Zhu Yuling, Yang Siwen, Chen Gang, Xing Jun
Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei, China.
Electric Power Research Institute of Guangdong Power Grid Corporation, Guangzhou, Guangdong, China.
J Chromatogr A. 2014 Aug 8;1354:101-8. doi: 10.1016/j.chroma.2014.05.068. Epub 2014 Jun 2.
A single "click" strategy is proposed for the preparation of a reversed-phase/weak cation-exchange mixed-mode silica-based sorbent (silica-WCX). Upon this strategy, both 1-dodecyne and 5-hexynoic acid were simultaneously immobilized onto azide-silica in varied ratio via Cu (I)-catalyzed azide-alkyne cycloaddition click reaction. The chemical compositions of silica-WCXs were characterized by elemental analysis, acid-base titration and Fourier transform-infrared spectroscopy. The results indicated that the actual mole ratio of n-dodecyl to carboxylic group on the sorbent is almost the same as the reactant ratio of 1-dodecyne to 5-hexynoic acid, and the repeatability of synthesis method is good. After that, two β-agonists, clenbuterol and ractopamine, were selected as model drug residues to evaluate the applicability of silica-WCX in matrix solid-phase dispersion extraction for the determination of basic drug residues in porcine liver by HPLC/UV. In comparison with some commercial sorbents, silica-WCX exhibited higher recoveries and better purification capability. Under the optimized conditions, linearity ranges were between 0.04 and 8.0μg/g for both analytes with coefficients of determination (R(2)) higher than 0.9997. The average recoveries at three spiked levels ranged from 92.5% to 105.0% with RSDs less than 6.6%.
本文提出了一种“点击”策略来制备反相/弱阳离子交换混合模式硅胶基吸附剂（硅胶-WCX）。通过该策略，1-十二炔和5-己炔酸通过铜（I）催化的叠氮化物-炔烃环加成点击反应以不同比例同时固定在叠氮化物硅胶上。通过元素分析、酸碱滴定和傅里叶变换红外光谱对硅胶-WCX的化学成分进行了表征。结果表明，吸附剂上正十二烷基与羧基的实际摩尔比与1-十二炔与5-己炔酸的反应物比例几乎相同，合成方法的重复性良好。之后，选择两种β-激动剂克伦特罗和莱克多巴胺作为模型药物残留，以评估硅胶-WCX在基质固相分散萃取中通过HPLC/UV测定猪肝中碱性药物残留的适用性。与一些商业吸附剂相比，硅胶-WCX表现出更高的回收率和更好的净化能力。在优化条件下，两种分析物的线性范围均为0.04至8.0μg/g，测定系数（R²）高于0.9997。三个加标水平的平均回收率为92.5%至105.0%，相对标准偏差小于6.6%。
