Separation And Detection Of Polar Components And Heavy Metal Ions In Crude Drugs By Imprinting Technique

In recent years,crude medicine has attracted wide attention due to its excellent curative effect and successful clinical practice.However,because of its extremely multitudinous composition of crude medicine,which often has complex structure as well as multiple physical and chemical properties,the composition identification and quality control has become an important research content.Crude drugs are mostly used in aqueous decoction,their aqueous extracts are generally mixed substance,mainly composed of hydrophilic polar compounds such as nucleosides,saponins,flavonoids,etc.,also there are huge differences in the amounts.Similarly,with the increasingly serious environmental pollution for the past few years,the problem of antibiotics and heavy metal residues in raw drugs has become a hot topic of concern.Therefore,it is urgent to develop an effective analytical method for its quality control and safety evaluation.Imprinting technology to similar to the template molecules（or ions）structure of the target have the effect of selective recognition and adsorption,the preparation of molecularly imprinted polymer is scheduled sex structure,fine properties such as high selectivity and high stability.Molecular imprinting technology is a technology used to prepare polymers that perfectly match template molecules in spatial structure and binding sites.Polymers synthesized based on molecular imprinting technology are called molecularly imprinted polymers,which can simulate the interaction between antigen-antibody,biotin-antibiotic and enzyme-substrate to achieve selective separation of target molecules.As a branch of imprinting technology,ionic imprinting polymer can be prepared by using inorganic ions as templates,which can realize specific recognition of target ions in complex sample matrix.This research is mainly divided into two parts:（1）The total ginsenosides were used as the template molecule to synthesize MIPs by molecular imprinting technique,and the MIPs were used as the high performance liquid chromatography stationary phase to separate polar compounds in crude drugs.The characterization of MIPs showed that MIPs were successfully prepared on the surface of silica gel microspheres.Based on this MIPs filling column,optimizing mobile phase ratio（methanol ratio and acetic acid content）to obtain the best separation and chromatographic conditions,which can achieve the effective separation of polar compounds in crude drugs.The reproducibility and 7-day stability of MIP/Si O₂ columns were evaluated,which showed that they had good reproducibility and stability.The above results show that the chromatographic stationary phase based on MIPs shows excellent separation performance,has good reproducibility and stability,and plays a crucial role in the separation and analysis of polar compounds.（2）Hg-IIPs was synthesized by ion imprinting technique using Hg²⁺as template,and the synthesis and detection conditions were optimized to obtain the best detection conditions,so as to ensure the accuracy of results.The results showed that the ionic polymer was successfully prepared on the surface of nano-silica.By drawing the linear curve of Hg²⁺concentration and fluorescence quenching coefficient F₀/F-1,trace Hg²⁺in ginseng samples can be detected.Its performance was evaluated continuously for 7 consecutive days to show its stability.The above experimental results show that the ion-imprinted polymer has significant advantages in sensitivity and stability,so it will have a very broad application prospect in the field of analysis and detection of heavy metal Hg²⁺in crude drugs.