Separation and identification of alkaloids in Stephania tetrandra by capillary electrophoresis electrospray-MS/MS
Liu, R-min.; He, F-yun.; Sun, A-ling.
Yao Xue Xue Bao 39(5): 363-366
2004
ISSN/ISBN: 0513-4870 PMID: 15338880 Document Number: 583697
Aim: To establish a method for separation and identification of alkaloids in Stephania tetrandra methanol extracts by using non-aqueous capillary electrophoresis interfaced with electrospray ionization ion trap mass spectrometry. Methods: 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 micro m ID, on-line UV detection occurred at 21 cm from the inlet of the capillary) was used. Ammonium acetate (50 mmol/litre) 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 micro litres/min; the collision energy of MS-MS was set at 30% and the least ion counts was 1x105. Results and conclusion: The alkaloids in S. tetrandra 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.