Determination of carbonyl compounds in electronic cigarette refill solutions and aerosols through liquid-phase dinitrophenyl hydrazine derivatization.

In this study, we report a 2,4-dinitrophenylhydrazine (DNPH) derivatization HPLC/UV method to quantify carbonyl compounds (CCs) either in electronic cigarette (EC) refill solutions or in vaped aerosols. Vaped aerosol samples were entrained in a 1 L atm min-1 ambient lab air stream and pulled through an impinger containing a DNPH solution for derivatization. The mass change tracking (MCT) approach was used to check mass balance. Refill solution samples were diluted (2, 4, and 10 times) in a DNPH/acetonitrile solution for derivatization. EC vaping samples were collected for 5, 10, or 15 puffs (2-s puff duration) with a 10-s interpuff interval. The DNPH derivatization method was used successfully for the estimation of both EC liquid CCs concentrations and vaping emission factors. The results for formaldehyde (FA), acetaldehyde (AA), and butyraldehyde (BA) were determined as 10.4 ± 3.10 μg mL-1 (27.6 ± 7.43 ng puff-1 ), 1.9 ± 0.83 μg mL-1 (4.4 ± 1.98 ng puff-1 ), and 4.4 ± 2.82 μg mL-1 (12.0 ± 7.43 ng puff-1 ), respectively.