Separation and identification of alkaloids in Stephania tetrandra by capillary electrophoresis electrospray-MS/MS / 药学学报

ABSTRACT

<p><b>AIM</b>To establish a method for separation and identification of alkaloids in Stephania tetrandra S. Moore methanol extracts by using non-aqueous capillary electrophoresis interfaced with electrospray ionization ion trap mass spectrometry.</p><p><b>METHODS</b>The molecular ions or adducts of alkaloids and fragments of specific parent ions were used for the identification. An uncoated capillary (86 cm x 75 microm ID, on-line UV detection occurred at 21 cm from the inlet of the capillary) was used. Ammonium acetate (50 mmol x L(-1)) containing 4% HAc in methanol was used as the running buffer; separation voltage was 25 kV. A coaxial sheath flow interface was used as the CE-MS interface; the electrospray voltage was 4.5 kV; the temperature of aluminium capillary was 170 degrees C; 60% isopropanol-39% water-1% HAc was used as the sheath liquid with the flow rate of 5 microL x min(-1); the collision energy of MS-MS was set at 30% and the least ion counts was 1 x 10(5).</p><p><b>RESULTS AND CONCLUSION</b>The alkaloids in Stephania tetrandra S. Moore methanol extracts were separated and identified by CE-ESI-MS/MS. The proposed method is of high accuracy and can be used for the investigation of traditional Chinese medicine.</p>