Departamento de Química Analítica, Instituto Universitario de Investigación en Química Fina y Nanoquímica IUNAN, Universidad de Córdoba, Campus de Rabanales, Edificio Anexo Marie Curie, 14071, Córdoba, Spain.
Anal Bioanal Chem. 2020 Sep;412(24):6341-6349. doi: 10.1007/s00216-020-02570-3. Epub 2020 Mar 16.
A lab-made stirring extraction unit based on a selective monolithic solid was developed. The monolith was formed by interconnected carbon nanotubes which were covered by a thin polymeric layer, where specific cavities were generated to provide selective recognition sites in the material. To reach this goal, a water-in-oil (W/O) medium internal phase emulsion (40/60 w/w%), was prepared and photopolymerized. The polymerization reaction took place in the organic or external phase containing the carbon nanotubes, polymeric monomers (cross-linker and functional monomer) and a molecule template. Therefore, it was possible to coat the nanotubes with a layer of molecularly imprinted polymer (MIP) with the target analyte while forming a monolithic and macroscopic structure. The developed selective monolithic stirring extraction units were applied for the determination of secbumeton and structurally related compounds (triazine herbicides) in peppermint mint and tea samples. Their adsorption capacity and selectivity were also compared with a non-imprinted polymer (NIP). Finally, the performance of the method was evaluated for quantitative analysis, achieving limits of detection (LODs) between 0.4 and 2.5 μg·L. The intra- and inter-day precision of the method was also evaluated as relative standard deviation, observing values which ranged from 3% to 9% and 9% to 15%, respectively. Graphical Abstract.
基于选择性整体材料开发了实验室制造的搅拌提取单元。整体由相互连接的碳纳米管组成，这些碳纳米管被一层薄的聚合物层覆盖，其中生成了特定的空腔，为材料中提供了选择性识别位点。为了实现这一目标，制备了水包油（W/O）内部相乳液（40/60 w/w%）并进行光聚合。聚合反应发生在含有碳纳米管、聚合单体（交联剂和功能单体）和分子模板的有机或外部相中。因此，有可能在形成整体和宏观结构的同时，用目标分析物涂覆纳米管的分子印迹聚合物（MIP）层。开发的选择性整体搅拌提取单元用于薄荷薄荷和茶样品中 secbumeton 和结构相关化合物（三嗪除草剂）的测定。还比较了它们的吸附能力和选择性与非印迹聚合物（NIP）。最后，对该方法的性能进行了定量分析评估，检测限（LOD）在 0.4 到 2.5 μg·L 之间。该方法的日内和日间精密度也作为相对标准偏差进行了评估，观察值分别在 3%到 9%和 9%到 15%之间。
