Content determination of four kinds of alkaloids in Uncaria by HPLC-MS-AIS

Abstract

ObjectiveTo determine the contents of four kinds of indole alkaloids （rhynchophylline， isorhynchophylline， corynoxeine， isocorynoxeine） in Uncaria by high-performance liquid chromatography-mass spectrometry-automatic internal standard （HPLC-MS-AIS）.MethodsChromatographic separation was performed using C18 column （3.0 mm×50 mm， 3.3 μm）， and the mobile phase， comprising 0.1% formic acid aqueous solution-acetonitrile （82∶18， V/V）， was eluted at a flow rate of 0.5 mL/min and column temperature of 30℃. Mass spectrometric detection was performed using an electrospray ionization source and positive multiple-reaction monitoring mode at a voltage capillary of 4 000 V. The mass-to-charge ratio （m/z） transition was 385.25/160.10 for rhynchophylline， 385.30/160.10 for isorhynchophylline， 383.25/160.15 for corynoxeine and 383.25/160.15 for isocorynoxeine， respectively. The injection volume was kept constant at 2 μL.ResultsThe linear concentration ranges of rhynchophylline， isorhynchophylline， corynoxeine and isocorynoxeine were 2.30~600.00 ng/mL （r=0.999 3）， 2.30~600.00 ng/mL （r=0.999 2）， 2.47~650.00 ng/mL （r=0.999 4） and 2.47~650.00 ng/mL （r=0.999 2）， respectively. The relative standard deviation （RSD） of precision and stability were all lower than 5.00%， the accuracy ranged from 92.40% to 104.10%， and the average recovery was 95.90%~104.60%.ConclusionHPLC-MS-AIS method is simple and accurate for the determination of four kinds of alkaloids in Uncaria， and can be used as a new method for quality control of Uncaria.

Keywords

• hplc-ms-ais method
• uncaria
• rhynchophylline
• isorhynchophylline
• corynoxeine
• isocorynoxeine
• content determination