Speciated isotope dilution mass spectrometry Speciation analysis

For analysis of solutions, ICP-mass spectrometry (ICP-MS) is very promising (Houk et al., 1980 Houk, 1986 Bacon et al., 1990). Recent advances in separation and preconcentration techniques are discussed by Horvath et al. (1991). Bacon et al. (1990) report that although ICP-MS is a multi-element technique, recent papers tend to concentrate on a small number of target elements. With isotope dilution mass spectrometry (IDMS), detection limits are further reduced (Heumann, 1988) IDMS is also suitable for accurate speciation in very low concentration levels of elements (Heumann, 1990). For the direct analysis of solid samples, glow discharge mass spectrometry (GD-MS) (Harrison etal., 1986) is of interest. Tolg (1988) has suggested that a substantial improvement in the absolute detection power of GD-MS, as applied to micro analysis, can be expected, at least in comparison with the ICP as ion source. 

The application of speciated isotope dilution mass spectrometry (SIDMS) in speciation analysis was described and discussed by Huo et al. [236]. According to Encinar [237], isotopic analysis of a solution can be used to evaluate the application of various speciation forms of elements in food and in medications. 

Huo, D., Kingston, H.M., Larget, B. Application of isotope dilution in elemental speciation speciated isotope dilution mass spectrometry (SIDMS). In Caraso, J.A., Sutton, K.L., Ackley, K.L. (eds.) Elemental Speciation New Approaches for Trace Element Analysis, pp. 277-313. Elsevier Science B.V, Amsterdam (2000)... 

GC-ICP-MS has the potential to facilitate simultaneous multielemental speciation analysis because species of Se, Pb, Hg, and Sn have volatile forms and can be analyzed in a single run. The use of ICP-MS as a detector enables calibration by isotope dilution mass spectrometry as weU as providing very low limits of detection (pg-ng range). 

Chapter 8 provides the reader with the basic principles of isotope dilution mass spectrometry used for elemental analysis and also discusses more advanced features of this calibration approach, such as its use in direct solid sample analysis and in elemental speciation work, wherein not the total amount but that of various chemical species of a target element need to be determined. 

Rodrlguez-Gonziles, R, Ruiz-Encinar, J., Garcla-Alonso, J. I., and Sanz-Medel, A. (2004) Development of a triple spike methodology for validation of butyltin compounds speciation analysis by isotope dilution mass spectrometry, Part I Synthesis of the spike, characterisation and development of the mathematical equations. J. Anal. At. Spectrom., 19, 685-91. 

Kingston, H. M., Dengwei Huo, S., Yusheng Lu, S., and Chalk, S. (1998) Accuracy in species analysis speciated isotope dilution mass spectrometry (SIDMS) exemplified by the evaluation of chromium species. Spectrochim. Acta B, 53,299-309. 

Mass spectrometry can be specific in certain cases, and would even allow on-line QA in the isotope dilution mode. MS of molecular ions is seldom used in speciation analysis. API-MS allows compound-specific information to be obtained. APCI-MS offers the unique possibility of having an element- and compound-specific detector. A drawback is the limited sensitivity of APCI-MS in the element-specific detection mode. This can be overcome by use of on-line sample enrichment, e.g. SPE-HPLC-MS. The capabilities of ESI-MS for metal speciation have been critically assessed [546], Use of ESI-MS in metal speciation is growing. Houk [547] has emphasised that neither ICP-MS (elemental information) nor ESI-MS (molecular information) alone are adequate for identification of unknown elemental species at trace levels in complex mixtures. Consequently, a plea was made for simultaneous use of these two types of ion source on the same liquid chromatographic effluent. 

The principle of the isotope dilution analysis (IDA) is described in Section 6.4. Due to its advantages as a definitive and accurate analytical method for the determination of element concentration via isotope ratio measurements, IDA is being increasingly applied in mass spectrometry, especially in ICP-MS and LA-ICP-MS as one of the most frequently used techniques. For example, the isotope dilution technique is employed in species analysis in biological systems, " e.g., for the determination of mercury species in tuna material,or in aquatic systems. Further applications of the isotope dilution technique are the determination of selenomethionine in human blood serum by capillary HPLC-ICP (ORC) MS ° or sulfur speciation in gas oil, diesel or heating fuel by LA-ICP-MS. Evans and co-workers have reported on the high accuracy analysis of sulfur in diesel fuel by IDA. ICP-SFMS has been employed for Si species analysis in biological or clinical samples and... 

See also Analytical Reagents Purification. Arsenic. Atomic Absorption Spectrometry Electrotfiermal. Atomic Mass Spectrometry Inductively Coupled Plasma. Dioxins. Elemental Speciation Oven/iew. Endocrine Disrupting Chemicals. Geochemistry Sediment. Humic and Fulvic Compounds. Isotope Dilution Analysis. Mass... 

See alsa Air Analysis Outdoor Air. Atomic Emission Spectrometry Microwave-Induced Plasma. Atomic Mass Spectrometry Inductively Coupled Plasma. Elemental Speciation Overview Practicalities and Instrumentation. Gas Chromatography Environmental Applications. Isotope Dilution Analysis. Isotope Ratio Measurements. 

See also Atomic Absorption Spectrometry Interferences and Background Correction. Atomic Emission Spectrometry Principles and Instrumentation Interferences and Background Correction Flame Photometry Inductively Coupled Plasma Microwave-Induced Plasma. Atomic Mass Spectrometry Inductively Coupled Plasma Laser Microprobe. Countercurrent Chromatography Solvent Extraction with a Helical Column. Derivatization of Analytes. Elemental Speciation Overview Practicalities and Instrumentation. Extraction Solvent Extraction Principles Solvent Extraction Multistage Countercurrent Distribution Microwave-Assisted Solvent Extraction Pressurized Fluid Extraction Solid-Phase Extraction Solid-Phase Microextraction. Gas Chromatography Ovenriew. Isotope Dilution Analysis. Liquid Chromatography Ovenriew. 

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