离子色谱法测定注射用氯唑西林钠中醋酸根离子含量

Determination of acetate ion in cloxacillin sodium for injection by ion chromatography

目的:建立离子色谱法测定注射用氯唑西林钠中醋酸根离子的含量。方法:采用TSKgel Super IC-AP阴离子柱(4.6 mm×150 mm,6μm),流动相为6.3 mmol·L^(-1)碳酸氢钠与1.1 mmol·L^(-1)碳酸钠的混合溶液,流速为0.8 m L·min^(-1),柱温为35℃,进样体积为10μL,抑制型电导检测。结果:氟离子等常见无机离子、甲酸根离子以及强破坏(高温破坏、光照破坏、酸破坏、碱破坏及氧化破坏)降解产物均不干扰醋酸根离子的测定。醋酸根离子在0.990 0~99.00μg·m L^(-1)范围内峰面积与质量浓度线性关系良好(r=0.999 9);平均加样回收率(n=9)为99.5%,RSD为0.3%;方法最低定量限为0.002 5%。有6个厂家的22批样品采用醋酸钠作为成盐剂,相应样品中残留的醋酸根离子含量在0.07%~0.83%之间。结论:建立的离子色谱法可用于注射用氯唑西林钠中醋酸根离子的含量测定。

Objective：To establish a method for determination of the content of acetate ion in cloxacillin sodium for injection by ion chromatography.Methods：The chromatographic separation was achieved on a TSKgel Super IC-AP anion column（4.6 mm×150 mm,6 μm）.The mobile phase was composed of a water solution containing 6.3 mmol·L-（-1） Na HCO3 and 1.1 mmol·L-（-1） Na2CO3 with isocratic elution at a flow rate of 0.8 m L·min-（-1）.The column temperature was set at 35 ℃ and the injection volume was 10 μL.Inhibitory electrical conductivity detector was used as the detector.Results：None of the following factors,including formate ion,fluorinion and other organic acids,and the degradation products after strong destruction by high temperature,UV light,acid solution,base solution and hydrogen peroxide solution,interfered with the determination of acetate ion.In the concentration range of 0.990 0-99.00 μg·m L（-1）,the area and the concentration showed good linear relationship（r=0.999 9）.The average recovery（n=9）was 99.5%（RSD=0.3%）.The lower limit of quantification was 0.002 5%.Sodium acetate was applied as salt-forming reagent in 22 batches of samples involving 6 manufactures.The residual acetate ion was found to be in the range of 0.07%-0.83%.Conclusion：The established method is suitable for the determination of the content of acetate ion in cloxacillin sodium for injection.