Synthesis of molecularly imprinted polymers of vanillic acid and extraction of vanillic acid from spiked blood serum

Vanillic acid (4-hydroxy-3-methoxybenzoic acid) is a phenolic acid found in many plant extracts. It is used as aflavoring and scent agent and produces a pleasant, creamy odor. It is widely used in many applications for therapeuticpurposes to flavoring agent. Molecularly imprinted polymers of vanillic acid were synthesized by precipitationpolymerization with a noncovalent approach for the extraction from blood serum. Three different imprinted polymershave been synthesized with varying molar ratio of monomer. The synthesized polymer particles were characterizedusing Fourier-transform infrared spectroscopy and scanning electron microscopy. The extraction efficiency of highlyselected imprinted polymer of vanillic acid from spiked blood serum was about 80%.

Study on Synthesis of Tumor Marker PHPAA Molecular Imprinted Polymers and Its Performance / 中国药房

OBJECTIVE:To synthesize 4-hydroxyphenylacetic acid(PHPAA)molecular imprinted polymers(MIPs),and to provide reference for separation and enrichment of PHPAA in urine of cancer patients. METHODS:With PHPAA as template molecule and azobisisobutyronitrile as evocating agent,MIPs was synthesized by precipitation polymerization using 4-vinyl pyridine(4-V),acrylamide(AM),1-vinyl imidazole(1-V)and o-diaminobenzene as functional monomers,ethylene glycol dimethacrylate(EGDMA)and trimethylolpropane trimethacrylate(TRIM)as crosslinking agent. Using scanning electron microscope,infrared spectrum,static adsorption test and molecular recognition performance test used adopted to characterize the structure and performance of MIPs. RESULTS:MIPs1(4-V,EGDMA)microspheres adhered seriously,and MIPs2(AM, EGDMA)microspheres are aggregated. MIPs3(1-V,TRIM),MIPs4(o-diaminobenzene,TRIM)microspheresare were dispersed and had good sphericity. Characteristic absorption peak of PHPAA was not found in infrared spectrum of MIPs. The adsorption capacity of each MIPs was higher than that of blank imprinted polymer without the template molecule,and increased as the increase of template molecular concentration. The adsorption capacity of MIPs3 was significantly higher than that of other MIPs,and its static distribution coefficient(0.14)of PHPAA was higher than that of other structural analogues [PHPA(0.06),TA(0.01)],selective separation factors of PHPAA to PHPA,PHPAA to TA were 2.3,11.5,respectively. CONCLUSIONS:MIPs synthesized with 1-V as functional monomer and TRIM as crosslinking agent has the ability of specific adsorption and selective recognition. It can used as solid phase extractant to separate and enrich low content of PHPAA in the urine of tumor patients.

Selective extraction of dimethoate from cucumber samples by use of molecularly imprinted microspheres / 药物分析学报

Molecularly imprinted polymers for dimethoate recognition were synthesized by the precipitation polymerization technique using methyl methacrylate (MMA) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross-linker. The morphology, adsorption and recognition properties were investigated by scanning electron microscopy (SEM), static adsorption test, and competitive adsorption test. To obtain the best selectivity and binding performance, the synthesis and adsorption conditions of MIPs were optimized through single factor experiments. Under the optimized conditions, the resultant polymers exhibited uniform size, satisfactory binding capacity and significant selectivity. Furthermore, the imprinted polymers were successfully applied as a specific solid-phase extractants combined with high performance liquid chromatography (HPLC) for determination of dimethoate residues in the cucumber samples. The average recoveries of three spiked samples ranged from 78.5% to 87.9% with the relative standard deviations (RSDs) less than 4.4% and the limit of detection (LOD) obtained for dimethoate as low as 2.3μg/mL.

Synthesis of theophylline molecular imprinted polymer microspheres and their properties / 中草药

Objective: To snythesize theophylline molecular imprinted polymer (MIP) microspheres. The influences of reaction conditions, including the category of solvent, reaction time, and the ratio of template to the cross-linking agent on the morphology and adsorption properties of MIP microspheres were studied. Methods: Theophylline MIP microspheres were prepared by precipitation polymerization with theophylline as template and ethyleneglycol dimethacrylate (EGDMA) as cross-linker. The microspheres were characterized by static adsorption and scanning electron microscopy (SEM). Results: The ratio of template to the cross-linking agent was 1:16, reaction time was 24 h, and acetontrile was the solvent. The theophylline MIP microspheres were regular microspheres. The MIP microspheres showed the high adsorption capacity and the partition coefficient of the microspheres adsorbing theophylline was 1.74. Conclusion: Theophylline MIP microspheres have the specific adsorption and recognition capabilities to the theophylline molecules.