电位滴定法和高效液相色谱法测定乌拉地尔含量的比较

Content Determination of Urapidil by Potentiometry Titration and HPLC

目的确定乌拉地尔原料更科学合理的含量测定方法。方法采用梅特勒DL-55型自动电位滴定仪,以冰醋酸和醋酐为溶剂,用高氯酸滴定液进行电位滴定。高效液相色谱法采用色谱柱为Syncronis C18(100 mm×2.1 mm,1.7μm);流动相为乙腈-0.05 mol·L-1磷酸二氢钠溶液(20:80),流速1.0 m L·min-1;检测波长268 nm;柱温35℃。结果电位滴定法的平均回收率为99.98%,RSD为0.41%(n=3)。高效液相色谱法的平均回收率为100.93%,RSD为0.60%(n=3)。电位滴定法和高效液相色谱法的测定结果在统计学上有显著性差异,电位滴定法回收率测定结果更接近100%。结论电位滴定法测定乌拉地尔的含量避免了对照品引起的误差,操作简单、快速,测定结果准确度高,更适宜于乌拉地尔原料的含量测定。

Objective To confirm the content determination method of urapidil in raw materials more scientifically and reasonably. Methods Mettler DL-55 potentiometric titration was used to titrate the content of urapidil by perchloric acid. Acetic acid and acetic anhydride were used as solvent. HPLC method was performed on a Syncronis Cls column （100 minx2.1 mm, l.7 /am）. The mobile phase was acetonitrile-0.05 mol.L-1 NaH2PO4 （20：80） with the flowing rate of 1.0 mL-min-1. The detection wavelength was set at 268 nm and the column temperature at 35℃. Results The average recovery rate of potentiometry titration was 99.98% and RSD was 0.41% （n=3）. The average recovery rate of HPLC was 100.93% and RSD was 0.60% （n=3）. The results of potentiometry titration and HPLC had significant statistic difference, and the recovery rate of potentiometry titration was closer to 100%. Conclusion Potentiometry titration could avoid the error due to the standard substance. The method is simple, fast, accurate and can be used to determine the content of urapidil.