Sensitive Determination of Panaxadiol Using Rhodamine B as Sensitizing Derivatization Reagent by Ultrahigh Performance Liquid Chromatography Triple Quadrupole Mass Spectrometry
Commercial Rhodamine B was first reported as a derivatization reagent labeling hydroxyl compound for mass spectrometry sensitization. In virtue of the strategy of ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME) combined with Rhodamine B derivatization, a new method of ultrahigh performance liquid chromatography triple quadrupole mass spectrometry (UHPLC-MS/MS) was developed for the sensitive determination of Panaxadiol (PD). UA-DLLME and derivatization conditions were investigated. PD in cosmetics and ginseng was extracted by UA-DLLME (150 mu L chloroform as extraction solvent, 500 mu L ethanol as disperser solvent, 3 min). Using Rhodamine B as precolumn derivatization reagent, the stable derivative of PD was obtained in acetonitrile at 70 degrees C for 30 min under microwave radiation (800 W) with the catalyst of N, N'-carbonyldiimidazole (CDI) and 4-dimethylaminopyridine (DMAP). And then the PD derivative was separated and detected within 3 min by multiple reaction monitoring (MRM) mode of UHPLC-MS/MS. The LOD was 4.0 ng L-1, and the LOQ was 15.0 ng L-1. This method had perfect linearity, precision and recovery results, and showed obvious advantages such as sensitivity and low matrix effect in comparison with the previously reported methods.