Analysis of gastrodin and tetramethylpyrazine in traditional Chinese preparations by micellar electrokinetic chromatography

A simple, rapid, and accurate micellar electrokinetic chromatographic method has been developed for determination of gastrodin and tetramethylpyrazine in three traditional Chinese preparations: Zhennaoning jiaonang, Yangxue shengfa jiaonang, and Xiaoshuan zaizao wan. Running buffer comprising 50 mM sodium tetraborate and 15 M sodium dodecylsulfate (SDS), pH 9.50, was found to be most suitable for the separation. All experiments was performed with a 47 cm (40 cm effective length)×75 μm ID uncoated fused-silica capillary and UV detection at 200 nm. The linear calibration ranges were 2.5–200 μg mL–1 (R = 0.999) for gastrodin and 5.0–200 μg mL–1 (R = 0.997) for tetramethylpyrazine; the detection limits were 0.5 μg mL–1 and 0.8 μg mL–1, respectively. Recoveries of the two analytes from the samples, calculated by use of a method described in detail in the text, were between 94.21 and 104.46%. The amounts of gastrodin and tetramethylpyrazine in the preparations were easily determined within 10 min.