石油化工原料精对苯二甲酸PTA中精对苯二甲酸（PTA），羧基苯甲醛（4-CBA），对甲基苯甲酸（p-TPL）检测方案(毛细管电泳仪)

重Analytical EquipmentHIGH PERFORMANCECAPILLARY ELECTROPHORESISSYSTEM之w<一、www.lumexinstruments.ccm DETERMINATION OF 4-CARBOXYBENZALDEHYDE & p-TOLUIC ACIDIN PURIFIED TEREPHTHALIC ACID ACCORDING TO ASTM D7881 & ASTM D7882 TEST METHODS ASTM D7881-13 ASTM D7882-13 INTRODUCTION These test methods cover the determination of 4-carboxybenzaldehyde (4-CBA， 4-formylbenzoic acid) andp-toluic acid (p-TOL， 4-methylbenzoic acid) in purified terephthalic acid (PTA) by capillary electrophoresis(CE) with normal or reverse voltage mode and UV detection. MEASUREMENT METHOD The measurement methods are based on capillary zone electrophoresis with direct UV detection at thewavelength of 200 nm. MEASUREMENT RANGE The measurement ranges for the components are presented in the table below. Compound Measurement range， mg/kg ASTM D7881-13 ASTM D7882-13 4-carboxybenzaldehyde 3-400 5-400 p-toluic acid 8-400 10-400 EQUIPMENT AND REAGENTS The CAPEL capillary electrophoresis system is used in measurements. Data acquisition， collection，processing， and output are performed using a personal computer running under WINDOWS XP/7/8/10operating system with installed dedicated software package ELFORUN. All reagents must be of analytical grade or better. EXAMPLES OF REAL ANALYSES (ASTM 7882-13) BGE： ohosphate， with sodium 1-heptanesulfonate Capillary： -tot 50 cm， ID 50 pm Injection： 3，3 kPa * 15 s (495 mbar*s) Voltage： +25 kV Temperature： +20 Detection： 200 nm The contents on this paper are subject to change without notice. To get more specific information， please contact the representative by sales@lumexinstruments.com 对苯二甲酸（PTA）是聚酯生产的主要原料之一，其中，4-CBA和p-TOL是PTA工艺反应中生成的主要杂质，其含量高低对聚酯产品质量影响较大。因此，4-CBA和p-TOL等杂质的检测对于 PTA的质量控制具有重要意义。依据GB/T 30921.1-2014标准，使用高效毛细管电泳系统分析工业用精对苯二甲酸中的杂质，羧基苯甲醛（4-CBA）和对甲基苯甲酸（p-TPL）含量进行分离。实验结果验证了毛细管电泳Capel一次可以同时测定对苯二甲酸中的 4 -CBA 和 p -TOL, 杂质均获得较好分离，操作简便，结果准确,完全够满足对苯二甲酸生产质控和产品质量检测的需求。