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首次以氯甲基化交联聚苯乙烯树脂(CMCPS)为载体和大分子引发剂、2,4-二氯苯氧乙酸(2,4-D)为模板、丙烯酰胺(AM)为单体、乙二醇二甲基丙烯酸酯(EDMA)为交联剂、溴化铜/2,2’-联吡啶(CuBr/Bpy)为催化剂,采用表面引发原子转移自由基聚合(SI-ATRP)技术,制备了2,4-二氯苯氧乙酸分子印迹聚合物(2,4-D MIPs),并研究了模板分子与功能单体比例对该印迹聚合物吸附量的影响。通过动态、静态及竞争试验考察了该印迹聚合物对2,4-D的吸附性能。结果表明:2,4-D MIPs对模板分子2,4-D具有良好的特异性识别作用;与2,4-二氯苯酚和2,4-二氯苯甲醛相比,2,4-D MIPs对2,4-D的选择性系数分别为2.84和3.75,相对选择性系数分别为2.31和2.29。采用Scatchard模型分析,可以得到两类结合位点,计算得到最大表观吸附量(Qmax)分别为76.92和142.91 mg/g,离解常数Kd分别为632.91和2 309.47 mg/L。将2,4-D MIPs作为固相萃取剂,对豆芽样品进行添加回收试验,回收率为86%~104%,相对标准偏差(RSD)为1.9%~10%,方法的检出限为20 ng/g。该印迹聚合物可以富集分离测定2,4-D,稳定性好,并且能重复使用。
Chlormethylated cross-linked polystyrene resin (CMCPS) as carrier and macroinitiator, 2,4-dichlorophenoxyacetic acid (2,4-D) as template and acrylamide , Ethylene glycol dimethacrylate (EDMA) as cross-linking agent and CuBr / Bpy (copper bromide) / 2,2’-bipyridine as catalyst, and using surface initiated atom transfer radical polymerization (2,4-D MIPs) were prepared. The effects of the ratio of template to functional monomer on the adsorption capacity of the imprinted polymer were investigated. The adsorption properties of 2,4-D on the imprinted polymer were investigated by dynamic, static and competitive tests. The results showed that 2,4-D MIPs had good specificity for recognizing the template molecule 2,4-D. Compared with 2,4-dichlorophenol and 2,4-dichlorobenzaldehyde, 2,4-D The selectivity coefficients of 2,4-D for MIPs were 2.84 and 3.75, respectively, and the relative selectivity coefficients were 2.31 and 2.29, respectively. Two types of binding sites were obtained by Scatchard analysis. The maximum apparent adsorption capacity (Qmax) were 76.92 and 142.91 mg / g, respectively. The dissociation constants Kd were 632.91 and 2 309.47 mg / L, respectively. The 2,4-D MIPs was used as solid-phase extractant to recover the bean sprouts samples. The recoveries were 86% -104% and the relative standard deviations (RSDs) were 1.9% -10%. The detection limit was 20 ng / g. The imprinted polymer can be enriched for separation and determination of 2,4-D, good stability, and can be reused.