Use of a silver-gelatin complex for the microdetermination of hydrogen sulphide in the atmosphere

Abstract

Gelatin forms a weak complex with silver(I) in alkaline medium, which was found to be suitable for the determination of 0.6–35 p.p.b. of hydrogen sulphide by spectrophotometry and 0.3–30 p.p.b. of hydrogen sulphide using a column packed with silica gel impregnated with the complex. The method was applied successfully to the determination of hydrogen sulphide under different environmental conditions. The molar absorptivity of the solution is 2.06 × 10⁴ l mol^–1 cm^–1 for the spectrophotometric procedure, which has a relative standard deviation of 1.2%, a confidence limit (for 20 determinations) of 11.976 ± 0.023% and a Sandell sensitivity of 1.65 × 10^–3µg cm^–2. The relative standard deviation and confidence limit for the column method (20 determinations) were 0.12% and 4.99 ± 0.003, respectively, even in the presence of sulphur dioxide and carbon monoxide.