ONLINE SOLID-PHASE EXTRACTION OF CEFTAZIDIME IN SERUM AND DETERMINATION BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A column-switching high-performance liquid chromatographic assay is de scribed for the determination of ceftazidime (a third-generation cepha losporin) in human serum. The method does not require prior sample pre treatment. Serum is directly injected in a first chromatographic colum n for sample clean-up and extraction. Thereafter, using an on-line col umn-switching system, the drug is quantitatively transferred and separ ated on a second, analytical column followed by determination using ul traviolet absorption at 258 nm. The technique allows direct, rapid, pr ecise, and simple determination of ceftazidime in serum over the range of 1-250 mu g/ml using 12.5 mu l of serum. This method was applied to study the pharmacokinetics of the drug in patients undergoing vascula r surgery.