Chemical profiling of household chemical products with high coverage of toxicant polarity using biphasic liquid extraction coupled with LC-MS and GC-MS

Abstract

The humidifier sterilizer scandal in 2011 caused lung injury to mor than 500 people, including some 100 deaths by polyhexamethylene guanidine poisoning. This scandal reminded us of the importance of toxicant characterization for household chemical products (HCPs). The Ministry of Environment is discovering over 20 HCPs containing unreported toxicants per month. However, the current regulation relies on targeted analysis of a few chemical species with a single instrument, which can limit the coverage of toxicant identification in HCPs. Biphasic liquid-liquid extraction (LLE) could effectively separate toxicants in HCPs into polar and nonpolar phase. Here, a high-coverage chemical profiling method is suggested using biphasic liquid extraction coupled with untargeted LC-MS/MS and GC-MS. A fabric softener and a car fragrance liquid were selected as target products for toxicant profiling. Two biphasic LLE based on Folch and methyl tert-butyl ether extraction methods were compared. The effect of solvent pH on extraction efficiency of acidic/basic compounds was evaluated. The polar phase was analyzed using UPLC-ESI-LTQ Orbitrap MS, while the nonpolar phase was analyzed using GC-quadrupole MS. For UPLC-MS/MS analysis, chemicals relevant to HCPs were analyzed with higher priority using a preference list of precursor selection from a public chemical database by Phillips et al. (Environ. Sci. Technol. 2018, 52, 5, 3125– 3135). Using NIST 17 CID MS/MS and EI/MS spectral library, potential toxicants were identified. This method could be effectively exploited for analysis of complex HCPs with a broad polarity range of chemicals.