高效液相色谱梯度洗脱法测定注射用美洛西林钠-舒巴坦钠中有关物质

目的建立HPLC梯度洗脱法测定注射用美洛西林钠-舒巴坦钠有关物质的方法。方法使用ZORBAX SB-C18色谱柱（4.6 mm×250 mm,5.0μm）,以磷酸盐缓冲液（5.44 g L-1磷酸二氢钾溶液,用磷酸调节pH至3.8,即得）和乙腈为流动相,梯度洗脱,流速为1.0 mL min-1,柱温为31℃,检测波长为215 nm。结果样品中有关物质完全洗出,美洛西林和舒巴坦主峰与有关物质峰均达到基线分离,舒巴坦杂质A、B分离度符合要求;舒巴坦杂质A、舒巴坦杂质B、舒巴坦和美洛西林与峰面积线性关系良好,相关系数（r）均〉0.997 2;舒巴坦杂质A相对舒巴坦校正因子为0.6,舒巴坦杂质B相对舒巴坦校正因子为0.5;舒巴坦杂质A、B检测限分别为3.11 ng和5.98 ng,定量限分别为10.36 ng和17.93 ng,舒巴坦检测限和定量限分别为8.46 ng和31.01 ng;美洛西林的检测限和定量限分别为12.20和40.25 ng;舒巴坦杂质A、B平均回收率（n=9）分别为100.9%和102.0%。结论该方法对注射用美洛西林钠舒巴坦钠有关物质的测定灵敏、准确、专属性强,适用于产品质量控制。

HPLC determination of related substances in mezloeillin sodium and sulbactam sodium for injection with gradient elution

Objective To establish an HPLC gradient elution method to determine related substances in mezloeillin sodium and sulbactam sodium for injection.Methods A ZORBAX SB C18 column（4.6 mm×250 mm,5.0 μm）,a mobile phase consisting of phosphate buffer（5.44 g L-1potassium dihydrogen phosphate solution and adjusted to pH 3.8 with phosphoric acid） and acetonitrile were used with gradient elution at 1.0 mL min-1.The column temperature was 31 ℃ and the detection wavelength was 215 nm.Results The related substances in mezloeillin sodium and sulbactam sodium sample were completely eluted and a baseline separation of mezloeillin and sulbactam from related substances was obtained.The impurity separation degree of shubatan A,and B met the requirement.The method showed good linearity for shubatan impurity A,shubatan impurity B,sulbactam and mezloeillin with all correlation coefficients（r） 0.997 2.The relative shubatan correction of shubatan impurity A was 0.6,and that of sulbactam impurity B was 0.5.The detection limit for sulbactam impurity A,sulbactam impurity B,sulbactam and mezloeillin was 3.11,5.98,8.46 and 12.20 ng.The quantitation limit for sulbactam impurity A,sulbactam impurity B,sulbactam and mezloeillin was 10.36,17.93,31.01 and 40.25 ng,respectively.The average recoveries（n = 9） of sulbactam impurity A and sulbactam impurity B were 100.9% and 102.0%.Conclusion The method is sensitive,accurate and highly specific for the determination of related substances in mezloeillin sodium and sulbactam sodium for injection,and it is suitable for the quality control.