Artefacts in the speciation of sulfides in anoxic sediments

Abstract

The determination of sulfides and trace metals in sediment is handicapped by preparation techniques which can alter the chemical speciation of the different elements before the analysis. In this work, sulfide species such as AVS (acid volatile sulfides) and CRS (chromium reducible sulfides) were determined in anoxic sediment and their transformation, their loss and their effect on metal speciation were evaluated. The experiments were concentrated on the determinands which are most commonly used or dedicated to the determination of sulfides and metals, with emphasis on artefacts potentially introduced during sediment preparation such as sample storage, drying or oxygen contamination.