A banana peel/silicon glue coated stir bar for extraction of aspirin, diclofenac, ibuprofen and mefenamic acid followed by high performance liquid chromatography-UV detection

Development of novel bis(2-ethylhexyl) phosphate-based magnetic deep eutectic solvent for the highly efficient enrichment of non-steroidal anti-inflammatory drugs from environmental water and milk samples

In this study, a new type of magnetic deep eutectic solvent (MDES) based on a novel non-ionic hydrogen bond acceptor of bis(2-ethylhexyl) phosphate, as well as heptanol and CoCl2, was synthesized with low viscosity, certain magnetism, and hydrophobicity. Subsequently, a vortex-assisted dispersive liquid-liquid microextraction method based on the MDES was developed to analyze five non-steroidal anti-inflammatory drugs (NSAIDs) followed by HPLC-UV. Due to the unique properties of MDES, it can spontaneously float onto surface of the sample solution and gather together after extraction, thereby omitting the time-consuming centrifugation process. Under the optimal extraction conditions, this method showed good linearity, low limit of detection, high precision, and high enrichment factor. Satisfactory spiked recoveries in the range of 85.2 %-115.2 % were obtained from two environmental water and two milk samples. Taken together, this simple, convenient, fast, safe, highly efficient, and reliable method can be applied to the analysis of NSAIDs from aqueous samples.

Hierarchically porous covalent organic framework doped monolithic column for on-line chip-based array microextraction of nonsteroidal anti-inflammatory drugs in microlitre volume of blood

BACKGROUND

Traditional blood drug analysis involves large blood consumption and complicated operations and a further reduction in blood consumption is urgently needed. Chip-based monolithic column microextraction is a good strategy for the pretreatment of small-volume samples, and new monolithic materials is the critical factor. Covalent organic frameworks (COFs) are good adsorbents due to large specific surface area and rich conjugated structure. However, the poor dispersion ability of COFs in prepolymer solution severely hinders the preparation of COFs doped monolithic columns. Herein, high internal phase emulsion with viscoelastic properties was adopted to fixed COF particles.

RESULTS

The COFs doped monolith exhibited a hierarchical porous structure and improved extraction efficiency for interest nonsteroidal anti-inflammatory drugs (NSAIDs) (68.2-77.3 vs 28.4-57.7 %). A chip-based monolithic column array was fabricated and coupled with high-performance liquid chromatography (HPLC)-ultraviolet detection for online determination of five NSAIDs in microlitre volume of blood. The throughput of the developed method was approximately 3 h-1, mainly determined by the separation time (22 min) of target NSAIDs in HPLC. Under the optimal conditions (200 μL sample solution, pH = 3 at a sampling folw rate of 5 μL min-1 and 20 μL of acetonitrile/10 mmol L-1 NaOH (9/1, v/v) as desorbent), the detection limit of 4.39-15.5 μg L-1 was obtained for target NSAIDs in blood with RSD of 7.8-15.3 % and R2 of 0.9943-0.9978. The method was applied to the analysis of human serum (20 μL) and dried blood spot, with recovery of 82.0-118 % for target NSAIDs.

SIGNIFICANCE

A method was proposed for the preparation of COF doped monolithic columns by emulsion polymerization, avoiding uneven distribution of COFs caused by their easy sedimentation in traditional free radical preparation of monolithic columns. Then a chip-based monolithic column array coupled with on-line HPLC-UV detection was established for the quantification of five NSAIDs in microlitre-blood samples. The developed method merits high automation and good anti-interference ability, with extremely low sample/reagents consumption.

Natural deep eutectic solvent-functionalized mesoporous graphitic carbon nitride-reinforced electrospun nanofiber: a promising sorbent in miniaturized on-chip thin film micro-solid-phase extraction prior to liquid chromatography-tandem mass spectrometry for measuring NSAIDs in saliva

To meet the needs of developing efficient extractive materials alongside the evolution of miniaturized sorbent-based sample preparation techniques, a mesoporous structure of g-C3N4 doped with sulfur as a heteroatom was achieved utilizing a bubble template approach while avoiding the severe conditions of other methods. In an effort to increase the number of adsorption sites, the resultant exfoliated structure was then modified with thymol-coumarin NADES as a natural sorbent modifier, followed by introduction into a nylon 6 polymer via an electrospinning process. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) surface area analysis validated S-doped g-C3N4 and composite production. The prepared electrospun fiber nanocomposite, entailing satisfactory processability, was then successfully utilized as a sorbent in on-chip thin film micro-solid-phase extraction of non-steroidal anti-inflammatory drugs (NSAIDs) from saliva samples prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Utilizing a chip device, a thin film μ-SPE coupled with LC-MS/MS analysis yielded promising outcomes with reduced sample solution and organic solvents while extending lifetime of a thin film sorbent. The DES-modified S-doped g-C3N4 amount in electrospun was optimized, along with adsorption and desorption variables. Under optimal conditions, selected NSAIDs were found to have a linear range of 0.05-100.0 ng mL-1 with an R2 ≥ 0.997. The detection limits were ranged between 0.02 and 0.2 ng mL-1. The intra-day and inter-day precisions obtained were less than 6.0%. Relative recoveries were between 93.3 and 111.4%.

Core-shell MOF@COFs used as an adsorbent and matrix for the detection of nonsteroidal anti-inflammatory drugs by MALDI-TOF MS

A core-shell material (UiO@TapbTp) has been developed as an adsorbent and matrix to detect nonsteroidal anti-inflammatory drugs (NSAIDS) by matrix laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in complex samples. The hybrid material is prepared by growing covalent organic framework (COF, TapbTp) layers in situ on an amino-modified metal-organic framework (MOF, UiO-66-NH₂). The combination of the MOF and COF overcomes their individual shortcomings and integrates both of their advantages. Compared with the bare COF and MOF, the core-shell composite exhibits improved enrichment ability and matrix performance. With the help of pre-enrichment under optimized conditions, the limits of detection (LODs) for ketoprofen, naproxen, and aspirin are reduced by nearly 1000 times, with values of 0.001 mg L^-1, 0.010 mg L^-1, and 0.001 mg L^-1, respectively, and the relative standard deviations (RSDs) are all below 12.35%. The good recoveries (84.8-118%) in (spiked) saliva and environmental water sample further verify the applicability of the method in complex samples.