Cao Yixue, Yang Fan, Xie Yuanyuan, Liu Song, Hua Lei, Zhang Siyu, Chen Ping, Wen Yuxuan, Li Haiyang, Wang Li
CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Anal Chem. 2023 Feb 28;95(8):4235-4242. doi: 10.1021/acs.analchem.2c05752. Epub 2023 Feb 16.
Ethyl carbamate (EC), a carcinogenic compound, is naturally produced in fermented foods and alcoholic beverages. Rapid and accurate measurement of EC is necessary and important for quality control and safety evaluation of Chinese liquor, a traditionally distilled spirit with the highest consumption in China, but it remains a great challenge. In this work, a direct injection mass spectrometry (DIMS) with time-resolved flash-thermal-vaporization (TRFTV) and acetone-assisted high-pressure photoionization (HPPI) strategy has been developed. EC was rapidly separated from the main matrix components, ethyl acetate (EA) and ethanol, by the TRFTV sampling strategy due to the retention time difference of these three compounds with large boiling point differences on the inner wall of a poly(tetrafluoroethylene) (PTFE) tube. Therefore, the matrix effect of EA and ethanol was effectively eliminated. The acetone-assisted HPPI source was developed for efficient ionization of EC through a photoionization-induced proton transfer reaction between EC molecules and protonated acetone ions. The accurate quantitative analysis of EC in liquor was achieved by introducing an internal standard method (ISM) using deuterated EC (-EC). As a result, the limit of detection (LOD) for EC was 8.88 μg/L with the analysis time of only 2 min, and the recoveries ranged from 92.3 to 113.1%. Finally, the prominent capability of the developed system was demonstrated by rapid determination of trace EC in Chinese liquors with different flavor types, exhibiting wide potential applications in online quality control and safety evaluation of not only Chinese liquors but also other liquor and alcoholic beverages.
氨基甲酸乙酯（EC）是一种致癌化合物，天然存在于发酵食品和酒精饮料中。快速准确地测定EC对于中国白酒（一种在中国消费量最高的传统蒸馏酒）的质量控制和安全评估至关重要，但这仍然是一个巨大的挑战。在这项工作中，开发了一种具有时间分辨闪蒸热汽化（TRFTV）和丙酮辅助高压光电离（HPPI）策略的直接进样质谱（DIMS）方法。由于这三种化合物在聚四氟乙烯（PTFE）管内壁上沸点差异较大，保留时间不同，通过TRFTV采样策略，EC能够快速从主要基质成分乙酸乙酯（EA）和乙醇中分离出来。因此，有效消除了EA和乙醇的基质效应。开发了丙酮辅助HPPI源，通过EC分子与质子化丙酮离子之间的光电离诱导质子转移反应，实现EC的高效电离。通过引入使用氘代EC（-EC）的内标法（ISM），实现了白酒中EC的准确定量分析。结果表明，EC的检测限（LOD）为8.88μg/L，分析时间仅为2分钟，回收率在92.3%至113.1%之间。最后，通过快速测定不同香型白酒中的痕量EC，证明了所开发系统的卓越能力，该系统在白酒以及其他酒类和酒精饮料的在线质量控制和安全评估中具有广泛的潜在应用。
