I am looking into building a cryogenic trap that will enable me to collect SO2 in addition to CO2 and N2. I am interested in comparing multiple isotope ratio distributions of freshwater organisms in benthic vs. pelagic foodwebs. Does have a variable-temperature trap design they consider superior to the one described in: Des Marais, D. 1978. Anal. Chem. 50(9)1405-1406? Any other tips/pitfalls regarding working with sulfur would be greatly appreciated. Thanks, Margaret xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Margaret B. Lansing U.S. Dept. of Commerce National Oceanic & Atmospheric Administration Great Lakes Environmental Research Laboratory 2205 Commonwealth Blvd. Ann Arbor, MI 48105 [log in to unmask] 313-741-2289 (lab) 313-741-2210 (office) 313-741-2055 (fax) xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx