[Polarographic determination of sulfide in water].

Sulfide has a sensitive polarographic wave in the system of NaOH-EDTA-triethanolamine. The addition of triethanolamine to the system improved the shape of the wave and increased the sensitivity. The peak current was directly proportional to the concentration of sulfide in the range of 0.002-5.000 ppm. The detection limit for water sample was 2 ppb, and the relative standard deviation and recovery were 2.3-7.2% and 94.0-102.0%, respectively. The proposed method is simple, accurate, sensitive and reproducible.