Study on chemical constituents of “decocted first and defoamed” of Ephedra Herba by UPLC-DAD-TOF/MS and HPLC-UV / 中草药

ABSTRACT

Objective To establish a method for detecting the chemical compositions of “decocted first and defoamed” of Ephedra Herba by UPLC-DAD-TOF/MS coupled with HPLC-UV, so as to clarify the difference of chemical constituents among them. Methods The analysis was performed on an ACQUITY UPLC® BEH C18 column (50 mm × 2.1 mm, 1.7 μm ) by UPLC-DAD-TOF/MS with gradient elution. The mobile phase consists of methanol and 0.1% formic acid-water at a flow rate of 0.3 mL/min. The column temperature was 40 ℃. The information of compounds was acquired on positive and negative mode. Similarly, HPLC-UV was applied for measuring the content of alkaloids respectively. The C18 column was used, the mobile phase was acetonitrile-0.1% phosphoric acid (containing 0.05% triethylamine) (99 1) at the flow rate of 1 mL/min, the detective wavelength was set up at 210 nm, and the column temperature was 30 ℃. Results There were less content in the upper foam, and the chemical components in the lower liquid and the whole liquid were basically same. Five alkaloids and one carboxylic acid (4-hydroxy-7-methoxyl-2-quinoline carboxylic acid) was identified from all kinds of liquids. However, the content of alkaloids in the upper foam was very low, and the content of three alkaloids in the whole solution was slightly higher than that in the lower liquid. Conclusion The defoamed method may not be related to the chemical compositions of alkaloids, but it still needs further research and verification.