Laboratorio de Materiales para Análisis Químico (MAT4LL), Departamento de Química, Unidad Departamental de Química Analítica, Universidad de La Laguna (ULL), 38206, San Cristóbal de La Laguna, Spain; Unidad de Investigación de Bioanalítica y Medio Ambiente, Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias (IUETSP), ULL, 38206, San Cristóbal de La Laguna, Spain.
Laboratorio de Materiales para Análisis Químico (MAT4LL), Departamento de Química, Unidad Departamental de Química Analítica, Universidad de La Laguna (ULL), 38206, San Cristóbal de La Laguna, Spain; Unidad de Investigación de Bioanalítica y Medio Ambiente, Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias (IUETSP), ULL, 38206, San Cristóbal de La Laguna, Spain; CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193, Aveiro, Portugal.
Anal Chim Acta. 2024 Nov 1;1328:343187. doi: 10.1016/j.aca.2024.343187. Epub 2024 Aug 30.
Magnetic ionic liquids (MILs) have been explored in dispersive liquid-liquid microextraction (DLLME). Their usage allows to substitute centrifugation and/or filtration steps by a quick magnetic separation. Besides, effervescence-assisted DLLME is one of the most known options to improve the dispersion of the extractant in the sample, while allowing to avoid the consumption of external energy during dispersion. Despite these interesting features, only one study incorporates MILs containing the tetrachloroferrate anion in effervescence tablets. These MILs are highly viscous and liquid at room temperature, thus compromising the stability of the tablets when used as extraction microdevices in effervescence-assisted DLLME, and only allowing their use in the conventional MIL-DLLME mode.
A new class of effervescence tablets containing a Ni(II)-based MIL, that is solid at room temperature, is here proposed. This type of tablets permits their use, for first time, in the in situ DLLME mode, occurring through the transformation of a water-soluble MIL into a water-insoluble MIL microdroplet. This way, the tablet formulation included: the MIL, the metathesis reagent lithium bis[(trifluoromethyl)sulfonyl]imide, NaHPO and KCO as effervescence precursors salts, and NaSO as salting-out and desiccating agent. The method is combined with high-performance liquid-chromatography and both fluorescence and ultraviolet detection, for the determination of monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and benzophenones (BPs), as biomarkers in urine. The method simply involved the addition of the effervescence tablet to the sample, thus taken place simultaneously the effervescence process and the metathesis reaction, without requiring any external energy consumption. The method presented limits of detection down to 10 ng L for OH-PAHs and to 0.60 μg L for BPs, inter-day relative standard deviations lower than 17 %, and average relative recoveries of 94 % in urine. The determined OH-PAHs contents in urine were between 0.40 and 16 μg L, and between 17.8 and 334 μg L for BPs.
We have developed the first MIL-based effervescence tablets that are completely solid, thus improving the stability and robustness of these microdevices with respect to previously reported tablets involving MILs, while permitting to perform into the in situ DLLME mode (thus gaining in extraction efficiency). This approach including the MIL-based effervescence tablets constitutes an alternative on-site platform for the analysis of urine, as satisfactory precision, accuracy, and sensitivity are achieved despite not involving any external energy input within the analytical sample preparation setup. This method also constitutes the first application of MIL-based effervescence tablets for bioanalysis.
磁性离子液体 (MIL) 已在分散液-液微萃取 (DLLME) 中进行了探索。它们的使用可以通过快速磁分离代替离心和/或过滤步骤。此外，鼓泡辅助 DLLME 是提高萃取剂在样品中分散度的最知名选项之一，同时允许在分散过程中避免消耗外部能量。尽管具有这些有趣的特点，但只有一项研究将含有四氯铁酸盐阴离子的 MIL 纳入鼓泡片剂中。这些 MIL 在室温下具有高粘性和液态，因此当用作鼓泡辅助 DLLME 中的萃取微器件时会影响片剂的稳定性，并且仅允许它们在传统的 MIL-DLLME 模式下使用。
这里提出了一种新的鼓泡片剂，其中包含一种室温下为固态的基于 Ni(II)的 MIL。这种类型的片剂允许首次在原位 DLLME 模式下使用，该模式通过将水溶性 MIL 转化为不溶性 MIL 微滴来实现。这样，片剂配方包括：MIL、反离子试剂双（三氟甲基磺酰）亚胺锂、NaHPO 和 KCO 作为鼓泡前体盐，以及 NaSO 作为盐析和干燥剂。该方法结合高效液相色谱法和荧光法和紫外检测法，用于测定尿液中的单羟基多环芳烃 (OH-PAHs) 和二苯甲酮 (BP)，作为生物标志物。该方法只需将鼓泡片剂添加到样品中，同时发生鼓泡过程和复分解反应，而无需消耗任何外部能量。该方法的检出限低至 10ng L 用于 OH-PAHs 和 0.60μg L 用于 BPs，日内相对标准偏差低于 17%，尿液中的平均相对回收率为 94%。在尿液中测定的 OH-PAHs 含量在 0.40 和 16μg L 之间，BP 为 17.8 和 334μg L 之间。
我们开发了第一批完全固态的基于 MIL 的鼓泡片剂，这提高了这些微器件的稳定性和坚固性，与之前涉及 MIL 的片剂相比，同时允许在原位 DLLME 模式下进行（从而提高了萃取效率）。这种方法包括基于 MIL 的鼓泡片剂，构成了用于尿液分析的现场平台的替代方案，尽管在分析样品制备装置中不涉及任何外部能量输入，但仍可实现令人满意的精密度、准确度和灵敏度。该方法也是基于 MIL 的鼓泡片剂在生物分析中的首次应用。
