Extraction And Separation Of Alkaloids From Plasma Using Homemade Four-hydrogen Furfural-based Monolithic Sorbents

The analysis of drugs in plasma can monitor the concentration change of drugs in vivo,and measure the effectiveness and safety of drugs,among them,there are many kinds of alkaloids with biological and pharmacological activities.Taking them for a long time or a large dose is easy to cause obvious pathological changes in the heart,liver and kidney,and more attention should be paid to their safety.However,due to the complex composition of plasma samples,biomaterials will seriously interfere with the analysis of drugs.Therefore,the sample must be pretreated to remove the interference of biological matrix and extract and enrich the target components.Solid phase extraction?SPE?is one of the most advantageous methods in the pretreatment of biological samples.Polymer monolithic material is an ideal SPE sorbent because of its good permeability,fast mass transfer and easy functional modification.In this paper,SPE sorbent based on tetrahydrofurfuryl was prepared,and on line solid phase extraction and high performance liquid chromatography?SPE-HPLC?were used to extract,enrich and determine alkaloids in mouse plasma and plant traditional Chinese medicine extracts.The polymer monolithic SPE sorbent was prepared by using tetrahydrofurfuryl methacrylate as monomer,using appropriate crosslinkers and porogens and initiating with azodiisobutyronitrile.The micro morphology and pore structure of SPE sorbent were characterized by scanning electron microscopy method and nitrogen adsorption desorption method.The results showed that the prepared SPE sorbent had micropore,mesoporous and macroporous structure,with a specific surface area of 54.99 m² g^-1.The SPE sorbent is combined with HPLC system,six alkaloids in mouse plasma,such as caffeine,hydroxyl-?-sanshool,hydroxy-?-sanshool,hydroxy-?-sanshool,hydroxy-?-iso sanshool and?-sanshool were quantitatively analyzed by on-line SPE-HPLC.The results showed that the recovery and quantitative limit of this method were in the range of 94.37%-101.57%and6.35-10.14 ng mL^-1,respectively.It can effectively and simply extract and determine six alkaloids in plasma at the same time.In order to increase the specific surface area of the polymer monolithic SPE sorbent,the previous experiment was improved.On the basis of tetrahydrofurfuryl methacrylate as monomer,the self-made covalent organic framework material was added to prepare the monolithic SPE sorbent.The micro morphology and pore structure of SPE sorbent were characterized by scanning electron microscopy method and nitrogen adsorption desorption method.The results show that the prepared SPE sorbent has uniform porous structure and large specific surface area of 80.01 m² g^-1.An on-line SPE-HPLC method was established for the extraction,enrichment,separation and analysis of Uncaria alkaloids in mouse plasma and Uncaria.The recovery of this method is between 94.48%and 105.84%,indicating a good accuracy.Through the detection the content of trace alkaloids in the plasma of mouse 1 h after intragastric administration?crude extract of Uncaria?,it is proved that this method has certain applicability.