毛细管电泳法测定PTA生产中的Br^-含量

Capillary electrophoresis determination of Br^- content during PTA production

采用毛细管电泳法测定精对苯二甲酸(PTA)生产过程中不同装置部位的Br^-含量,探讨了该方法的实验条件。结果表明:以2 g/L正庚烷磺酸钠、4 g/L正己烷磺酸钠及2.25 mg/L十六烷基三甲基氯化铵的混合溶液为缓冲液,在分离电压-10 kV,波长200 nm,进样压力4.14 kPa,温度30℃,进样时间20 s的条件下,测定PTA生产装置不同监控点的Br^-含量,试样中的醋酸、PTA、对羧基苯甲醛、对甲基苯甲酸不干扰测定,对二甲苯(PX)对Br^-有增敏作用,可以通过在制作工作曲线的标准溶液中加入相应量的PX来消除干扰;该方法的回收率为98.1%～103.0%,相对标准偏差为0.61%。

The capillary electrophoresis determination of Br- content was studied for different equipment units during purified terephthalie acid （PTA） production. The experimental conditions were discussed. The results showed that Br- content can be determined at different detection points of FTA plant under the following conditions ： the mixture solution of 2 g/L sodium 1-heptanesulfonate, 4 g/L sodium hexane-l-sulphonate and 2.25 mg/L n-hexadecyltrimethylammonium chloride as a buffer, seperation voltage - 10 kV, wave length 200 nm, inject pressure 4.14 kPa, temperature 30 ℃, inject time 20 s. The determination will not be disturbed by acetic acid, PTA, 4-earboxybenzaldehyde andp -toluic acid in samples. The substance of p-xylene has a sensitizing effect on the determination of Br- content, which can be eleminated by introducing a reasonable amount of PX in the standard solution for the working curve. The recovery rate of this method was 98.1% - 103.0%, and the relative standard deviation was 0.61%.