Volatile organic sulfur compounds in a stratified lake.

Three volatile organic sulfur compounds (VOSCs), dimethyl sulfide (DMS), carbon disulfide (CS(2)), and dimethyl disulfide (DMDS), were detected in the stratified water column of a lake (Linsley Pond) in Connecticut. The compounds DMS and DMDS appeared in both the oxic and the anoxic portions of the water column, CS(2) was primarily found in anoxic hypolimnion. Algal metabolism and/or bacterial degradation of sulfur-containing amino acids or other organic materials are potential sources of VOSCs in the oxic lake water. Reactions of hydrogen sulfide with organic compounds and microbial degradation of organic matter may be responsible for the production of VOSCs in the anoxic lake water. The vertical distribution patterns of these three VOSCs varied from month to month in the summer, but the daily profiles obtained in one 5-day period in the summer displayed consistency. No clear diurnal pattern for any of the three VOSCs was observed. Based on observation that these VOSCs were not present in surface and near surface waters of Linsley Pond, freshwater inputs of reduced sulfur compounds to the atmosphere may be insignificant.