顺序注射化学发光分析法测定空气中的甲醛

基于碱性条件下甲醛对没食子酸-过氧化氢发光反应的增敏作用,建立了顺序注射与化学发光检测联用测定空气中甲醛的新方法。在选定的实验条件下,甲醛浓度与发光强度在1.0×10^-7~2.0×10^-3 mol/L范围内呈线性关系,相关系数0.999 3,方法的检出限(3σ)为5.0×10^-8 mol/L。对1.0×10^-6 mol/L的甲醛进行11次连续测定的相对标准偏差为2.1%,每小时可实现连续测定140次以上。方法的回收率为92.0%~108.0%,对环境标准样品中甲醛的测定结果与推荐值一致。

A Sequential Injection Method Coupled with Chemiluminescence Detection for the Determination of Formaldehyde in Air

A simple and sensitive sequential injection procedure coupled with chemiluminescence detection was developed for the determination of formaldehyde in air, which was based on the chemiluminescence reaction of formaldehyde, gallic acid and hydrogen peroxide in an alkaline media. The experimental parameters affecting the analytical sensitivity were optimized. Under the optimized condition, the chemiluminescence intensity changes linearly with the concentration of formaldehyde over the range of 1.0×10-7~2.0×10-3 mol/L, with a correlation coefficient of 0.999 3. The relative standard deviations of the method for 1.0×10-6 mol/L formaldehyde was 2.1% (n=11). The detection limit was 5.0×10-8 mol/L and sample throughput was 140 samples per hour. Good recoveries were obtained for spiked samples, and the results achieved were in good agreement with the certified values for standard reference material. The proposed method has several merits including sensitivity, automation, simplicity, less reagent consumption and waste generation and has been applied for the measurement of formaldehyde content in air.