基于六氟异丙醇-长链烷酸/烷醇体系的新型双模式液相微萃取技术及其药物分析应用

Analytical scientists in pharmaceutical analysis are being plagued by a major scientific problem: to determine trace target analytes with diverse properties (their contents are even lower than the detection limits of advanced analytical instruments) from complex sample matrices. To solve this problem, this project will develop several novel liquid-phase microextraction systems based on the combination of dispersive liquid-liquid microextraction (DLLME) and supramolecular solvent microextraction (SMSME) technique, using hexafluoroisopropanol (HFIP, a solvent with excellent properties of high density and strong hydrogen bond donor capacity etc.) as dispersing agent, self-assembly agent as well as density-regulating agent, and long chain alkyl acids/alcohols with low toxicity and low density as extraction agents. These new systems will be used for the extraction of various drugs in a wide of polarity, proteins and polysaccharides to investigate their extraction capabilities for organic compounds with low molecular weight (most of them are drugs) and their restricted access properties against macromolecules. Moreover, these new systems will be applied to extract pharmaceutical substances or special impurities from different complex matrices such as injections, tablets, urine, plasma, animal tissue and environmental water. Importantly, several key scientific problems, including collection difficulty of low density extraction solvents at low volume, poor extraction efficiency of polar analytes, and uneasiness of one-step direct extraction of the analytes from complex samples, will be solved after the accomplishment of this project. The additional purpose of this project is to cultivate professional talents in pharmaceutical analysis with innovative thinking.

在药物成分分析、药物活性分析乃至环境和食品药物残留分析中，药物分析学家正面临着不同基质样品中目标分析物含量超低微（甚至低于现有分析仪器检出限）、结构性质多样，以及样品基质复杂、严重干扰分析结果可靠性的科学问题。对此，本项目拟基于分散液液微萃取(DLLME)、超分子溶剂微萃取(SMSME)技术，选择低毒性低密度长链烷酸/烷醇两亲物质为萃取剂，以具有高密度、强氢键给体能力等优越特性的六氟异丙醇(HFIP)为分散剂、自组装剂及密度调节剂，构建DLLME-SMSME双模式新型液相微萃取体系，研究新体系对不同性质药物的萃取特性和HFIP-长链烷酸/烷醇超分子溶剂对蛋白质、多糖等大分子的限进特性，并将新体系应用于不同液体、固体样品中不同性质药物的萃取。重点解决微量低密度萃取相难收集、极性药物萃取不理想及复杂生物基质等样品中药物一步直接萃取难实现的关键科学问题。培养具有创新性思维的高级药物分析专业人才。

微量低密度萃取相难收集、极性物质萃取不理想以及复杂生物基质样品中目标物一步直接萃取难实现，是传统液相微萃取方法中存在的主要科学问题。本项目选择低毒性、低密度的长链烷酸（C8-C12）/烷醇（C6-C12）为两亲物质，创造性地巧妙利用六氟异丙醇（HFIP）的高密度、强氢键给体能力、强溶解能力等优越特性，将 HFIP 作为两亲物质的溶剂、自组装诱导剂和密度调节剂，构建 HFIP介导的长链烷酸/烷醇新型超分子溶剂萃取体系。将超分子溶剂萃取体系与分散液液微萃取、中空纤维液相微萃取等液相微萃取技术联合，建立新型双模式液相微萃取方法，应用于不同基质样品（水样，注射液，尿样，血样，固体食品）中不同极性痕量/微量物质（药物，有机污染物和重金属离子）的萃取富集。. 结果表明：少量HFIP（<10%或5%或3%，v/v）即可介导长链烷酸/烷醇在水溶液中形成高密度的超分子溶剂，并且这些超分子溶剂的形成区域均较宽，尤其是HFIP-烷醇超分子溶剂的形成不受体系pH和一定离子强度的影响，这为它们的萃取应用提供了切实可行性。HFIP-烷酸/烷醇超分子溶剂均由反向胶束聚集体组成，聚集体内腔亲水、外部疏水，聚集体的内腔尺寸随着体系中HFIP加入量的增加而增大。因此，HFIP-烷酸/烷醇超分子溶剂可以通过物理作用（尺寸排阻大分子）和化学作用（HFIP和烷酸/烷醇使大分子沉淀和絮凝）两方面表现出显著的限进特性，其对蛋白质（牛血清白蛋白，卵清白蛋白，谷蛋白，溶菌酶）、多糖（淀粉、壳聚糖）和腐植酸的排阻率均大于80%。HFIP-烷酸/烷醇之间的氢键和疏水作用以及HFIP-H2O之间的氢键作用是HFIP-烷酸/烷醇超分子溶剂形成的主要驱动力。而反向胶束聚集体的亲水内腔大小以及目标物与超分子溶剂之间的相互作用（氢键和疏水）共同决定HFIP-烷酸/烷醇超分子溶剂对目标物的萃取效率。所建立的两种新型双模式液相微萃取方法（HFIP-烷酸/烷醇超分子溶剂萃取-分散液液微萃取、HFIP-烷酸/烷醇超分子溶剂萃取-中空纤维液相微萃取）对不同极性（强极性-非极性）的目标物均显示出较好的萃取富集效果；对于液体样品，萃取后所形成的微量超分子溶剂萃取相因密度高位于下相，易于收集；对于复杂基质样品（尿样、血样、固体食品），目标物的萃取富集和蛋白质等大分子干扰组分的排除可以一步实现，简单快速，基质效应小（70%-132%）。