Acrylamide [BSA]

This work proposes controllable molecular sieving using the cross-linked copoly(poly(ethylene glycol) acrylate/poly(ethylene glycol) diacrylate) (copoly(PEGA/PEGDA)) hydrogels as a sieving matrix for DNA in capillary electrophoresis (CE). Attempts were made to control the separation performance using different gel components, including the initiator concentration (C-APS), total concentration (C-t) of monomers, the ratio (R) of PEGA to PEGDA, and the length of the cross-linker (L-c). Results reveal that the molecular sieving effect in the copoly(PEGA/PEGDA) gel can be controlled by C-t, R, C-APS, and L-c, especially by the former two parameters. Higher C-t and lower R provided smaller average pore size, resulting in better separation of small-size DNA fragments, while lower C-t and higher R allowed better separation of large-size DNA fragments. Moreover, using a representing gel component, the repeated test showed a run-to-run precision of RSD < 0.9% (n = 10 tests), a column-to-column precision of RSD < 5.9% (n = 5 columns), and a day-to-day precision of RSD < 5.2% (n = 25 tests in 5 days) for the migration time. The results also reveal the rapid and high-resolution separation for 20-140 bp DNA fragments using the copoly(PEGA/PEGDA) gel when tuned to a lower R and lower C-t. When high C-t was used, the copoly(PEGA/PEGDA) gel capillary was found to have better repeatability and higher resolution than the authentic poly(acrylamide) gels owing to the better volume stability upon polymerization.

The specific of magnetic molecularly imprinted polymers (Fe3O4@SiO2-MIPs) for kaempferol were fabricated by using acrylamide (AM) as the functional monomer, azobisisobutyronitrile (AIBN) as the initiator and ethylene glycol dimethacrylate (EGDMA) as the cross-linker. The Fe3O4@SiO2-MIPs showed high adsorption capacity (3.84 mg/g) for kaempferol, and the adsorption equilibrium was achieved within 50 min. The specific recognition capacity of Fe3O4@SiO2-MIPs was 3.02 times as high as that of Fe3O4@SiO2 NIPs. The Fe3O4@SiO2-MIPs showed high selectivity towards kaempferol over structural analogues. The recoveries of proposed method at three spiked levels analysis were ranged from 90.5% to 95.4% with the relative standard deviations (RSD) less than 5%. The obtained Fe3O4@SiO2-MIPs were successfully applied for the extraction and determination of kaempferol from apple samples. The established method was simple and feasible, which showed high selectivity, fast separation and satisfactory recoveries for real sample analysis. (C) 2020 Elsevier B.V. All rights reserved.