离子色谱法测定果汁中乳酸、富马酸、柠檬酸的含量

建立离子色谱测定果汁中的乳酸、富马酸、柠檬酸的分析方法。利用Onguard II RP柱进行预处理除去疏水性物质,使用IonPac AS19(250 mm×4 mm)色谱柱,IonPac AG19(250 mm×4 mm)保护柱,以氢氧化钾溶液梯度淋洗,采用自循环抑制电导检测的方法对苹果汁样品中的乳酸、富马酸、柠檬酸含量进行检测。该方法能够准确地测定果汁中乳酸、富马酸、柠檬酸的含量,线性方程的相关系数在0.999以上,样品的加标回收率为90.7%～102.8%,测定结果的相对标准偏差为0.41%～1.43%(n=6),样品的定量限分别为0.5,0.2,0.3 mg/L。该法操作简单,环境友好,灵敏度高,测定结果准确可靠,能满足果汁中有机酸含量的测定要求。

Determination of Lactate,Fumarate and Citrate in Fruit Juice by Ion Chromatography

A new method for determination of lactate,fumarate and citrate in fruit juice was developed and validated based on ion chromatography. Onguard II RP cartridges were used to remove hydrophobic substances in the fruit juice. The content of lactate,fumarate and citrate in fruit juice were determined by using IonPac AS19 chromatographic column and IonPac AG19 guard column, potassium hydroxide gradient elution and circulation suppression conductometric. The calibration curves of correlation coefficients were more than 0.999 for these organic acids. The recoveries were between 90.7%-102.8%and the relative standard deviation of determination results was between 0.41%-1.43%（n=6）. The detection limits were 0.5,0.2,0.3 mg/L for lactate,fumarate and citrate, respectively. The method is environmental friendly and has high sensitivity,good selectivity, and can meet the requirement of the determination of organic acids content in fruit juice.