Concurrent Quantification of Emerging Chemicals of Health Concern in e-Cigarette Liquids by High-Performance Liquid Chromatography–Tandem Mass Spectrometry

Emerging chemicals of concern (ECCs), including phthalate plasticizers, flame retardants, and phenolic compounds, are likely present in electronic nicotine delivery system (ENDS) replacement solutions (e-liquids) which are often packaged, stored in, and/or can contact with, plastic, glass, and metal materials. Developing and validating an efficient analytical method for concurrent quantification of ECCs in e-liquids are thus needed to inform evidence-based safety evaluation of ENDS products. In this study, we developed and validated a “dilute-and-shoot” method using high-performance liquid chromatography coupled with tandem mass spectrometry to simultaneously measure organophosphate flame retardants (OPFRs), phthalate plasticizers, and tetrabromobisphenol A (TBBPA) in e-liquids. We analyzed samples in positive electrospray ionization mode (ESI+) for OPFRs and phthalates and negative ESI– for TBBPA. The method has a total runtime of 10 min. The optimized procedure was able to deliver broad dynamic linearit...