Sulfide by Direct Measure
Method Abstract #132
Scope and Application
This method conforms to Standard Method 4500-S2 G and ASTM D 4658. It determines the concentration of sulfide ions in a water sample.
The concentration of sulfide is determined by a silver/sulfide ion selective electrode. After calibrating with known standards, the sample’s response can be compared to the calibration curve and a concentration determined. An alkaline antioxidant reagent (AAR) may be added to samples and standards to inhibit oxidation of sulfide by oxygen and to provide a constant ionic strength and pH.
Sample Calibration Curve
*Data for this measuring range was obtained using laboratory prepared standards formulated from potassium chloride. The measuring range may be increased by using larger capacity analysis vessels and/or auto-dilution.
**The Method Detection Limit (MDL) was determined based on data obtaining a coefficient of variance better than 30%. Results may differ depending on laboratory practices and sample matrix.