Development of a thermal desorption-gas chromatography–mass spectrometry method for determining personal care products in air

This study describes the development of a new analytical method for determining 14 personal care products (PCPs) – nine synthetic musks, four parabens and one insect repellent – in air samples. The method is based on active sampling on sorbent tubes and thermal desorption-gas chromatography–mass spectrometry analysis, and is rapid, sensitive and drastically reduces the risk of sample contamination. Three kinds of tubes and traps were tested, those filled with Tenax TA being the most suitable for this study. Method validation showed good repeatability and reproducibility, low detection limits (between 0.03 ng m−3 for DPMI and 12.5 ng m−3 for propyl paraben) and good linearity for all compounds. Stability during storage indicated that samples must be kept refrigerated at 4 °C and analysed within 1 week of collection. The applicability of the technique to real samples was tested in different indoor and outdoor atmospheres. The total PCP values for indoor air ranged from 135 ng m−3 in a pharmacy to 2838 ng m−3 in a hairdresser's, whereas the values for outdoor air ranged from 14 ng m−3 for a suburban environment to 26 ng m−3 for an urban environment. In general, the most abundant synthetic musks were galaxolide (5.9–1256 ng m−3), musk xylene (1.6–766 ng m−3) and tonalide (1.1–138 ng m−3). Methyl and ethyl paraben (2.4–313 ng m−3 and 1.8–117 ng m−3, respectively) were the most abundant parabens. Although thermal desorption methods have been widely used for determining volatile organic compounds, they are rarely used with semi-volatile compounds. This study thus demonstrates that the thermal desorption method performs well with semi-volatile compounds and, for the first time, that it can be used for determining PCPs.