Yamashita K, Motohashi M, Yashiki T
Takeda Analytical Research Laboratories, Ltd., Osaka, Japan.
J Chromatogr. 1992 May 20;577(1):174-9. doi: 10.1016/0378-4347(92)80616-x.
An automated high-performance liquid chromatographic method using column switching was established for the simultaneous determination of cefotiam (I) and delta 3-cefotiam (II) in human plasma after oral administration of cefotiam hexetil dihydrochloride. The method allowed the determination of analytes in plasma by the direct injection of diluted specimen with phosphate buffer. The analytes were enriched onto the C18 short pretreatment column by 0.05 M phosphate buffer (pH 7.7), while proteins and endogenous hydrophilic substances in plasma were washed off to waste. The enriched analytes were then back-flushed onto the analytical C18 column, separated by a mixture of 0.05 M phosphate buffer (pH 7.7)-acetonitrile (88:12, v/v) and detected by the ultraviolet absorbance at 254 nm. Recoveries from spiked plasma were quantitative, and the coefficients of variation were below 4%. The lower detection limits in plasma were 10 ng/ml for both I and II. Concentrations of I and II in plasma determined by the present method were in good agreement with those obtained by the conventional deproteinization method.
建立了一种采用柱切换的自动高效液相色谱法，用于在口服盐酸头孢替安酯后同时测定人血浆中的头孢替安（I）和δ3-头孢替安（II）。该方法允许通过将稀释后的样品直接注入磷酸盐缓冲液来测定血浆中的分析物。分析物通过0.05M磷酸盐缓冲液（pH 7.7）富集到C18短预处理柱上，同时血浆中的蛋白质和内源性亲水性物质被冲洗至废液中。然后将富集的分析物反冲至分析C18柱上，用0.05M磷酸盐缓冲液（pH 7.7）-乙腈（88:12，v/v）的混合物进行分离，并在254nm处通过紫外吸光度进行检测。加标血浆的回收率是定量的，变异系数低于4%。血浆中I和II的最低检测限均为10ng/ml。用本方法测定的血浆中I和II的浓度与用传统脱蛋白法获得的浓度高度一致。
