HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF BUSULFAN IN HUMAN SERUM WITH ONLINE DERIVATIZATION, COLUMN-SWITCHING AND ULTRAVIOLET ABSORBENCY DETECTION

A high-performance liquid chromatographic (HPLC) method is described f or the determination of busulfan in human serum using on-line derivati zation and column switching. Busulfan was extracted from serum with a mixture of diethyl ether and dichloromethane. After the evaporation of the organic layer, the reconstituted residue was injected into the HP LC system and busulfan was derivatized with sodium diethyldithiocarbam ate on the first short column. The back-flushed derivative was then se parated on the second column. Finally, after column switching, the hea rt-cut fraction containing the derivative was further analysed on the third column and monitored with ultraviolet absorbance detection at 27 8 nm. The lower limit of quantitation in serum was 10 ng/ml.