以复合磁性纳米材料为萃取剂结合MALDI-TOF-MS快速分析检测有机污染物

This project focuses on the synthesis of various kinds of magnetic nanocomposites, which can serve both as solid-phase extraction adsorbents (SPE) and MALDI matrix, and their application in extracting organic contaminants from environmental or biological samples rapidly and measuring directly using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS). Core/shell structured or embedded polymers or hydrophilic carbon with low degree of graphitization coated magnetic nanocomposites, gold/silver/platinum nanoparticles loaded magnetic nanomaterials and magnetic carbon nanotubes, graphene, or fullerene composites are synthesized through coprecipitation, thermal decomposition, and sol-gel methods. These magnetic nanocomposites have large surface areas, uniform particle size and good dispersion and biocompatibility. The extraction performance of the prepared magnetic nanocomposites to organic contaminants and enhanced desorption/ionization efficiency of targets under the action of laser pulses on these nanocomposites are investigated and an efficient magnetic SPE method will be established to achieve the efficient, sensitive and rapid analysis of trace contaminants in environmental or biological samples in conjunction with MALDI-TOF-MS detection technology. In this project, novel sample pretreatment and detection method is established through creative combination of nanomaterials, magnetic separation, SPE technology and MALDI-TOF-MS detection technique, which simplifies the sample pretreatment method, decreases targets loss and shortens the analytical time.

项目旨在合成多种可同时作为固相萃取吸附剂和MALDI基质的复合磁性纳米材料，探讨其在环境或生物样品中快速萃取富集有机污染物并直接用基质辅助激光解析电离飞行时间质谱（MALDI-TOF-MS）检测中的应用。采用共沉淀、热分解、溶胶-凝胶等方法制备出表面积大、粒径均一、分散性和生物相容性好的具有核/壳式或包埋式结构的聚合物或亲水性碳包覆的、负载纳米金/银/铂的和磁性碳纳米管、石墨烯或富勒烯等复合磁性纳米材料吸附剂。考察吸附剂对有机污染物的萃取能力和辅助激光诱导解析和离子化的性能，建立环境或生物样品中有机污染物的高效萃取富集方法，与MALDI-TOF-MS检测技术联用，实现对复杂基体样品中微量污染物的高效、灵敏、快速分析。项目创造性地将纳米材料、磁性分离、固相萃取技术和MALDI-TOF-MS分析检测技术结合为一体，简化了样品前处理方法，减少了目标物的损耗，缩短了目标污染物分析检测的分析时间。

按照项目研究计划，制备了氮硫掺杂的碳量子点、金属有机框架（MOFs）和共价有机框架（COFs）材料，以这些材料为MALDI基质，采用基质辅助激光解析电离飞行时间质谱（MALDI-TOF MS）来检测水样中的多环芳烃、全氟化合物、卤代阻燃剂、有机氯农药、内分泌干扰物等有机污染物。利用MOFs和COFs比表面积大、吸附能力强的特点，建立了固相萃取（SPE）- MALDI-TOF MS相结合快速分析水体样品中有机污染物的方法。其中，负载纳米金颗粒的锆基质金属有机框架（Zr-MOFs）复合材料由于纳米金颗粒优越的基质辅助解吸/离子化功能和MOFs的强吸附能力，可以实现水样中全氟化合物、卤代阻燃剂、有机氯农药、内分泌干扰物的同时识别和检测；而基于共价有机框架材料LZU-1的SPE-MALDI-TOF MS方法可以更灵敏地检测水样中的全氟化合物，其中PFOS的检测限可达到亚ppt级。为了更加便利、快速地检测水样中的有机污染物，通过层层组装技术，将兼具MALDI基质功能和吸附性能的纳米金颗粒和聚多巴胺负载到聚偏氟乙烯膜上。该膜片具有类pH试纸功能，将其浸入到水中，使污染物富集在表面；取出晾干后即可进行MALDI-TOF MS检测，进而可以快速“指示”样品中有机污染物的存在。以MALDI为离子源和调节电喷雾离子源碰撞池的离子累积时间，利用傅立叶转换电子回旋共振质谱（FT-ICR-MS）对天然有机质的成分进行了全面鉴定。这些研究成果发表SCI论文16篇，申请国家发明专利两项。