柱切换HPLC法测定腹水中左旋氧氟沙星的含量

Determination of levofloxacin in ascites by column-switching high performance liquid chromatography

目的：应用柱切换 ＨＰＬＣ技术直接测定腹水中左旋氧氟沙星含量。方法：采用磷酸二氢钾缓冲溶液（ｐＨ ２． ２）－０． ０５ ｍｏｌ／Ｌ四丁溴化化铵（１００： ４）为预处理流动相，经 μＢｏｎｄａｐａｋ Ｃ１８柱预处理后，切换到 Ｉｒｒｅｇｕｌａｒ－Ｈ Ｃ１８分析柱，以甲醇－磷酸二氢钾缓冲溶液（ｐＨ ２． ２）－０． ０５ｍｏｌ／Ｌ四丁基溴化铵（３０： ７０：４）为分析流动相进行分离测定，紫外线检测波长为 ２９４ｎｍ。结果：左旋氧氟沙星浓度在０．１６～１６μｇ／ｍｌ范围内具有良好的线性关系，相关系数为 ０．９９９ ７；方法平均回收率为 １０３．５％，日内及日间差均小于２．５％；最低检测浓度 ５０ｎｇ／ｍｌ。 结论：样品无需预处理，直接进样分析测定，方法简便可行。

Objective:To develop an analytical method to determine the concentration of levofloxacin in ascites by HPLC without pretreatment. Methods:Good separation was achieved under the following conditions: potassium dihydrogen phosphate buffer solution (pH 2. 2)-0. 05 mol/L tetrabutylammonium bromide (100:4) was used as the pretreating mobile phases. Before transited into the analytical column (Irregular-H C18), the samples were pretreated online by the column μ Bondapak C18. Finally methanol-potassium dihydrogen phosphate buffer solution (pH 2. 2)-0. 05 mol/L tetrabutylammonium bromide (30: 70: 4) was used as the analytical mobile phases. The wavelength of UV detection was 294 nm. Results: The assay was linear for levofloxacin in the range of 0. 16 ～ 16 μg/ml concentration. The correlation coefficient r= 0. 999 7. The mean method recovery was 103. 5 %,while the relative standard deviation for the within-day and between-days precision were all less than 2. 5 %. The minimum detective concentration was 50 ng/ml. Conclusion: This method is simple,rapid and accurate. It can be operated without pretreatment.