6410a triple quadrupole mass spectroscopy

Eight ginsenoside peaks were detected by liquid chromatography (Agilent 1200 Series) coupled with 6410A triple quadrupole mass spectroscopy (Agilent, Santa Clara, California, USA). Samples were ionized and detected by electrospray ionization–mass spectrometry with the selected ion-monitoring mode of negative ions. The nebulizer gas was set to 10 L/min at a temperature of 320°C and the capillary voltages were set to 4 kV. Separation was achieved using the XDB-C₁₈ column (50 mm × 4.6 mm i.d., 1.8 μm; Agilent) with a column oven temperature of 35°C. The mobile phase was composed of (A) 5mM ammonium acetate–formic acid (0.1%, vol/vol) and (B) methanol. The mobile phase B was kept at 50% for 2 min and then gradually increased to 90% for 25 min. The flow rate was kept at 0.35 mL/min, and 5 μL of the sample solution was injected in each run.

Eight ginsenoside peaks were detected using liquid chromatography (Agilent 1200 Series) coupled with 6410A triple quadrupole mass spectroscopy (Agilent, USA). Samples were ionized and detected by electrospray ionisation mass spectrometry with the selected ion monitoring mode for negative ions. The following ions were extracted for the quantitative analysis of ginsenosides: m/z 784.5 (ginsenoside Rg₂), m/z 799.5 (ginsenoside Rf and Rg₁), m/z 945.6 (ginsenoside Re and Rd), m/z 1077.6 (ginsenoside Rb₂ and Rc), and m/z 1107.6 (ginsenoside Rb₁). The quantity of the ginsenosides was determined by comparison with the chromatogram of a standard mixture of the ginsenosides, purchased from Sigma-Aldrich (St Louis, MO, USA). The nebulizer gas was set to 10 L/min at a temperature of 320°C, and the capillary voltages were set to 4kV. Separation was achieved using a XDB-C18 column (50 mm × 4.6 mm i.d., 1.8 μm, Agilent, USA), with a column oven temperature of 35°C. The mobile phase was composed of (A) 5mM ammonium acetate-formic acid (0.1%, v/v) and (B) methanol. B was kept at 50% for 2 min and then gradually increased to 90% for 25 min. The flow rate was kept at 0.35 mL/min, and 5 μL of the sample solution was injected in each run.