CHEMetrics test kits measure total acid soluble sulfides and employ the methylene blue methodology. Sulfides react with dimethyl-p-phenylenediamine in the presence of ferric chloride to produce methylene blue.

• Analysis time: 5 minutes

CHEMets® test kits utilize self-filling ampules and vacuum pulls the sample up from a snap cup into the ampule when the tip is broken off. After tilting the ampule several times to mix the sample and reagent and waiting for the color to develop (usually 2 minutes or less), the analyst quantifies the result using the provided cylindrical comparator (for concentrations ≤1ppm) or flat comparator (for concentrations ≥1ppm).

Results are expressed as ppm (mg/L) S.

Sulfides are naturally present in ground waters as a result of leaching from sulfur-containing mineral deposits. Surface waters do not usually contain high sulfide concentrations. Sulfides result from the decomposition of organic matter, from bacterial sulfate reduction under anaerobic conditions and from various chemical processes.