反相高效液相色谱法同时测定人血浆中的西诺沙星和萘啶酸

Separation and Determination of Cinoxacin and Nalidixic Acid in Human Plasma by Reverse-phase High Performance Liquid Chromatography

提出了同时测定人血浆中的西诺沙星和萘啶酸的高效液相色谱方法。采用反相C18柱、2 5 4nm紫外检测 ,乙腈 甲醇 0 0 1mol/L草酸 (30∶5∶6 5 ,V/V ;pH 4 5 5 )体系 ,实现了二者的良好分离。分别考察了磷酸缓冲溶液和草酸缓冲溶液作为流动相弱溶剂 ,结果草酸缓冲溶液能有效改善峰形 ,降低检测限。在不同pH值 (pH 2 .80 ,4.0 8,4.5 5 )进行了实验 ,pH 4.5 5获得最佳分离。最低检测量分别为 0 14ng(西诺沙星 )和 0 2 4ng(萘啶酸 )。比文献报道的同类药物最低检测量低 10倍。

A method for the determination of cinoxacin and nalidixic acid in human plasma by reverse-phase high performance liquid chromatography is introduced. The single separation system involves a RP-C18 column, a ultraviolet detector at 254 nm and CH3CN-CH3OH-0.01 mol/L HOOCCOOH (30:5:65; pH 4.55). The influence of two kind of buffer (phosphate buffer and oxalate buffer) in mobile phase on the separation were studied. Oxalate buffer can improve tailing peak and decrease detection limits. Three pH values (pH 2.80, 4.08, 4.55) were studied, pH 4.55 can give best separation result. The detection limits of cinoxacin and nalidixic acid were 0.14 ng and 0.24 ng, respectively.