Synthesis of tetracycline-imprinted polymer microspheres by reversible addition-fragmentation chain-transfer precipitation polymerization using polyethylene glycol as a coporogen

Abstract

Tetracycline (TC)-imprinted microspheres have been synthesized by reversible addition-fragmentation chain-transfer precipitation polymerization using PEG as a coporogen. In the synthesis, methacrylic acid and ethylene dimethacrylate were used as the functional monomer and cross-linker, respectively. 2,2'-Azobisisobutyronitrile was the initiator, and cumyl dithiobenzoate was the chain-transfer reagent. Although monodispersed microspheres were obtained using acetonitrile as porogen, the particles cannot be used in the column extraction because of the high backpressure. To increase the porosity of the material, PEG was introduced as a coporogen. The influence of the molecular weight and concentration of PEG on the morphology, binding affinity, and porosity of the molecularly imprinted polymers (MIPs) have been studied. The results demonstrated that PEG as a macroporogen increased the porosity of the polymers. Meanwhile, the column backpressure was reduced using the MIPs with higher porosity. The binding affinity of the MIPs was increased when a low concentration of PEG was employed, while it was decreased when the ratio of PEG 12,000/monomers was >0.8%. Under the optimized conditions, TC-imprinted microspheres with good selectivity and size uniformity have been obtained, which facilitates its application in the column extraction for TC determinations.

Microsphere Polymers in Molecular Imprinting: Current and Future Perspectives

“…Recent studies has successfully developed RAFTPP for different templates [ 76 , 77 , 78 ], especially as drug delivery systems [ 82 ], different CTA [ 73 , 74 ] and different matrices [ 104 ]. As a commonly used approach to produce MIMs, RAFTPP has wide possibilities for further applications in various fields, such as environmental monitoring (e.g., removing toxic compounds from natural products [ 75 ]), food analysis, clinical diagnostics, bioimaging and stimuli-responsive drug delivery (see Table 1 ).…”

Determination of macrolide antibiotics residues in pork using molecularly imprinted dispersive solid‐phase extraction coupled with LC–MS/MS

“…Therefore, a 2:3 ratio of chloroform to acetonitrile was chosen. Furthermore, the effect of different porogen volumes (10,15,20,25,30, and 35 mL) on adsorption was investigated ( Figure 2B). The adsorption capacity of MIP initially increases with the increasing porogen volume, but it gradually decreases with porogen volumes higher than 20 mL.…”

“…Moreover, 1% acetic acid in acetonitrile is the optimal extraction solvent, with the recoveries of more than 80% for all target analytes. Then the extraction solution from pork sample was subjected to MIDSPE procedure, and different adsorbent amounts (10,15,20, and 30 mg) were investigated in this study. The results show that the recoveries of MALs increase with the rising of adsorbent amounts.…”

“…Among these approaches, polymers with uniform size and shape can be produced by precipitation polymerization without grinding or sieving [7]. Even though MIPs F I G U R E 1 Chemical structures of seven macrolide antibiotics prepared by precipitation polymerization often have low yields, their outstanding advantages in terms of adsorption kinetics and imprinting effects have drawn the attention of scientists [8][9][10].…”

Desenvolvimento de uma fase extratora com polímeros de impressão molecular para extração em fase sólida de Venlafaxina, O-desmetilvenlafaxina e N-desmetilvenlafaxina em amostras de plasmas e análises por cromatografia líquida de ultra eficiência acoplada à espectometria de massas em tandem (UPLC-MS/MS).

“…A conversão de radicais primários a radicais iniciadores, geralmente não é quantitativa, uma vez que os radicais primários podem sofrer rearranjo, fragmentação ou interação com solvente ou outros componentes do meio reacional, originando radicais secundários(MOAD et al, 2006). No entanto, recentes publicações têm obtido excelentes resultados emABDOUSS et al, 2012;BASOZABAL et al, 2013;LIAN;HE;WANG, 2014;LIU et al, 2014;NUNEZ et al, 2010). Na síntese do MIP, frequentemente utiliza-se uma quantidade molar de iniciador radicalar correspondente a 1% do numero total de mols de duplas polimerizáveis presentes no meio reacional.…”