Water-dispersible pH/thermo dual-responsive microporous polymeric microspheres as adsorbent for dispersive solid-phase extraction of fluoroquinolones from environmental water samples and food samples

Effective extraction and determination of 24 quinolones in water and egg samples using a novel magnetic covalent organic framework combined with UPLC-MS/MS

The excessive use of quinolones (QNs) has seriously threatened human health. In this study, a novel functionalized magnetic covalent organic framework Fe3O4@SiO2@Ah-COF was fabricated with biphenyl-3,3',5,5'-tetracarbaldehyde and hydrazine hydrate (85%) as monomers and was used as a magnetic solid-phase extraction (MSPE) absorbent for the determination of 24 QNs in water and egg samples through ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The extraction parameters of MSPE were optimized, including pH, adsorbent dosage, adsorption time, and eluent type. An effective and rapid detection method was then established, which showed good linearity (R2 ≥ 0.9990), low limits of detection (0.003-0.036 μg L-1) and low limits of quantitation (0.008-0.110 μg L-1) for QNs. The good recoveries of 24 QNs in water and egg samples were in the range of 70.3-106.1% and 70.4-119.7%, respectively, with relative standard deviations lower than 10% (n = 5). As a result, Fe3O4@SiO2@Ah-COF is a promising magnetic adsorbent, and the established method was successfully applied for the determination of 24 QNs in water and egg samples.

Preparation of amine-modified amphiphilic resins for the extraction of trace pharmaceuticals and personal care products in environmental waters

Herein, four amine-modified amphiphilic resins were synthesized and utilized as solid-phase extraction (SPE) materials to enrich pharmaceuticals and personal care products (PPCPs) from environmental water. The obtained materials (Strong anion-exchange amphiphilic materials, SAAMs; Weak anion-exchange amphiphilic materials, WAAMs) possessed large specific surface area (473-626 m²/g), high ion exchange capacity (0.89-1.97 mmol/g), and small contact angle (74.41-79.74°), indicating good hydrophilicity. The main factors affecting the efficiency of the extraction process were studied, including column volume, column flow rate, sample salinity and sample pH. Notably, the trend observed in absolute recovery was significantly correlated with the Zeta potential of the employed adsorbents. Furthermore, based on the obtained materials, a method of SPE coupled with ultra-performance liquid chromatography and tandem mass spectrometry (SPE/LC-MS/MS) was developed, and then utilized to determine PPCPs in the samples collected from the Yangtze River Delta. The Method detection limit (MDL) and Method quantification limit (MQL) ranged from 0.05 to 0.60 ng/L and 0.17 to 2.00 ng/L, respectively, with a relative standard deviation (RSD) below 6.3%, demonstrating good accuracy and sensitivity. As evidenced by comparison with previous literature, the developed method exhibited satisfactory performance, showing great potential for further commercial application in the extraction of trace PPCPs from environmental water samples.

Poly-(MMA-IL) filter paper: A new class of paper-based analytical device for thin-film microextraction of multi-class antibiotics in environmental water samples using LC-MS/MS analysis

A paper-based polymeric ionic liquid (p-Poly-(MMA-IL)) was successfully developed by grafting the polymeric ionic liquid on the surface of commercial filter paper (FP) by using the dipping method, presenting a new cost-effective film. The newly developed p-Poly-(MMA-IL) FP was then applied as a paper-based thin-film microextraction (p-TFME) analytical device to extract 14 compounds as representative of five groups of antibiotic drugs, which were sulfonamides, tetracyclines, fluoroquinolones, penicillin and macrolides in environmental water samples. Besides, p-Poly-(MMA-IL) FP, p-Poly-(MMA) FP, and unmodified filter paper were successfully characterised by FTIR, NMR, FESEM, TGA, and XRD techniques. They underwent significant parameters optimisation, which affected the extraction efficiency. Under optimal conditions, the proposed (p-Poly-(MMA-IL) FP-TFME) device method was evaluated and applied to analyse multi-class antibiotic drugs in environmental water samples by using a liquid chromatography-mass spectrometry (LC-MS). The validation method showed that a good linearity (0.1 μg L^-1 - 500 μg L^-1) was noted (R² > 0.993, n = 3). Detection and quantification limits were within 0.05 μg L^-1 - 4.52 μg L^-1 and 0.15 μg L^-1 - 13.6 μg L^-1, respectively. The relative standard deviation (RSD) values ranged at 1.4%-12.2% (intra-day, n = 15) and 4.4%-11.0% (inter-day, n = 10). The extraction recoveries of environmental water samples ranged from 79.1% to 126.8%, with an RSD of less than 15.4% (n = 3). The newly developed paper-based polymeric ionic liquid (p-Poly-(MMA-IL) FP) for analysis of multi-class antibiotic drugs under the p-TFME analytical device procedure was successfully achieved with limited sample volume and organic solvent, fast extraction, and feasible in daily analysis. The detection concentration and relative RSD of multi-class antibiotics determined in various environmental water samples by the proposed method (n = 5) were within 0.44 μg L^-1 - 54.41 μg L^-1 and 0.69%-15.56%, respectively. These results signified the potential of the p-Poly-(MMA-IL) FP-TFME device as an efficient, sensitive and environmentally friendly approach for analysing antibiotics.

Covalent Organic Framework/Polyacrylonitrile Electrospun Nanofiber for Dispersive Solid-Phase Extraction of Trace Quinolones in Food Samples

The extraction of quinolone antibiotics (QAs) is crucial for the environment and human health. In this work, polyacrylonitrile (PAN)/covalent organic framework TpPa–1 nanofiber was prepared by an electrospinning technique and used as an adsorbent for dispersive solid-phase extraction (dSPE) of five QAs in the honey and pork. The morphology and structure of the adsorbent were characterized, and the extraction and desorption conditions for the targeted analytes were optimized. Under the optimal conditions, a sensitive method was developed by using PAN/TpPa–1 nanofiber as an adsorbent coupled with high-performance liquid chromatography (HPLC) for five QAs detection. It offered good linearity in the ranges of 0.5–200 ng·mL⁻¹ for pefloxacin, enrofloxacin, and orbifloxacin, and of 1–200 ng·mL⁻¹ for norfloxacin and sarafloxacin with correlation coefficients above 0.9946. The limits of detection (S/N = 3) of five QAs ranged from 0.03 to 0.133 ng·mL⁻¹. The intra-day and inter-day relative standard deviations of the five QAs with the spiked concentration of 50 ng·mL⁻¹ were 2.8–4.0 and 3.0–8.8, respectively. The recoveries of five QAs in the honey and pork samples were 81.6–119.7%, which proved that the proposed method has great potential for the efficient extraction and determination of QAs in complex samples.

Use of hydroxypropyl β-cyclodextrin hybrid monolithic material as adsorbent for dispersive solid-phase extraction of fluoroquinolones from environmental water samples

In this study, the hydroxypropyl β-cyclodextrin hybrid monolithic material was fabricated and firstly applied as adsorbent for dispersive solid-phase extraction coupled with high-performance liquid chromatography to detect trace-level seven fluoroquinolones in water samples. The prepared hydroxypropyl β-cyclodextrin hybrid monolithic material was characterized by fourier transform infrared spectroscopy, scanning electron microscopy and adsorption experiments, which showed excellent specific adsorption to the target fluoroquinolones. Under the optimized conditions, the extraction methodology showed satisfactory precision with relative standard deviations between 2.6 and 5.6%, good linearity (R² ≥0.9990) and satisfactory recoveries (82.5∼91.8%). The limits of detection and limits of quantification of the method were in the range of 0.4∼1.2 ng mL^-1 and 1.4∼4.0 ng mL^-1 respectively, which confirmed the possibility of quantifying trace levels. Furthermore, the material could be reused at least five times. These results demonstrated that the hydroxypropyl β-cyclodextrin hybrid monolithic material was a promising adsorbent for fluoroquinolones, and the established method combined dispersive solid-phase extraction with high-performance liquid chromatography was suitable for the determination of fluoroquinolones in aqueous samples. This article is protected by copyright. All rights reserved.

A polymer-based dispersive solid phase extraction combined with deep eutectic solvent based-dispersive liquid-liquid microextraction for the determination of four hydroxylated polycyclic aromatic hydrocarbons from urine samples

A new and efficient extraction procedure was proposed and used for the simultaneous extraction of four hydroxylated metabolites polycyclic aromatic hydrocarbons from urine samples. The extraction procedure was started by dissolving an organic polymer into a water-miscible organic solvent (iso-propanol) and its injection into the sample solution. The sorbent was re-precipitated in all parts of the solution as tiny particles and the analytes were adsorbed onto the sorbent. After that, the sorbent was separated and the adsorbed analytes were eluted by choline chloride: dichloroacetic acid deep eutectic solvent. The elution solvent was mixed with choline chloride-3,3-dimethyl butyric acid deep eutectic solvent and the mixture was applied in dispersive liquid-liquid microextraction procedure for more concentration of the analytes. After optimization, the method validation was followed according to International Council Harmonization guidelines and the results showed that wide linear ranges (26-500 000 ng/L) and low limits of detection (3.6-7.2 ng/L) and quantification (11-26 ng/L) were obtained. Satisfactory enrichment factors (435-475) and extraction recoveries (87-95%), and acceptable relative standard deviations (equal or less than 8.6%) were obtained. Finally, the introduced method was successfully applied for determination of the analytes in urine samples obtained from tobacco smokers.

Determination of quinolones in environmental water and fish by magnetic metal organic frameworks based magnetic solid-phase extraction followed by high-performance liquid chromatography-tandem mass spectrometry

The widespread use of quinolones has become an increasing global public health threat. In this study, IRMOF-3 coated SiO₂/Fe₃O₄ were prepared via a facile room-temperature method. The prepared IRMOF-3 coated SiO₂/Fe₃O₄ was used as a sorbent for magnetic solid phase extraction, and then combined with high-performance liquid chromatography-tandem mass spectrometry for the determination of 10 quinolines. The extraction conditions of magnetic solid phase extraction were studied in detail, and the optimal conditions were established. Under the optimal experimental conditions, the limits of quantification of 10 quinolones were in the range of 0.005-0.01 μg L^-1, the relative standard deviations were 6.58-10.6% (n=7), the enrichment factors were 21.0-23.8 for water samples. The limits of quantification of 10 quinolones were in the range of 0.10-0.20 μg kg^-1, the relative standard deviations were 5.95-14.5% (n=7), the enrichment factors were 1.08-1.24 for fish samples. The proposed method was applied for the determination of 10 quinolones in river water, aquacultural water and a fish sample, and enrofloxacin and ciprofloxacin were found in the fish sample.

Application of stimuli-responsive materials for extraction purposes

Stimuli-responsive materials, frequently designated as "smart/intelligent materials", can modify their structure or properties by either a biological, physical, or chemical stimulus which, if properly controlled, could be used for specific applications. Such materials have been studied and exploited in several fields, like electronics, photonics, controlled drugs administration, imaging and medical diagnosis, among others, as well as in Analytical Chemistry where they have been used as chromatographic stationary phases, as part of sensors and for extraction purposes. This review article pretends to provide an overview of the most recent applications of these materials (mostly polymeric materials) in sample preparation for extraction purposes, as well as to provide a general vision of the current state-of-the-art of this field, their potential use and future applications.

Determination of fluoroquinolones in foods using ionic liquid modified Fe3O4/MWCNTs as the adsorbent for magnetic solid phase extraction coupled with HPLC

In this work, a simple and sensitive method based on Fe₃O₄/multi-walled carbon nanotubes/ionic liquid (Fe₃O₄/MWCNTs/IL) as the adsorbent for magnetic solid phase extraction coupled with high performance liquid chromatography was developed for the determination of trace fluoroquinolones in foods. After a simple one-pot solvothermal synthesis, Fe₃O₄/MWCNTs were further modified with an amine-terminated ionic liquid to enhance their dispersibility and extraction capacity. The morphology, structure and magnetic properties of the composite adsorbent were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction spectrometry and vibrating-sample magnetometry. Under the optimized extraction and detection conditions, the studied fluoroquinolones were enriched effectively and separated well and their UV signals were linear to their concentrations in the range of 4-1000 ng mL^-1, with correlation coefficients ranging from 0.9958 to 0.9990. The enrichment factors were 29.1-43.9 fold and the limits of detection were 0.33-0.78 ng mL^-1. The spiked recoveries were 85.4-105.9% for milk and 85.2-103.7% for pork samples, with relative standard deviations of 0.8-5.7%. The developed method provided a fast, sensitive and reliable determination platform for fluoroquinolones in complex real samples.

The preparation of a core–shell stationary phase by the in situ polymerization of a hydrophilic polymer on the surface of silica and its chromatographic performance

A method for the in situ polymerization of polymers on a silica surface was developed.