高效液相色谱法测定左卡尼汀注射液的含量及杂质A

Content and impurity A of levocarnitine injection determined by high performance liquid chromatography

目的建立一种以阴离子色谱柱为分离介质测定左卡尼汀注射液含量及杂质A的高效液相色谱法。方法色谱柱为Pheno Sphere 5u SAX 80A（250 mm×4.60 mm）,柱温30℃;流动相为乙腈∶磷酸盐溶液（磷酸二氢钾6.81 g/L,以氢氧化钠溶液调节p H为4.7）=65∶35;检测波长为205 nm,进样量20μl;流速1.0 ml/min,外标法计算。结果左卡尼汀和杂质A得到有效分离,分离度〉1.5,辅料及流动相不干扰测定;左卡尼汀的检出限和定量限分别为0.5、2μg/ml,左卡尼汀杂质A的检出限、定量限分别为20、50 ng/ml;左卡尼汀在1034~8274μg/ml范围内线性关系良好（r2=0.99996）,杂质A在0.25~25μg/ml范围内线性关系良好（r2=0.99987）;左卡尼汀和杂质A平均回收率分别为101.29%（RSD=0.55%）、100.35%（RSD=1.79%）。结论该方法专属、准确、简便,可用于左卡尼汀注射液的含量和杂质A测定。

Objective To establish a high performance liquid chromatography （HPLC） method determining the content and impurity A of levocarnitine injection selecting anion chromatographic column as separation medium. Methods The column was PhenoSphere 5u SAX 80A （250×4.60 mm） and the column temperature was 30 ℃.The mobile phase was the ratio of acetonitrile and phosphate solution （potassium dihydrogen phosphate of 6.81 g/L regulated by sodium hydroxide solution with the pH of 4,7） was 65：35.The detection wavelength was 205 nm and injection volume was 20 μl. The flow velocity was 1.0 ml/min and,the outcome were calculated by external standard method. Results Levocarnitine and impurity A was effectively separated,and the degree of separation was over 1.51Determination was not interfered by adjuvant material or mobile phase.The limit of detection （LOD） and limit of quantitation （LOQ） of levocarnitine was 0.5 μg/ml and 2 μg/ml respectively.The LOD and LOQ of impurity A in levocarnitine was 20 ng/ml and 50 ng/ml respectively. Ranging from 1034 to 8274 μg/ml,levocarnitine displayed a good linear relationship （r2=0.99996）.Ranging from 0.25 to 25 μg/ml,impurity A displayed a good linear relationship （r2=0.99987）.The average recovery rate of levocarnitine and impurity A was 101.29% （RSD=0.55%） and 100.35% （RSD=I.79%）. Conclusion The established method is specific,accurate and convenient,which can be, used for the determination of content and impurity A in levocarnitine injection.