Isotope analyses sulphur

Farquhar J, Wing BA (2003) Multiple sulfur isotope analysis applications in geochemistry and cosmochemistry. Earth Planet Sci. Lett 213 1-13 Farquhar J, Johnston DT, Wing BA, Habicht KS, Canfield DE, Airieau S, Thiemens MH (2003) Multiple sulphur isotope interpretations for biosynthetic pathways implications for biological signatures in the sulphur isotope record. Geobiology 1 27-36... 

C.E. Rees, B.D. Holt (1991) The isotopic analysis of sulphur and oxygen. In H.R. Krouse, V.A. Grinenko (eds.) Stable Isotopes Natural and Anthropgenic Sulphur in the Environment. Scope 43. John Wiley Sons, Chichester, pp. 43-64. 

Nehlich, Olaf, and Michael P. Richards. 2009. Estabhshing collagen quality criteria for sulphur isotope analysis of archaeological bone collagen. Archaeological and Anthropological Sciences 1 59-75. 

It seems appropriate therefore to consider briefly the preparation of hydrogen, carbon dioxide and nitrogen required for the isotopic analysis of H, and content respectively. The preparation of carbon dioxide and sulphur dioxide for analysis of and content will not be considered in detail as these isotopes have as yet very limited application in a clinical context. 

Finally, organic samples requiring analysis of isotopic content, may be combusted in a stream of oxygen to provide the carbon dioxide for isotopic analysis. Several combustion systems have been used that differ only in minor components designed to remove contaminants such as sulphur or the halogens [97,98]. 

As with other procedures for the production of a gas sample for isotopic analysis, caution is required to ensure complete conversion at each stage of the preparation to obviate kinetic fractionation. Sulphides may be oxidized directly to SO2 for isotopic analysis [113] and recently methods have been developed for the thermal decomposition of sulphates [114,115]. An alternative approach is the initial conversion of either sulphate or sulphide to hydrogen sulphide [116, 117] from which the sulphur is precipitated as silver sulphide. This latter sulphide is easily oxidised in a reproducible manner to provide pure SO2 for isotopic analysis. 

A more detailed study of the nitration of quinolinium (l) in 80-05 % sulphuric acid at 25 °C, using isotopic dilution analysis, has shown that 3-) 5-) 6-, 7- and 8-nitroquinoline are formed (table 10.3). Combining these results with the kinetic ones, and assuming that no 2- and 4-nitration occurs, gives the partial rate factors listed in table 10.4. Isoquinolinium is 14 times more reactive than quinolinium. The strong deactivation of the 3-position is in accord with an estimated partial rate factor of io for hydrogen isotope exchange at the 3-position in the pyridinium ion. It has been estimated that the reactivity of this ion is at least 10 less than that of the quinolinium ion. Based on this estimate, the partial rate factor for 3-nitration of the pyridinium ion would be less than 5 x io . 

Riches, J., Read, R.W., Black, R.M. (2007). Analysis of the sulphur mustard metabolites thiodiglycol and thiodiglycol sulphoxide in urine using isotope-dilution gas chromatography-ion trap tandem mass spectrometry. J. Chromatogr. B Analyt. Technol. Biomed. Life Sci. 845(1) 114-20. 

Whereas conventional methods for analysing sulphur isotope compositions need >10 mg of physically separated sample and long analytical times, in contrast, the EA-IRMS technique uses small samples (1-2 mg) and has short analysis times. This achieves the high physical resolution and large sample populations needed for adequate study of biological variation in Archaean sulphide-rich organic sediments. 

Rice, PM. 1987. Pottery Analysis A Sourcebook. Chicago University of Chicago Press. Richards M.P., B.T. Fuller, and R.E.M. Hedges. 2001. Sulphur isotopic variation in ancient bone... 

New concepts were developed that permitted the synthesis and analysis of (pro) chiral materials to be undertaken without the introduction of sulphur (Abbott et al., 1978 Knowles, 1980 Cullis and Lowe, 1978). The isotopes and were stereospecifically introduced in place of in a... 

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