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COLORIMETRIC SENSOR FOR DETECTING HYDROGEN CYANIDE
WO14096474
Both cyanide anion in solution (CN-) and hydrogen cyanide as a gas (HCN) are contaminant molecules, extremely toxic and dangerous in physiological systems as well as in the environment. Currently there are many colorimetric sensors for detection of CN-, however they generally do not offer adequate selectivity in the presence of other pollutants. Researchers at the University of Valencia have designed new colorimetric sensors for CN- and HCN, which have excellent selectivity and detection limits within the commonly accepted security ranges. For both applications, the invention is based on the use of a diphenylmethane-quinone compound. For the specific case of HCN gas, the compound is deposited on a solid support of basic nature.
Applications: The invention is applicable to the fabrication of sensing devices, especially as personal protection systems. These systems are useful in various industrial sectors that generate HCN (wood, plastic, steel, jewelry, mining, petrochemical, etc.) as well as in public buildings susceptible to attacks (stations, airports, etc.) Advantages: The main advantages provided by the invention are: - Detection Limits: The direct reaction between the sensor and the HCN leads to a marked color change with detection limits below 1 ppm. - Selectivity: in the presence of other gases such as CO, HCl, NH3, H2S, at concentrations up to 50 ppm - Environmentally friendly: no heavy metals used. - Reversibility: The reaction is reversible by irradiation with UV light so it can be reused in successive cycles - Minimizing false positives: Regeneration by UV radiation occurs only if the sensor reacted with HCN.