Quantitative analysis of melphalan and its major hydrolysate in patients and animals by reversed-phase high-performance liquid chromatography.

The detection of 4-bis-(2-hydroxyethyl)amino-1-phenylalanine (L-DOH) in blood samples taken from patients after treatment with melphalan [4-bis-(2-chloroethyl)amino-1-phenylalanine, L-PAM] suggests that the quantification of this major hydrolysate of L-PAM can be of considerable importance in L-PAM chemotherapy. A reversed-phase high-performance liquid chromatographic procedure has been developed for the quantitative analysis of both L-PAM and L-DOH in biological samples, with a detection sensitivity of 0.1 ppm. This method provides a distinct separation of L-PAM (retention time 12 min) and L-DOH (retention time 6.5 min), with no interference from the biological background (retention time 1.4--3 min).