Rapid determination of sulfide in waste waters by continuous flow analysis and gas diffusion and a potentiometric detector

The continuous-flow system is based on a flow-through gas diffusion unit and a potentiometric detection with sulfide-selective electrode. The sampling rate is about 15 h^?1. In the 0.5–600 mg l^?1 sulfide range, the mean slope of the response is 30.2 ± 0.3 mV per decade. The percentage transference of H₂S across the teflon membrane is 48 ± 1%. Up to sample concentrations of 50 mg l^?1 sulfide, results agree well with those obtained by a distillation method. Sample storage is discussed.