反相离子对高效液相色谱法测定左卡尼汀注射液中杂质A的含量

An ion pair reversed phase high performance liquid chromatography method for determination of impurity A in levocarnitine injection

目的:建立离子对高效液相色谱法测定左卡尼汀注射液中杂质A的含量。方法:采用Zorbax SB-C18色谱柱(4.6 mm×250 mm,5μm),流动相为磷酸盐缓冲液[(取磷酸11.5 mL,加水约1800 mL,用1 mol.L-1氢氧化钠溶液调pH至3.0,加水至2000 mL),加庚烷磺酸钠1.1 g,振摇使溶解]-甲醇(95∶5),流速1.0 mL.min-1,检测波长为215 nm。结果:左卡尼汀杂质A与主药峰得到良好分离,分离度达到1.772,在1～100μg·mL-1的范围内,杂质A浓度与峰面积之间呈现良好线性关系,r2=0.9996(n=6),3批左卡尼汀注射液中杂质A的平均含量为0.0052%。结论:该方法简便、准确、专属,可用于该注射液的质量控制。

Objective： To establish a method to determine the impurity A content of levocarnitine injection by the ion pair high performance liquid chromatography.Methods： The Zorbax SB-C18 column（4.6 mm × 250 mm,5 μm） was used with a mobile phase consisting of phosphate buffer solution[（11.5 mL phosphoric acid was dissolved in 1800 mL water,adjusted to pH = 3.0 using 1 mol.L-1sodium hydroxide solution,and then brought up to full volume 2000 mL with water）,finally 1.1 g sodium heptanesulfonate was added and dissolved by shaking] and methanol（95∶ 5） at a flow rate of 1.0 mL.min-1;the detection wavelength was 215 nm.Results： Levocarnitine and impurity A was completely separated by this method,and their resolution was 1.772.The linearity of peak area of impurity A was good in the range of 1-100 μg.mL-1（r2 = 0.9996,n = 6）.The average content of impurity A in levocarnitine injection was 0.0052%.Conclusions： The established method is specific,accurate and convenient,which can be used for quality control of levocarnitine injection.