功能化席夫碱共价有机材料介质的研制及其在痕量组分富集中的应用

Complex samples with complex matrices which usually induce severe interference, and target analytical compounds of complex samples are usually at very low concentrations. How to accurately extraction, separation and enrichment of trace targets compounds in complex samples, the development of high-efficiency, selective enrichment medium, as well as new enrichment techniques and methods are the key to achieve accurate and high sensitivity analysis of trace substances. Schiff-base porous covalent organic materials (Schiff-base COMs) are a class of porous polymers which is composed of light elements and connected by stronger covalent bonds. Schiff-base COMs possess fascinating features like large specific surface area, low density, high porosity, tunable pore size, modified surface and high hydrothermal stability, and so on. The project intend to designed and synthesize new materials of functional enrichment medium based on Schiff-base COMs, the novel enrichment medium through effective assembly and immobilization. The self-assembly Schiff-base COMs medium will used as the solid phase microextraction (SPME) coatings and magnetic composite materials by in-situ chemical bonding method with fused-silica fiber or magnetic nanoparticles surface. The fabrication method can be obtained stable and controllable thickness of SPME coating and magnetic composite materials. Due to the high surface area and porosity of Schiff-base COMs medium, the target analytes will be high-efficiency enrichment. By precise control of the microporous structure and functional groups of Schiff-base COMs medium, the target analytes will be selective enrichment. Then, the Schiff-base COMs medium actually applied in quantitative analysis of monoamine neurotransmitters and their metabolites, phenols and nitrofurans compounds. The aim of our work is providing new methods and technologies for developing new high extraction capacity or selective enrichment mediums, improving the enrichment and efficient sensitive analysis of the target trace compounds in complex sample.

复杂样品的痕量分析因基体复杂、待测物含量低，如何准确地提取、分离和富集复杂样品中的目标痕量物，发展高效、选择性的富集介质以及富集新技术与新方法是实现痕量物质准确、高灵敏分析的关键。Schiff-base COMs是一类由轻质元素通过共价键连接而成的聚合物，具有比表面积大、孔隙率高、孔径可控、表面可修饰和稳定性好等优点。本项目拟通过分子设计合成功能化的Schiff-base COMs新材料，进行有效组装和固载，原位化学键合法在石英纤维和磁性纳米粒子表面自组装Schiff-base COMs介质，构建牢固稳定、厚度可控的SPME涂层和磁性复合材料。利用Schiff-base COMs的多孔性和高比表面积实现痕量物质的普适性高效富集，通过精确调控Schiff-base COMs微孔结构和功能化基团，实现目标痕量物质的选择性富集，并用于实际样品中单胺类神经递质、酚类、硝基呋喃类痕量组分的分离分析。

席夫碱共价有机材料（COMs）是醛和胺的有机单体根据席夫碱反应原理缩合形成的一类新型多孔材料。COMs具有比表面积大、孔隙率高、孔径尺寸可控、结构可功能化和物化稳定性好等优点，COMs材料优异的物化性能使其非常适于作为复杂样品中痕量目标物的分离富集介质。本研究开展了：（1）以均苯三甲酰肼（BTH）和对苯二甲醛（PD）、间苯二甲醛（BD）、联苯二甲醛（BDD）为原料，二甲基亚砜为溶剂，根据席夫碱反应原理，合成了3种新型的酰腙键聚合物凝胶（BTH-PD、BTH-BD和BTH-BDD），对材料进行结构和性能表征，表明材料具有良好的物化性能。（2）以BTH-PD材料为固相萃取（SPE）介质，结合高效液相色谱（HPLC）联用分析黄酮类化合物，建立了SPE/HPLC分析方法，线性范围在1.5～100μg/mL之间，检出限（LOD）为0.68～0.85μg/mL，样品的加标回收率为78.1～90.7%，方法实现了石上柏药材中3种黄酮化合物的应用分析。（3）以BTH-BD粉末为SPE介质用于4种硝基呋喃类药物的分离富集，结合HPLC进行分析检测，建立了SPE/HPLC分析方法，线性范围在1.0～200μg/L之间，LOD为0.10～0.50μg/L，加标回收率在78.5～96.8%之间，RSD为2.1～9.3%（n=3），方法成功实现了饲料样品中硝基呋喃类药物的应用分析。（4）以均苯三甲酰肼和对苯二甲醛为有机单体，1,4-二氧六环、均三甲苯和乙酸为溶剂介质，合成了腙键共价有机聚合物（BTH-PD-COP），通过结构鉴定和性能表征表明材料具有良好的物理化学性质。（5）以1,3,5-三甲酰基间苯三酚（Tp）和对苯二胺（Pa-1）为有机单体，溶剂热法制备TpPa-1，将其作为填充柱在线微固相萃取（μ-SPE）介质，结合HPLC检测双酚类化合物。建立了μ-SPE/HPLC分析方法，线性范围为0.2～100μg/L，LOD为0.05～0.06μg/L，在塑料盒中检出双酚A的量为0.31µg/g，样品的加标回收率为80.5-116%，RSD为1.7～9.2%（n=3），TpPa-1在线μ-SPE色谱联用实现了塑料制品中双酚类化合物的应用分析。综上研究表明，席夫碱COMs材料作为新型萃取介质在样品前处理领域具有良好的应用前景。本项目研究共发表7篇文章，其中SCI收录2篇，申请发明专利1件。