Solid-phase extraction coupled with ultraviolent diffuse reflectance spectroscopy to fulfill sensitive and selective determination of phosgene

Abstract

ABSTRACTA simple, rapid, sensitive, and selective method was proposed to detect phosgene by solid-phase extraction coupled with ultraviolent diffuse reflectance spectroscopy. First, phosgene reacts with aniline solution to produce N,N′-diphenylcarbamide, then nylon membrane was selected as solid-phase material to enrich N,N′-diphenylcarbamide and separate it from mixture solution. At last, nylon membrane-concentrated N,N′-diphenylcarbamide was measured directly to collect ultraviolent diffuse reflectance spectrum without any elution. Some parameters such as membrane pore, vacuum degree, and volume of sample were optimized. Under the optimal conditions, the relationship between the mass x of phosgene and absorbance y at 257 nm was described in a linear equation of y = 0.0141x + 0.0025 with a squared correlation coefficient of 0.9920, the limit of detection of phosgene was estimated as low as 0.2466 µg. The developed method was evaluated by applying to detect phosgene content in real samples and comparing with aniline in ultraviolet spectrophotometric method, which is adopted by the standard method of China. The relative errors of two methods were between −7.03% and 3.60%, and the relative standard deviations were from 6.55% to 9.31%, which are comparable to the standard method and verified the feasibility of the current method. These results demonstrated that the proposed method could be applied to the detection of phosgene with good accuracy and precision.