Determination of total sulfur in soils and plant materials by ion chromatography

Abstract

An accurate and precise ion Chromatographie (IC) method is described for determination of total S in soils and plant materials. It involves ignition of a mixture of soil and NaHCO₃or plant material and NaHCO₃containing Ag₂O at 550°C for 3 h. The residue is dissolved in 1MHOAc, diluted with deionized water, filtered, and analyzed for S0^2‐ ₄by a Dionex model 2002i ion Chromatograph. Results by the IC method of seven Iowa soils, three Chilean soils, and 10 plant materials agreed closely with those obtained by the methylene blue method after alkaline oxidation with NaOBr. In general, the IC method was more precise than the methylene blue method. The method is simple and requires a minimum of analytical skill. A single operator can analyze 30–40 soil or plant samples in a normal working day.