Gilles, Can you more specific about what the lipids do to the "chemicals" and site a reference? Greg Stable Isotope Geochemistry wrote: > You can run the samples in an EA-IRMS but lipid extract first. The lipids > tend to destroy the chemicals due to microdistillation prior to the flash in > the EA. You will probably need about 10mg depending on the %S of course > > Gilles > > > -----Message d'origine----- > > De : Robert Van Hale [mailto:[log in to unmask]] > > Envoyé : 24 février, 2002 17:24 > > À : [log in to unmask] > > Objet : [ISOGEOCHEM] Organic S extn > > > > > > Dear all, > > We have a student wishing to measure isotopic composition of > > organic sulphur > > in mussel tissue as a tracer for civic sewerage discharge. > > Can anyone please > > provide refs or notes for the methods of extraction of > > sulphur from tissue > > and collection as sulphate or sulphide. > > Thanks in advance, > > > > Robert Van Hale > > Department Of Chemistry > > University of Otago > > PO Box 52 > > Dunedin > > New Zealand > > pH (+64)(3) 479 7915 > > Fax (+64)(3) 479 7906 > > [log in to unmask] > > Isotopes'R'us > > -- ======================================= Gregory A. Wandless Chemist US Geological Survey MS954 Reston, VA 20192 Email:[log in to unmask] Phone: (703) 648-6189 =======================================