Sulphide in Soils
Sulphide is released from dried and ground samples as hydrogen sulphide by steam distillation with sulphuric acid. The hydrogen sulphide is collected in a solution of 0.5M sodium hydroxide. Sulphide is then analysed by automated colorimetric analysis on an Aquakem 600 discrete analyser using N,N–dimethyl-p-phenylenediamine.