MINIATURIZED HPLC AND IONSPRAY MASS-SPECTROMETRY APPLIED TO THE ANALYSIS OF PACLITAXEL AND TAXANES

Analysis of the antitumor agent Paclitaxel, related taxane analogues a nd yew tree bark extracts has been carried out ming an HPLC system cap able of performing chromatographic separations with conventional, smal l-bore, and micro-bore columns. Both diode array detector and mass spe ctrometry were incorporated into this system, providing additional spe ctral and structural information for identification of unknown samples . In conjunction with some basic theoretical studies dealing with mini aturized HPLC systems, experiments were designed to minimize the contr ibution of extra-column variances. Three chromatographic columns, 4.6, 2, and 1 mm i.d., were evaluated using a standard mixture consisting of Paclitaxel and three analogues. The experimental results obtained i n these columns demonstrated good correlation with theoretical calcula tions with respect to the sensitivity enhancement. Studies on the comb ination of miniaturized HPLC with ionspray mass spectrometry for Pacli taxel samples showed dramatic improvement of MS performance as compare d to conventional LC/MS. The advantages of this miniaturized LC/MS sys tem are evidenced by enhanced mass sensitivity, which was more than tw o order of magnitude higher when changed from a 4.6 mm i.d. column to a 2.0 mm i.d. column, greatly improved peak shape, and the potential g ain of efficiency. These studies demonstrate great potential of miniat urized HPLC/MS systems for structural characterization and confirmatio n of various pharmaceutical compounds. (C) 1997 Elsevier Science B.V.