“开/关”型极性/电荷可控聚合物刷磁性吸附剂及其分离富集性能

Different types of separation and enrichment technologies based on solid-phase adsorption have become efficient sample pretreatment methods for the analysis of complex samples. However, the current preparation methods of adsorbent have two problems to be resolved. One is uncontrollable selectivity of adsorbent, and another is the lower recovery of target due to the loss of target during the washing process. This program aims to resolve these two problems by developing a new method of adsorbent structure design to functionalize magnetic particles with polar/charge-controlled “on/off” polymer brushes via combination of atom transfer radical polymerization and chain-end functionalization technologies. Using quinolones and β-receptor agonists as targets, this program will investigate the regulating effect of the proportion of hydrophobic to charged groups in the inner of the brushes on the adsorption selectivity, and also explore the extraction procedure and the possibility of preventing the loss of the target during washing process and improving the recovery of target by changing the composition of adsorption, washing and elution solvent to swicth the “on/off” state on the end of the brushes. Finally, the dispensive solid-phase combined with LC/MS method is established to analyse quinolones and β-receptor in actual samples to show the application of the adsorbent in pretreatment of complex samples.

基于固相吸附的各种分离富集技术已成为复杂样品分析的有效前处理技术。然而,目前吸附剂制备方法存在着吸附剂的选择性难以调控、在洗脱过程中因目标物损失而导致的回收率低的问题。本项目以磁性粒子为载体，采用原子转移自由基聚合(ATRP)结合聚合物链末端功能化技术，探索在载体表面上构筑极性/电荷可控、兼具“开/关”状态切换功能的聚合物分子刷，建立一种吸附剂表面结构设计的新方法。以喹诺酮和β-受体激动剂为富集对象，研究聚合物刷内疏水性和离子性基团组成对吸附选择性的调控作用；通过改变固相萃取过程中吸附、洗涤和解析溶剂组成，切换聚合物分子刷末端功能分子的“开/关”状态，研究“开/关”型吸附剂的萃取操作规律，明确“开/关”结构对阻止目标物的损失、提高目标物回收率的作用。建立磁性萃取-LC/MS分析方法，分析实际样品中的喹诺酮和β-受体激动剂，阐明该吸附剂在复杂样品分析中的应用价值。

基于固相吸附的各种分离富集技术已成为复杂样品分析的有效前处理技术。然而,目前吸附剂制备方法存在着吸附剂的选择性难以调控、在洗脱过程中因目标物损失而导致的回收率低的问题。针对该问题，本项目开发了多种吸附剂新载体，提出了采用原子转移自由基聚合（ATRP）结合聚合物侧链和链端修饰技术，在载体表面上构筑极性/电荷可控以及兼具“开/关”状态切换功能的聚合物分子刷修饰方法，制备了多种选择性可调型吸附剂以及“开/关”型吸附剂。通过研究聚合物结构与吸附性能的关系，阐明了聚合物刷内疏水性和离子性基团组成对吸附选择性的调控作用；通过改变固相萃取过程中吸附、洗涤和解析溶剂组成，切换聚合物分子刷末端功能分子的“开/关”状态，提出了“开/关”型吸附剂的萃取原理，明确“开/关”结构对阻止目标物的损失、提高目标物回收率有重要作用。总之，本项目用ATRP聚合技术，通过选择聚合单体、修饰方式，设计材料表面的吸附层拓扑结构，能够提高吸附剂的吸附选择性、吸附容量和回收率。本项目首次提出的“开/关”吸附剂拓扑结构和固相萃取原理，是分离科学领域内固相萃取的新原理和新方法。以这些吸附剂为核心，建立了生物样品、环境样品、食品中目标物的色谱分离或固相萃取方法，提高了分析方法的灵敏度。研究成果对于吸附剂以及吸附界面的开发具有重要的理论意义和应用价值，同时对其它材料的结构设计具有借鉴作用。