测定浓缩菠萝汁中乳酸的毛细管气相色谱法

Determination of Lactic Acid in Concentrated Pineapple Juice by Capillary Gas Chromatography

建立了毛细管气相色谱快速测定浓缩菠萝汁中乳酸的方法 ,样品经甲醇 -浓硫酸衍生化处理 ,四氯化碳萃取 ,采用氢火焰检测器 ,SUPELCOWAX_10石英毛细管柱 ,外标法定量 ,GC -MS确认;在0.01～1g/L的范围内乳酸含量与峰面积具有良好的线性关系 ,标准曲线的相关系数为0.999 ,检出限为0.008g/L,回收率为90%～96 % ,相对标准偏差为4.0 % ;方法具有快速、简便。

A method for the determination of lactic acid in concentrated pineapple juice has been established by capillary gas chromatography. The lactic acid in sample is derivatized with methanol-sulfuric acid and extracted with carbon tetrachloride. A capillary column(SUPELCOWAX- 10) and flame ionization detector are employed. A external standard method is used for quantitative determination and GC-MS for qualitative determination. The linear range, correlation coefficient, detection limit, recoveries and relative standard deviation are 0.01～1 g/L, 0.999, 0.008 g/L, 90%～96% and 4.0%, respectively. The method proved to be simple, rapid, accurate and practical.