A study on the applicability of zinc acetate impregnated silica substrate in the collection of hydrogen sulfide by active sampling

A novel device for the hydrogen sulfide determination in air was developed based on the collection on zinc acetate impregnated silica substrate in glass tubes, followed by ion chromatographic quantification after sulfide oxidation to sulfate in an alkaline solution of H2O2. Laboratory tests were conducted in controlled atmosphere to evaluate uptake rate, linearity, sample stability, influence of relative humidity and interfering gases. A pilot study was also conducted in the field in order to assess the applicability of the substrate and to understand the effect that gases such NO2 and CH4 can have on the efficiency of collection of H2S. The device has shown to have several advantages with respect to the charcoal substrate, that is the one of choice as reported by National Institute of Occupational Safety and Health (NIOSH) method. In particular it does not suffer from sulfur background and it is not influenced by interfering gases such as NO2 and CH4 .