基于特征离子分析酱香白酒中挥发性有机酸

Qualitative Analysis of Volatile Organic Acid in Jiangxiangxing Baijiu by Characteristic Ions

采用带氢火焰离子化检测器(FID)与质谱检测器(MS)的气相色谱,对比分析了酱香白酒中乙酸、丙酸、丁酸、戊酸和己酸5种挥发机酸在WAX与WAXms两种强极性毛细管色谱柱上的分离保留行为以及被干扰情况。结果表明,5种挥发性有机酸在WAX色谱柱上存在严重的拖尾现象,在实际酒样分析时各酸的色谱峰也被其他物质干扰,在FID上的响应也低于干扰物质。在WAXms色谱柱上,5种挥发性有机酸能够实现完全分离且无拖尾现象,通过选择性提取质荷比43作为乙酸、74作为丙酸,60作为丁酸、戊酸和己酸的特征离子,能够消除酱香白酒中其他物质对酸峰的干扰。5种挥发性有机酸在0.5~60.0μg·mL^(-1)有良好线性关系,检出限为0.02~0.06μg·mL^(-1),加标回收率为99.2%~99.8%。基于特征离子的气质分析方法适用于酱香白酒挥发性有机酸的定量分析。

The separation and retention behaviors of acetic acid,propionic acid,butyric acid,valeric acid and hexanoic acid in Jiangxiangxing Baijiu on WAX and WAXms capillary chromatography columns were analyzed by gas chromatography with flame ionization detector(FID)and mass spectrometry detector(MS).The results showed that the five volatile organic acids had serious peak trailing on WAX column,and the peaks of each acid were also disturbed by other substances in actual wine.The response signal of the five volatile organic acids on FID was lower than that of the interfering substances.On WAXms column,the five volatile organic acids could be completely separated without peak trailing.The interference of other substances in wine to acid peak could be eliminated by selective extraction of mass charge ratio 43 as acetic acid,74 as propionic acid,60 as butyric acid,valeric acid and hexanoic acid.The five volatile organic acids had a good linear relationship at 0.5~60.0μg·mL^(-1),the detection limit was 0.02μg·mL^(-1) to 0.06μg·mL^(-1),and the recovery rate was 99.2%to 99.8%.The method based on characteristic ions with gas chromatography mass spectrometry is suitable for the quantitative analysis of volatile organic acids in Jiangxiangxing Baijiu.