Pipette tip solid-phase extraction and ultra-performance liquid chromatography/mass spectrometry based rapid analysis...

Pipette tip solid-phase extraction (PT-SPE) is a technique popular in sample preparation of biological fluids and protein hydrolysates. In this study, we developed a microtechnic using a pipette tip packed with C18 as sorbent for extraction and purification of bioactive compounds, picroside-I, II and III, in crude herbal extracts from Picrorhiza scrophulariiflora (P. scrophulariiflora). Compared to conventional SPE, PT-SPE is fast, easy to operate, and the tools are very accessible (pipette tip and tube, without expensive SPE set-up). Moreover, it is also cost-effective because significant amount of sorbent and solvents can be saved. The eluate was analyzed by ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS). Afterwards, the method was fully validated and the results demonstrated that the PT-SPE-UPLC-MS/MS method is an excellent technique for analysis of the herbal medicine. Finally, this PT-SPE-UPLC-MS/MS strategy was successfully applied to analyze the crude extracts from P. scrophulariiflora samples within 10min (2min for PT-SPE and 8min for UPLC), 3.5mL solvents (including water, 0.3mL for PT-SPE and 3.2mL for UPLC), and 2mg C18 sorbent for each sample. We believe this method to be very practical and, in particular, to be suitable for widespread herbal medicine analysis.