Fast detection of hydrogen sulfide using a biodegradable colorimetric indicator system

A fast, colorimetric indicator system was developed by combining chitosan as a three‐dimensional biopolymer matrix and ferrous sulfate (FeSO4) as a colorimetric indicator of hydrogen sulfide (H2S) gas. Chitosan filmogenic suspensions (3.0% w/w) were obtained and FeSO4 was incorporated at 2.0 wt%. The colour parameters were measured using a colorimeter, after subjecting the system to various H2S exposure times. The novelty of this work is the biodegradability, a test performed in soil, which showed a weight loss of about 67% after 60 days, and the fast device formation indicating the presence of H2S gas. The chitosanFeSO4 system detected the presence of H2S in concentrations equal to or greater than 100 ppm within 30 s of exposure and produced a visual black colour as a response to the presence of H2S. Copyright © 2011 Society of Chemical Industry A fast and colorimetric indicator system was developed combining chitosan as three‐dimensional biopolymer matrix and a colorimetric indicator for hydrogen sulfide gas.