Determination of stachydrine hydrochloride and leonurine hydrochloride in Yimucao preparations by HPLC-MS

To establish the quantitative method of stachydrine hydrochloride and leonurine hydrochloride in the preparations of Leonuri Herba. The contents of stachydrine hydrochloride and leonurine hydrochloride in the preparations of Leonuri Herba were determined by HPLC-MS. The chromatographic column was Waters XBridge Amide(4.6 mm×250 mm,5 μm). The mobile phase was acetonitrile-0.1% formic acid in gradient mode,at the flow rate of 1.0 mL• min⁻¹,with the split ratio of 1∶4. MS conditions for the ESI ion source,positive ion mode,selective ion scan(SIM) of stachydrine hydrochloride(m/z 144.0) and leonurine hydrochloride(m/z 312.0) was measured. The linear ranges of stachydrine hydrochloride was 0.562 8-281.4 μg•L-1（r=0.999 8）. The linear ranges of leonurine hydrochloride was 0.521 2-260.6 μg•L-1（r=0.999 8）. The method is accurate,simple,and reliable,and can be used to determine the contents of stachydrine hydrochloride and leonurine hydrochloride in the preparations of Leonuri Herba.