ISO 15178

Soil Quality — Determination of Total Sulfur by Dry Combustion

Applicability: Applies to all types of air-dried soil samples without restriction to specific soil classes, textures, or geographic origin. The method targets combustible (oxidizable) sulfur forms; because the difference between total sulfur and combustible sulfur is negligible for most soils, the method is effectively valid for total sulfur determination across practically all soil types encountered in environmental and agricultural analysis.

Purpose: Determines total sulfur content by combusting a weighed, air-dried soil sample at high temperature in an oxygen-rich environment, oxidizing all sulfur-containing compounds to sulfur dioxide, which is then measured by infrared absorption or other suitable detection. The dry combustion approach provides complete recovery of all sulfur forms (organic, pyritic, and sulfate) in a single measurement step, avoiding the incomplete extraction that can affect wet chemical methods. Results are used in soil quality assessments, environmental contamination screening, geochemical surveys, and agricultural suitability studies where sulfur levels affect soil health and plant nutrition.