Determination of 6-mercaptopurine in acute lymphoblastic leukemia patients' plasma by high-performance liquid...

A simple, selective, sensitive, and rapid high-performance liquid chromatography (HPLC) method is described for the quantitation of 6-mercaptopurine (6-MP) in plasma of patients with acute lymphoblastic leukemia (ALL). Pharmacokinetic data are presented for seven children with ALL receiving 6-MP therapy. A sensitivity of greater than or equal to 2 ng/ml in plasma was achieved on a reverse-phase octadecylsilane column using an HPLC system following a cleanup step with a solid-phase extraction cartridge. The chromatogram was monitored at 325 nm. Analytical recovery of 6-MP was 90%. The coefficients of variation for intra- and interday variabilities were 2.51 and 4.23%. This assay method is clinically useful for pharmacokinetic studies of 6-MP in ALL patients.