DETERMINATION OF THE ANTICANCER DRUG METABOLITE WR1065 USING PRECOLUMN DERIVATIZATION AND DIODE-LASER INDUCED FLUORESCENCE DETECTION

A liquid chromatographic (LC) procedure using alumina as stationary ph ase in both the pre- and the analytical column, is reported for the de termination of WR1065, the active metabolite of the amino- and thiol-c ontaining anticancer drug WR2721. After pre-column derivatization of t he thiol group, the analyte is determined by LC with diode laser induc ed fluorescence detection in the near-infrared. Selective removal of e xcess label is achieved by means of column switching; it allows the de tection of 5 x 10(-9) M WR1065 in water and 10-fold diluted, deprotein ated plasma samples. The detection limit is determined by the derivati zation reaction and not by the fluorescence detection of the labelled analyte. Endogeneous thiols do not interfere.