DEVELOPMENT OF AN ION-PAIR HPLC METHOD FOR THE DETERMINATION OF 2,4-TOLUENDIAMINE AND 2,6-TOLUENDIAMINE IN HUMAN PLASMA

An ion-pair HPLC method is presented for the determination in plasma o f 2,4- and 2,6-toluendiamine (TDA), known carcinogens. The chromatogra phic conditions consisted in isocratic elution on a reversed phase Cls column with 5 mM octanesulfonic acid in methanol-water, 45:55, as mob ile phase. UV detection was performed at 235 nm. Samples were analyzed after a simple single step liquid-liquid extraction and the method wa s validated by measurement of precision (interassay and intraassay), s ensitivity, specificity, linearity, and recovery. The detection limit for both TDAs in plasma was 20 ng mL(-1). The correlation coefficients based on the intraassay calibration curve were 0.998 and 0.997 for 2, 6- and 2,4-TDA, respectively. The intraassay accuracy, expressed in te rms of recovery, was found to be up to 89.91 % and 97.05 % for 2,6- an d 2,3-TDA, respectively.