对-羟基苯甲酸是常用的化学试剂和化工原料,其质量的优劣主要取决于邻、间位杂质含量。对-羟基苯甲酸分析主要是采用高效液相色谱法。分析对-羟基苯甲酸的主要困难在于对位和间位异构体的分离,大量的对-羟基苯甲酸易于掩盖间-羟基苯甲酸出峰。本工作采用吸附色谱,以含乙酸的二氯甲烷-乙醇为流动相,使邻、间、对-羟基苯甲酸获得了较好的分离。柱后通过双紫外检测器串联进行测定。 Para-hydroxybenzoic acid is commonly used chemical reagents and chemical raw materials, the quality of its pros and cons mainly depends on the adjacent, inter-bit impurity content. Para-hydroxybenzoic acid analysis is mainly using high performance liquid chromatography. The major difficulties in the analysis of p-hydroxybenzoic acid are the separation of para and meta isomers, and the large amount of p-hydroxybenzoic acid tends to mask the peak of m-hydroxybenzoic acid. In this work, adsorption chromatography with acetic acid in dichloromethane - ethanol as the mobile phase, so that o, p, p-hydroxy benzoic acid obtained better separation. The column was measured by double UV detector in series.