Development of a Standard Test Method for Insecticides in Indoor Air by GC-MS with Solid-Phase Adsorption/Solvent Extraction

<p>Semi-volatile organic compounds (SVOCs), which can cause indoor air pollution, include plasticizers, insecticides, and flame retardants. In Japan, the Ministry of Health, Labour and Welfare has set guidelines for indoor air concentrations of di-n-butyl phthalate and di-2-ethylhexyl phthalate in plasticizers and fenobucarb, diazinon, and chlorpyrifos in insecticides. However, this analytical method has only been tentatively proposed for more than 20 years. In this study, we attempted to construct an analytical method for insecticides for which guideline values have been established based on recently standardized sampling and extraction methods for phthalates in indoor air. The results of the recovery tests for the insecticides were excellent, with recovery rates and relative standard deviations in the ranges 88%–104% and 1.4%–7.5%, respectively. Furthermore, the limits of detection and quantification were less than 1/50 of the current guideline values. Additionally, inter-laboratory validation was conducted at five research institutions. By excluding outliers with the Grubbs test, the accuracies were in the ranges of 81.9%–126.3%, 76.8%–121.7%, and 76.7%–112.8% for chlorpyrifos, diazinon, and fenobucarb, respectively. The target ranges for repeatability (RSD_r) and reproducibility (RSD_R) were 30% and 35%, respectively, and the validation results met these criteria. Based on these results, we propose the developed method as the standard test method for insecticide-originated pollutants in indoor air in Japan.</p>