We are currently receiving more and more water samples that contain either sulfide and/or organics for D and O-18 analysis because of an increased focus on groundwater/surface water interaction studies. This tends to cause problems when analysing for D using H2 equilibration because of poisoning of the Pt catalyst and also when using our LGR. Does anyone have suggestions as to how to treat the samples before analysis. I am assuming that we may be able to preciptate the S using either Zinc Acetate or silver wire but would appreciate advice from anyone who has had success with similar problem samples.
CSIRO Isotope Analysis Lab, Adelaide, Australia