Examination of Analytical Method for Mothproofing Agents to Revise the Official Methods Based on “Act on the Control of Household Products Containing Harmful Substances”

Abstract

In Japan, the use of mothprooˆng agents [dieldrin and 4,6-dichloro-7-(2,4,5-trichlorophenoxy)-2-tri‰uoromethylbenzimidazole; DTTB] in textiles is regulated by the Act on the Control of Household Products Containing Harmful Substances. Since o‹cial analytical methods for these agents have been in place for approximately 40 years, we developed an improved method in a previous study. In the present study, we validated this method. Accordingly, six laboratories analyzed the sample prepared at 3 mg/g (1/10 of the regulation value) and 30 mg/g (the regulation value). The high accuracy of the results for these samples in almost all the cases (accuracy: 70 120％, repeatability: ＜ 10％, reproducibility: ＜ 15％), conˆrmed the validity of the method. In addition, we examined three samples that were distributed before the introduction of the regulation. The analysis results for these samples showed little variation between laboratiories, indicating that our method is also applicable to actual samples. Meanwhile, the quantitative value was clearly lower in one laboratory than in the others. We presumed that the enhanced eŠect of the sample matrix (matrix eŠect) on the internal standards in GC-MS analysis was the main cause for this trend. Therefore, we examined the analytical method using polyethylene glycol 300 (PEG) as an analyte protectant. As PEG minimized the GC-MS response diŠerence between the standard solution and the matrix-containing solution, GC-MS analysis with PEG would be useful for matrix eŠect measurements in this method.