Determination of busulfan in human plasma using high-performance liquid chromatography with pre-column derivatization and fluorescence detection

A rapid, sensitive and reproducible high-performance liquid chromatographic assay for busulfan in human plasma was developed. After extraction of plas ma samples with acetonitrile and methylene chloride, busulfan and the inter nal standard [1,5-bis(methanesulfonyloxy)pentane] were derivatized with 8-m ercaptoquinoline to yield fluorescent compounds which were detected with a fluorescence detector equipped with filters of 360 nm (excitation) and 425 nm (emission). Calibration graphs showed a linear correlation (r>0.9990) ov er the concentration range of 20-2000 ng/ml. The recovery of busulfan from plasma standards was 70+/-5%. The detection and quantification limits for b usulfan in plasma samples were established at 9 ng/ml and 20 ng/ml, respect ively. The intra- and inter-assay variations were lower than 8% and 10%, re spectively. The applicability of the method was verified by analyzing the p lasma concentrations of busulfan in a patient to whom it was administered o rally on two different days. (C) 1999 Elsevier Science B.V. All rights rese rved.