Summary of the technology
The main advantages provided by the this colorimetric sensor 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.
Description of the tech for sale
Both cyanide anion in solution (CN-) and hydrogen cyanide as a gas (HCN) are contaminant molecules, extremely toxic and dangerous in both physiological systems and 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. Regarding the detection of HCN, colorimetric systems marketed so far use an indirect route for the detection, with a pH indicator which detects the HCl generated by the reaction of HCN with HgCl2. The use of this type of mercury salts generates a significant pollutant load, what makes especially interesting the fact of looking for new effective and environmentally friendly alternatives. Spanish Researchers 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. The correct choice of the compound has allowed obtaining a carbon center with electrophilicity suitable for the cyanide anion. This compound, unlike other similar commercial molecules, maintains its characteristics and reactivity once deposited on a suitable solid support. Thus, researchers have designed the first colorimetric sensor for gaseous HCN, with direct reaction. The technology is fully developed and available for demonstration. It could be useful in industries generating HCN as life safety system.
Main advantages of its use
- The major innovation of this invention is the fact of developing new colorimetric sensors for detecting hydrogen cyanide without using heavy metals.
- The invention is applicable to the fabrication of sensing devices, especially as life safety 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).