Enantioselective analysis of bambuterol in human plasma using microwave-assisted chiral derivatization coupled with ultra high performance liquid chromatography and tandem mass spectrometry.

ABSTRACT

In this study, an enantioselective analytical method based on microwave-assisted chiral derivatization coupled with ultra high performance liquid chromatography and tandem mass spectrometry was developed for the determination of bambuterol enantiomers in human plasma. The chiral derivatization reaction was greatly accelerated by microwave irradiation. Under the optimized conditions, both the derivatization time and separation time on column was only 3 min, and the lower limit of quantification was 2.5 pg/mL. The recoveries were in the range of 90.1-93.0% without significant matrix effect. Compared with the conventional heating chiral derivatization, microwave-assisted chiral derivatization obtained higher chiral derivatization yields with much shorter time due to the effect of microwave irradiation. Furthermore, the racemization during the derivatization reaction was systematically investigated. The results showed the concentration of acetic acid and the reaction time had significant effects on the racemization, which could be well controlled during microwave-assisted chiral derivatization for the short reaction time. Finally, this novel approach was demonstrated by determining bambuterol in human plasma of a clinical pharmacokinetic study in eight healthy volunteers. On the basis of the results, microwave-assisted chiral derivatization coupled with ultra high performance liquid chromatography and tandem mass spectrometry as a simple and effective enantioselective analysis technique for the determination of chiral drugs in complex biological samples showed great promise.