A novel approach to quantifying elemental sulfur (S⁰) in environmental samples

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Accurate quantification of elemental sulfur (S0) is crucial for monitoring sulfur-involved processes.
• Current S0 detection methods are often time-consuming or utilize hazardous chemicals.

Purpose of the Study:

• To develop and validate a novel, efficient, and safer method for determining S0 in environmental samples.

Main Methods:

• Elemental sulfur (S0) is oxidized to sulfur trioxide (SO3) in a calorimeter under high oxygen pressure.
• The resulting SO3 is absorbed in sodium bicarbonate solution and analyzed via ion chromatography (IC).
• Method validation involved testing standard samples, potential interferents, and environmental samples.

Main Results:

• The new method demonstrated high accuracy with R² = 0.999 correlation and recovery rates ≥95%.
• Low relative standard deviation (RSD) of ≤1% and accurate measurement of samples with ≥25 mg S0 (error < 5%) were achieved.
• Thiosulfate was identified as a key interferent requiring pretreatment for accurate analysis.

Conclusions:

• The developed calorimeter-IC method provides a more efficient, cost-effective, safer, and accurate approach for elemental sulfur quantification.
• This method offers significant advantages over existing techniques for environmental monitoring.