Determination of antileukemic diimidazolinyl compounds in plasma of experimental animals by high-performance liquid chromatography.

A method is reported for the determination of the fluorescent, antileukemic diimidazolinyl compounds 261/96(1). 253/152(2) and 272/131(3) in plasma. HPLC is performed on a RP-2 10 microns column with a mobile phase of methanol/water (1:1, v/v), to which 0.005 mol/l octanesulfonic acid sodium and 0.003 mol/l dimethyloctylamine are added. Samples are prepared by precipitation of plasma proteins with a mixture of methanol-70% perchloric acid. The assay is linear up to 750 ng/ml for all compounds with limits of determination of 4 ng/ml, 2 ng/ml and 0.5 ng/ml for compounds 1, 2 and 3, respectively. Coefficients of variation are below 10 percent at all concentrations studied.