Validation and application of an rapid HPLC-MS method for the determination of salvianic acid A in human plasma

A rapid liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS) method was developed and validated for the determination of salvianic acid A in plasma of Chinese healthy subjects after oral administration of Qishenyiqi dropping pills. After liquid-liquid extraction with ethyl acetate, salvianic acid A was chromatographed on a Agilent Zorbax XDB-C18 column using a gradient mobile phase consisting of water (0.1% formic acid)-acetonitrile (0.1% formic acid) at a flow rate of 0.45 mL/min. The detection was performed in multiple reaction monitoring mode, using the transitions of m/z 196.9→134.8 and m/z 320.9→151.9 for salvianic acid A and chloroamphenicol, respectively. The method was linear over the range of 0.50-500 ng/mL using only 100 μL of plasma and the lower limit of quantification was 0.50 ng/mL. Intra-day and inter-day precisions (in terms of % RSD) were all <15% and the accuracies (in terms of % RE) were within the range of±15%, and recoveries were between 85.0 and 115%. The validated method was successfully applied to pharmacokinetic study of Qishenyiqi dropping pills in Chinese healthy subjects. After oral administration, Tmax and Cmax values were 1.33 ± 0.52 h and 21.1 ± 3.92 ng/mL, respectively. Plasma concentrations declined with t1/2Z of 1.76 ± 0.33 h.