HPLC柱切换法测定血浆和尿样中头孢克肟浓度

用双泵HPLC柱切换系统直接进样测定血浆和尿样中头孢克肟(cefixime,CFIX)的浓度。血浆和尿样的回收率分别为99.1%和98.6%;最低检测浓度分别为0.05和0.2μg/ml;日内和日间的RSD小于5%;血浆和尿样浓度分别在0.1～3.2和1.0～32μg/ml范围内呈线性相关。此方法集样品净化、富集成分和色谱分析一次连续进行,操作简便、快速,可以进较大的样品量,灵敏度相对明显提高。

DETERMINATION OF CEFIXIME IN HUMAN PLASMA AND URINE USING HIGH PERFORMANCE LIQUID CHROMATOGRAPHY COLUMN SWITCHING TECHNIQUE

A double column and double pump HPLC switching system is described for the analysis of cefixime in human plasma and urine. The system used μBondapak C₁₈ short pretreatment column for on--line sample clean--up and a Hitachi GEL 3056 (ODS) analytical column for separation. A mixed solution of 0. 01 mol/L H₃PO₄--0. 1 mol/L KH₂PO₄--H₂O (20:1:79) was used as the pretreatment mobile phase and CH₂CH--0.01 mol/L H₃PO₄--0. 1 mol/L KH₂PO₄--H₂O (13:20:1:66) was used as analytical mobile phase. The compound in plasma and urine is detected by ultraviolet absorption at 286 nm and 314 nm, respectively. The absolute recoveries of the method in plasma and urine were 99.1% and 98.6% respectively. The relative standard deviations of the method are 0.70～3.82% and 0.80～3.73% in plasma, 1.53～3.08% and 1.31～2.67% in urine between days and day--to--day. Linear calibration curve for cefixime was measured over the range of 0. 1～3.2μg/ml in plasma and 1.0～32. 0 μg/ml in urine, and the correlation coefficients were all 0.9999. The detection limit was 0. 05μg/ml in plasma and 0.2 μg/ml in urine. The plasma and urine samples were diluted with water and injected directly onto the HPLC system. The operation is simple and the relative sensitivity is markedly increased because of higher recoveries and larger loading capacity of the sample.