Speciated isotope dilution mass spectrometry

SIDMS Speciated isotope dilution mass spectrometry... 

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)... 

EPA Method 6800—Elemental and speciated isotope dilution mass spectrometry, http //www.epa.gOv/sw-846/pdfs/6800.pdf. 

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. 

Ultraviolet spectroscopy has been applied to the determination of lead and lead speciation studies [407]. Scaule and Patterson [408] used isotope dilution-mass spectrometry to determine the lead profile in the open North Pacific Ocean. 

Gallus, S.M. and Heumann, K.G. (1996) Development of gas-chromatography inductively-coupled plasma isotope-dilution mass-spectrometry system for accurate determination of volatile element species. 1. Selenium speciation./. Anal. At. Spectrom., 11, 887-892. 

Nusko, R. and Heumann, K.G. (1997) Crm/CrVI speciation in aerosol particles by extractive separation and thermal ionization isotope dilution mass spectrometry. Fresenius J. Anal. Chem., 357, 1050-1055. 

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. 

K. G. Heumann, L. Rottman, J. Vogl, Elemental speciation with liquid chromatography Dinductively coupled plasma isotope dilution mass spectrometry, J. Anal. Atom. Spectrom., 9 (1994), 1351D1355. 

Heumann, K. G., Rottmann, L., Vogl, J. Elemental speciation with bquid chromatography-inductively coupled plasma isotope dilution mass spectrometry. J Anal At Spectrom 1994,9, 1351-1355. 

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). 

The concentration of iodine in freshwater is normally much lower than that in seawater however, in some particular regions, the groundwater may contain higher levels of iodine. The iodine in precipitation and river water is normally 0.5-5 ng/1, which is more than 10 times lower than that in seawater. The more sensitive ICP-MS and NAA are normally used for the speciation of iodine in freshwater (Reifenhauser and Heumann, 1990 Wuilloud et al., 2003 Hou, 2004). Reifenhauser and Heumann (1990) developed a method by combining isotope dilution mass spectrometry... 

Isotope dilution mass spectrometry is an accurate and sensitive technique for determining toxic trace elements in food matrices. Lead, cadmium, and thallium have been analyzed rapidly down to very low levels by ICP-MS. The latter technique is particularly useful for simultaneous measurement of a wide range of elements. Because the toxicity of an element can be highly dependent on its chemical form, ICP-MS is also useful in the speciation of toxic minerals in foodstuffs by combination with HPLC or SEC. 

Methods also employed for determination of inorganic lead include isotope dilution mass spectrometry, flame atomic fluorescence spectrometry, and molecular absorption spectrometry, but these methods are not used for routine applications. Methods for the determination of organolead speciation are high-performance liquid chromatography with a separation of the species and flame AAS or UV detection. 

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. 

Encinar, J. R., Schaumloffel, D., Ogra, Y., and Lobinski, R., Determination of selenomethionine and selenocysteine in human serum using speciated isotope dilution-capillary HPLC-inductively coupled plasma collision cell mass spectrometry, Analytical Chemistry 76(22), 6635-6642, 2004. 

RodriguezMarttn-Doimeadios, R. C.,Monperrus,M.,Krupp,E.,Amouroux,D.,andDonard, O. F. X. (2003) Using speciated isotope dilution with GC-inductively coupled plasma mass spectrometry to determine and unravel the artificial formation of monomethylmercury in certified reference sediments. Anal. Chem., 75, 3202—11. 

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. 

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