Simultaneous determination of four tanshinones in Salvia miltiorrhiza by pressurized liquid extraction and capillary electrochromatography.

A pressurized liquid extraction (PLE) and CEC were developed for the simultaneous determination of four tanshinones (dihydrotanshinone I, cryptotanshinone, tanshinone I, and tanshinone IIA) in Salvia miltiorrhiza. High extraction efficiency (>98.5%) was achieved under the optimum PLE conditions. A good separation was obtained by using a Hypersil C18 capillary (3 microm, 100 microm/25 cm) with a mixture of 30 mM Tris-HCl (pH 8.5)-ACN (1:3, v/v) as BGE solution running at 20 kV and 20 degrees C within 12 min. All the calibration curves showed good linearity (r2 >0.9958) within test ranges. The developed method showed good repeatability for the quantification of four investigated components in S. miltiorrhiza with intra- and interday variations of less than 4.4 and 6.8%, respectively. The validated method was successfully applied to quantify four tanshinones in S. miltiorrhiza, which is helpful to control the quality of S. miltiorrhiza.