Simultaneous determination of ginsenoside Rb 1 and Rg 1 in human plasma by liquid chromatography–mass spectrometry

Abstract

A liquid chromatographic–mass spectrometric (LC/MS) method for the simultaneous determination of ginsenoside Rb 1 and Rg 1 in human plasma was developed. The method involved the protein precipitation followed by analysis of ginsenoside Rb 1 and Rg 1 in an Atlantis C 18 column with the gradient elution of acetonitrile and ammonium formate (10 mM, pH 3.0) at a flow rate of 0.2 ml/min. The analytes were determined using electrospray negative ionization mass spectrometry in the selected ion monitoring mode. The standard curves for ginsenoside Rb 1 and Rg 1 were linear over the concentration range of 10.0–1000 ng/ml. The lower limit of quantification was 10.0 ng/ml using 100 μl plasma sample. The coefficient of variation of intra- and inter-day assays for ginsenoside Rb 1 and Rg 1 at three quality control levels ranged from 1.0 to 6.8% and 5.4 to 9.8%, respectively. Ginsenoside Rb 1 and Rg 1 were stable in blank human plasma at room temperature for 24 h and following three freeze–thaw cycles.