Zhang Chengjiang, Luo Xialin, Wei Tianfu, Hu Yufei, Li Gongke, Zhang Zhuomin
School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China; School of Pharmacy, Zunyi Medical University, Zunyi, 563003, China.
School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China.
J Chromatogr A. 2017 Oct 13;1519:28-37. doi: 10.1016/j.chroma.2017.09.002. Epub 2017 Sep 4.
A new dynamic covalent polymer (DCP) gel was well designed and constructed based on imine chemistry. Polycondensation of 4,4'-biphenyldicarboxaldehyde and 1,3,5-benzenetricarbohydrazide via Schiff-base reaction resulted in an acylhydrazone bond gel (AB-gel) DCP. AB-gel DCP had three-dimensional network of interconnected nanoparticles with hierarchically porous structure. AB-gel DCP was successfully fabricated as a monolithic column by an in-situ chemical bonding method for online enrichment and separation purpose with excellent permeability. AB-gel DCP based monolithic column showed remarkable adsorption affinity towards target analytes including sulfonamides (SAs) and fluorescent whitening agents (FWAs) due to its strong π-π affinity, hydrophobic effect and hydrogen bonding interaction. Then, AB-gel DCP based monolithic column was applied for online separation and analysis of trace SAs and FWAs in food samples coupled with high-performance liquid chromatography (HPLC). Sulfathiazole (ST) and sulfadimidine (SM2) in one positive weever sample were actually found and determined with concentrations of 273.8 and 286.3μg/kg, respectively. 2,5-Bis(5-tert-butyl-2-benzoxazolyl) thiophene (FWA184) was actually quantified in one tea infusion sample with the concentration of 268.5ng/L. The spiked experiments suggested the good recoveries in range of 74.5-110% for SAs in weever and shrimp samples with relative standard deviations (RSDs) less than 9.7% and in range of 74.0-113% for FWAs in milk and tea infusion samples with RSDs less than 9.0%. AB-gel DCP monolithic column was proved to be a promising sample preparation medium for online separation and analysis of trace analytes in food samples with complex matrices.
基于亚胺化学原理，成功设计并构建了一种新型动态共价聚合物（DCP）凝胶。4,4'-联苯二甲醛与1,3,5-苯三碳酰肼通过席夫碱反应发生缩聚反应，生成了一种酰腙键凝胶（AB-凝胶）DCP。AB-凝胶DCP具有由相互连接的纳米颗粒组成的三维网络结构，且具有分级多孔结构。通过原位化学键合方法，成功将AB-凝胶DCP制备成整体柱，用于在线富集和分离，具有出色的渗透性。基于AB-凝胶DCP的整体柱对包括磺胺类药物（SAs）和荧光增白剂（FWAs）在内的目标分析物表现出显著的吸附亲和力，这归因于其强大的π-π亲和力、疏水作用和氢键相互作用。然后，将基于AB-凝胶DCP的整体柱应用于食品样品中痕量SAs和FWAs的在线分离与分析，并与高效液相色谱（HPLC）联用。在一个阳性鲈鱼样品中实际检测到了磺胺噻唑（ST）和磺胺二甲嘧啶（SM2），其浓度分别为273.8和286.3μg/kg。在一个茶汤样品中实际定量检测到了2,5-双（5-叔丁基-2-苯并恶唑基）噻吩（FWA184），浓度为268.5ng/L。加标实验表明，在鲈鱼和虾样品中，SAs的回收率良好，范围为74.5-110%，相对标准偏差（RSDs）小于9.7%；在牛奶和茶汤样品中，FWAs的回收率范围为74.0-113%，RSDs小于9.0%。事实证明，AB-凝胶DCP整体柱是一种很有前景的样品前处理介质，可用于在线分离和分析复杂基质食品样品中的痕量分析物。
