乳粉中α-亚麻酸气相色谱法测定方法及其不确定度的评定

Determination of α-Lionlenic acid in milk powder and Evaluation of uncertainty of the analysis method

本文介绍了一种用气相色谱法测定乳品中α-亚麻酸的分析方法,方法简便、快速,同时可以进行亚油酸的测定,方法的检出限为0.33ng,线性范围是0.550～91.0ng,回归方程是A=126889C+150.63,加标回收率在90.3～106.5%。并且讨论了使用本方法测定α-亚麻酸分析结果的不确定度,不确定度为:5.6%。

A method for the determination of α-Lionlenic acid in milk powder was developed using capillary chromatography （GC）. The calibration curve （A = 126889C ＋150.63） was found to be linear over the range of 0.550 - 91.0ng and the detection limit is 0.33ng （S/N=3）. The average recovery is 98.4% .When the same sample was analyzed for 6times ,the RSD of the area of the peak for α- Lionlenic acid is 1.6% .The combined relative standard uncertainty of the method is 5.6% ,and the expanded uncertainty is 11.2% （coverage faetor is equal 2）.