离子色谱法测定饲料添加剂中有机酸和无机酸含量

Determination of organic and inorganic acid in the feed additive by ion chromatography

本实验建立了同时测定饲料添加剂中甲酸、乳酸、柠檬酸及磷酸的离子色谱方法(IC)。样品采用酸碱结合的预处理方法提取饲料添加剂中的4种酸。色谱条件为RFC-30KOH淋洗液发生器、AS11-HC离子色谱柱,抑制电导检测。此方法各种有机酸和无机酸线性关系良好(相关系数为0.9995～0.9998),线性范围为1～20mg/L,回收率为98%～106%,分析方法快速简便。

The method was established for measuring the formic acid,lactic acid,citric acid and phosphoric acid in the feed additive by ion chromatography （IC）.Those four acids were pretreated using alkali combined with acid.IonpacAS11-HC was selected as the separation column, 10 - 30 mmol/L KOH produced by RFC-30 eluent generator and the detection was performed by the suppressed conductivity detector.It showed good linear relationship （correlation coefficient was 0.9995 - 0.9998）between the peak area of those four acids and linear range was 1 - 20 mg/L,and the recovery ratio was 98 % - 106 %.This analysis method was fast and convenient.