LOQs) ranged from 2.0 mg kg- 1 for Mn to 77.3 mg kg- 1 for P. The accuracy and precision of the proposed method were evaluated by analysis of standard reference materials (SRMs) of Western phosphate rock (NIST 694), Florida phosphate rock (NIST 120C) and Trace elements in multi-nutrient fertilizer (NIST 695), considered to be adequate for simultaneous determination. Twenty-one samples of mineral fertilizers collected in Sergipe State, Brazil, were analyzed. For all samples, the As, Ca, Cd and Pb concentrations were below the LOQ values of the analytical method. For As, Cd and Pb the obtained LOQ values were below the maximum limit allowed by the Brazilian Ministry of Agriculture, Livestock and Food Supply (Ministério da Agricultura, Pecuária e Abastecimento - MAPA). The optimized method presented good accuracy and was effectively applied to quantitative simultaneous determination of the analytes in mineral fertilizers by inductively coupled plasma optical emission spectrometry (ICP OES).

  6. Design and experimental verification of CMOS magnetic-based microbead detection using an asynchronous intra-chip inductive-coupling transceiver

    Science.gov (United States)

    Niitsu, Kiichi; Kobayashi, Atsuki; Yoshida, Kohei; Nakazato, Kazuo

    2017-01-01

    In this study, an asynchronous intra-chip inductive-coupling transceiver was used to design and experimentally verify a CMOS magnetic-based microbeads detection system. Magnetic microbeads were employed for the surrounding living cells. These microbeads increased the magnetic flux and enabled the operation of an intra-chip inductive-coupling transceiver with a low transmitter supply voltage. Thus, by sensing the change in transmitter supply voltage, the system detected the living cells surrounded by microbeads. To verify the effectiveness of the proposed approach, a test chip was fabricated using 0.25 µm CMOS technology. The measured results successfully demonstrated the detection of microbeads.

  7. Quantitative characterization of solid epoxy resins using comprehensive two dimensional liquid chromatography coupled with electrospray ionization-time of flight mass spectrometry.

    Science.gov (United States)

    Julka, Samir; Cortes, Hernan; Harfmann, Robert; Bell, Bruce; Schweizer-Theobaldt, Andreas; Pursch, Matthias; Mondello, Luigi; Maynard, Shawn; West, David

    2009-06-01

    A comprehensive multidimensional liquid chromatography system coupled to Electrospray Ionization-Mass Spectrometry (LCxLC-ESI-MS) was developed for detailed characterization and quantitation of solid epoxy resin components. The two orthogonal modes of separation selected were size exclusion chromatography (SEC) in the first dimension and liquid chromatography at critical conditions (LCCC) in the second dimension. Different components present in the solid epoxy resins were separated and quantitated for the first time based on the functional groups and molecular weight heterogeneity. Coupling LCxLC separations with mass spectrometry enabled the identification of components resolved in the two-dimensional space. Several different functional group families of compounds were separated and identified, including epoxy-epoxy and epoxy-alpha-glycol functional oligomers, and their individual molecular weight ranges were determined. Repeatability obtained ranged from 0.5% for the main product to 21% for oligomers at the 0.4% concentration level.

  8. Analysis of perfluoroalkyl substances in cord blood by turbulent flow chromatography coupled to tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Llorca, Marta; Perez, Francisca [Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Farre, Marinella, E-mail: mfuqam@cid.csic.es [Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Agramunt, Silvia [Centre for Research in Environmental Epidemiology (CREAL), Barcelona (Spain); IMIM (Hospital del Mar Research Institute), Barcelona (Spain); Kogevinas, Manolis [Centre for Research in Environmental Epidemiology (CREAL), Barcelona (Spain); IMIM (Hospital del Mar Research Institute), Barcelona (Spain); CIBER Epidemiologia y Salud Publica (CIBERESP), Barcelona (Spain); National School of Public Health, Athens (Greece); Barcelo, Damia [Department of Environmental Chemistry, IDAEA-CSIC, Barcelona (Spain); Catalan Institute for Water Research (ICRA), Girona (Spain); King Saud University, Riyadh (Saudi Arabia)

    2012-09-01

    A fast on-line analytical method based on turbulent flow chromatography (TFC) in combination with tandem mass spectrometry has been applied for the first time for the analysis of eighteen perfluoroalkyl substances (PFASs), in cord blood. A simple and rapid sample pre-treatment was optimised consisting on protein precipitation of 100 {mu}L of sample with acetonitrile (1:1) followed by centrifugation during 10 min. The method was adapted to be sensitive enough and robust with minimum sample injection volume requirements (20 {mu}L). The optimised methodology presented method limits of detection (MLOD) between 0.031 and 0.76 {mu}g/L, detection capabilities (CC{alpha}) in the range between 0.005 and 0.99 {mu}g/L and decision limits (CC{beta}) ranging from 0.006 to 1.16 {mu}g/L. The recoveries in blank blood were calculated by spiking experiments with a mixture of 18 PFASs and established between 70 and 126% for most of compounds. Isotopic dilution was carried out for quantification of selected analytes. In-house validation of this new approach was carried out according to the requirements in the 2002/657/EC Decision. Finally the good applicability of this new approach was proved by the analysis of 60 cord blood samples from two different Mediterranean cities, Barcelona (Spain) and Heraklion (Greece). Ions perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) were found at highest concentration and the more frequently compounds were PFHxS, PFOS and perfluorooctanoic acid (PFOA). The newly developed method proved to be suitable for large-scale epidemiologic studies, and to the data on PFASs exposure during pregnancy. -- Highlights: Black-Right-Pointing-Pointer An on-line method has been developed for the analysis of 18 perfluoroalkyl substances. Black-Right-Pointing-Pointer The method is based on turbulent flow chromatography tandem mass spectrometry. Black-Right-Pointing-Pointer The method was applied in 60 cord blood samples from 2 Mediterranean cities

  9. Determination of inorganic pharmaceutical counterions using hydrophilic interaction chromatography coupled with a Corona CAD detector.

    Science.gov (United States)

    Huang, Z; Richards, M A; Zha, Y; Francis, R; Lozano, R; Ruan, J

    2009-12-05

    A simple generic approach was investigated for the determination of inorganic pharmaceutical counterions in drug substances using conventional high performance liquid chromatographic (HPLC) instruments. An intuitive approach combined Corona charged aerosol detection (CAD) with a polymer-based zwitterionic stationary phase in the hydrophilic interaction chromatography (HILIC) mode. Two generic methods based on this HILIC/CAD technique were developed to quantitate counterions such as Cl-, Br-, SO(4)(2-), K+, Ca2+ and Mg2+ in different pharmaceutical compounds. The development and capability of this HILIC/CAD technique analysis were examined. HILIC/CAD was compared to ion chromatography (IC), the most commonly used methodology for pharmaceutical counterion analysis. HILIC/CAD was found to have significant advantages in terms of: (1) being able to quantitate both anions and cations simultaneously without a need to change column/eluent or detection mode; (2) imposing much less restriction on the allowable organic percentage of the eluents than IC, and therefore being more appropriate for analysis of counterions of poorly water-soluble drugs; (3) requiring minimal training of the operating analysts. The precision and accuracy of counterion analysis using HILIC/CAD was not compromised. A typical precision of <2.0% was observed for all tested inorganic counterions; the determinations were within 2.0% relative to the theoretical counterion amount in the drug substance. Additionally, better accuracy was shown for Cl- in several drug substances as compared to IC. The main drawback of HILIC/CAD is its unsuitability for many of the current silica-based HILIC columns, because slight dissolution of silica leads to high baseline noise in the CAD detector. As a result of the universal detection characteristics of Corona CAD and the unique separation capabilities of a zwitterionic stationary phase, an intuitive and robust HPLC method was developed for the generic determination of

  10. Determination of citrus limonoid glucosides by high performance liquid chromatography coupled to post-column reaction with Ehrlich’s Reagent

    Science.gov (United States)

    A method for the identification and quantification of citrus limonoid glucosides in juices based upon high performance liquid chromatography (HPLC) separation coupled to post-column reaction with Ehrlichs’s reagent has been developed. This method utilizes a phenyl stationary phase and an isocratic ...

  11. Design and implementation of an automated liquid-phase microextraction-chip system coupled on-line with high performance liquid chromatography

    DEFF Research Database (Denmark)

    Li, Bin; Petersen, Nickolaj J.; Payán, María D Ramos

    2014-01-01

    An automated liquid-phase microextraction (LPME) device in a chip format has been developed and coupled directly to high performance liquid chromatography (HPLC). A 10-port 2-position switching valve was used to hyphenate the LPME-chip with the HPLC autosampler, and to collect the extracted...

  12. Application of the Reversed-phase Liquid Chromatography Coupled to Ion Trap Mass Spectrometry with Principal Components Analysis for Metabonomics Studies of Scutellarin in Rat Urine

    Institute of Scientific and Technical Information of China (English)

    Xiao Rong RAN; Sheng Zhu SI; Qiong Lin LIANG; Guo An LUO

    2006-01-01

    Metabonomics, a novel systemic approach, was applied to studies of Traditional Chinese Medicine scutellarin in rat urine. The liquid chromatography coupled with ion trap mass spectrometry combined with PCA was used in this paper. With this methodology, two potential metabolites of scutellarin were detected and the nine ions responsible for the gender variation and one ion for the dosage variation were found.

  13. Numerical Simulation of Plasma-Dynamical Processes in the Technological Inductively Coupled RF Plasmatron with Gas Cooling

    Directory of Open Access Journals (Sweden)

    Yu. M. Grishin

    2016-01-01

    Full Text Available The electrodeless inductively coupled RF plasmatron (ICP torches became widely used in various fields of engineering, science and technology. Presently, owing to development of new technologies to produce very pure substances, nanopowders, etc., there is a steadily increasing interest in the induction plasma. This generates a need for a broad range of theoretical and experimental studies to optimize the design and technological parameters of different ICP equipment.The paper presents a numerical model to calculate parameters of inductively coupled RF plasmatron with gas-cooling flow. A finite volume method is used for a numerical solution of a system of Maxwell's and heat transfer equations in the application package ANSYS CFX (14.5. The pseudo-steady approach to solving problems is used.A numerical simulation has been computed in the application package ANSYS CFX (14.5 for a specific design option of the technological ICP, which has a three-coils inductor and current amplitude in the range J к = 50-170 A (3 MHz. The pure argon flows in the ICP. The paper discusses how the value of discharge current impacts on the thermodynamic parameters (pressure, temperature and the power energy in discharge zone. It shows that the ICP can generate a plasma stream with a maximum temperature of about 10 kK and an output speed of 10-15 m/s. The work determines a length of the plasma stream with a weight average temperature of more than 4 kK. It has been found that in order to keep the quartz walls in normal thermal state, the discharge current amplitude should not exceed 150 A. The paper shows the features of the velocity field distribution in the channel of the plasma torch, namely, the formation of vortex in the position of the first coil. The results obtained are important for calculating the dynamics of heating and evaporation of quartz particles in the manufacturing processes for plasma processing of quartz concentrate into high-purity quartz and

  14. Fast quantification of endogenous carbohydrates in plasma using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry.

    Science.gov (United States)

    Zhu, Bangjie; Liu, Feng; Li, Xituo; Wang, Yan; Gu, Xue; Dai, Jieyu; Wang, Guiming; Cheng, Yu; Yan, Chao

    2015-01-01

    Endogenous carbohydrates in biosamples are frequently highlighted as the most differential metabolites in many metabolomics studies. A simple, fast, simultaneous quantitative method for 16 endogenous carbohydrates in plasma has been developed using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry. In order to quantify 16 endogenous carbohydrates in plasma, various conditions, including columns, chromatographic conditions, mass spectrometry conditions, and plasma preparation methods, were investigated. Different conditions in this quantified analysis were performed and optimized. The reproducibility, precision, recovery, matrix effect, and stability of the method were verified. The results indicated that a methanol/acetonitrile (50:50, v/v) mixture could effectively and reproducibly precipitate rat plasma proteins. Cold organic solvents coupled with vortex for 1 min and incubated at -20°C for 20 min were the most optimal conditions for protein precipitation and extraction. The results, according to the linearity, recovery, precision, matrix effect, and stability, showed that the method was satisfactory in the quantification of endogenous carbohydrates in rat plasma. The quantified analysis of endogenous carbohydrates in rat plasma performed excellently in terms of sensitivity, high throughput, and simple sample preparation, which met the requirement of quantification in specific expanded metabolomic studies after the global metabolic profiling research.

  15. Comprehensive two-dimensional gas chromatography coupled with fast sulphur-chemiluminescence detection: implications of detector electronics.

    Science.gov (United States)

    Blomberg, Jan; Riemersma, Toby; van Zuijlen, Manfred; Chaabani, Hassan

    2004-09-24

    Within the petrochemical industry, there has been a growing interest in methods capable of providing detailed information on the distribution of sulphur-containing compounds in various product streams, going down to the level of separating and quantifying individual sulphur species. Since no single capillary gas chromatographic column is able to perform this separation, a refuge to multi-dimensional separation techniques has to be taken. In this respect, comprehensive two-dimensional gas chromatography (GC x GC) coupled with sulphur chemiluminescence detection (SCD) has shown to be highly promising. It has been suggested, however, that the detector volume of an SCD restricts its potential to keep up with the fast second-dimension separations of contemporary GC x GC. In this paper, we will demonstrate that the lack of speed of the SCD does not originate from its physical dimensions, but is largely determined by the speed of the electronics used. Additionally, some typical examples will be presented to illustrate the potential of GC x GC coupled with fast SCD.

  16. Miniaturized ultra-high performance liquid chromatography coupled to electrochemical detection: Investigation of system performance for neurochemical analysis.

    Science.gov (United States)

    Van Schoors, Jolien; Maes, Katrien; Van Wanseele, Yannick; Broeckhoven, Ken; Van Eeckhaut, Ann

    2016-01-04

    The interest in implementation of miniaturized ultra-high performance liquid chromatography (UHPLC) in neurochemical research is growing because of the need for faster, more selective and more sensitive neurotransmitter analyses. The instrument performance of a tailor designed microbore UHPLC system coupled to electrochemical detection (ECD) is investigated, focusing on the quantitative monoamine determination in in vivo microdialysis samples. The use of a microbore column (1.0mm I.D.) requires miniaturization of the entire instrument, though a balance between extra-column band broadening and injection volume must be considered. This is accomplished through the user defined Performance Optimizing Injection Sequence, whereby 5 μL sample is injected on the column with a measured extra-column variance of 4.5-9.0 μL(2) and only 7 μL sample uptake. Different sub-2 μm and superficially porous particle stationary phases are compared by means of the kinetic plot approach. Peak efficiencies of about 16000-35000 theoretical plates are obtained for the Acquity UPLC BEH C18 column within 13 min analysis time. Furthermore, the coupling to ECD is shown suitable for microbore UHPLC analysis thanks to the miniaturized flow cell design, sufficiently fast data acquisition and mathematical data filtering. Ultimately, injection of in vivo samples demonstrates the applicability of the system for microdialysis analysis.

  17. Determination of total phthalates in edible oils by high-performance liquid chromatography coupled with photodiode array detection.

    Science.gov (United States)

    Xie, Qilong; Sun, Dekui; Han, Yangying; Jia, Litao; Hou, Bo; Liu, Shuhui; Li, Debao

    2016-03-01

    The previously reported procedure for the determination of the total phthalate in fatty food involved the extraction of phthalates using chloroform/methanol followed by the removal of the solvents before alkaline hydrolysis requiring 20 h and derivatization of phthalic acid. In this study, a phase-transfer catalyst (tetrabutylammonium chloride) was used in the liquid-liquid heterogeneous hydrolysis of phthalates in oil matrix shortening the reaction time to within 25 min. The resulting phthalic acid in the hydrolysate was extracted by a novel molecular complex based dispersive liquid-liquid microextraction method coupled with back-extraction before high-performance liquid chromatography coupled with photodiode array detection. Under the optimal experimental conditions, the linearity of the method was in the range of 0.5-12 nmol/g with the correlation coefficients (r) >0.997. The detection limit (S/N = 3) was 0.11 nmol/g. Intraday and interday repeatability values expressed as relative standard deviation were 3.9 and 7.1%, respectively. The recovery rates ranged from 82.4 to 99.0%. The developed method was successfully applied for the analysis of total phthalate in seven edible oils.

  18. Liquid chromatography coupled with time-of-flight and ion trap mass spectrometry for qualitative analysis of herbal medicines

    Institute of Scientific and Technical Information of China (English)

    Xiao-Fei Chen; Hai-Tang Wu; Guang-Guo Tan; Zhen-Yu Zhu; Yi-Feng Chai

    2011-01-01

    With the expansion of herbal medicine (HM) market, the issue on how to apply up-to- date analytical tools on qualitative analysis of HMs to assure their quality, safety and efficacy has been arousing great attention. Due to its inherent characteristics of accurate mass measurements and multiple stages analysis, the integrated strategy of liquid chromatography (LC) coupled with time-of-flight mass spectrometry (TOF-MS) and ion trap mass spectrometry (IT-MS) is well-suited to be performed as qualitative analysis tool in this field. The purpose of this review is to provide an overview on the potential of this integrated strategy, including the review of general features of LC-IT-MS and LC-TOF-MS, the advantages of their combination, the common procedures for structure elucidation, the potential of LC-hybrid-IT-TOF/MS and also the summary and discussion of the applications of the integrated strategy for HM qualitative analysis (2006-2011). The advantages and future developments of LC coupled with IT and TOF-MS are highlighted.

  19. Proteomic analysis of Taenia ovis metacestodes by high performance liquid chromatography-coupled tandem mass spectrometry.

    Science.gov (United States)

    Zheng, Yadong

    2017-03-15

    Taenia ovis metacestodes reside in the muscle of sheep and goats, and may cause great economic loss due to condemnation of carcasses if not effectively controlled. Although advances have been made in the control of T. ovis infection, our knowledge of T. ovis biology is limited. Herein the protein profiling of T. ovis metacestodes was determined by liquid chromatography-linked tandem mass spectrometry. A total of 966 proteins were identified and 25.1% (188/748) were annotated to be associated with metabolic pathways. Consistently, GO analysis returned a metabolic process (16.27%) as one of two main biological process terms. Moreover, it was found that 24 proteins, including very low-density lipoprotein receptor, enolase, paramyosin and endophilin B1, were abundant in T. ovis metacestodes. These proteins may be associated with motility, metabolism, signaling, stress, drug resistance and immune responses. Furthermore, comparative analysis of 5 cestodes revealed the presence of Taenia-specific enolases. These data provide clues for better understanding of T. ovis biology, which is informative for effective control of infection.

  20. Description and validation of coupling high performance liquid chromatography with resonance Rayleigh scattering in aminoglycosides determination

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Lei [Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing (China); Peng Jingdong, E-mail: hxpengjd@swu.edu.cn [Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing (China); Tang Jinxia; Yuan Binfang; He Rongxing; Xiao Ying [Chemistry and Chemical Engineering, Southwest University, 400715 Chongqing (China)

    2011-11-14

    Graphical abstract: Theoretical and experimental analysis had proved that aminoglycosides reacted with Congo red to form binary compounds simultaneously, which led to a novel HPLC-RRS strategy being applied in substances which are not fluorescing and not UV absorbed. Highlights: {yields} A novel HPLC-RRS strategy was shown in this study. {yields} Theoretical and experimental analysis had proved the feasibility of this method. {yields} Because of its specificity, no interference from the matrix was observed. {yields} The analytes in biological matrix were all well resolved without any interference. {yields} It provided new insights for analytes lack of useful spectroscopic and electrochemical properties. - Abstract: In view of the fact that many substances generally exhibit very little ultraviolet absorbance and the absence of native fluorescence, a new strategy with simple instrumentation and excellent analytical performance combining high performance liquid chromatography (HPLC) with resonance Rayleigh scattering (RRS) was developed. It was validated for the quantification of aminoglycosides (AGs). This fact was also carefully calculated by quantum chemistry. However, the sensitivity was probably limited by the volume of flow-through cell. Therefore, the result calls for a suitable one to ensure optimal RRS signal. Interestingly, when serum or urine samples of analytes were analyzed by this method, they were all well resolved without any interference, which would hold a new perspective to be applied in the determination of substances in biological matrix.

  1. Simultaneous analysis of multiple neurotransmitters by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry.

    Science.gov (United States)

    Tufi, Sara; Lamoree, Marja; de Boer, Jacob; Leonards, Pim

    2015-05-22

    Neurotransmitters are endogenous metabolites that allow the signal transmission across neuronal synapses. Their biological role is crucial for many physiological functions and their levels can be changed by several diseases. Because of their high polarity, hydrophilic interaction liquid chromatography (HILIC) is a promising tool for neurotransmitter analysis. Due to the large number of HILIC stationary phases available, an evaluation of the column performances and retention behaviors has been performed on five different commercial HILIC packing materials (silica, amino, amide and two zwitterionic stationary phases). Several parameters like the linear correlation between retention and the distribution coefficient (logD), the separation factor k and the column resolution Rs have been investigated and the column performances have been visualized with a heat map and hierarchical clustering analysis. An optimized and validated HILIC-MS/MS method based on the ZIC-cHILIC column is proposed for the simultaneous detection and quantification of twenty compounds consisting of neurotransmitters, precursors and metabolites: 3-methoxytyramine (3-MT), 5-hydroxyindoleacetic acid (5-HIAA), 5-hydroxy-L-tripthophan, acetylcholine, choline, L-3,4-dihydroxyphenylalanine (L-DOPA), dopamine, epinephrine, γ-aminobutyric acid (GABA), glutamate, glutamine, histamine, histidine, L-tryptophan, L-tyrosine, norepinephrine, normetanephrine, phenylalanine, serotonin and tyramine. The method was applied to neuronal metabolite profiling of the central nervous system of the freshwater snail Lymnaea stagnalis. This method is suitable to explore neuronal metabolism and its alteration in different biological matrices.

  2. Analysis of fatty alcohol derivatives with comprehensive two-dimensional liquid chromatography coupled with mass spectrometry.

    Science.gov (United States)

    Elsner, Victoria; Laun, Sabrina; Melchior, David; Köhler, Michael; Schmitz, Oliver J

    2012-12-14

    A simultaneous separation of anionic (fatty alcohol sulfates, fatty alcohol ether sulfates), non-ionic (alkyl polyglucosides, fatty alcohol ethoxylates) and amphoteric (cocamidopropyl betaines) surfactants was performed by comprehensive two-dimensional liquid chromatography (LCxLC) utilizing a ZIC(®)-HILIC column in the first dimension, a Reprosphere 100 C8-Aqua column in the second dimension and a 10-port two position valve as the interface. The volume of the two sample loops were 25 or 50 μL and allow a one or two minute modulation at a 25 μL/min flow rate. In the first dimension, a gradient of acetonitrile and an ammonium acetate buffer was used to separate polyethoxylated surfactants by their degree of ethoxylation (EO number) whereas in the second dimension, a separation by alkyl chain was performed using a methanol/ammonium acetate buffer gradient. A baseline separation of the above mentioned surfactants according to both EO number and alkyl chain was achieved. The best performance was used to compare two different LCxLC-QTOF MS systems, which demonstrate that a transfer of the method from one system to a totally different system is possible. However, because of the differences in delay volume and extra-column volume between these systems the separation power is changed.

  3. Determination of catecholamines by ion chromatography coupled to acidic potassium permanganate chemiluminescence detection

    Institute of Scientific and Technical Information of China (English)

    Hong Wei Wu; Mei Lan Chen; Dan Shou; Yan Zhu

    2012-01-01

    A simple,fast,sensitive,highly selective and eco-friendly analytical method for the determination of catecholamines in human urine by ion chromatography (IC) with chemiluminescence (CL) detection was described in this paper.Using 12 mmoi/L H2SO4 without any organic additive as eluent,three catecholamines including epinephrine (EP),norepinephrine (NE) and dopamine (DA)were well separated on a cation-exchange column.The CL detection was based on the reaction of analytes with acidic potassium permanganate in the presence of formaldehyde as an enhancer.The absence of methanol and acetonitrile in eluent made the proposed method more sensitive and eco-friendly.Under the optimal conditions,the linear range of the proposed method was in the range of 0.02-0.5 μg/mL.The limit of detection (LOD) was in the range of 0.6 and 5.1 μg/L.The relative standard deviations (RSD) for 0.1 μg/mL mixed standard solution were in the range of 0.8-1.9% (n =11).The method has been applied to the determination of catecholamines in human urine successfully.Excellent spiked recoveries were achieved for catecholamines ranged from 91.2% to 112.7%.

  4. Design of Dual-Polarization Horn-Coupled Kinetic Inductance Detectors for Cosmic Microwave Background Polarimetry

    CERN Document Server

    Bryan, Sean; Che, George; Day, Peter; Flanigan, Daniel; Johnson, Bradley R; Jones, Glenn; Kjellstrand, Bjorn; Limon, Michele; Mauskopf, Philip; McCarrick, Heather; Miller, Amber; Smiley, Brian

    2015-01-01

    Mapping the polarization of the Cosmic Microwave Background is yielding exciting data on the origin of the universe, the reionization of the universe, and the growth of cosmic structure. Kilopixel arrays represent the current state of the art, but advances in detector technology are needed to enable the larger detector arrays needed for future measurements. Here we present a design for single-band dual-polarization Kinetic Inductance Detectors (KIDs) at 20% bandwidths centered at 145, 220, and 280 GHz. The detection and readout system is nearly identical to the successful photon-noise-limited aluminum Lumped-Element KIDs that have been recently built and tested by some of the authors. Fabricating large focal plane arrays of the feed horns and quarter-wave backshorts requires only conventional precision machining. Since the detectors and readout lines consist only of a single patterned aluminum layer on a SOI wafer, arrays of the detectors can be built commercially or at a standard university cleanroom.

  5. Diffusion effects on the determination of surface catalysis in Inductively Coupled Plasma facility

    Science.gov (United States)

    Viladegut, Alan; Düzel, Ümran; Chazot, Olivier

    2017-03-01

    Atomic recombination is an important process to consider when computing the heat flux transferred to the wall of a re-entry vehicle. Two chemical processes are influencing the species diffusion in the boundary layer surrounding a re-usable Thermal Protection System: gas phase reactions and catalytic recombination at the surface. The coupling between them is not normally taken into account when determining the catalytic recombination coefficient (γ) in plasma facilities. This work aims to provide evidence of such coupling based on both a theoretical analysis and an experimental campaign in the VKI-Plasmatron facility. Recombination coefficient measurements at off-stagnation point configuration on a linear copper calorimeter are provided. An evolution from a high-catalytic to a low-catalytic condition due to the boundary layer growth along the probe is observed. This result is consistent with a parametric analysis carried out using the in-house non-equilibrium boundary layer solver, which shows how the experimentally determined catalysis could be influenced by the amount of gas-phase recombination inside the boundary layer.

  6. A Solution to Inductive Power Coupling in a Time-Cycled Atom Trap for Beta Decay

    Science.gov (United States)

    Lawrence, Liam; Behr, John; Anholm, Melissa; McNeil, James

    2016-09-01

    The TRINAT group at TRIUMF uses lasers and magnetic fields to confine, cool, and polarize a cloud of beta-decaying neutral alkali atoms to test weak force asymmetry. To alternate between trapping and polarizing the atoms, the trapping magnetic field must be switched on and off. This time-changing magnetic field, created by a pair of co-axial coils, produces eddy currents-and consequentially resistive heating-in nearby conductors. This heating may cause undesirable effects, including damage to the delicate pellicle mirrors which are to be used in future experiments. Previously, the current waveform in the coils consisted of two periods of a sinusoid during the on time of the trapping field (this reduces leftover field from eddy currents during the polarization time). We have calculated the relative power coupled to the pellicle mirror mount for various waveforms, and determined that using half a period of a lower-frequency sinusoid couples an order of magnitude less power than the original waveform, and approximately 2 times less than a trapezoidal wave. We measured the lifetime of the trap subject to this new waveform and found it is possible to achieve a lifetime comparable to that of a continuous trap, our best result differing by less than 5 percent.

  7. Complexation studies with lanthanides and humic acid analyzed by ultrafiltration and capillary electrophoresis-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Kautenburger, Ralf; Beck, Horst Philipp

    2007-08-03

    For the long-term storage of radioactive waste, detailed information about geo-chemical behavior of radioactive and toxic metal ions under environmental conditions is necessary. Humic acid (HA) can play an important role in the immobilisation or mobilisation of metal ions due to complexation and colloid formation. Therefore, we investigate the complexation behavior of HA and its influence on the migration or retardation of selected lanthanides (europium and gadolinium as homologues of the actinides americium and curium). Two independent speciation techniques, ultrafiltration and capillary electrophoresis coupled with inductively coupled plasma mass spectrometry (CE-ICP-MS) have been compared for the study of Eu and Gd interaction with (purified Aldrich) HA. The degree of complexation of Eu and Gd in 25 mg l(-1) Aldrich HA solutions was determined with a broad range of metal loading (Eu and Gd total concentration between 10(-6) and 10(-4) mol l(-1)), ionic strength of 10 mM (NaClO4) and different pH-values. From the CE-ICP-MS electropherograms, additional information on the charge of the Eu species was obtained by the use of 1-bromopropane as neutral marker. To detect HA in the ICP-MS and separate between HA complexed and non complexed metal ions in the CE-ICP-MS, we have halogenated the HA with iodine as ICP-MS marker.

  8. A hybrid model of radio frequency biased inductively coupled plasma discharges: description of model and experimental validation in argon

    Science.gov (United States)

    Wen, De-Qi; Liu, Wei; Gao, Fei; Lieberman, M. A.; Wang, You-Nian

    2016-08-01

    A hybrid model, i.e. a global model coupled bidirectionally with a parallel Monte-Carlo collision (MCC) sheath model, is developed to investigate an inductively coupled discharge with a bias source. This hybrid model can self-consistently reveal the interaction between the bulk plasma and the radio frequency (rf) bias sheath. More specifically, the plasma parameters affecting characteristics of rf bias sheath (sheath length and self-bias) are calculated by a global model and the effect of the rf bias sheath on the bulk plasma is determined by the voltage drop of the rf bias sheath. Moreover, specific numbers of ions are tracked in the rf bias sheath and ultimately the ion energy distribution function (IEDF) incident on the bias electrode is obtained. To validate this model, both bulk plasma density and IEDF on the bias electrode in an argon discharge are compared with experimental measurements, and a good agreement is obtained. The advantage of this model is that it can quickly calculate the bulk plasma density and IEDF on the bias electrode, which are of practical interest in industrial plasma processing, and the model could be easily extended to serve for industrial gases.

  9. Investigations and system design for simultaneous energy and data transmission through inductively coupled resonances

    Science.gov (United States)

    Schmidt, C.; Lloret Fuentes, E.; Buchholz, M.

    2015-11-01

    Wireless Power Transfer (WPT) with simultaneous data transmission through coupled magnetic resonators is investigated in this paper. The development of this system is dedicated to serve as a basis for applications in the field of Ambient Assisted Living (AAL), for example tracking vital parameters remotely, charge and control sensors and so on. Due to these different scenarios we consider, it is important to have a system which is reliable under the circumstance of changing positioning of the receiving device. State of the art radio systems would be able to handle this. Nevertheless, energy harvesting from far field sources is not sufficient to power the devices additionally on mid-range distances. For this reason, coupled magnetic resonant circuits are proposed as a promising alternative, although suffering from more complex positioning dependency. Based on measurements on a simple prototype system, an equivalent circuit description is used to model the transmission system dependent on different transmission distances and impedance matching conditions. Additionally, the simulation model is used to extract system parameters such as coupling coefficients, coil resistance and self-capacitance, which cannot be calculated in a simple and reliable way. Furthermore, a mathematical channel model based on the schematic model has been built in MATLAB©. It is used to point out the problems occurring in a transmission system with variable transmission distance, especially the change of the passband's centre frequency and its bandwidth. Existing solutions dealing with this distance dependent behaviour, namely the change of the transmission frequency dependent on distance and the addition of losses to the resonators to increase the bandwidth, are considered as not inventive. First, changing the transmission frequency increases the complexity in the data transmission system and would use a disproportional total bandwidth compared to the actually available bandwidth

  10. Coupling Temperature Control with Electrochemically Modulated Liquid Chromatography: Fundamental Aspects and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Lisa M. Ponton

    2004-12-19

    The primary focus of the doctoral research presented herein has been the integration of temperature control into electrochemically modulated liquid chromatography (EMLC). The combination of temperature control and the tunable characteristics of carbonaceous EMLC stationary phases have been invaluable in deciphering the subtleties of the retention mechanism. The effects of temperature and E{sub app} on the retention of several naphthalene disulfonates were therefore examined by the van' Hoff relationship. The results indicate that while the retention of both compounds is exothermic at levels comparable to that in many reversed-phase separations, the potential dependence of the separation is actually entropically affected in a manner paralleling that of several classical ion exchange systems. Furthermore, the retention of small inorganic anions at constant temperature also showed evidence of an ion exchange type of mechanism. While a more complete mechanistic description will come from examining the thermodynamics of retention for a wider variety of analytes, this research has laid the groundwork for full exploitation of temperature as a tool to develop retention rules for EMLC. Operating EMLC at elevated temperature and flow conditions has decreased analysis time and has enabled the separation of analytes not normally achievable on a carbon stationary phase. The separation of several aromatic sulfonates was achieved in less than 1 min, a reduction of analysis time by more than a factor of 20 as compared to room temperature separations. The use of higher operating temperatures also facilitated the separation of this mixture with an entirely aqueous mobile phase in less than 2 min. This methodology was extended to the difficult separation of polycyclic aromatic hydrocarbons on PGC. This study also brought to light the mechanistic implications of the unique retention behavior of these analytes through variations of the mobile phase composition.

  11. Gas chromatography coupled with atomic absorption spectrometry — a sensitive instrumentation for mercury speciation

    Science.gov (United States)

    Emteborg, Håkan; Sinemus, Hans-Werner; Radziuk, Bernard; Baxter, Douglas C.; Frech, Wolfgang

    1996-07-01

    New instrumentation for the speciation of mercury is described, and is applied to the analysis of natural water samples. The separation of mercury species is effected using gas chromatography of derivatized mercury species on a widebore capillary column. The solvent is vented using a bypass valve and the separated mercury species are pyrolysed on-line at 800°C for production of mercury atoms. These are then detected by atomic absorption spectrometry (AAS) at the 253.7 and 184.9 nm lines simultaneously in a quartz cuvette. The use of the 184.9 nm line provides a more than five-fold increase in sensitivity compared with the conventional 253.7 nm line and an absolute detection limit of 0.5 pg of mercury. The dynamic range of the combined analytical lines provides a linear response over more than three orders of magnitude. A number of organic compounds not containing mercury are also detected following pyrolysis, especially at the 184.9 nm line. These background species must not co-elute at the retention times for methyl- and inorganic mercury, as otherwise a positive interference would result. By maximizing the chromatographic resolution and minimizing the band broadening in the cuvette by use of a make-up gas, the retention times of interest are freed from co-eluting background peaks. The instrumentation has been applied to the determination of ng l -1 concentrations of methyl- and inorganic mercury in Lake Constance, Germany and within the Lake Constance drinking water supply organization, Bodenseewasserversorgung (BWV). The accuracy for the sum of methyl- and inorganic mercury has been assessed by comparison with an independent method for total mercury based on AAS detection implemented at BWV. Relative detection limits using 1 litre water samples and 15 ml injections of the final hexane extract were 0.03 ng l -1 for methylmercury and 0.4 ng l -1 for inorganic mercury based on the 3j criterion.

  12. Coupling Temperature Control with Electrochemically Modulated Liquid Chromatography: Fundamental Aspects and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ponton, Lisa M. [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    The primary focus of the doctoral research presented herein has been the integration of temperature control into electrochemically modulated liquid chromatography (EMLC). The combination of temperature control and the tunable characteristics of carbonaceous EMLC stationary phases have been invaluable in deciphering the subtleties of the retention mechanism. The effects of temperature and Eapp on the retention of several naphthalene disulfonates were therefore examined by the van' Hoff relationship. The results indicate that while the retention of both compounds is exothermic at levels comparable to that in many reversed-phase separations, the potential dependence of the separation is actually entropically affected in a manner paralleling that of several classical ion exchange systems. Furthermore, the retention of small inorganic anions at constant temperature also showed evidence of an ion exchange type of mechanism. While a more complete mechanistic description will come from examining the thermodynamics of retention for a wider variety of analytes, this research has laid the groundwork for full exploitation of temperature as a tool to develop retention rules for EMLC. Operating EMLC at elevated temperature and flow conditions has decreased analysis time and has enabled the separation of analytes not normally achievable on a carbon stationary phase. The separation of several aromatic sulfonates was achieved in less than 1 min, a reduction of analysis time by more than a factor of 20 as compared to room temperature separations. The use of higher operating temperatures also facilitated the separation of this mixture with an entirely aqueous mobile phase in less than 2 min. This methodology was extended to the difficult separation of polycyclic aromatic hydrocarbons on PGC. This study also brought to light the mechanistic implications of the unique retention behavior of these analytes through variations of the mobile phase composition.

  13. Gas chromatography coupled to atmospheric pressure ionization mass spectrometry (GC-API-MS): review.

    Science.gov (United S