高效液相色谱法测定对苯二甲酸中的4－羧基苯甲醛和对甲基苯甲酸

以ＺｏｒｂａｘＳＡＸ４．６ｍｍ（ｉ．ｄ．）×２５０ｍｍ色谱柱，０．２５ｍｏｌ／ｌＮＨ＿４Ｈ＿２ＰＯ＿４／１０％ＣＨ＿３ＣＮ／ｐＨ４．３０流动相，采用高效液相色谱法，外标法定量测定ＣＴＡ或ＰＴＡ中微量或痕量的４－ＣＢＡ和ＰＴ酸，１２ｍｉｎ可完成一次色谱分离。探讨了流动相的组成对分离效果的影响，方法的相对标准偏差，４－ＣＢＡ小于４．３％；ＰＴ酸小于２．４％。平均回收率，４－ＣＢＡ为９３．１％；ＰＴ酸为９６．３％。

Determination of 4-Carboxybenzaldehyde and p-Toluic Acid in Terephthalic Acid by High Performance Liquid Chromatography

A rapid method was developed for the determination of 4-carboxybenzamehyde(4-CBA)andP-toluic acid in crude terephthalic acid(CTA) and purified terephthalic acid(PTA)by high per-formance liquid chromatography(HPLC).The HPLC stationary phase was Zorbax SAX and themobile phase consisted of 0.25mol/l NH_4 H_2 PO_4 water solution with 10 vol%CH_3 CN,and the pHwas adjusted to 4.30 by ammonium hydroxide, The column temperature was kept at 30℃,Thewavelength of UV detector was set at 240 nm for CTA and 250 nm for PTA. The retentiontimes for 4-CBA,p-toluic acid,and terephthalic acid were 3.8,4.6,and 6.6 minutes respective-ly. The recoveries of 4-CBA were 90.1%─95.9%,and of p-toluic acid 94.8%-98.5%,Therelative standard deviations were 2.5%-4.3%for 4-CBA and1.7%-2.4%for p-toluic acid.