Evolution and current advances in sorbent-based microextraction configurations.

This review overviews the main developments achieved in analytical sample preparation regarding the use of solid sorbents as extractants in different sorbent-based miniaturized, micro-scale and microextraction methods. Two main groups are proposed for the classification of the current approaches, based on their operational mode: micro-solid-phase extraction (µ-SPE) and solid-phase microextraction (SPME), while describing their respective main sub-modes: static- and dispersive-µ-SPE, and SPME with fibers and in tube SPME. Furthermore, other important sorbent-based microscale approaches (e.

Mixed Functionalization of Organic Ligands in UiO-66: A Tool to Design Metal-Organic Frameworks for Tailored Microextraction.

The mixed-ligand strategy was selected as an approach to tailor a metal-organic framework (MOF) with microextraction purposes. The strategy led to the synthesis of up to twelve UiO-66-based MOFs with different amounts of functionalized terephthalate ligands (H-bdc), including nitro (-NO) and amino (-NH) groups (NO-bdc and NH-bdc, respectively). Increases of 25% in ligands were used in each case, and different pore environments were thus obtained in the resulting crystals.

Influence of Ligand Functionalization of UiO-66-Based Metal-Organic Frameworks When Used as Sorbents in Dispersive Solid-Phase Analytical Microextraction for Different Aqueous Organic Pollutants.

Four metal-organic frameworks (MOFs), specifically UiO-66, UiO-66-NH₂, UiO-66-NO₂, and MIL-53(Al), were synthesized, characterized, and used as sorbents in a dispersive micro-solid phase extraction (D-µSPE) method for the determination of nine pollutants of different nature, including drugs, phenols, polycyclic aromatic hydrocarbons, and personal care products in environmental waters. The D-µSPE method, using these MOFs as sorbents and in combination with high-performance liquid chromatography (HPLC) and diode-array detection (DAD), was optimized. The optimization study pointed out to UiO-66-NO₂ as the best MOF to use in the multi-component determination.