Unveiling per- and polyfluoroalkyl substances contamination in e-cigarette refill liquids: A comprehensive analytical...

A robust analytical method was developed for the determination of per- and polyfluoroalkyl substances (PFAS) in e-cigarette refill liquids using solid-phase extraction (SPE) with weak anion-exchange sorbent, followed by detection with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The design of experiment approach was employed to optimize sample preparation, leading to the validation of the method with limits of detection for PFAS ranging from 0.24 to 1.1 pg/mL. The method demonstrated inter-day repeatability of <17 % and relative recovery values between 89 % and 123 %. Additionally, the study explored the composition of e-cigarette refill liquids, focusing on the concentrations of primary constituents, such as vegetable glycerine and propylene glycol. Direct PFAS exposure through e-cigarette use might be of significant health concern due to vaping. Additionally, such products may serve as new source of PFAS release raising emerging issues about environment. Potential PFAS contamination in e-cigarette refill liquids may include manufacturing processes, packaging materials, or components of the e-cigarette devices, in result, leading to exposure during inhalation. A total of 31 e-cigarette refill liquid samples from various brands were analysed, revealing that PFAS were present mainly at trace levels. However, elevated concentrations exceeding 25 pg in 1 mL of commercial e-cigarette refill liquids were determined for PFNA, PFHxA, PFBS, HFPO-DA (GenX), and N-EtFOSAA. Among these, PFBS exhibited the highest detection frequency, occurring in 39 % of the samples. Notably, at least one of PFAS compounds was detected in 84 % of the samples analysed. Moreover, the higher PFAS content was determined in e-cigarette refill liquids with a nicotine content of 20 mg/mL than those with 6 mg/mL.