高效液相色谱法测定对苯二甲酸中微量有机杂质

Determination of trace organic impurities in terephthalic acid by high performance liquid chromatography

采用乙腈甲酸水溶液体系,建立了高效液相色谱测定对苯二甲酸中微量有机杂质对羧基苯甲醛(4-CBA)和对甲基苯甲酸(p-TOL)的方法,考察了流动相组成和配比对分离效果的影响。实验结果表明,在4-CBA(2.0~737.3)mg/kg,p-TOL(63.0~504.91)mg/kg范围内,4-CBA和p-TOL的标准曲线呈现良好的线性关系,方法的相对标准偏差均小于2%(重复进样5次),加标回收率分别为97.8%~103.8%和97.4%~103.2%,检测限分别为0.41 mg/kg和1.92 mg/kg。可同时用于精对苯二甲酸(PTA)和中纯度对苯二甲酸的产品质量控制,也可用于PTA生产过程中粗对苯二甲酸的测定。

A high performance liquid chromatographic method was studied by using acetonitrileformic acid solution as mobile phase for the quantitative analytical characterization of trace impurities comprising 4-carboxybenzaldehyde （4-CBA） and p-toluic acid （p-TOL） in terephthalic acid. Mobile phase was examined in the study. The results showed that the peak height of 4-CBA and p-TOL gave good linearity in the ranges of 4-CBA 2.0-737.3 mg/kg, p-TOL 63.0-504.91 mg/kg; the recoveries of 4-CBA and p-TOL were between 97.8%-103.8% and 97.4%-103.2%. Relative standard deviations were below 2% （repeat injection 5 times）. The limits of detection were 0.41 mg/kg and 1.92 mg/kg for 4-CBA and p-TOL. The study provided a new strategy for trace impurities analysis in terephthalic acid samples using HPLC with better sensitivity and application. By using the new method, quality controlof PTA, middle purity terephthalic acid and crude terephthalic acid could be satisfied.