特定化合物稳定同位素分析是近年来研究的重点，基于液相色谱-同位素比值质谱（LC-IRMS）技术建立了白酒中乙醇δ13C值的测定方法。分析了白酒挥发性组分对乙醇δ13C值测定的干扰，研究了流动相流速和色谱柱温度对白酒中乙醇分离及对δ13C值测定的影响，优化后的色谱条件为流速0.35 mL/min，柱温30℃，样品中乙醇浓度范围为0.14～1.08 g/L。方法的重复性和再现性标准偏差均优于0.09‰（n=10）。用该法和气相色谱-燃烧-稳定同位素比值质谱技术同时测定10个白酒样品，两种方法的测定结果具有显著相关性关系（R2=0.999）。该法操作简单，检测限可低至0.14 g/L，且结果更稳定、准确。%Compound-specific stable isotope analysis (CSIA) has become the research focus in recent years. On the basis of S&T development, the determination of ethanolδ13C isotope ratio of Baijiu by liquid chromatography coupled with isotope ratio mass spectrometry (LC-IRMS) has been developed. In this study, several parameters influencing the separation of ethanol from liquor matrix and influencing the measurement ofδ13C of ethanol were investigated and then optimized as follows:mobile phase was at 0.35 mL/min, column temperature at 30℃, ethanol concentration for injection was in the range of 0.14 g/L to 1.08 g/L. The results showed that the analytic precision of the method was better than 0.09‰(n=10). 10 liquor samples were determined by this method and by the official method (gas chromatography-combustion-isotope ratio mass spectrometry) respectively. There were significant correlations (R2=0.999) between the measured results of the two methods. LC-IRMS had the advantages including simple operation, low detection limit (0.14 g/L), and high accuracy.
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