Hi Mia
There is an alternative to conventional S isotopic analysis by IRMS which is straightforward, no carryover issues, and uses Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
Rebeca Santamaria Fernandez at LGC in the UK has recently published in this area,
Rebeca Santamaria-Fernandez, Ruth Hearn, Jean-Claude Wolff, J. Anal. At. Spectrom., 2008, (9),1294-1299,
Detection of counterfeit tablets of an antiviral drug using 34S measurements by MC-ICP-MS and confirmation by LA-MC-ICP-MS and HPLC-MC-ICP-MS http://xlink.rsc.org/?DOI=b802890g

and has another publication in preparation but this time for delta 13C measurements.
I also have one using ICP-MS for d34S measurements which led to Rebecas work.
RClough, P.Evans, T.Catterick, E.H.Evans, Delta 34S Measurements of Sulfur by Multicollector
Inductively Coupled Plasma Mass Spectrometry, Analytical Chemistry, 78, 17, 2006, 6126.
Paul Mason has also published in this field.


The instrument required is a Neptune ICP-MS from Thermo and I believe that the university in Stellenbosch has recently acquired one so you might like to contact them. Sample throughput is high, 10 minutes for a solution or laser ablation based sample, possibly longer if you add liquid chromatography.
Yours
Rob




Dr. Robert Clough
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