Kataoka Hiroyuki, Ishizaki Atsushi, Saito Keita, Ehara Kentaro
School of Pharmacy, Shujitsu University, Nishigawara, Okayama 703-8516, Japan.
Molecules. 2024 Sep 20;29(18):4472. doi: 10.3390/molecules29184472.
Despite advancements in the sensitivity and performance of analytical instruments, sample preparation remains a bottleneck in the analytical process. Currently, solid-phase extraction is more widely used than traditional organic solvent extraction due to its ease of use and lower solvent requirements. Moreover, various microextraction techniques such as micro solid-phase extraction, dispersive micro solid-phase extraction, solid-phase microextraction, stir bar sorptive extraction, liquid-phase microextraction, and magnetic bead extraction have been developed to minimize sample size, reduce solvent usage, and enable automation. Among these, in-tube solid-phase microextraction (IT-SPME) using capillaries as extraction devices has gained attention as an advanced "green extraction technique" that combines miniaturization, on-line automation, and reduced solvent consumption. Capillary tubes in IT-SPME are categorized into configurations: inner-wall-coated, particle-packed, fiber-packed, and rod monolith, operating either in a draw/eject system or a flow-through system. Additionally, the developments of novel adsorbents such as monoliths, ionic liquids, restricted-access materials, molecularly imprinted polymers (MIPs), graphene, carbon nanotubes, inorganic nanoparticles, and organometallic frameworks have improved extraction efficiency and selectivity. MIPs, in particular, are stable, custom-made polymers with molecular recognition capabilities formed during synthesis, making them exceptional "smart adsorbents" for selective sample preparation. The MIP fabrication process involves three main stages: pre-arrangement for recognition capability, polymerization, and template removal. After forming the template-monomer complex, polymerization creates a polymer network where the template molecules are anchored, and the final step involves removing the template to produce an MIP with cavities complementary to the template molecules. This review is the first paper to focus on advanced MIP-based IT-SPME, which integrates the selectivity of MIPs into efficient IT-SPME, and summarizes its recent developments and applications.
尽管分析仪器的灵敏度和性能有所提高，但样品前处理仍然是分析过程中的一个瓶颈。目前，固相萃取因其易于使用和较低的溶剂需求，比传统的有机溶剂萃取应用更为广泛。此外，还开发了各种微萃取技术，如微固相萃取、分散微固相萃取、固相微萃取、搅拌棒吸附萃取、液相微萃取和磁珠萃取，以最小化样品量、减少溶剂使用并实现自动化。其中，以毛细管作为萃取装置的管内固相微萃取（IT-SPME）作为一种先进的“绿色萃取技术”受到关注，它结合了小型化、在线自动化和减少溶剂消耗的特点。IT-SPME中的毛细管分为以下几种构型：内壁涂层型、颗粒填充型、纤维填充型和棒状整体型，可在抽吸/排出系统或流通系统中运行。此外，整体柱、离子液体、受限进样材料、分子印迹聚合物（MIP）、石墨烯、碳纳米管、无机纳米颗粒和金属有机框架等新型吸附剂的开发提高了萃取效率和选择性。特别是MIP，是在合成过程中形成的具有分子识别能力的稳定的定制聚合物，使其成为用于选择性样品前处理的特殊“智能吸附剂”。MIP的制备过程包括三个主要阶段：识别能力的预安排、聚合和模板去除。形成模板 - 单体复合物后，聚合产生聚合物网络，模板分子固定在其中，最后一步是去除模板以产生具有与模板分子互补空腔的MIP。本综述是第一篇专注于基于MIP的先进IT-SPME的论文，该技术将MIP的选择性整合到高效的IT-SPME中，并总结了其最新进展和应用。
