High-performance liquid chromatographic assay for bumetanide in plasma and urine.

A new high-performance liquid chromatographic (HPLC) method was developed for the analysis of bumetanide in plasma and urine. A reversed-phase column was fitted to the instrument and fluorescent (excitation lambda = 338 nm, emission lambda = 433 nm) and UV (254 nm) detectors were utilized to monitor simultaneously bumetanide and the internal standard, acetophenone, respectively. The assay is rapid, sensitive, and specific. Plasma bumetanide concentrations can be detected as low as 5 ng/ml using a 0.20-ml sample. Time-consuming extraction and/or derivatization steps are not required. The only clean-up procedure involved is the precipitation of plasma proteins with acetonitrile.