Indirect atomic absorption determination of total and inorganic sulfur in low organic matter soils

Abstract

Existing methods using barium (Ba) to quantify sulfur (S) are not sensitive enough for the accurate determination of the small quantities of total and inorganic S normally present in soils with low organic matter content. Other methods of quantification with higher sensitivity are either very time consuming or very expensive to implement. The aim of this study was to find suitable methods to accurately determine low concentrations of total and inorganic S in soils. The methods had to utilize conventional equipment, be time‐efficient, and inexpensive. Indirect atomic absorption spectrophotometric methods by which the total S content of low organic matter soils can be determined accurately and reliably to a limit of 3.5 mg S/kg, and inorganic S to a limit of 0.3 mg S/kg, are proposed. These methods are relatively simple and inexpensive to execute. Total S (a two day routine) or inorganic S (a three day routine) can be determined at a rate of 72 samples per eight hour man day.