Preparation Of Imprinted Polymer Monolithic Micro-column For Macrolides And Its Application

Molecularly imprinted polymers?MIPs?were synthesized by bulk polymerization using tylosin as virtual template molecule,and then the polymers were used to prepare molecularly imprinted solid phase extraction?MISPE?cartridge.A method based on MISPE coupling with liquid chromatography-tandem mass spectrometry?LC-MS/MS?for determination of ten macrolides at low concentration level in environmental water samples was developed.Mean recoveries of ten macrolides from natural waters,spiked at 0.04,0.1 and 0.4 ?g/L,ranged from 68.0% to 100.9%,with intra-day and inter-day coefficient of variation below 15.0%.Limits of detection?LODs?and limits of quantification?LOQs?of ten drugs were in range of 1.0 15.0 ng/L and 3.0 ⁴0.0 ng/L,respectively.The results showed that the MISPE cartridge was better than C₁₈,HLB and SCX cartridges in terms of both recovery and cleanup.A molecularly imprinted polymer monolithic micro-column?MIPMMC?,using roxthromycin as template molecule,was synthesized in a pipette tip by molecular imprinting technique in-situ polymerization.To optimize preparation conditions of MIPs,five monomers including methacrylic acid,acrylamide,vinyl pyridine,etc.and different ratios and volumes of porogenic solvents?toluene and dodecanol?were investigated.The optimal formula was as follows: 1.0 mmol roxthromycin,4.0 mmol methacrylic acid,20.0mmol ethyleneglycol dimethacrylate,12.5 m L toluene:dodecanol?1:6,v:v?,30.0 mg2,2'-azobisisobutyronitrile.The characteristics of the prepared MIP were tested using scanning electron microscopy,Infrared spectrum?IR?,the specific surface area and thermal gravimetric analysis.Roxithromycin-imprinted polymers synthesized showed some class-specific to macrolides.The drugs such as clarithromycin,azithromycin and tulathromycin etc.,are similar to the template in structure,achieved a high imprinting factor?IF?and adsorption capacity.The polymers prepared in a pipette tip were used as a MIPMMC,which was connected with infusion pump for solid phase extraction?SPE?.The extraction conditions were optimized as follows: conditioning with acetonitrile,loading with sample acetonitrile solution,washing with acetonitrile and water,respectively,and eluting with 2% ammonia in methanol.Accordingly,a novel method based on the MIPMMC coupled to LC-MS/MS was developed for the determination of macrolides drugs in muscles.After purifing with MISPE cartridge,average recoveries of six MALs in muscle samples?chicken,swine and cattle?spiked at 5.0,10.0 and 20.0 ?g/kg,were in range 75.3% 92.8% with coefficient of variation less than 15.0%.The sensitive,accurate and reliable method developed is suitbale for the monitoring of macrolides residues in muscle samples.