A new paper sensor method for field analysis of acid volatile sulfides in soils

Monitoring of biogenic sulfide is important as AVS represent a reactive pool responsible for immobilization of toxic metals. We propose a new sulfide paper sensor method (SPS) for semi-quantitative determination of AVS in which developed color is compared to a reference chart. The method was validated against the ion-selective microelectrode and the purge and trap methods. For field work, readings should fall within 1 to 10 moles S2-. Considering that the volume of soil to be sampled can range between 1 to 10 cm3, the corresponding sulfides concentration spans from 0.06 to 10 mmoles S2- cm-3. The SPS method is highly suitable for field screening and has sensitivity levels comparable to laboratory methods.