Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, China.
Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, China.
J Chromatogr A. 2018 Aug 10;1562:19-26. doi: 10.1016/j.chroma.2018.05.047. Epub 2018 May 24.
A novel microwave-accelerated reversible addition fragmentation chain transfer (RAFT) polymerization strategy has been introduced to shorten reaction time and improved polymerization efficiency of the conventional molecularly imprinting technology based on RAFT. Magnetic molecular imprinted polymers (MMIPs) were successfully synthesized much more efficiently using 17β-estradiol (E2) as a template for the determination of estrogen residues. The resultant MMIPs had well-defined thin imprinted film, favoring the fast mass transfer. Moreover, the reaction time, which was just 1/24 of the time taken by conventional heating, was significantly decreased, improving the reaction efficiency and reducing the probability of side reactions. Meanwhile, the obtained polymers have good capacity of 6.67 mg g and satisfactory selectivity to template molecule with the imprinting factor of 5.11. As a result, a method combination of the resultant MMIPs as solid phase extraction sorbents and high-performance liquid chromatography was successfully set up to determinate three estrogen residues in milk samples. For E2, estrone, and estriol, the limit of detections were calculated to be 0.03, 0.08, and 0.06 ng mL, respectively, and the limit of quantifications were 0.11, 0.27, and 0.21 ng mL, respectively. At the spiked level of 1, 5, and 10 ng mL, the recoveries of the three estrogens were ranged from 69.1% to 91.9% and the intra-day relative standard deviation (RSD) was less than 5.7%. In addition, the resultant MMIPs exhibited good reproducibility and reusability with the inter-batch RSD of 5.3% and the intra-batch RSD of 6.2%, respectively. Overall, the realization of this strategy facilitates the preparation of MMIPs with good architecture and high reaction efficiencies for the analysis of complicated real samples.
一种新型的微波加速可逆加成-断裂链转移（RAFT）聚合策略被引入，以缩短常规基于 RAFT 的分子印迹技术的反应时间并提高聚合效率。磁性分子印迹聚合物（MMIPs）以 17β-雌二醇（E2）为模板，成功地更有效地合成，用于测定雌激素残留。所得 MMIPs 具有定义明确的薄印迹膜，有利于快速传质。此外，反应时间大大缩短，仅为常规加热时间的 1/24，提高了反应效率，降低了副反应的概率。同时，所得聚合物对模板分子的结合能力良好，容量为 6.67mg/g，印迹因子为 5.11。因此，成功建立了一种将所得 MMIPs 作为固相萃取吸附剂和高效液相色谱相结合的方法，用于测定牛奶样品中的三种雌激素残留。对于 E2、雌酮和雌三醇，检测限分别计算为 0.03、0.08 和 0.06ng/mL，定量限分别为 0.11、0.27 和 0.21ng/mL。在 1、5 和 10ng/mL 的加标水平下，三种雌激素的回收率在 69.1%至 91.9%之间，日内相对标准偏差（RSD）小于 5.7%。此外，所得 MMIPs 表现出良好的重现性和可重复性，批间 RSD 分别为 5.3%和 6.2%。总的来说，这种策略的实现有利于制备具有良好结构和高反应效率的 MMIPs，用于分析复杂的实际样品。
