顶空气相色谱质谱法快速测定液体食品中的挥发性酸

建立了一种用于快速测定食品中挥发性有机酸的分析方法.利用顶空技术对样品进行前处理,并与气相色谱质谱联用,用离子选择对11种挥发性有机酸进行定量分析.在优化的实验条件下,方法线性关系良好,线性范围为0.20 ～5 mg/L.11种挥发性有机酸的相关系数均大于0.998 6,检出限为0.000 2 ～35.5 mg/L,比全扫描检出限低1 ～3个数量级.11种挥发性有机酸的回收率为93% ～99%,相对标准偏差均小于10%.该方法简便、快速、重复性好、定性定量准确,适于食品中挥发性有机化合物的检测.

Analysis of Volatile Acids in Food by Headspace Gas Chromatography-Mass Spectrometry

A headspace gas chromatography-mass spectrometry(HS/GC-MS)method was developed and validated for determination of volatile acids including acetic acid,propionic acid,butyric acid,iso-valeric acid,valeric acid,3-methylpentanoic acid,caproic acid,heptanoic acid,caprylic acid,nonanoic acid and capric acid,in food. The volatile acids were isolated from samples using a headspace (HS)system,then identified and quantified by GC-MS. The experimental conditions were optimized and the performance of the system was evaluated. Under the optimal conditions,Linear calibration curves were obtained with correlation coefficients of more than 0.998 6. The linear range is between 0.20-5 mg/L .The detection limits were in the range of 0.000 2-35.5 mg/L,which was lower one to three levels than that of the scan method. The average recoveries of 11 volatile acids ranged from 93% to 99% with RSDs less than 10%. The method was simple,rapid,reproducible and accurate,and was suitable for the quantitative analysis of volatile acids in food.