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The present study mainly focused on the assessment of developmental toxicity induced by exposure to brodifacoum (BDF) in zebrafish at early life stages.Zebrafish embryos were exposed to 0.2, 0.4, and 0.8 mg/L of BDF from 6 to 96 hr post-fertilization (hpf), and the toxic effects of BDF on early embryonic development were investigated in terms of morphological changes, oxidative stress, and alterations in heart development-related genes.The experimental results showed that BDF significantly decreased the heart rate, survival rate, body length, and spontaneous movements of zebrafish embryos at 0.8 mg/L, and the morphological developmental abnormalities were also observed at 96 hpf. In addition, exposure to BDF significantly increased oxidative stress levels in zebrafish embryos by increasing the enzymatic activities of catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) levels, and decreased glutathione (GSH) levels. Furthermore, BDF treatment-induced alterations in the expression levels of the heart development-related genes (gata4, sox9b, tbx2b, and nppa).Results from this study indicated that exposure to BDF could lead to marked growth inhibition and significantly alter the activities of antioxidant enzymes in zebrafish embryos. Moreover, BDF exposure exhibited severe cardiotoxicity and significantly disrupted heart development-related genes. The results indicated that BDF could induce developmental and cardiac toxicity in zebrafish embryos.

In this study, magnetic pomelo peel-derived biochar composite was fabricated and applied as a low-cost adsorbent for the simultaneous extraction of morphine-like opioids named morphine, codeine, and 6-monoacetylmorphine from wastewaters, prior to their determination via liquid chromatography-mass spectrometry. A total of four biochar products were synthesized under different pyrolytic temperatures of 400, 500, 600, and 700°C, respectively, and the 400°C biochar was found to have the greatest extraction ability, with enrichment factors of 34, 58, and 61 for the three drugs. The primary adsorption mechanism includes π-π interaction and H-bonding. Parameters affecting the extraction of opioids were optimized. Under optimum conditions (such as pH = 7; adsorbent amount = 15 mg; sample volume = 20 ml; eluent solvent, 200 µl of methanol), the method was proved to be linear in the range of 0.05-10.0 µg/L, with coefficients of determination greater than 0.99, and the limits of detection were 0.006-0.010 µg/L. In-batch and inter-batch precisions were 1.8%-6.5% and 4.8%-10.6%, respectively. The method was successfully applied to the determination of the target opioids in the samples of influent and effluent wastewater. The developed method by using magnetic pomelo peel-derived biochar could potentially be applied for the effective estimation of illicit drug consumption.

Western dietary patterns have been unfavorably linked with mental health. However, the long-term effects of habitual fried food consumption on anxiety and depression and underlying mechanisms remain unclear. Our population-based study with 140,728 people revealed that frequent fried food consumption, especially fried potato consumption, is strongly associated with 12% and 7% higher risk of anxiety and depression, respectively. The associations were more pronounced among male and younger consumers. Consistently, long-term exposure to acrylamide, a representative food processing contaminant in fried products, exacerbates scototaxis and thigmotaxis, and further impairs exploration ability and sociality of adult zebrafish, showing anxiety- and depressive-like behaviors. Moreover, treatment with acrylamide significantly down-regulates the gene expression of tjp2a related to the permeability of blood–brain barrier. Multiomics analysis showed that chronic exposure to acrylamide induces cerebral lipid metabolism disturbance and neuroinflammation. PPAR signaling pathway mediates acrylamide-induced lipid metabolism disorder in the brain of zebrafish. Especially, chronic exposure to acrylamide dysregulates sphingolipid and phospholipid metabolism, which plays important roles in the development of anxiety and depression symptoms. In addition, acrylamide promotes lipid peroxidation and oxidation stress, which participate in cerebral neuroinflammation. Acrylamide dramatically increases the markers of lipid peroxidation, including (±)5-HETE, 11(S)-HETE, 5-oxoETE, and up-regulates the expression of proinflammatory lipid mediators such as (±)12-HETE and 14(S)-HDHA, indicating elevated cerebral inflammatory status after chronic exposure to acrylamide. Together, these results both epidemiologically and mechanistically provide strong evidence to unravel the mechanism of acrylamide-triggered anxiety and depression, and highlight the significance of reducing fried food consumption for mental health.

Abuse of new psychoactive substances increases risk of addiction, which can lead to serious brain disorders. Fentanyl is a synthetic opioid commonly used in clinical practice, and behavioral changes resulting from fentanyl addiction have rarely been studied with zebrafish models. In this study, we evaluated the rewarding effects of intraperitoneal injections of fentanyl at concentrations of 10, 100, and 1000 mg/L on the group shoaling behavior in adult zebrafish. Additional behavioral tests on individual zebrafish, including novel tank, novel object exploration, mirror attack, social preference, and T-maze memory, were utilized to evaluate fentanyl-induced neuro-behavioral toxicity. The high doses of 1000 mg/L fentanyl produced significant reward effects in zebrafish and altered the neuro-behavioral profiles: reduced cohesion in shoaling behavior, decreased anxiety levels, reduced exploratory behavior, increased aggression behavior, affected social preference, and suppressed memory in an appetitive associative learning task. Behavioral changes in zebrafish were shown to be associated with altered neurotransmitters, such as elevated glutamine (Gln), gamma-aminobutyric acid (GABA), dopamine hydrochloride (DA), and 5-hydroxytryptamine (5-HT). This study identified potential fentanyl-induced neurotoxicity through multiple neurobehavioral assessments, which provided a method for assessing risk of addiction to new psychoactive substances.

The problem of opioid abuse has become a global problem. Thus, creating an urgent need for highly sensitive detection of opioid substances. In this work, we developed a method for the controllable preparation of Ag@Au nanocrystals (Ag@Au NCs) for highly sensitive SERS detection of fentanyl and its analogs. By regulating the concentration of ligands on the surface of silver seed, we successfully prepared Ag@Au NCs with three different morphologies, including core-satellite, yolk shell and hollow structure. Firstly, we explored the SERS-enhancing effect of Ag@Au NCs with different morphology using rhodamine 6G as the molecule to be tested. The results show that the core-satellite Ag@Au NCs has the best SERS effect, and the lowest detection concentration for R6G reached to 10

In this study, a biochar-based magnetic solid-phase microextraction method, coupled with liquid chromatography-mass spectrometry, was developed for analyzing fentanyl analogs from urine sample. Magnetic biochar was fabricated through a one-step pyrolysis carbonization and magnetization process, followed by an alkali treatment. In order to achieve desired extraction efficiency, feed stocks (wood and bamboo) and different pyrolysis temperatures (300-700°C) were optimized. The magnetic bamboo biochar pyrolyzed at 400°C was found to have the greatest potential for extraction of fentanyls, with enrichment factors ranging from 58.9 to 93.7, presumably due to H-bonding and π-π interactions between biochar and fentanyls. Various extraction parameters, such as type and volume of desorption solvent, pH, and extraction time, were optimized, respectively, to achieve the highest extraction efficiency for the target fentanyls. Under optimized conditions, the developed method was found to have detection limits of 3.0-9.4 ng/L, a linear range of 0.05-10 μg/L, good precisions (1.9-9.4% for intrabatch, 2.9-9.9% for interbatch), and satisfactory recoveries (82.0-111.3%). The developed method by using magnetic bamboo biochar as adsorbent exhibited to be an efficient and promising pretreatment procedure and could potentially be applied for drug analysis in biological samples.

Anisodamine is one of the major components of the tropine alkaloid family and is widely used in the treatment of pain, motion sickness, pupil dilatation, and detoxification of organophosphorus poisoning. As a muscarinic receptor antagonist, the low toxicity and moderate drug effect of anisodamine often result in high doses for clinical use, making it important to fully investigate its toxicity. In this study, zebrafish embryos were exposed to 1.3-, 2.6-, and 5.2-mM anisodamine for 7 days to study the toxic effects of drug exposure on pigmentation, mineral density, craniofacial area, and eye development. The results showed that exposure to anisodamine at 1.3 mM resulted in cranial malformations and abnormal pigmentation in zebrafish embryos; 2.6- and 5.2-mM anisodamine resulted in significant eye development defects and reduced bone density in zebrafish embryos. The associated toxicities were correlated with functional development of neural crest cells through gene expression (col1a2, ddb1, dicer1, mab21l1, mab21l2, sox10, tyrp1b, and mitfa) in the dose of 5.2-mM exposed group. In conclusion, this study provides new evidence of the developmental toxicity of high doses of anisodamine in aqueous solutions to organisms and provides a warning for the safe use of this drug.

Acrylamide (AA) occurs in both various environmental and dietary sources and has raised widespread concern as a probable carcinogen. Glycidamide (GA) is the main genotoxic metabolite through P450 2E1 (CYP2E1). In the present study, we investigated the protective effect of (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin (EC) against AA- and GA-induced hepatotoxicity in HepG2 cells. The results demonstrated that EC and EGCG inhibited AA- and GA-induced cytotoxicity and mitochondria-mediated cellular apoptosis. Moreover, exposure to AA (100 μg/mL) and GA (50 μg/mL) caused cell cycle arrest and DNA damage, while EC and EGCG ranging from 12.5 to 50 μg/mL rescued cell cycle arrest and inhibited DNA damage. Furthermore, EC and EGCG down-regulated pro-apoptotic protein Bax and Caspase 3 after a 24-h treatment in HepG2 cells exposed to AA (100 μg/mL) or GA (50 μg/mL). Also, the intervention with EC or EGCG up-regulated the expression of DNA repair related protein PARP and down-regulated the expression of Cleaved-PARP. Besides, EC exerted better protective effect than EGCG against AA- and GA-induced cytotoxicity in HepG2 cells. Altogether, EC and EGCG were effective in protecting AA- and GA-induced hepatotoxicity via rescuing cellular apoptosis and DNA damage, as well as promoting cell cycle progression in HepG2 cells.

Acetylcholinesterase (AChE) is the crucial enzyme in the central nervous system. It is the target of various organophosphorus nerve agents and pesticides, and the inhibition of AChE is a therapeutic strategy for the treatment of various neurological-related diseases. The Glu202 is a key residue adjacent to the catalytic His447 and plays important role in catalysis. Although the Glu202 has long been considered as negatively charged in many studies, more and more evidences support a protonated Glu202. However, Glu202 is freely accessible by solvent, and thus it seems more reasonable for Glu202 to majorly take the deprotonated state. In the present work, we carried out a series of molecular dynamics simulations with the Glu202 adopting different protonation states. Our results show that the protonated Glu202 is important in maintaining the key hydrogen bond network that supports the catalytic triad, whereas the deprotonated Glu202 results in the collapse of the key hydrogen bond network which consequently destabilizes the catalytic His447. We also notice that different protonation states of Glu202 merely alters the binding mode of ACh. However, since the catalytic His447 is disrupted if Glu202 is deprotonated, His447 can not facilitate the nucleophilic attack performed by Ser203. Therefore, the catalytic efficiency of ACh hydrolysis should be remarkably decreased if Glu202 is deprotonated. Our findings suggest that, when designing and developing highly active AChE inhibitors or proposing mechanistic hypotheses for AChE-catalyzed reactions, the protonated state of Glu202 should be considered.

Benzoylecgonine (BZE) is the major toxic metabolite of cocaine and is responsible for the long-term cocaine-induced toxicity owing to its long residence time in humans. BZE is also the main contaminant following cocaine consumption. Here, we identified the bacterial cocaine esterase (CocE) as a BZE-metabolizing enzyme (BZEase), which can degrade BZE into biological inactive metabolites (ecgonine and benzoic acid). CocE was redesigned by a reactant-state-based enzyme design theory. An encouraging mutant denoted as BZEase2, presented a >400-fold improved catalytic efficiency against BZE compared with wild-type (WT) CocE. In vivo, a single dose of BZEase2 (1 mg kg-1 , IV) could eliminate nearly all BZE within only two minutes, suggesting the enzyme has the potential for cocaine overdose treatment and BZE elimination in the environment by accelerating BZE clearance. The crystal structure of a designed BZEase was also determined.

In this study, the potentials of utilizing corn straw-derived biochar in environmental sample pretreatment were examined. An one-step magnetization and carbonization process was developed to prepare magnetic biochar by mixing corn straw powder with Fe2+/Fe3+ and then pyrolyzed at different temperatures (400–800 °C). The obtained magnetic biochars were characterized by using scanning electron microscopy, Brunauer–Emmett–Teller isotherms, X-ray diffraction and Fourier transform infrared spectroscopy. Various extraction affecting parameters, such as Fe2+/Fe3+content, pyrolytic temperature, species of desorption solvent, extraction and desorption time, respectively, were studied and optimized. Results showed that the magnetic biochar pyrolyzed at 700 °C exhibited the best extraction performance, with enrichment factors ranging from 52 to 210, presumably due to H-bonding and π-π interactions between biochar and organophosphorus, as well as to the high surface area and pore volume of biochar. The magnetic biochar-based extraction was further combined with gas chromatography–mass spectrometry (GC/MS) to analyze trace organophosphorus pesticides from environmental samples. The method demonstrated good linearity (0.1–50 µg·L−1), low limits of detection (0.02–0.11 µg·L−1), and high recoveries (72.4–96.8%) from spiked water and soil samples. The results of this study suggested the promising potentials of utilizing corn straw-derived biochar for efficiently enriching trace organophosphorus pesticides from complex environmental samples.

Bimetallic nanoparticles have received extensive attention due to their unique physical and chemical properties, including enhanced optical properties, chemical stability, and better catalytic activity. In this article, we have successfully achieved the controllable preparation of Ag@Au nanoparticles via a seed-mediated growth method. By regulating the amount of seeds—silver nanospheres—we realized that Ag@Au nanoparticles gradually changed from spherical to a sea-urchin-like structure. The structure and composition of the prepared nanoparticles were characterized via scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and high-angle circular dark field scanning transmission electron microscopy (HAADF-STEM). In addition, we use the prepared Ag@Au nanoparticles as a substrate material for highly sensitive surface-enhanced Raman spectroscopy (SERS). Using 4-aminothiophenol (4-ATP) as the test molecule, we explored the SERS enhancement effects of Ag@Au nanoparticles with different structures. Furthermore, we used Ag@Au nanoparticles for SERS to detect the drug fentanyl, and realized the label-free detection of fentanyl, with the lowest detection concentration reaching 10−7 M. This research not only provides a method for preparing bimetallic Ag@Au nanoparticles with different structures, but also provides a reference for the application of Ag@Au nanoparticles in the field of detection technology.

In this work, defective Zr-based metal-organic framework was successfully synthesized and evaluated as a dispersive micro-solid-phase extraction sorbent for efficient preconcentration and determination of fungicides in complex water samples. The defective Zr-based metal-organic framework crystal with increased adsorption capacity was successfully synthesized by employing formic acid as the modulator. The extraction conditions, including the pH, extraction time, desorption solvent and desorption time, were comprehensively investigated. Under optimum conditions, it was found that dispersive micro-solid-phase extraction method, coupled with LC/MS, exhibited a good linear relationship with correlation coefficients greater than 0.9980. The relative standard deviations of inter-day and intra-day precisions ranged from 2.6 % to 9.2 % and the limits of detection ranged from 0.004 to 0.036 μg·L-1 . These merits, combined with their satisfactory recoveries (> 80 %), suggested the great potential of defective Zr-based metal-organic framework as a new adsorbent for efficient extraction of trace fungicides. This method exhibits good application potential for the pretreatment of fungicides from environmental water samples. This article is protected by copyright. All rights reserved.

In this study, an alternative method for synthesizing magnetic cobalt adeninate metal-organic frameworks was developed, and the synthesized materials were examined for their potential application for separating and enriching benzodiazepines from complex samples. Benzodiazepines, widely used as hypnotics, muscle relaxants, sedatives, and anxiolytics, are a class of drugs that require accurate detection and monitoring. Results showed that Fe3 O4 nanoparticles could be well anchored onto the external surface of cobalt adeninate metal-organic frameworks by using amino-silane as a linkage. Their adsorption of benzodiazepines was mainly promoted by intermolecular hydrogen binding, π-π interactions and electrostatic attraction. Their potential application was evaluated by extraction of benzodiazepines in urine and wastewater samples prior to liquid chromatography with mass spectrometry. Under optimum conditions, the calibration curves were linear with a correlation coefficient of ≥0.9928 in the concentration range of 10-5000 ng/L for lorazepam and 5-5000 ng/L for estazolam, chlordiazepoxide, alprazolam, midazolam and triazolam. The limits of detection were in the range of 0.71-2.49 ng/L. The percent of extraction recoveries were 80.2-94.5% for urine and 84.1-94.4% for wastewater, respectively. Results suggested that magnetic cobalt adeninate metal-organic frameworks could potentially be a promising material for enriching benzodiazepines from urine and wastewater with high accuracy and precision.

Modern agriculture has gained significant economic benefits worldwide with the use of genetically modified (GM) technologies. While GM crops provide convenience to humans, their biosafety has attracted increasing concern. In this study, the Illumina MiSeq was used to perform a high-throughput sequencing of the V3-V4 hypervariable regions of 16S rRNA gene (16S rDNA) amplicons to compare the rhizosphere bacterial communities of the EPSPS/GAT dual transgenic glyphosate-tolerant soybean line Z106, its recipient variety ZH10, and Z106 with glyphosate application (Z106G) during flowering, seed filling, and maturing stages under field settings. At each of the three stages, the alpha and beta diversity of rhizosphere bacterial communities revealed no significant differences between ZH10, Z106, and Z106G. However, some bacterial taxa demonstrated a greater proportional contribution, particularly the nitrogen-fixing rhizobium Ensifer fredii, in the rhizospheric soil of Z106 at the seed filling and maturing stages, when compared to ZH10 and Z106G. The present study therefore suggests that the EPSPS/GAT dual transgenic line Z106 and exogenous glyphosate application have a minimal effect on the composition of the soybean rhizosphere bacterial community but have no impact on the structure of the rhizosphere microbial community during a single planting season.

A graphene monolithic column was fabricated in a capillary using π-electron-rich poly(N-vinylcarbazole-divinylbenzene) as the supporter through in situ one-step polymerization for the enrichment of...

A sensitive microextraction method based on a new poly(methacrylic acid-ethylene glycol dimethacrylate-N-vinylcarbazole) monolithic capillary column, coupled with gas chromatography and electron capture detection, was established for the determination of three benzodiazepines (estazolam, alprazolam, and triazolam) in urine and beer samples. Owing to the abundant π electrons and polar surface of N-vinylcarbazole, N-vinylcarbazole-incorporated monolith showed a higher extraction performance than neat poly(methacrylic acid-ethylene glycol dimethacrylate) because of the enhanced π-π stacking interactions derived from the π-electron-rich benzene groups from N-vinylcarbazole. The monolith exhibited a homogeneous and continuous structure, good permeability, and a long lifetime. Factors affecting the extraction such as solution pH, salt concentration, sample volume, desorption solvent, and desorption volume were investigated. Under the optimized conditions, limits of detection of 0.011-0.026 ng/mL were obtained. The one-column and column-to-column precision values were ≤7.2 and ≤9.8%, respectively. The real samples were first diluted with deionized water and then treated by the monolith microextraction before gas chromatography analysis. The recoveries were 81.4-93.3 and 83.3-94.7% for the spiked samples, with relative standard deviations of 4.1-8.1 and 3.8-8.5%, respectively. This method provides an accurate, simple, and sensitive detection platform for drug analysis.

A zirconium terephthalate metal-organic framework-incorporated poly(N-vinylcarbazole-co-divinylbenzene) monolith was fabricated in a capillary by a thermal polymerization method. The optimized monolith had a homogeneous structure, good permeability, and stability. The monolith could be used for the effective enrichment of fungicides through π-π interactions, electrostatic forces, and hydrogen bonds. The potential factors that affect the extraction efficiency, including ionic strength, solution pH, sample volume, and eluent volume, were investigated in detail. The monolith-based in-tube solid-phase microextraction coupled with ultra-high-performance liquid chromatography and high-resolution Orbitrap mass spectrometry was performed for the analysis of five fungicides (pyrimethanil, tebuconazole, hexaconazole, diniconazole, and flutriafol) in environmental samples. Under the optimized conditions, the linear ranges were 0.005-5 ng/mL for pyrimethanil, 0.01-5 ng/mL for flutriafol, and 0.05-5 ng/mL for other fungicides, respectively, with coefficients of determination ≥0.9911. The limits of detection were 1.34-14.8 ng/L. The columns showed good repeatability (relative standard deviations ≤9.3%, n = 5) and desirable column-to-column reproducibility (relative standard deviations 5.3-9.4%, n = 5). The proposed method was successfully applied for the simultaneous detection of five fungicides in water and soil samples, with recoveries of 90.4-97.5 and 84.0-95.3%, respectively.

In this study, we report a facile method to prepare magnetic zeolitic imidazolate framework-7@graphene oxide (mag-ZIF-7@GO) composites with the assistance of polydopamine. Moreover, their potential for extracting fungicides from environmental water and soil samples is evaluated. Combining ZIF units and GO layers synergistically enhances the preconcentration of fungicides. A sensitive magnetic solid-phase extraction method based on mag-ZIF-7@GO coupled to LC-MS is developed to determine seven fungicides (pyrimethanil, triadimenol, flutriafol, tebuconazole, hexaconazole, diniconazole and bitertanol) as a function of optimised salt concentration, pH, extraction time, and desorption time. Under optimal conditions, the method exhibits good linearity, repeatability, and reproducibility. The limits of detection and limits of quantification for the seven fungicides are 0.58–2.38 ng/L and 1.95–7.94 ng/L, respectively. Furthermore, the proposed method is applied to determine trace fungicides in environmental water and soil samples, with recoveries of 81.8–96.7%, 87.2–96.3%, and 82.4–93.4% for pond water, river water, and soil, respectively. Therefore, this method has great potential for trace analysis of pollutants in complex environmental matrices.

A poly(N-vinylcarbazole-co-divinylbenzene) (NVC/DVB) monolithic column was successfully prepared in a silanized capillary for microextraction of six benzodiazepines (BZPs) in complex samples. The polymerization was optimized primarily by changing the ratio of porogen content. The optimized polymer monolith had a homogeneous and continuous column bed, good permeability and mechanical stability. Poly(NVC/DVB) had good affinity to BZPs because of its through-pore structure and strong π-π stacking interactions derived from the rich benzene functional groups in the polymer. Potential factors that affect the extraction efficiency were studied in detail. In the optimized method, 3 mL of sample (pH 2) was extracted with the polymer monolithic column and eluted with 80 μL of methanol, and the eluent was analysed with ultra-high-performance liquid chromatography and quadrupole high resolution Orbitrap mass spectrometry (UHPLC/Q-Orbitrap MS). Under these conditions, the developed method gave the linear range of 0.005–0.5 ng/mL for most of the six BZPs, whereas 0.05–0.5 ng/mL for nitrazepam, 0.01–0.5 ng/mL for lorazepam, respectively, with coefficients of determination (R2) ≥ 0.9991. The detection limits (LODs) were 1.08–6.04 ng/L, and the quantification limits (LOQs) were 3.60–20.1 ng/L. The method repeatability was investigated in terms of intra- and inter-day precision, which were indicated by relative standard deviations (RSDs) of ≤8.3% and ≤9.9%, respectively. Finally, the proposed method was successfully applied to detect BZPs in beer and human urine samples. The percentages of extraction recovery were 80.4–94.2% for beer and 79.6–95.2% for urine.

In this study, a novel sample preparation technique coupled with liquid chromatography was developed to determine the trace residues of antibiotics in food samples. Target analytes were extracted by accelerated solvent extraction (ASE), followed by the concentration and cleanup using micro-solid-phase extraction (μ-SPE). Variables affecting the ASE and μ-SPE were optimized to achieve the maximum extraction efficiency, besides the performance of the developed method was evaluated. Low detection limits of 7.4–16.3 ng/g and low quantification limits of 24.7–53.8 ng/g were achieved under optimized conditions. The recoveries of antibiotics ranged from 92 to 105 % with relative standard deviation of less than 9.3 %. The predominance was showed when compared to conventional ASE and μ-SPE. According to the results, ASE-μ-SPE was proved to be a simple and effective sample preparation method for the analysis of trace organic contaminants in food samples.

Zeolitic imidazolate frameworks (ZIFs) consist of metal nodes connected to imidazolate linkers, having both the properties of metal-organic frameworks (MOFs) and inorganic zeolites, such as controllable pore sizes, high porosity and surface areas, as well as exceptional thermal and chemical stability, thereby making them a class of attractive materials for diverse analytical applications. In this study, we reported a facile magnetization process of ZIF-7 (zinc benzimidazolate) for simultaneous magnetic extraction of polycyclic aromatic hydrocarbons (PAHs) by simply mixing ZIF-7 and polydopamine (PDA)-coated Fe3O4 nanoparticles (PDA@Fe3O4) in solutions. Functional groups (-OH and -NH2), provided by PDA as a highly efficient molecular linker, could attract and anchor ZIF-7 through noncovalent adsorption and covalent cross-link interactions, thereby promoting the complete magnetization of ZIFs and enhancing their stability and reusability. The bridging ligand benzimidazolate, could be bonded with PAHs because of its high surface area, large pores, accessible coordinative unsaturated sites (π-complexation), and π-π stacking action. This ZIF-based magnetic solid-phase extraction (SPE), coupled with gas chromatography/tandem mass spectrometry (GC/MS), was further evaluated for analysis of PAHs from rainwater and air samples of particulate matter less than 2.5μm in diameter (PM2.5). The main effective parameters, including ionic strength, solution pH, extraction time, desorption solvent and desorption time, were investigated, respectively. Under optimized conditions, the developed method based on Fe3O4@PDA/ZIF-7 gave detection limits of 0.71-5.79ng/L, and quantification limits of 2.50-19.2ng/L for PAHs, respectively. The relative standard deviations for intra-day and inter-day analyses were in the range of 3.1-9.1% and 6.1-12.7%, respectively. The PAHs founded in PM2.5 were in the range of 0.40-6.79ng/m(3). Good recoveries (>82%) with low relative standard deviations (≤9.2%) were achieved. This method was demonstrated to be an accurate, convenient and sensitive pretreatment procedure for trace analysis of environmental water and air samples.

An active magnetic metal-organic framework (MOF) hybrid material was prepared using a novel in situ solvothermal method in the presence of magnetite (Fe3O4) particles, that holds much promise for large-scale synthesis. MIL-101(Fe), an iron terephthalate with pore structure and high resistance to water and common solvents, was functionalized as a model with superparamagnetic qualities, using Fe3O4. The electrostatic interaction between Fe3O4 and metal ions was thereby used to chemically stabilize magnetic nanoparticles, and thus MOF crystals were uniformly enclosed by Fe3O4 to form a homogeneous magnetic product identified as a Fe3O4/MIL-101 composite. This hybrid material with magnetic susceptibility but with the lowest possible loading amount of Fe3O4 was examined, and its potential application for magnetic solid-phase extraction of six organophosphorus pesticides (OPPs) from human hair and urine samples, followed by gas chromatography analysis, was assessed. The main effect parameters including solution ionic strength, desorption solvent, extraction time and desorption time were investigated in sequence. Under optimized conditions, this method showed low detection limits (0.21–2.28 ng/mL), wide linearity, and good precision (1.8–8.7% for intra-day, 2.9–9.4% for inter-day). The matrix interference produced by hair or urine could be effectively eliminated using this method, and satisfactory recoveries of the spiked samples were 76.8–94.5% and 74.9–92.1%, respectively, indicating that the Fe3O4/MIL-101 sorbents are feasible for the analysis of trace analytes from biological samples.

The new catalyst system of chiral SalenCo(OAc)/chiral ionic liquid was developed to catalyze the asymmetric cycloaddition reaction of CO2 and epoxides yielding the chiral cyclic carbonates. The synergistic effect between them is discussed.

A magnetic carbon nanotube hybrid material was prepared using a chemical co-precipitation method. The Fe3O4 nanoparticles were enclosed onto the surface of the acid multi-walled carbon nanotubes (AMWNTs), and they were identified as Fe3O4/AMWNTs composites. This hybrid materials displayed typical superparamagnetic behavior, good dispersibility, and good adsorption capacity for pyrethroid pesticides. A magnetic solid-phase microextraction (MSPE) procedure based on Fe3O4/AMWNTs composites, combined with gas chromatography, was developed for the quantification of six pyrethroid pesticides in water and honey samples. Several important parameters affecting the extraction efficiency for six pyrethroid pesticides were optimized in sequential order, including ionic strength, extraction time and desorption time. Under the optimized conditions, this method showed wide linearity ranging from 0.5 µg/L to 50 µg/L with correlation coefficients (R2) higher than 0.990. The limits of detection (LODs) ranged from 0.07 µg/L to 0.20 µg/L at a singal-to-noise ratio of 3. The relative standard deviations (RSDs) ranged from 3. 8% to 8. 1%. Satisfactory recoveries (> 78.4%) were obtained for the simultaneous analysis of the six pyrethroid pesticide residues in river water, fish-pond water and two honey samples. This method is sensitive and simple. It can meet the actual requirement for the analysis of trace analytes from environmental water and honey samples.

The new catalyst system of chiral SalenCo(OAc)/chiral ionic liquid was developed to catalyze the asymmetric cycloaddition reaction of CO2 and epoxides yielding the chiral cyclic carbonates. The synergistic effect between them is discussed.