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[en] Complete text of publication follows. The use of mathematical correction equations, cool plasma, and dynamic reaction cells is frequent for correcting polyatomic interferences in ICP-MS. For carbon-rich matrixes, the 40Ar12C+ polyatomic ion affects the accuracy of Cr determination based on its main isotope. The aim of this work was to evaluate the employment of an ICP-MS equipped with a collision-reaction interface (CRI, Varian 820-MS) for carbon interference correction on Cr determination at m/z 52. The CRI allowed gas introduction directly into the plasma expansion zone, through modified sampler and skimmer cones, and H2 was tested as collisional and reactional gas. The gas flow-rate, point of introduction and plasma operational settings were systematically evaluated to achieve the lowest detection limits and robust method conditions. Based on typical residual carbon content in acid digestates, solutions containing from 0.1 to 2.0 % m v-1 carbon were prepared to evaluate carbon effect on Cr determination. Oxalic acid was used as carbon source. Preliminary results showed that H2 introduction through the skimmer, kept at 80 mL min-1 flow rate, presented better efficiency than through the sampler because lower BEC values (background equivalent concentration) were obtained. At flow rates lower than 60 mL min-1, Cr recovery value was around 170 % (2.0 % w v-1 carbon) due to the positive interference caused by 40Ar12C+. Using a H2 flow rate of 80 mL min-1, accurate recoveries for 5.0 μg L-1 Cr were achieved. The BEC obtained when using the CRI was ten fold lower than that obtained without using it. The effect of different RF powers (0.60-1.50 kW) and nebulizer flow-rates (0.90-1.10 L min-1) on sensitivity was also studied. The BEC and SBR values were similar for all tested RF powers. The analytical signal was improved using higher flow-rate. However, in order to obtain a low CeO+/Ce+ ratio for plasma (< 3%), plasma was operated at 1.50 kW and 0.90 L min-1. The CRI was fundamental to eliminate carbon effects, and its performance was improved by using robust operation conditions. The authors kindly acknowledge the financial support from the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Grant 2006/59083-9), CNPq and CAPES.
[en] Full text: First results of a new research project on chemical nanoparticle characterization are presented. Monodisperse micro-droplets of known analyte concentrations are used for calibration since monodisperse standard reference particles are not available. The droplets are injected directly or after prior desolvation into the ICP. Atomization and ionization of analytes are studied spectroscopically by end-on ICPOES, and criteria for complete atomization of particles are given. Our first results already allow estimates on the applicability and some limitations of the method. (author)
[en] This work presents a new chemo sensor Labetalol (LBT) hydrochloride 5 -[1-hydroxy-2-(1-methyl-3-phenylpropylamino)ethyl] salicylamide hydrochloride (LBT) was applied for spectrophotometric determination of UO22+ in aqueous solution. The chemo sensor LBT react with UO22+ forming a new complex UO22+ /LBT at wavelength of 314 nm. The absorbance of the linear calibration curve increases by in creasing UO22 + concentration at linear range of (1.0 – 16.1) × 10-6 mol L-1 with a correlation coefficient (R2= 0.998). The experimental conditions affecting the absorbance development were studied and optimized. The complexes stoichiometry was measured a the absorbance spectra 314 nm and the results were found to be 1:1 (metal: ligand) ratio. The present chemo sensor LBT was effectively validated with respect to linearity, precision, accuracy, detection and quantification limits. For more accurate analysis, the apparent molar absorptivity, Beer’s law, Ringbom and Sandell’s sensitivity have been studied. The results of analysis were statistically compared with those obtained by ICP -OES as a reference method show that, the Student’s t-and F-values at 95% confidence level are less than the theoretical values, which confirmed that there is no significant difference between the chemo sensor LBT and the reference method in the same studied conditions. The chemo sensor LBT provide a simple, sensitive and inexpensive spectrophotometric determination without any complicated equipment. It was also successfully applied for the direct determination of UO22+ in different aqueous samples with satisfactory results
[en] This short course includes information on these topics and subtopics: (I) Nuclear Properties: (A) Historic roots; (B) Nomenclature; (C) Nuclear Stability and abundance; (D) Uses of isotopic techniques; (II) Instrumentation: (A) Sources; (B) Mass resolving elements; (C) Detectors; (III) Making Isotopic Measurements by ICP-MS: (A) Deadtime Correction; (B) Mass Discrimination; (C) Signal /Noise considerations; (IV) Applications and examples: (A) Isotope dilution; (B) Double Spike; (C) Biological Application; (D) Environmental Application; (E) Geological
[en] A pneumatically-driven, high efficiency nebulizer is explored for helium inductively coupled plasma mass spectrometry. The aerosol characteristics and analyte transport efficiencies of the high efficiency nebulizer for nebulization with helium are measured and compared to the results obtained with argon. Analytical performance indices of the helium inductively coupled plasma mass spectrometry are evaluated in terms of detection limits and precision. The helium inductively coupled plasma mass spectrometry detection limits obtained with the high efficiency nebulizer at 200 μL/min are higher than those achieved with the ultrasonic nebulizer consuming 2 mL/min solution, however, precision is generally better with high efficiency nebulizer (1-4% vs. 3-8% with ultrasonic nebulizer). Detection limits with the high efficiency nebulizer at 200 μL/min solution uptake rate approach those using ultrasonic nebulizer upon efficient desolvation with a heated spray chamber followed by a Peltier-cooled multipass condenser
[en] Complete text of publication follows. Quantification methods in biological and biomedical applications are a topical research theme. However, accurate determinations of bio-molecules in real-life biological samples represent one of the greatest challenges. MS based approaches often follow the strategy to quantify relative changes, e.g. the relative change in protein amount observed between two biologically different states. ICP-MS is the unrivalled detector for quantification of elemental traces and has been propagated as the method of choice for accurate absolute quantification in biological samples. Quantification via hetero-elements or elemental labelling of the investigated bio-molecules was suggested. This work deals with the evaluation of measurement uncertainty of elemental speciation analysis in the case of bio-analytical applications relying on extraction protocols (e.g. selenium speciation analysis in yeast, speciation studies addressing species metabolism in cell models). Absolute quantification will be critically discussed with regard to sample preparation and ICP-MS detection.
[en] In this study, the mineral composition of a pate made with red deer meat (maral meat), beans and a protein enriching additive was determined. To do so, three formulations of the pate (with different meat, additive and bean ratios) were produced. For each formulation, the content of mineral elements was then determined using inductively coupled plasma mass-spectrometry (ICP-MS). Increased level of minerals, such as K, P, Na, Ca and Mg were obtained in formulations where the additive and the beans were added. The addition of beans significantly increased Ca and P content. The mineral content of the overall better balanced formulation of the maral meat pate was compared to that of other pates. (author)
[en] This document presents a tutorial description of several concepts and definitions of limits of quantitation, such as the so-called 10 s, the RSDnet, the method limit, the lower limit of the calibration graph and the uncertainty approaches. Use, advantages, limitations and complexity of the various approaches are illustrated with some examples taken from atomic spectrometry, using ICP-AES, ICP-MS and LIBS. Information that can be deduced from the calibration graph is emphasized
[en] Graphite finds widespread use in nuclear reactors as moderator, reflector, and fuel fabricating components because of its thermal stability and integrity. The manufacturing process consists of various mixing, moulding and baking operations followed by heat-treatment between 2500 °C and 3000 °C. The high temperature treatment is required to drive the amorphous carbon-to-graphite phase transformation. Since synthetic graphite is processed at high temperature, impurity concentrations in the precursor carbon get significantly reduced due to volatilization. However boron may might partly gets converted into boron carbide at high temperatures in the carbon environment of graphite and remains stable (B_4C: boiling point 3500 °C) in the matrix. Literature survey reveals the use of various methods for determination of boron. Previously we have developed a method for determination of boron in graphite electrodes using inductively coupled plasma mass spectrometry (ICP-MS). The method involves removal of graphite matrix by ignition of the sample at 800°C in presence of saturated barium hydroxide solution to prevent the loss of boron. Here we are reporting a modification in the method by using calcium carbonate in place of barium hydroxide and using beryllium (Be) as an internal standard, which resulted in a better precession. The method was validated by spike recovery experiments as well as using another technique viz. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The modified method was applied in evaluation of boron concentration in the graphite reference material prepared
[en] The review is devoted to the major advances in laser sampling. The advantages and drawbacks of the technique are considered. Specific features of combinations of laser sampling with various instrumental analytical methods, primarily inductively coupled plasma mass spectrometry, are discussed. Examples of practical implementation of hybrid methods involving laser sampling as well as corresponding analytical characteristics are presented. The bibliography includes 78 references