Determination of sodium tanshinone IIA sulfonate in plasma by liquid chromatography‐electrospray ionisation‐tandem mass spectrometry

Sodium tanshinone IIA sulfonate (STS) is a water‐soluble derivative of tanshinone IIa, an important lipophilic component contained in Salvia miltiorrhizae . A simple, sensitive and robust quantification method for STS based on LC‐ESI‐MS/MS was developed and validated, and has been successfully applied to the pharmacokinetic study. Liquid–liquid extraction was used for extracting STS from biological samples, with a satisfactory recovery exceeding 75% at all test concentrations. Isocratic mobile phase consisted of 75% acetonitrile and 25% water containing 0.005% ammonia acetate (pH 3). Good retention and baseline separation for STS and the selected internal standard, diclofenac sodium, were obtained on a Shim‐pack VP‐ODS analytical column under this condition. The method was linear in the concentration range of 1–500 ng/mL. The intra‐ and inter‐day precisions (RSD%) were within 9.0%. The deviation of the assay accuracies was within ±10.0%. STS was proved to be stable during all sample storing, preparation and analytic procedures. With a lower limit of quantitation at 1 ng/mL, this method has been proved to be sensitive enough for the pharmacokinetic study of STS. The plasma profile of STS followed a single intravenous dosing was well fitted to a three compartmental model. Copyright © 2007 John Wiley & Sons, Ltd.