A Selective Chromogenic and Fluorogenic Film Kit for Determination of Cyanide in Water and Soil Samples

Abstract

A single, quick, and effective film kit for the quantification of cyanide ions in water and soil samples was developed. The film kit consists of a polymeric membrane of sodium carboxymethyl cellulose and hydroxypropyl methyl cellulose that contains matrix dispersed SBA-15 particles impregnated with the molecular sensor. The molecular sensor is highly selective for the chromogenic and fluorometric detection of CN⁻, whose recognition mechanism is based on the nucleophilic addition to the dicyanovinyl group linked to an anthracenyl moiety. The analytical evaluation was carried out for quantification of CN⁻ with the film kit and with the free sensor using UV–vis spectroscopy and fluorescence spectroscopy. The detection limit for the film kit by fluorescence spectroscopy was 0.6 μM CN⁻, which is lower than the WHO guideline for cyanide in drinking water. This method was successfully validated, and the application in real water and soil samples gave excellent results, suggesting that the film kit is versatile for determining CN⁻ in these media.