Application Of Molecularly Imprinted Polymer For Detection Of The Residues Of Four Classes Of Veterinary Drugs

Molecularly imprinted polymer is the synthetic material with artificial recognition sites that can capture the specific target molecule and the structurally related molecules.Due to its advantages of environmental protection,durability,and reusability,this technology has been widely used for extraction and purification of veterinary drug in recent years.This study mainly discusses the application of molecularly imprinted polymer for the detection of phenothiazines,quinolones,sulfonamides and tetracyclines in animal-derived foods.First,the three-dimensional structures of two pseudo templates and four phenothiazines were studied by using computation simulation.Two molecularly imprinted polymers were then synthesized separately by using the two templates,and the results showed that the recognition capabilities of the two molecularly imprinted polymers were consistent with the theoretical calculation.Then a solid phase extraction column was developed for the extraction of 4 phenothiazines in meat(pork,chicken)followed by determination with high performance liquid chromatography.The results showed that the solid phase extraction cartridge could adsorb the four phenothiazines.The adsorption capacities for the four drugs were in a range of 42.5-48.1 μg,and the recoveries were in a range of 93-98%.The solid phase extraction column could be reused for at least 60 times.The four drugs were fortified into the blank meat samples to be extracted and determined.The results showed that the detection limits for the four drugs were in the range of 1.0-10 ng/mL,the limits of quantification were in the range of 3.0-30 ng/mL,and the recoveries were in the range of 70.3-96.1%.Secondly,the three-dimensional structures of four pseudo templates,eight fluoroquinolones and eight sulfonamides were studied by using computation simulation.After comparing the four pseudo template based polymers,a dual-template molecularly imprinted polymer was synthesized.The results showed that the recognition ability of the dual-template molecularly imprinted polymer was consistent with the theoretical calculation.A solid-phase extraction cartridge was then prepared for extraction of fluoroquinolones and sulfonamides in meat(pork,chicken)followed by determination with ultra performance liquid chromatography.The results showed that the solid phase extraction column can adsorb 8 fluoroquinolones and 8 sulfonamides.The adsorption capacities for the 16 drugs were in a range of 34.9-74.2 μg with recoveries in the range of 92%-99%.The solid phase extraction cartridge can be reused at least 80 times.The 16 drugs were fortified into the blank meat samples to be extracted and detected.The results showed that the detection limits of the method for the 16 drugs were in a range of 1.0-3.4 ng/mL,the limits of quantification were in a range of 3.0-10.3 ng/mL,and the recoveries were in a range of 86.1%-109.4%.Thirdly,a mix-template molecularly imprinted polymer was synthesized,which can capture 8 fluoroquinolones,8 sulfonamides and 4 tetracyclines simultaneously with recoveries higher than 92%.The polymer was then used to develop a matrix solid phase dispersion method for extraction of the 20 drugs in pork followed by determination with ultra performance liquid chromatography.The 20 drugs were fortified into the blank meat samples to be extracted and detected.The results showed that the detection limits for the 20 drugs were in a range of 0.5-3.0 ng/mL,the limits of quantification were in a range of 1.5-6.0 ng/mL,and the recoveries were in a range of 74.5%-102.7%.In this study,the sample pretreatment method based on molecularly imprinted polymer has the merits of high selectivity and high durability.It greatly improves the efficiency of the residue detection method,and can be used for determination of the residues of the four classes of veterinary drugs in foods of animal origin.