| Objective:The aim of the article is to study the extraction and separation of angular-type pyranocoumarins from peucedanum praeruptorum.Optimize the extraction method by utilizing ultrasonic technique.Study the influence of capillary electrophoresis based on mixed micelles system on the separation of three angular-type pyranocoumarins(praeruptorin A,B and C)whose chemical structures are similar.Establish an analytical method to simultaneously separate the three angular-type pyranocoumarins using micellar electrokinetic capillary chromatography.And apply the proposed method to the determination of praeruptorin A,B and C in Peucedani Radix and its medicinal preparations.Moreover,the proposed method will provide scientific reference for quality control of Peucedani Radix and its medicinal preparations.Methods:(1)Chloroform was used as the organic solvent for extraction and the technique of ultrasonic extraction was employed to study the extraction of three analytes in Peucedani Radix.In order to obtain optimal extraction method,the influence of ultrasonic power and temperature,extraction time on extraction rate were investigated.(2)The experiment was performed on capillary electrophoresis apparatus(Beckman)which is equipped with diode array detector(DAD).Sodium dodecyl sulphate(SDS)and sodium cholate(SC)were used as surfactants to form mixed micelles.The running buffer was consist ofborate solution,SDS,SC and moderate amount of acetonitrile.The influence of surfactants concentration,acetonitrile proportion,concentration and pH of buffer,running voltage and temperature on separation were investigated.The optimal separation condition was 20 mM borate buffer containing 40 mM sodium cholate(SC),22 mM sodium dodecyl sulphate(SDS)and 25%(v/v)acetonitrile(pH 10.0);15 kV of voltage;25? of temperature;detection at 224 nm.Injection was carried out by pressure at 0.5 psi for 5 s.The separation was carried out on an uncoated fused silica capillary with a dimension of 40.2 cm(30.0 cm to the detect window)× 75 ?m internal diameter.The established method was subjected to validation and was applied to the analysis of Peucedani Radix and its medicinal preparations.Results:(1)When 3.0 g powder of Peucedani Radix was extracted with 100 mL chloroform by ultrasonication(240 W)in 40? for 40 min,the extraction content of 3 analytes in Peucedani Radix was highest.So the above condition was the optimal project for extraction of praeruptorin A,B and C from Peucedani Radix.(2)Under the optimal condition,three analytes achieved completely separation within 16 min.A good linearity was obtained with correlation coefficients from 0.9988 to 0.9995.The limits of detection(LODs)and limits of quantitation(LOQs)ranged from 0.50 to 0.80 ?g/mL and from 1.50 to 2.50 ?g/mL,respectively.The RSD of intraday and interday are 1.6% and 2.7% for praeruptorin A,1.2% and 1.1% for praeruptorin B,1.3% and 2.1% for praeruptorin C,respectively.The average recoveries range from 95.3% to 103.4%.The established method was applied to simultaneous determination of praeruptorin A,B and C in Peucedani Radix and its medicinal preparations.Compared with reported HPLC methods,the contents results were in the same order of magnitude.Conclusion:In this article,the extraction method utilizing ultrasonic technique for extraction ofangular-type pyranocoumarins from peucedanum praeruptorum was obtained.And the micellar electrokinetic chromatography method using SDS and SC as mixed micelles was established to simultaneously separate praeruptorin A,B and C whose chemical structures are similar.The proposed method has been successfully applied to the separation and determination of praeruptorin A,B and C in Peucedani Radix and its medicinal preparations.And the established method can offer scientific reference to quality control of Peucedani Radix and its medicinal preparations.Moreover,the micellar electrokinetic chromatography method using SC and SDS as mixed micelles may offer potential of separating other coumarins which have similar chemical structures. |
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