离子色谱法测定一元有机酸

Determination of Monoprotic Organic Acids by Ion Chromatography

离子色谱法测定了一元有机酸如乳酸、乙酸、乙醇酸、甲酸与丙酮酸,以及F^-离子,对淋洗液的组成进行了选择。以1.5ml/min的0.8mmol/l Na_2CO_3在Dionex HPIC-AS6和AG6上分离,抑制电导检测。其中除乳酸和乙酸由于部分重叠,在5～50μg/ml范围的相关系数为0.998和0.988外,其余物质的峰面积线性相关系数为0.999以上,检测限均低于50ng/ml而线性范围达1000μg/ml以上。用这种方法测定了饮料如黄酒和啤酒中的一元有机酸。

The monoprotic organic acids such as lactic acid, acetic acid, glycollic acid, formic acid, andpyruvic acid, as well as fluoride are determined by ion chromatography. The compositions ofeluant are discussed. The optiumum condition is as follows: the species are separated with 1.5ml/min of 0.8 mmol/l Na_2CO_3 in Dionex HPIC-AS6 and AG6, and detected by suppressedconductivity detection. The linear correlation coefficients of peak area of species are over 0.999,except lactate and acetic acid are 0.998 and 0.988 in the range of 5-50 μg/ml because ofpartial overlap. The limits of detection are below 50 ng/ml and linear range are over 1000 μg/ml. The monoprotic organic acids in the beverages such as wine and beer are analysed.