• Analytical Science and Technology
• /
• v.7 no.3
• /
• pp.261-269
• /
• 1994

The iodide formed stoichiometrically for sulfide by its oxidation with iodate was extracted as an ion-pair with methylene green into 1,2-dichloroethane and the extract was measured spectrophotometrically at 656nm for the determination of sulfide. Hydrogen sulfide separated from the sample matrix was introduced into a solution containing pH 3.5 acetate buffer and iodate, in which the hydrogen sulfide was completely converted into iodide. A linear calibration graph was obtained over the range $3{\times}10^{-7}{\sim}1.2{\times}10^{-5}M$ sulfide($0.0096{\sim}0.384{\mu}g$ of $S^{2-}/ml$) and the detection limit was $0.0032{\mu}g/ml$. The apparent molar absorptivity and a correlation coefficient(r) were $6.7{\times}10^4L\;mole^{-1}\;cm^{-1}$ and 0.999, respectively. When applied to the stream water samples, the proposed method gave a relative standard deviation of 1.59% at $5{\times}10^{-6}M$ sulfide level.