Gran电位滴定法测定诺氟沙星及其胶囊的含量

Gran potentiometric titration in quantitative determination of norfcoxacin and its capsule

诺氟沙星(NX)含量测定采用电位滴定法,以0.2mol/LKCl 溶液作离子强度调节剂,用 NaOH 标准溶液滴定。滴定剂分步等体积加入,测定其 pH 值。以强碱滴定水不溶性弱酸计量点后之Gran 函数对滴定剂体积作图,直线外推法求滴定终点。用上述方法测定 NX,结果与美国药典法一致。模拟胶囊回收率和标准加入回收率分别为:99.56%和99.53%。

With potentiometric titration method,nor-fcoxacin(NX)was titrated with NaOH standardsolution.0.2 mol/L KCl solution served as ionicstrength adjustor(ISA).The titrant was addedstepwise in equal volume,and the pH was mea-sured.The Gran function after the stoichiometricpoint of the water insoluble weak acid titrated bystrong base plotted the volumes of titration.Theend point of the titration was obtained from thelinear extrapolation.The results of NX measure-ment are in agreement with those of pharmacopeiaof the United States.The average recovery of sim-ulated capsule and standard addition was 99.56%and 99.53% respectively.