Gran图解法测定苯妥英钠及其片剂的含量

Determination of dilantin and its content in tablets by means of Gran graphics

本文研究了以电位滴定为测定手段,用Gran图解法测定苯妥英钠及其片剂中含量的方法。该法以0.1 mol/l KCl溶液为离子强度调节剂(ISA),分步等体积滴入滴定剂,测定相应的pH值,按强酸滴定弱碱计量点后之Gran函数(V_0+V_t)×10^(-pH)州对滴定剂体积V_t作图,用直线外推法求滴定终点。

This article presenrs a method for determining dilantin and its conrent in tablets by means of Gran graphics based on potentiometer titration. With o.1mol/LKCI solution as ionic strength adjustor(ISA),the titrant is fed in a step way in equivalent Volumes to determine the pH value.After titration of weak base with strong acid,the volume of the titrant Vt is graphed in terms of Gran func- tion(V_0+V_t)×10^(-pH).The end point of titration can be derived by method of straight line extrapolation.