Admicelle Dispersive Solid Phase Extraction-HPLC For Determination Of Alkaloids In Chinese Materia Medica Preparation And Human Urine

As an important resource for the prevention and treatment of various diseases,traditional Chinese medicines?TCMs?have been used for more than 1000 years.In recent years,in order to understand the efficacy and mechanism of traditional Chinese medicine,more and more people began to study its active ingredients.Rhizoma coptidis is a very important Chinese medicine plant,containing a variety of alkaloids,such as jatrorrhizine,berberine,coptisine and palmatine.These active ingredients have the pharmacological effects of anti-virus,anti-inflammation,anti-bacteria,heat-clearance,damp-dryness and detoxification.These active ingredients play a synergistic effect to treat diseases in traditional Chinese medicinal preparations.The alkaloids are often used in quality evaluation and pharmacokinetics study of traditional Chinese medicines containing rhizome coptidis.Two kinds of novel dispersive solid-phase extraction methods were established based on the admicelle formed on the surface of metal oxides for the analysis of alkaloids in Gegen-qinlian oral liquid and human urine.This thesis is divided into three chapters,its main contents are as follows:Chapter 1: The pharmacological effects of several kinds of alkaloids and their research values were introduced.The research progress of the application of micelle in sample preparation was summarized,and great efforts were put on cloud point extraction,micelle solid-phase extraction and magnetic micelle dispersive solid-phase extraction.Finally,the research background and research content of this article were introduced.Chapter 2: A novel dispersive admicelle solid phase extraction method based on sodium dodecyl sulfate?SDS?-coated Fe₃O₄ nanoparticles was developed for the selective adsorption and enrichment of berberine,coptisine and palmatine in Gegen-qinlian oral liquid prior to HPLC-UV detection.Fe₃O₄ nanoparticles were synthesized via chemical co-precipitation method and characterized by transmission electron microscopy.Under acidic condition,the surface of Fe₃O₄ nanoparticle was coated with anion surfactant SDS to form a nano-sized admicelle magnetic sorbent.Owing to electrostatic interaction,the alkaloids were adsorbed onto the oppositely charged admicelle magnetic nanoparticles.Quick separation of the analyte-adsorbed nanoparticles from the sample solution was achieved with the help of applied magnetic field.Some important parameters,such as the amount of Fe₃O₄ NPs,pH,the amount of SDS,type of desorption solvent and extraction time were carefully investigated and optimized to achieve the best extraction efficiency.Under the optimal conditions,satisfactory extraction recoveries were obtained for the three alkaloids in the range of 87.9%-108.1% with relative standard deviations less than 3.8 %.In this method,magnetic nanoparticles have superparamagnetism,it can be quickly separated from the sample solution under the action of magnetic field.Compared with the conventional SPE and dispersive solid-phase extraction,it reduced the tedious separation operation,such as leaching,elution and centrifugation.Thus,it saved the separation time distinctly.Negatively charged admicelle can combined with positively charged alkaloids.Due to the high negative charge density of the admicelle surface,the admicelle has high selectivity and extraction efficiency.This method combines the advantages of admicelle and magnetic nanomaterials and has been successfully applied for the determination of the three alkaloids in two batches of Gegen-qinlian oral liquids.Chapter 3: Admicelle formed by SDS on the surface of Al₂O₃ was used as adsorbent for dispersive solid-phase microextraction?DMSPE?,with a glass syringe as DMSPE device.Under acidic condition,the surface of Al₂O₃ was coated with anion surfactant SDS to form admicelle to extract jatrorrhizine,berberine,coptisine and palmatine from human urine after oral administration of Gegen-qinlian oral liquid.The admicelle and urine were separated with high pressure filter,at the same time,the admicelle was enriched on the membrane filter.Later,the alkaloids were eluted with methanol,dried under the protection of nitrogen gas and redissolved.Finally,the analytes were detected with HPLC-UV.Some important parameters,including the amount of Al₂O₃ NPs,pH,the amount of SDS,elution conditions,extraction time and dilution ratio of the urine were carefully investigated and optimized to achieve the best extraction efficiency.Under the optimal conditions,the four alkaloids in human urine samples were analyzed.The results showed that four alkaloids had good linear relationship with R2 over 0.999.The recoveries were in the range of 86.1%-99.2%.The relative standard deviation of was below 4.4%.In this paper,with the help of glass syringe and high pressure filter,the analytes were separated from the sample solution.It solves the problem that the SDS-Al₂O₃ admicelle is difficult to be separated from the sample solution.This method is simple,environmentally friendly and cost-effective.This is the first time that the Al₂O₃-SDS admicelle is combined with dispersive solid-phase microextraction and applied to the detection of four alkaloids in human urine.