Mia
Further to my original posting about using multicollector ICP-MS for delta 34S measurements you could also try the University of Cape Town, Anton Le Roex in the Department of Geological Sciences, who have a NU Instruments MC-ICP-MS which could also perform the analysis for you. Always glad to be able to recommend more than one instrument manufacturer.

As an aside on this issue Rebeca at LGC has also published on delta13C values by ICP-MS, which opens up the possibility of direct liquid chromatography D13C determinations.
See

Precise and Traceable 13C/12C Isotope Amount Ratios by Multicollector ICPMS, Rebeca Santamaria-Fernandez,* David Carter, and Ruth Hearn, Anal. Chem. 2008, 80, 5963–5969


Rob