An evaluation of wet chemical methods for quantifying sulfur fractions in freshwater wetland peat 1

The specificity and efficiency of procedures for fractionating total S into inorganic and organic constituents were evaluated by analyzing a series of known standards. Acid volatilization was specific for FeS. Chromium reduction recovered over 90% of the S from FeS, S 0 , and FeS 2 . Acetone extraction followed by chromium reduction of the filtrate was specific for S 0 . Hydriodic acid reduction recovered > 90% of the S from FeS, SO 4 2 − , and p‐nitrophenyl sulfate, an organic aryl ester sulfate analog. The Zn‐HCl reduction procedure is of questionable value, only partially recovering S from SO 4 2− , S 0 , and FeS 2 . None of these procedures affected l ‐methionine. Analyses were performed on both moist and oven‐dried peat from Big Run Bog, West Virginia. Oven‐drying of peat samples increased estimates of ester sulfate S and SO 4 2− ‐S and decreased estimates of carbon‐bonded S, which was calculated by difference.