Flow-injection Chemiluminescence Determination Of The Alkaloids From Corydalis Yanhusuo

Corydalis yanhusuo W. T. Wang, belonging to the genus Corydalis, the family Papaveraceae, is commonly known as Yuanhu. It is one of the genuine medicinal materials. According to Chinese pharmacopoeia, the dry tubers of C. yanhusuo plant have medicinal value. In this paper, the new determining methods of the alkaloids and tetrahydropalmatine in C. yanhusuo were established by Flow-injection Chemiluminescence analysis(CL-FIA). The sensitivity and possibility of the CL-FIA method was proved by passed the interference test, and compared the experimental data with the counterparts of method HPLC and UV respectively. The main contents and results were as follows.(1) This part mainly adopted the response surface design and orthogonal design to abtain some validity parameters for the extraction and separation of C. yanhusuo alkaloids. Under the optimal conditions, the average extraction rate of alkaloids was 0.594%-0.606% by the UV determining method and the average extraction rate of tetrahydropalmatine was 0.0605%-0.0623% by the HPLC determining method. This part established a solid foundation for making further study of flow injection chemiluminescence analysis of corydalis alkaloids.(2)This studies have found that total alkaloids could work on the chemiluminescence of Luminol-H2O2, Luminol-K3Fe(CN)6 and Ce4+-Rh B system in both alkaline and acidic medium. Based on this, three simple and effective determing methods of alkaloids were established. Under the optimal conditions, the linear ranges of total alkaloids of three determing methods were 0.11392-0.34176μg·mL-1, 0.01424-0.11392μg·mL-1 and 0.01424-0.22784μg·mL-1 respectively, the detection limits were respectively 0.08403μg·mL-1, 0.00920μg·mL-1 and 0.00906μg·mL-1, and the yield of alkaloids were respectively 0.602%, 0.595% and 0.597%. The comparisons between the experimental data of the CL-FIA method and the counterparts of UV method showed that the determining results of the two methods were consistent with each other, but the Ce4+-Rh B system was better in precision and linearity range.(3) This studies have also found that tetrahydropalmatine could inhibit the chemiluminescence of Luminol-KMnO4-OH-, Luminol-NaIO4 and KMnO4-Luminol-H+ system in both alkaline and acidic medium. On the basis of enhancement effect, three flow injection chemiluminescence methods were developed for the determination of tetrahydropalmatine. Under the optimal conditions, the linear ranges of tetrahydropalmatine of three determing methods were 0.0570-0.2848μg·mL-1, 0.01139-0.03418μg·mL-1 and 0.1139-0.3418μg·mL-1 respectively, the detection limits were 0.02966μg·mL-1, 0.00869μg·mL-1 and 0.04138μg·mL-1 respectively, and the yield of tetrahydropalmatine were respectively 0.0618%, 0.0612% and 0.0612%. And then the final comparison of those methods with three chemiluminescence systems showed that Luminol-KMnO4-OH- system was more feasible. The comparison between the experimental data of method CL-FIA with the counterparts of method HPLC showed that the accuracy of the CL-FIA was lower than HPLC.This research also found that the different components of the chemiluminescence system, the proper instrument parameters and the concentration of main reagents were the keys to influence the selectivity and specificity of active constituent detection in traditional Chinese medicines. Above all, CL-FIA had been applied successfully to determine alkaloids or tetrahydropalmatine in C. yanhusuo with its so many advantages, such as high sensitivity, wide linear range and easy to realize automation, etc.