Another study to detect formaldehyde

Another study to detect formaldehyde gas with high sensitivity and easy colorimetric sensors was performed by Feng et al. In this study, they found a better and easier method than methods based on nucleophilic amine additives that use a simple pH indicator to detect basicity changes upon the reaction of a nonvolatile primary amine with formaldehyde. amine-terminated PEG was used To create a reaction matrix to identify formaldehyde. they used 6 different pH indicators in 5 different polymer formulations to optimally select the indicators and polymeric amine that were printed on PVDF membranes. After the exposure array to the 20 ppm formaldehyde (IDLH), color changes were observed even with the naked eye after 1 min. Using HCA analysis, it detected concentrations of 20ppm to 250ppb in 1 minute without error and accurately detected concentrations of much less, ie 75 and 50ppb in 10 minutes. Also using hydrophobic dyes as well as hydrophobic PVDF membrane, Were able to minimize the effect of moisture changes.