高效液相色谱法和电位滴定法测定盐酸萘甲唑啉原料药含量

Determination of Naphazoline Hydrochloride by HPLC and Potentiometry Titration

目的:分别建立电位滴定法和高效液相色谱法测定盐酸萘甲唑啉原料药含量。方法:高效液相色谱法采用Waters XBridge C 18色谱柱(4.6 mm×250 mm,5μm),流动相为磷酸二氢钾缓冲液(取3.0 g磷酸二氢钾,加水800 mL使溶解,加3.0 mL三乙胺,用磷酸调节pH值至3.0,加水稀释至1000 mL)-乙腈(80∶20,体积比),流速为1.0 mL·min^(-1),检测波长280 nm,柱温30℃。电位滴定法以乙醇为溶剂,用氢氧化钠标准溶液(0.1 mol·L^(-1))滴定,电位法判定终点。结果:高效液相色谱法:在0.02~76μg·mL^(-1)范围内线性关系良好,r=0.9998;方法精密度RSD为0.3%(n=6);平均回收率为100.2%(n=9),RSD为0.5%。电位滴定法:在0.12~0.25 g范围内线性关系良好,r=0.9998;方法精密度RSD为0.15%(n=6);平均回收率为100.2%(n=9),RSD为0.15%。结论:电位滴定法和高效液相色谱法的含量测定结果无显著性差异,均可用于盐酸萘甲唑啉含量测定。HPLC法相较于电位滴定法,专属性高,精密度好,使用样品量少,有利于环保,故推荐首选HPLC法。

Objective:To establish a potentiometry titration method and an HPLC method for the determination of naphazoline hydrochloride.Methods:The HPLC method was performed on a C 18 column(4.6 mm×250 mm,5μm)with mobil phase of potassium dihydrogen phosphate buffer(take 3.0 g potassium dihydrogen phosphate,add 800 mL water to dissolve it,add 3.0 mL triethylamine,adjust pH value to 3.0 with phosphoric acid,add water to dilute to 1000 mL)-acetonitrile(80∶20,V/V)at flow rate of 1.0 mL·min^(-1).The UV detection was set at 280 nm and the colum temperature was matained at 30℃.Ethanol was used as solvent for potentiometry titration.The sample solution was titrated with 0.1 mol·L^(-1)sodium hydroxide solution.The end point was decided by potentiometric method.Results:HPLC:the liner range for naphazoline hydrochloride was 0.02~76μg·mL^(-1)(r=0.9998),the precision RSD was 0.3%(n=6),the average recovery was 100.2%with an RSD of 0.5%(n=9).Potentiometry titration:the liner range for 0.12~0.25 g(r=0.9998),the precision RSD was 0.15(n=6),the average recovery was 100.2%with an RSD of 0.15%(n=9).Conclusion:There was no significant difference between the results of potentiometry titration method and HPLC method and indicated that two methods both could be used to determine the content of naphazoline hydrochloride substances.Compared with potentiometric titration,HPLC method has the advantages of high specificity,good precision,less sample quantity and environmental protection.Therefore,HPLC method is recommended as the first choice.