Elemental sulfur in sediments: analytical problems.

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Elemental sulfur (S₈) determination is challenging due to its decomposition at elevated temperatures.
• Optimizing gas chromatography-mass spectrometry (GC-MS) conditions is crucial for accurate S₈ analysis.

Purpose of the Study:

• To develop and validate a modified GC-MS method for elemental sulfur (S₈) determination.
• To identify optimal GC-MS parameters, particularly temperature, to prevent S₈ decomposition.
• To apply the validated method for quantifying S₈ in marine sediment samples.

Main Methods:

• A modified gas chromatography-mass spectrometry (GC-MS) method was developed.
• Key parameters, including injector and column temperatures, were optimized to prevent S₈ decomposition.
• The method was validated and applied to bottom sediment samples from the Gulf of Gdansk.

Main Results:

• Optimal GC-MS conditions were established with injector and column temperatures not exceeding 180°C to prevent S₈ decomposition into smaller sulfur species.
• The method successfully quantified S₈ in Baltic Sea sediments, with concentrations ranging up to 0.1432 mg/g dry weight.
• Addition of activated copper (approx. 200 mg) proved effective in removing interfering sulfur species from sediment extracts.

Conclusions:

• The modified GC-MS method provides a reliable approach for elemental sulfur (S₈) determination in environmental samples.
• Controlling temperature is critical to avoid S₈ degradation during GC-MS analysis.
• The study successfully quantified S₈ in Baltic Sea sediments and demonstrated an effective method for sulfur removal from extracts.