Study of tanshinone IIA tissue distribution in rat by liquid chromatography‐tandem mass spectrometry method

Abstract A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for determining tanshinone IIA in rat tissues. After a single step liquid–liquid extraction with diethyl ether, tanshinone IIA and loratadine (internal standard) was subjected to LC/MS/MS analysis using positive electro‐spray ionization under selected reaction monitoring mode. Chromatographic separation of tanshinone IIA and loratadine was achieved on a Hypersil BDS C 18 column (i.d. 2.1 × 50 mm, 5 µm) with a mobile phase consisting of methanol–1% formic acid (90:10, v/v) at a flow rate of 300 µL/min. The intra‐day and inter‐day precision of the method were less than 10.2 and 12.4%, respectively. The intra‐day and inter‐day accuracies ranged from 99.7 to 109.7%. The lowest limit of quantification for tanshinone IIA was 1 ng/mL. The method was applied to a tanshinone IIA tissue distribution study after an oral dose of 60 mg/kg to rats. Tanshinone IIA tissue concentrations decreased in the order of stomach > small intestine > lung > liver > fat > muscle > kidneys > spleen > heart > plasma > brain > testes. Tanshinone IIA still could be detected in most of the tissues at 20 h post‐dosing. These results indicate that the LC/MS/MS method was rapid and sensitive to quantify tanshinone IIA in different rat tissues. Copyright © 2007 John Wiley & Sons, Ltd.