Magnetic Solid Phase Extraction Based on Nanostructured Magnetic Porous Porphyrin Organic Polymer for Simultaneous Extraction and Preconcentration of Neonicotinoid Insecticides From Surface Water

Enhanced Tetracycline Adsorption Using KOH-Modified Biochar Derived from Waste Activated Sludge in Aqueous Solutions

Antibiotic pollution poses a serious environmental concern worldwide, posing risks to ecosystems and human well-being. Transforming waste activated sludge into adsorbents for antibiotic removal aligns with the concept of utilizing waste to treat waste. However, the adsorption efficiency of these adsorbents is currently limited. This study identified KOH modification as the most effective method for enhancing tetracycline (TC) adsorption by sludge biochar through a comparative analysis of acid, alkali, and oxidant modifications. The adsorption characteristics of TC upon unmodified sludge biochar (BC) as well as KOH-modified sludge biochar (BC-KOH) were investigated in terms of equilibrium, kinetics, and thermodynamics. BC-KOH exhibited higher porosity, greater specific surface area, and increased abundance of oxygen-based functional groups compared to BC. The TC adsorption on BC-KOH conformed the Elovich and Langmuir models, with a maximum adsorption capacity of 243.3 mg/g at 298 K. The adsorption mechanisms included ion exchange, hydrogen bonding, pore filling, and electrostatic adsorption, as well as π-π interactions. Interference with TC adsorption on BC-KOH was observed with HCO3-, PO43-, Ca2+, and Mg2+, whereas Cl-, NO3-, and SO42- ions exhibited minimal impact on the adsorption process. Following three cycles of utilization, there was a slight 5.94% reduction in the equilibrium adsorption capacity, yet the adsorption capacity remained 4.5 times greater than that of unmodified sludge BC, underscoring its significant potential for practical applications. This research provided new insights to the production and application of sludge biochar for treating antibiotic-contaminated wastewater.

Reviewing neonicotinoid detection with electroanalytical methods

Neonicotinoids, as the fastest-growing class of insecticides, currently account for over 25% of the global pesticide market. Their effectiveness in controlling a wide range of pests that pose a threat to croplands, home yards/gardens, and golf course greens cannot be denied. However, the extensive use of neonicotinoids has resulted in significant declines in nontarget organisms such as pollinators, insects, and birds. Furthermore, the potential chronic, sublethal effects of these compounds on human health remain largely unknown. To address these pressing issues, it is crucial to explore and understand the capabilities of electrochemical sensors in detecting neonicotinoid residues. Surprisingly, despite the increasing importance of this topic, no comprehensive review article currently exists in the literature. Therefore, our proposed review aims to bridge this gap by providing a thorough analysis of the use of electrochemical methods for neonicotinoid determination. In this review article, we will delve into various aspects of electrochemical analysis, including the influence of electrode materials, employed techniques, and the different types of electrode mechanisms utilized. By synthesizing and analysing the existing research in this field, our review will offer valuable insights and guidance to researchers, scientists, and policymakers alike.

Fabrication of Nitrogen Based Magnetic Conjugated Microporous Polymer for Efficient Extraction of Neonicotinoids in Water Samples

Facile and sensitive methods for detecting neonicotinoids (NEOs) in aquatic environments are crucial because they are found in extremely low concentrations in complex matrices. Herein, nitrogen-based magnetic conjugated microporous polymers (Fe3O4@N-CMP) with quaternary ammonium groups were synthesized for efficient magnetic solid-phase extraction (MSPE) of NEOs from tap water, rainwater, and lake water. Fe3O4@N-CMP possessed a suitable specific surface area, extended π-conjugated system, and numerous cationic groups. These properties endow Fe3O4@N-CMP with superior extraction efficiency toward NEOs. The excellent adsorption capacity of Fe3O4@N-CMP toward NEOs was attributed to its π-π stacking, Lewis acid-base, and electrostatic interactions. The proposed MSPE-HPLC-DAD approach based on Fe3O4@N-CMP exhibited a wide linear range (0.1-200 µg/L), low detection limits (0.3-0.5 µg/L), satisfactory precision, and acceptable reproducibility under optimal conditions. In addition, the established method was effectively utilized for the analysis of NEOs in tap water, rainwater, and lake water. Excellent recoveries of NEOs at three spiked levels were in the range of 70.4 to 122.7%, with RSDs less than 10%. This study provides a reliable pretreatment method for monitoring NEOs in environmental water samples.

Novel ferrofluid based on water-based deep eutectic solvents: application in dispersive liquid-liquid microextraction of naphthalene-derived plant growth regulators in edible oil

A new ferrofluid extractant (Fe3O4 @SiO2-WDES) was ingeniously prepared by coating magnetic Fe3O4 @SiO2 microspheres with water-based deep eutectic solvent (WDES) and used for dispersive liquid-liquid microextraction (DLLME) and HPLC determination of naphthalene-derived plant growth regulators (PGRs, i.e., 1-naphthylacetic acid, 2-naphthylacetic acid, 1-naphthoxy acetic acid, 2-naphthyloxyacetic acid and 1-naphthylacetamide) in edible oil. Herein, mass transfer of the analytes in DLLME was significantly enhanced via increasing the contact surface by employing the microspheres as the supporter and dispersant of WDES, and phase separation can be efficiently achieved using an external magnet rather than centrifugation in traditional DLLME. Response surface methodology (RSM) based on Box-Behnken design (BBD) was employed for the optimization of core experimental conditions, and Analytical Eco-Scale and Analytical GREEnness Metric Approaches were adopted to evaluate the degree of greenness of the procedure. Under the optimal conditions, satisfactory performances of linearity ranged from 5 to 100 μg/L (R2 ≥ 0.9982), limit of detection (0.58-0.91 μg/L), limit of quantitation (1.9-3.0 μg/L), precision (RSDs ≤ 5.5%), recovery (81.3%-108.1%) and negligible matrix effect were achieved, which introduced a promising alternative route for the determination of naphthalene-derived plant growth regulators in edible oil.

A chitin-based magnetic hyper-cross-linked polymer for highly efficient enrichment of neonicotinoids in lemon juice and tomatoes

A chitin-based magnetic hyper-cross-linked polymer (labeled as Ch-MHCP) has been successfully synthesized and utilized for highly-effective solid-phase extraction of neonicotinoid insecticides (NEOs). The extraction capability of Ch-MHCP for four common NEOs is higher than that of four commercial sorbents including octadecyl-silane C18, oasis hydrophilic/lipophilic balanced sorbent, oasis mixed anion sorbent and poly-phenylacetic mixed anion sorbent. The large number of hydroxyl and amide groups as well as benzene rings in Ch-MHCP allow the H-bond and π-π* interaction to be the principal adsorption mechanism of Ch-MHCP for NEOs. Besides, polar interaction was also involved in the adsorption process. In combination of Ch-MHCP based extraction technique with high-performance liquid chromatography, a novel analytical method for sensitive detection of NEOs in lemon juice and tomatoes has been established. At optimal conditions, wide linear ranges were obtained to be 0.20-100 ng mL-1 for lemon juice and 0.80-1000 ng g-1 for tomatoes. The detection limits were 0.06-0.12 ng mL-1 for lemon juice and 0.24-0.60 ng g-1 for tomatoes. This work not only provides a powerful tool for simultaneously detecting four NEOs in lemon juice and tomatoes, but also offers a new insight into the preparation of bio-based magnetic sorbents for adsorption/removal of pollutants.

Detection of neonicotinoids in agricultural products using magnetic molecularly imprinted polymers-surface enhanced Raman spectroscopy

In this paper, magnetic molecularly imprinted polymers-surface-enhanced Raman spectroscopy (MMIPs-SERS) for rapidly analyzing acetamiprid and thiacloprid in agricultural products has been firstly developed. The magnetic imprinted polymers were obtained by polymerizing the imprinted layers on the surface of magnetic nanoparticles. The polymers were detailed characterized by using series of analytical techniques, and their adsorption and recognition performance were validated by adsorption tests. The results showed that the magnetic molecularly imprinted polymers possessed typically core-shell structure and exhibited class-specific recognition, fast adsorption saturation (only 1 min), and good magnetic separation performance towards targets. The adsorption and desorption conditions for MMIPs-SERS detection system were carefully investigated. Under optimum conditions, the good linear detection range of 1∼20 μg/g with LODs of 23.7-68.8 ng/g for acetamiprid and thiacloprid in peach and pear samples was obtained. Through the reusable and spiked experiments, the developed MMIPs-SERS method based on Au NPs as enhanced substrate was validated to be highly sensitive, accurate, efficient and applicable in analyzing neonicotinoids from pear and peach samples. This study provided a rapid and simple detection method for neonicotinoids with effective separation and detection properties based on the synergistic effect of imprinted polymers and SERS. More importantly, this developed method have good application potential in rapid analyzing field for neonicotinoids due to the amazing rapid adsorption time for extracting targets from complex food matrix (only 1 min).

Porphyrin/phthalocyanine-based porous organic polymers for pollutant removal and detection: Synthesis, mechanisms, and challenges

The growing global concern about environmental threats due to environmental pollution requires the development of environmentally friendly and efficient removal/detection materials and methods. Porphyrin/phthalocyanine (Por/Pc) based porous organic polymers (POPs) as a newly emerging porous material are prepared through polymerizing building blocks with different structures. Benefiting from the high porosity, adjustable pore structure, and enzyme-like activities, the Por/Pc-POPs can be the ideal platform to study the removal and detection of pollutants. However, a systematic summary of their application in environmental treatment is still lacking to date. In this review, the development of various Por/Pc-POPs for pollutant removal and detection applications over the past decade was systematically addressed for the first time to offer valuable guidance on environmental remediation through the utilization of Por/Pc-POPs. This review is divided into two sections (pollutants removal and detection) focusing on Por/Pc-POPs for organic, inorganic, and gaseous pollutants adsorption, photodegradation, and chemosensing, respectively. The related removal and sensing mechanisms are also discussed, and the methods to improve removal and detection efficiency and selectivity are also summarized. For the future practical application of Por/Pc-POPs, this review provides the emerging research directions and their application possibility and challenges in the removal and detection of pollutants.

Porphyrin-based hypercrosslinked polymers as sorbents for efficient extraction of nitroimidazoles from water, honey and chicken breast

In this work, a series of 5,10,15,20-tetraphenylporphyrin (TPP)-based hyper crosslinked polymers were prepared by Friedel-Crafts reaction. Among them, the HCP-TPP-BCMBP, which was prepared by using TPP as the monomer and with 4,4'-Bis(chloromethyl)-1,1'-biphenyl (BCMBP) as the cross-linking agent, had the best adsorption capability for the enrichment of the nitroimidazoles of dimetridazole, ronidazole, secnidazole, metronidazole, and ornidazole. Then, a solid-phase extraction (SPE) method with the HCP-TPP-BCMBP as adsorbent coupled with HPLC-UV detection for the determination of nitroimidazole residues in honey, environmental water, and chicken breast samples was established. The influence of the main factors that affect the SPE, i.e., sample solution volume, sample loading rate, sample pH, and eluent and its volume, were studied. Under the optimal conditions, the limits of detection (S/N = 3) for the nitroimidazoles were measured to be in the range of 0.02-0.04 ng mL^-1, 0.4-1.0 ng g^-1 and 0.5-0.7 ng g^-1 for environmental water, honey, and chicken breast samples, with the determination coefficients being in the range of 0.9933-0.9998. The analytes recoveries by the method in fortified samples fell in the range from 91.1% to 102.7% for environmental water, from 83.2% to 105.0% for honey, and from 85.9% to 103.0% for chicken breast samples, and the relative standard deviations for the determination were less than 10%. It shows that the HCP-TPP-BCMBP has a strong adsorption capability for some polar compounds.

A comprehensive review on the pretreatment and detection methods of neonicotinoid insecticides in food and environmental samples

•

The metabolism and residue status of neonicotinoids were briefly summarized in this work.

•

Sample pretreatment techniques for the analysis of neonicotinoids were critically discussed.

•

The commonly used detection methods for neonicotinoids residues were also pointed out.

In recent years, the residues of neonicotinoid insecticide in food and environmental samples have attracted extensive attention. Neonicotinoids have many adverse effects on human health, such as cancer, chronic disease, birth defects, and infertility. They have substantial toxicity to some non-target organisms (especially bees). Hence, monitoring the residues of neonicotinoid insecticides in foodstuffs is necessary to guarantee public health and ecological stability. This review aims to summarize and assess the metabolic features, residue status, sample pretreatment methods (solid-phase extraction (SPE), Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS), and some novel pretreatment methods), and detection methods (instrument detection, immunoassay, and some innovative detection methods) for neonicotinoid insecticide residues in food and environmental samples. This review provides detailed references and discussion for the analysis of neonicotinoid insecticide residues, which can effectively promote the establishment of innovative detection methods for neonicotinoid insecticide residues.

Facile synthesis of hypercrosslinked polymer as high-efficiency adsorbent for the enrichment of nitroimidazoles from water, honey and chicken meat

Design and fabrication of functionalized hypercrosslinked polymers (HCPs) for enhancing their performance by using green renewable monomers has attracted considerable research interest. In this study, hydroxyl‑functional HCP (labeled as OHHCP) was prepared via the knitting method by applying natural naringenin as a monomer for the first time. Due to the good hydrophilicity and strong H-bonding ability, the OHHCP showed high extraction capacity for nitroimidazoles. Thus, it was successfully applied as a potent adsorbent for solid phase extraction of five nitroimidazoles in water, honey and chicken meat, followed by high-performance liquid chromatography-diode array detector analysis. At the optimized conditions, the limit of detections (S/N = 3) of the proposed method for water, honey and chicken samples were 0.02 - 0.06 ng mL^-1, 0.5 - 1.0 ng g^-1 and 0.8 - 1.0 ng g^-1, respectively. The recoveries were 80.0 - 110%, and the relative standard deviations were below 10.0%. The OHHCP also displayed good application prospects for other organic compounds with H-bonding capability. This study highlights the facile preparation of OH-functionalized HCPs from renewable and natural resources as potent adsorbents for polar compounds.

Synthesis of nitrogen-rich magnetic hypercrosslinked polymer as robust adsorbent for the detection of neonicotinoids in honey, tomatoes, lettuce and Chinese cabbage

In this study, a novel nitrogen-rich magnetic hypercrosslinked polymer (Fe3O4@Ph-HCP) was fabricated via a facile one-pot reaction of 1,3,5-triphenylbenzene, 2,4-dichloropyrimidine and phenyl-functionalized magnetic Fe3O4 nanoparticles. The Fe3O4@Ph-HCP possessed high specific surface, abundant nanopores and good stability. Especially, Fe3O4@Ph-HCP exhibited excellent adsorption capability with fast adsorption rate to neonicotinoid insecticides. It was applied as a superior magnetic adsorbent for rapid enrichment and isolation of four neonicotinoid insecticides (thiamethoxam, imidacloprid, acetamiprid and thiacloprid) from honey, tomato, lettuce and Chinese cabbage samples prior to high performance liquid chromatography-diode array detection. Under the optimized conditions, the good linearity was obtained in the range of 1-1000 ng g-1 for honey, tomato, lettuce and Chinese cabbage samples, and the detection limits (S/N = 3) were 0.30-0.67 ng g-1 for honey, 1-1.5 ng g-1 for tomato, lettuce and Chinese cabbage. The spiked recoveries were 80.1-111%, and relative standard deviations were less than 10.0%. These results demonstrate that the developed method can be used as a good alternative method for sensitive determination of neonicotinoid insecticides in complex samples.

Combination of zeolitic imidazolate framework-67 and magnetic porous porphyrin organic polymer for preconcentration of neonicotinoid insecticides in river water

A nanostructured material composed of zeolitic imidazolate framework-67 and magnetic porous porphyrin organic polymer (ZIF-67@MPPOP) was successfully synthesized and applied for the enrichment of neonicotinoid insecticides in river water. The analytes were detected and quantified using high performance liquid chromatography coupled with diode array detector (HPLC-DAD) and liquid chromatography mass spectrometry (LC-MS). Influential experimental parameters were optimized using response surface methodology based on Box Behnken design. The adsorption capacities were 69.46, 80.53, 85.39 and 90.0 mg g^-1 for thiamethoxam, imidacloprid, acetamiprid and clothianidin, respectively. At optimal experimental conditions, low limit of detection (LOD), limit of quantification (LOQ) and linearity were 0.0091-0.04 µg L^-1, 0.04-0.13 µg L^-1 and (0.04-600 µg L^-1), respectively. The relative standard deviation used to evaluate the reproducibility and repeatability of the method was less than 5%. Finally, the method was employed for determination of four neonicotinoid insecticides in river water.