查看文章

A rapid, accurate and sensitive method has been developed and validated for the quantitative simultaneous determination of four cephalosporins, cephalexin and cefadroxil (first-generation), cefaclor (second-generation) and cefataxim (third-generation), in pharmaceuticals as well as in human blood serum and urine. A Spherisorb ODS-2 250×4-mm, 5-μm analytical column was used with an eluting system consisting of a mixture of acetate buffer (pH 4.0)–CH₃OH 78–22% (v/v) at a flow-rate 1.2 ml/min. Detection was performed with a variable wavelength UV–Vis detector at 265 nm resulting in limit of detection of 0.2 ng for cefadroxil and cephalexin, but only 0.1 ng for cefotaxime and cefaclor per 20-μl injection. Hydrochlorothiazide (HCT) (6-chloro-3,4-dihydro-7 sulfanyl-2H-1,2,4-benzothiadiazine-1-1-dioxide) was used as internal standard at a concentration of 2 ng/μl. A rectilinear relationship was observed up to 8 …