Due to the rapid gain of market share of electronic cigarettes (ECs), concerns about their safety and quality have been raised over the last few years. In Europe, safety and quality standards for ECs have been introduced regionally. For example, the British Standards Institution (BSI) specified the metals to be monitored in e-liquids and aerosols of ECs^[1]. The method for the determination of these metals was validated and reported^[2]. In addition, the United States Food and Drug Administration (FDA) reported that safety concerns exist regarding EC user exposure to harmful and potentially harmful constituents (HPHCs). To date, a study for a simultaneous determination method for the metals described in the HPHC list in addition to the metals specified by BSI has not been reported. The purpose of this study was to develop and validate a method for the simultaneous determination of 13 metals (Be, Al, Cr, Fe, Co, Ni, Cu, As, Se, Ag, Cd, Sn and Pb) in EC emissions.

EC aerosol was generated according to CORESTA Recommended Method No. 81 and collected by electrostatic precipitation. Based on Standard Methods 3125, developed by American Public Health Association, the condensate was dissolved in nitric acid and an aliquot of this solution was analysed by inductively coupled plasma mass spectrometry (ICP-MS) equipped with a collision/reaction cell. Requirements for method validation such as linearity, accuracy and precision were evaluated. For example, for each metal the linearity of the calibration curve was verified to yield a correlation coefficient larger than 0.999 for the range from 0.02 to 10 µg/50 puffs. Also matrix effects were evaluated in the presence of glycerol or propylene glycol which ranged from 100 to 300 mg/50 puffs.

[1] British Standards Institution, PAS 54115, 2015
[2] OTTE S., NOWAK S., INTORP M.; CORESTA SSPT 2015, ST 10