Simple Assay for Accurate Determination of [S]sulfate Reduction Activity

A method is described for the assay of [S]sulfate reduction in which filter paper wicks are used to trap [S]sulfide. The simplicity of the technique enables large numbers of samples to be conveniently processed. Enhanced sensitivity is achieved since all acid-volatile [S]sulfides produced during the incubation period are counted. Recovery of radioactivity from added Na(2)S is excellent (mean, 100.1%; standard deviation, 1.81; n = 9) and is unaffected by sulfide concentrations of up to 400 mug per sample. Field trial results with anoxic sediment samples are presented.