An Efficient Assay for Simultaneous Quantification of Ethyl Carbamate and Phthalate Esters in Chinese Liquor by Gas Chromatography-Mass Spectrometry

An efficient assay was developed by gas chromatography-mass spectrometry (GC-MS) for simultaneous quantifying of ethyl carbamate (EC) and phthalate esters (PAEs, dibutylphthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP)) in Chinese liquor. Samples were directly detected using ethyl-d5 carbamate (D5-EC) and diisoamyl phthalate (DIPP) as internal standards without any pretreatment. The detection limits were 0.56, 0.70, and 1.13 mu g/L for EC, DBP, and DEHP, respectively. The average recoveries were 97.0-104.0, 96.9-105.0, and 85.0-124.2% for EC, DBP, and DEHP with relative standard deviations of 0.5-1.3, 1.6-4.2, and 2.2-5.3%, respectively. The proposed method is suitable for routine analysis of EC and PAEs in liquor due to its shorter detection time and simple pretreatment. With assistance of the established method, the contents of EC, DBP, and DEHP in Chinese liquor during the distillation process were assayed and a higher level of EC was found in the head and tail of liquor distillation.