Abstract: In order to analyze the carbonyls in e-liquids, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to simultaneously determine eight carbonyls in e-liquids, including formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, 2-butanone, and butyraldehyde. The carbonyls in e-liquids reacted with 2, 4-dinitrophenylhydrazine (DNPH) forming hydrazone derivatives under acidic conditions. The analysis results of carbonyls by LC-MS/MS and HPLC methods were compared, and the solvent background and uniformity of reaction system were investigated. After optimizing DNPH concentration, acid solution concentration and reaction time, the stability of derivative solution was studied. The results showed that: 1) The interference of complex e-liquid matrix could be eliminated by using LC-MS/MS method due to its high sensitivity and good selectivity. 2) Compared with methanol, acetonitrile presented a smaller solvent background and was chosen to prepare DNPH solution. 3) The homogeneity of sample solution with high glycerol content was improved by adding water as dispersant in e-liquid. 4) The stability of hydrazone derivatives was improved by adding pyridine in derivative solution. 5) The correlation coefficients of the eight carbonyls were more than 0.999 in corresponding concentration ranges, LOQs were between 17-93 ng/g, and the spiked recoveries ranged from 92.5% to 106.4% with intra- and inter-day RSDs in the ranges of 3.2%-6.2% and 4.1%-7.9% respectively. This method is suitable for determining large quantities of e-liquid samples with better linear, high sensitivity and precision, simple and fast pretreatment.