气相色谱法测定饮品中一氯乙酸含量
GC Determination of Monochloroacetic Acid in Drink
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摘要: 提出了气相色谱法测定饮品中一氯乙酸含量的方法。样品经甲基叔丁基醚萃取,再经甲醇衍生后用DB-1701石英毛细管色谱柱分离,电子捕获检测器检测。选择1,2-二溴丙烷作为内标物。一氯乙酸的浓度在低、中、高3个浓度范围内的线性相关系数均大于0.996 0,方法测定下限(10S/N)小于10.0 μg·kg-1。以8种空白饮品为基体,在3个添加水平进行加标回收试验,平均回收率在72.4%~107%之间,5家实验室测定值的相对标准偏差(n=6)在0.39%~9.0%之间。Abstract: Gas chromatography was applied to the determination of monochloroacetic acid in drinks. The sample was extracted with methyl tert-butyl ether, and the extract was derivatized with methanol. DB-1701 quartz capillary chromatographic column was used for separation; and electron capture detector was used for determination with 1,2-dibromopropane as internal standard. Values of correlation coefficient in 3 ranges of low, middle and high concentration found were more than 0.996 0. Values of lower limit of determination (10S/N) found were less than 10.0 μg·kg-1. Using blank sample of drinks as matrixes, recovery was tested at 3 different concentration levels and values of recovery found were in the range from 72.4% to 107% with RSD′s (n=6) in the range from 0.39% to 9.0%.