Pb-based metal organic framework as substrate: Chemical vapor generation-visual/smartphone colorimetric analytical system for sensitive and selective detection of sulfide ion in water and beers.

A visual/smartphone colorimetric system was developed for the sensitive and selective detection of sulfide ion (S) using chemical vapor generation (CVG) as a gaseous sampling technique. S in samples were converted into HS after the addition of HSO, which separated from the solution during CVG process, ensuring high efficiency of vapor generation (sensitivity) and eliminated interferences (selectivity). The HS was subsequently reacted with Pb-BTC and PbS was thus formed, causing the test paper turned to black. It was utilized for the detection of S by visual/smartphone colorimetric system. Detectable limits of 0.05 μg/mL and 0.2 μg/mL were obtained under smartphone mode and visual mode, respectively. Furthermore, this colorimetric system was successfully used for the analysis of S in several beer samples and water samples, with recoveries ranging 97 %-111 %. This system represents a potential miniaturized, easy used and high-effective method for rapid and on-site detection of S.