Determination of volatile organic compounds in refill fluids of electronic cigarettes by headspace solid-phase micro extraction and gas chromatography–mass spectrometry

Abstract

An optimized analytical method was employed to detect volatile organic compounds (VOCs) in refill fluids of electronic cigarettes (EC) using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS). The GC-MS conditions, including injector, oven, interface, and ion source temperatures, were optimized for the analysis of volatile compounds in EC refill fluids. The experimental parameters for GC-MS were as follows: the injector temperature was set to 280 °C, the oven temperature program initiated at 40 °C for 2 minutes, then ramped at 8 °C/min up to 80 °C, followed by a rapid ramp at 60 °C/min up to 250 °C. The interface and ion source temperatures were maintained at 260 °C and 270 °C, respectively. Samples underwent incubation at 50 °C for 5 minutes and were then extracted for 20 minutes using a SPME fiber composed of divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS), which proved to be the most effective for analyte extraction [1,2]. The optimized method was applied to study the volatile profile of 19 EC refill fluid samples with different aromas. In total, 68 compounds were identified. The dominant compounds were esters (benzyl acetate, linalyl acetate), aldehydes and ketones (menthol, vanillin), terpenes and terpenoids (limonene, camphor, linalool) and carboxylic acids (acrylic acid, valeric acid). The results substantiated that the optimized HS-SPME GC-MS method could provide an efficient and convenient approach to study the flavor characteristics of EC refill fluid.