Acid volatile sulfide determination in sediments using elemental analyzer with thermal conductivity detector

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Geochemistry

Background:

• Accurate determination of acid volatile sulfides (AVS) in sediments is critical for understanding sulfur cycling and metal bioavailability.
• Existing methods for AVS quantification can be complex or lack sufficient accuracy and reproducibility.
• Sediment sulfur speciation impacts environmental processes, necessitating robust analytical approaches.

Purpose of the Study:

• To develop and validate a novel method for quantifying acid volatile sulfides (AVS) in sediments.
• To utilize a common elemental analyzer for a streamlined AVS determination process.
• To assess the accuracy and reproducibility of the proposed AVS measurement technique.

Main Methods:

• Employing an elemental analyzer with a thermal conductivity detector for sulfur analysis.
• Utilizing a mixture of tin (Sn) and vanadium pentoxide (V(2)O(5)) for pyrolysis and combustion.
• Calculating acid volatile sulfides (AVS) by subtracting non-volatile sulfur (NVS) from total sulfur (TS) after acidic attack.

Main Results:

• The method accurately determines total sulfur (TS) validated against certified reference materials.
• Recovery rates for acid volatile sulfide (AVS) in spiked river sediment ranged from 97.7% to 99.6%.
• The method demonstrated good reproducibility with a standard deviation of approximately 0.015% for sulfur content between 0-3%.

Conclusions:

• The proposed elemental analyzer method provides an accurate and reproducible means for determining acid volatile sulfides (AVS) in sediments.
• This technique offers a reliable approach for sediment sulfur analysis, contributing to environmental monitoring and research.
• The validated method supports precise quantification of AVS, essential for assessing environmental risks and biogeochemical processes.