acid volatile sulfides (AVS)

Sulfides in sediments that liberate hydrogen sulfide on reaction with cold dilute acid (mainly FeS or MnS in sediments). AVS is used as a parameter together with SEM (simultaneously extractable metals) to predict toxicity of sediments.
AVS may be chemically available by acid extraction without being bioavailable. Thus, AVS can reduce metal toxicity by binding metals in anoxic soils or sediments, thereby rendering them unavailable to most living organisms.