复杂体系痕量有机物微萃取基础研究：器件设计和表面修饰

This project focuses on the fast and reliable microextraction of trace organic compounds from complex samples, to effectively overcome the poor reproducibility and long extraction time in current methods. Stable extraction interface and accelerated molecule transfer are chosen as the two key research objectives. The membrane-based microextraction methods, such as headspace membrane-based liquid phase micro extraction (HF-LPME), hollow fiber-based liquid liquid microextraction (HF-LLME), hollow fiber-based liquid liquid liquid microextraction (HF-LLLME), are chosen as optimal research models. First, the membrane device will be re-designed, and it will be fabricated based on electrospinning techniques. The transfer resistance in membrane solvent and in extraction phases will be decreased, and the effective extraction surface area per extraction phase will be increased, so the microextraction will be accelerated. Second, the membrane surface will be modified selectively to tune the pore size and its chemical properties, so the flow impact and chemical interference from sample solution will be largely inhibited, and the selectivity of membrane extraction will be further enhanced. Third, ion pair reagents for ionized organic compounds will be screened and added into the membrane solvent, so their electro-membrane extraction will be improved. Four, these novel devices, surface modification methods, and ion pair reagents will be verified systematically. Some trace organic compounds in complex samples, such as phenols from environment water, pesticides residue in vegetables and juices, and gibberellins in plant tissues, will be extracted, analyzed, and identified on LC-MS/MS and GC-MS. Finally, HF-LPME, HF-LLME, HF-LLLME and other sample preparation methods will be further developed, and can be applied in complex samples. More important, these conclusions about molecular transfer acceleration, microextraction device design, and surface modification will be of great benefit to the development of sample preparation methods and membrane science.

本项目以复杂体系中痕量有机物快速稳定微萃取为目的，针对结果重现性差、萃取时间长两个基本问题，提炼出高稳定萃取界面和快速分子传质两个关键科学问题；优选膜微萃取体系，开展以下研究：（1）设计、制备萃取新器件，缩短分子传质距离，提高膜有效萃取面积，加快分子传质；（2）选择修饰膜表面，调节膜孔直径和表面化学性质，抑制样品溶液对膜界面的物理扰动和化学污染，提高界面选择性和稳定性；（3）筛选离子对试剂，提高可电离有机物的电膜萃取效率；（4）以环境水体中挥发性酚类、蔬菜果汁中农药残留、植物激素赤霉素为验证对象，结合色谱-质谱分离鉴定手段，发展气相液膜微萃取、液液两相膜微萃取、液液液三相膜微萃取技术，推进复杂体系痕量有机物快速稳定样品前处理方法的发展。其中分子传质过程、器件设计、表面化学的研究结果，将为其它样品前处理方法、膜科学的发展提供重要科学借鉴。

项目针对影响微萃取选择性和萃取速率的关键因素：器件设计与表面化学修饰，选取典型复杂体系痕量有机物：植物激素（赤霉素、油菜素甾醇）、环境有机物（包括酚类、农药、多环芳烃、二元有机酸）、血液药物、多肽等，发展了多种微萃取器件：中空纤维膜液液液微萃取器（HF-LLLME）、电膜萃取（EME）、二维微固相萃取（2DμSPE）、多孔钛快速固相微萃取（ST-SPME）、活体固相微萃取（in-vivo SPME）、微型超声萃取（μSE）、微型加压溶剂萃取（μAPLE）等；发展了多种表面修饰方法：核壳电纺丝材料、丙酮活化聚酰亚胺电纺丝、氢氟酸腐蚀活化多孔钛、聚氯乙烯修饰中空纤维膜等。代表性工作有：.1、针对GAs的分析挑战，发展水渗透辅助HF-LLLME、EME方法。水渗透过程将萃取过程与后续浓缩过程合二为一，突破了HF-LLLME的理论平衡极限。考察了有机胺转运载体对EME选择性、聚氯乙烯涂层对无机离子电迁移的抑制作用。结合HPLC-MS/MS，成功测定了水稻、拟南芥等实际样品。.2、针对BRs的分析挑战，发展2DμSPE等方法，硼酸亲和与反相疏水正交萃取，结合柱上衍生，与HPLC-MS/MS在线联用，建立了痕量BRs的定量分析方法。另，研制了植物样品前处理自动装置，自2013年5月起，在北京植物所应用示范。.3、针对药物快速监测需求，发展in-vivo SPME方法，设计了微流控芯片器件，实现两分钟平衡血液药物固相微萃取样品制备，结合HPLC-MS/MS，实现活体动物长时间的药代监测。.4、针对极性SVOCs的固相微萃取-热解析进样分析需求，发展了聚酰亚胺纳米电纺丝膜萃取、聚酰亚胺吸附搅拌棒、多孔钛过滤等萃取器件、微型加压溶剂萃取器件、小型超声萃取器件，并用于实际水样、大气中痕量有机酚、有机氯、多环芳烃、农药中间体、有机酸等定量分析。.项目对微萃取器件、表面化学修饰开展了深入研究，大幅提高了微萃取方法的选择性、稳定性和萃取速度，有力推动复杂体系痕量有机物分析方法的发展。项目研究共发表SCI文章19篇，授权发明专利6项，申请发明专利4项。