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Sludge based catalysts (SBCs) has been considered as a promising and viable approach to sludge reclamation. Herein, we fabricated bimetallic Fe-Ti doped SBCs via a facile synthesis with sludge containing polyacrylamide (PAM) as N-precursor. The adsorption capacity and degradation efficiency of as-synthesized SBCs were assessed using tetracycline (TC) as a target pollutant, in which PAM in sludge played a dual role by promoting porosity, active sites, and structural defects beneficial for persulfate (PS) activation. Fe-Ti doping induced the activation of PS by a fast redox cycle of Fe3+/Fe2+ associated with the coexistence of Ti4+/Ti3+, which enabled an efficient electron transfer between the catalyst and PS. The synergistic effect of PAM-derived N doping and Fe-Ti bimetals resulted in prevention of iron leaching and enhanced catalyst stability over a wide pH range. The surface SO4•− was the primary oxidant in the TC degradation process based on free-radical quenching experiments, and degradation pathways of TC were proposed given the intermediate evidence from UPLC-HRMS analysis. This study promotes the reclamation of PAM-containing sludge providing an eco-friendly and efficient process to activate PS for wastewater treatments.

In this study, SiO2-composited biochar decorated with Fe/Mn was prepared by co-pyrolysis method. The degradation performance of the catalyst was evaluated by activating persulfate (PS) to degrade tetracycline (TC). The effects of pH, initial TC concentration, PS concentration, catalyst dosage and coexisting anions on degradation efficiency and kinetics of TC were investigated. Under optimal conditions (TC = 40 mg L−1, pH = 6.2, PS = 3.0 mM, catalyst = 0.1 g L−1), the kinetic reaction rate constant could reach 0.0264 min−1 in Fe2Mn1@BC-0.3SiO2/PS system, which was 12 times higher than that in the BC/PS system (0.00201 min−1). The electrochemical, X-ray diffractometer (XRD), Fourier transform infrared spectrum (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis showed that both metal oxides and oxygen-containing functional groups provide more active sites to activate PS. The redox cycle between Fe(II)/Fe(III) and Mn(II)/Mn(III)/Mn(IV) accelerated the electron transfer and sustained the catalytic activation of PS. Radical quenching experiments and electron spin resonance (ESR) measurements confirmed that surface sulfate radical (SO4•−) play a key role in TC degradation. Three possible degradation pathways of TC were proposed based on high-performance liquid chromatography coupled with high-resolution mass spectrometry (HPLC-HRMS) analysis, the toxicity of TC and its intermediates was analyzed by bioluminescence inhibition test. In addition to the enhanced catalytic performance, the presence of silica also improved the stability of the catalyst, as confirmed by cyclic experiment and metal ion leaching analysis. The Fe2Mn1@BC-0.3SiO2 catalyst, derived from low-cost metals and bio-waste materials, offer an environmentally friendly option to design and implement heterogenous catalyst system for pollutant removal in water.

Due to the harmful effects of estrogens and their prevalence in animal foods, accurate analysis of estrogen levels in animal foods is imperative in order to effectively assess food safety risks and ensure consumer safety. Therefore, a rapid and accurate method based on PRiME HLB solid phase extraction (SPE) cartridge purification and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed to determine nine estrogen residues in bullfrogs. The nine estrogens included estriol (E3), 17

As a recycling use of waste activated sludge (WAS), we used high-temperature pyrolysis of WAS to support bimetallic Fe–Mn with nitrogen (N) co-doping (FeMn@N–S), a customized composite catalyst that activates peroxysulphate (PS) for the breakdown of tetracycline (TC). First, the performance of TC degradation was evaluated and optimized under different N doping, pH, catalyst dosages, PS dosages, and contaminant concentrations. Activating PS with FeMn@N–S caused the degradation of 91% of the TC in 120 min. Next, characterization of FeMn@N–S by XRD, XPS and FT-IR analysis highlights N doping is beneficial to take shape more active sites and reduces the loss of Fe and Mn during the degradation reaction. As expected, the presence of Fe–Mn bimetallic on the catalyst surface increases the rate of electron transfer, promoting the redox cycle of the catalyst. Other functional groups on the catalyst surface, such as oxygen-containing groups, accelerated the electron transfer during PS activation. Free radical quenching and ESR analysis suggest that the main contributor to TC degradation is surface-bound SO4•−, along with the presence of single linear oxygen (1O2) oxidation pathway. Finally, the FeMn@N–S composite catalyst exhibits excellent pH suitability and reusability, indicating a solid practicality of this catalyst in PS-based removal of antibiotics from wastewater.

To establish a rapid, accurate and sensitive method by liquid chromatography-tandem mass spectrometry with isotope internal standard dilution technique for the determination of chlorpromazine and promethazine and their metabolites in swine tissues.The swine tissues sample was extracted with acetonitrile and purified on MCX cartridge. The liquid chromatography separation was performed on an ACQUITY UFLC® HSS T3(100 mm×2.1 mm, 1.8 μm) with a linear gradient elution program of 0.1%(V/V) fomic acid-acetonitrile and 0.1%(V/V) formic acid-water solution as the mobile phase. The analytes were analyzed using ESI operating in the positive multiple reaction monitoring(MRM) mode.The limits of quantitation(LOQs) and limits of detection(LODs) for the target objects were 0.12-0.51 μg/kg and 0.04-0.17 μg/kg, respectively. The calibration curves were linear in range of 0.1-20.0 μg/L for chlorpromazine and promethazine, and 0.5-100.0 μg/L for their metabolites(chlorpromazine sulfoxide and isopropyl sulfoxide). The recoveries were between 90.8%-106.0%, and the relative standard deviations(RSDs) were between 1.9%-6.2%(n=6).The method is highly sensitive and accurate, and is suitable for the analysis of chlorpromazine and promethazine and their metabolites(chlorpromazine sulfoxide and isopropyl sulfoxide) in swine tissues.

An analytical method based on dispersive solid-phase extraction (d-SPE) and ultrafast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) was employed for the determination of 43 mycotoxins in chestnut flour and wheat flour. A total of 128 samples consisting of 48 chestnut samples and 80 wheat flour samples were collected randomly and subjected to analysis. Finally, five specific toxins were selected as markers to identify these two foodstuffs. Acetonitrile-water (84∶16, v/v) was used to extract mycotoxins from chestnut flour and wheat flour. After extraction, the supernatant was transferred to the d-SPE equipment, using which purification was performed with C

To investigate the dietary exposure of Ningbo residents to quinolones and tetracyclines antibiotics in animal derived foods, so as to estimate the health risk caused by the exposure.Animal derived foods in Ningbo markets from 2018 to 2020 were collected and analyzed by ultra-fast liquid chromatography-tandem mass spectrometry. Based on the result of the measurements, median(M), P97.5, average and the maximum values of the data were obtained. Coupling the food intake data of residents in Zhejiang Province, an international point estimate model was applied to evaluate the health risk caused by the dietary exposure.Enrofloxacin, ciprofloxacin, ofloxacin, doxycycline, oxytetracycline were detected in freshwater fishes, cultured pseudosciaena crocea, freshwater shrimps, chicken, eggs and pork. The detection rates of enrofloxacin, ciprofloxacin, ofloxacin, doxycycline, oxytetracycline were 21.2%(77/363), 11.6%(42/363), 2.8%(10/363), 1.4%(5/363), 0.6%(2/363), respectively. The dietary exposure of adults and children from animal derived foods were in the range of 0.8-909.0 and 0.6-518.9 ng/(kg·d), respectively. The hazard quotient(HQ) values were in the range of 0.000030-0.17.Quinolone and tetracycline antibiotics such as enrofloxacin and oxytetracycline have no dietary health risk to the population.

Mass transfer and oxidant utilization are perhaps two of the most critical issues in sulfate radical (SO4•−) based advanced oxidation technologies (AOTs) and their scaled-up implementation. In this study, we propose using hydrodynamic cavitation (HC), considered a green, effective method, to promote both mass transfer and oxidant utilization in zero-valent iron (Fe0) activated persulfate (PS) system. Whilst the BET surface area of Fe0 was increased by 8 times after HC treatment, concentration of Fe2+ derived from Fe0 oxidation is greatly increased for effective PS activation. The reappearance of Fe0 and Fe2+ after cavitation ensured a good reusability of the catalyst. Likewise, the impact of pH revealed that TC adsorption on catalyst at acidic pH favored its degradation compared with that at higher pH. With respect to oxidant utilization, it is observed that PS even at a high dosage (2.8 mM) was completed converted within 30 min in the HC-Fe0/PS system. According to SEM, TEM, and BET analysis, we conclude that the microjets induced by cavitation bubbles or direct abrasion by HC agitation have contributed to the removal of hydroxide/oxide layers on the Fe0 surface, thus reactivating its catalytic activity. Given these reasons, we observed up to 97.80% removal of Tetracycline (TC), the model pollutant, with a synergistic coefficient as high as 2.62. After confirming SO4•− as the most dominant reactive species, five degradation pathways of TC were proposed given the intermediate evidence from LC-MS/MS analysis and density functional theory (DFT) calculations. Results from this study could provide new insights into the role of HC on PS activation and shed light on the potential implementation of the SO4•−-based AOTs for scaled-up wastewater treatments.

Nowadays, anesthetics are widely used in fishery production processes, such as fish breeding, surgery, and fresh aquatic product transportation. Because of the widespread application of anesthetic drugs in aquatic products, there is an increasing demand for the rapid and sensitive detection of anesthetic drugs in aquatic products. The complex aquatic product matrix contains a variety of interfering substances, such as proteins, fats, and phospholipids, along with anesthetic drug residues at very low concentrations; therefore, it is necessary to adopt appropriate pretreatment methods for improving the sensitivity of detection. In this study, a dispersive solid-phase extraction (DSPE) method, combined with high-performance liquid chromatography, was established for the simultaneous detection of seven anesthetic drugs in aquatic products, viz. procaine, oxybuprocaine, tricaine, eugenol, methyl eugenol, isoeugenol, and methyl isoeugenol. For the DSPE step, pretreatment conditions, such as extraction solvent, extraction time, adsorbent amount, and DMSO dosage, were optimized. Sample pretreatment is a three-step process. First, in ultrasound-assisted extraction, 2.0 g samples were extracted using 10.0 mL 1.0% formic acid in acetonitrile under ultrasound conditions for 10 min. Then, DSPE was performed with mixed adsorbents: the solvent extracts were cleaned using 20 mg poly(styrene-glycidylmethacrylate) microspheres (PS-GMA), 50 mg primary secondary amines (PSA), and 10 mg C18, followed by separation by centrifugation. Finally, DMSO-assisted concentration was applied: the organic layer was collected and was dried at 40 ℃ in a N

Pressurized vertical electro-osmotic dewatering (PVEOD) has been regarded as a feasible method to achieve sludge deep-dewatering, but the dewatering efficiency is still challenged by high electric resistance. This study employed cationic polyacrylamide (CPAM) as a skeleton builder to enhance electro-osmotic flow in PVEOD. The sludge dewatering efficiency and synergistic effect of CPAM and PVEOD were elucidated. The sludge morphology, surface property, extracellular polymeric substances (EPS) destruction and migration, spatial distributions of proteins and polysaccharides, and current changes were investigated. After the addition of optimal CPAM dose, the sludge formed a uniform and porous structure that provided water channels and enhanced electric transport, thus promoting EPS destruction. The sludge moisture content (MC) analysis indicated the more liberation of bound water due to EPS destruction. Besides, the re-flocculation of disintegrated sludge flocs improved the sludge filtration and thus dewaterability. Instantaneous energy consumption (Et,0.5) was optimized and two-step synergistic mechanism was thus proposed. These findings indicated that the combination of CPAM and PVEOD is a promising strategy to broaden the scope of industrial application of sludge deep-dewatering.

The electrochemical Fenton (electro-Fenton) pretreatment was explored as an attractive dewatering method for excess sludge produced in municipal wastewater treatment plants (MWTPs). The effects of initial pH, applied current density, zero valent iron (ZVI) dosage, and H2O2 concentration on sludge dewaterability and filterability were demonstrated by measuring water content (WC) and capillary suction time (CST) of conditioned sludge, respectively. Using radical scavenging tests, the significantly reduced WC and CST values in the electro-Fenton pretreatment compared to unconditioned sludge were attributed to both surface-bound OH and aqueous OH responsible for attacking and degrading extracellular polymeric substances (EPS). The component of tightly bound EPS (TB–EPS) was degraded to a greater extent as compared to soluble EPS (S–EPS) and loosely bound EPS (LB–EPS), resulting in the release of bound water to the aqueous phase. Protein and polysaccharide measurements in EPS fractions, together with FT–IR spectra, confirmed the preference of protein oxidation by OH. On the other hand, in the electro-Fenton process, ZVI was first electro-oxidized to Fe2+ for use in the Fenton reaction, then to Fe3+ that was subsequently reduced to Fe2+ under the applied electrical field, thereby leading to the cycle of iron (Fe2+ → Fe3+ → Fe2+). Moreover, ZVI/Fe3+ acted as scaffolds for agglomeration of flocs into large and compact particles for improved filterability. Results of this study could provide a basis to optimize the sludge dewatering process using the electro-Fenton pretreatment in MWTPs.

To establish a rapid and accurate method for the determination of trace acetaldehyde, acrolein, methacrylaldehyde, crotonaldehyde in the air by ultra-fast liquid chromatography-tandem mass spectrometry(UFLC-MS/MS).The air sample was concentrated and derivatived by 3-methyl-2(3 H)-benzothiazolonhydrazone(MBTH), and the effect of derivative conditions including the concentration of MBTH, the pH, the derivative time and temperature was investigated. The stability of derivatives, the cracking mechanism of mass spectrometry, the matrix effect of the method and air sampling efficiency were studied. The chromatographic separation was carried out on a Shim-pack XR-ODS II column(100 mm×2. 0 mm, 2. 2 μm) by using water/methanol solution as the mobile phase with the gradient elution. Detection was performed in positive multi-reaction monitoring(MRM) mode for quantification by using external standard method.The four analytes showed good linear relationship within the range of 1. 00-100 μg/L(calculated by aldehyde) with a correlation coefficient r≥0. 9990. The limits of quantitation(LOQs) of the method(concentrated with 10 L air) were 0. 5 μg/m~3 in air, for acetaldehyde, acrolein, methacrylaldehyde, crotonaldehyde. The recoveries of the method were 90. 6%-97. 8% at the three spiked levels, and the relative standard deviations(RSDs) were between 1. 9%-6. 4%(n=6), the average sampling efficiency was between 91. 0%-97. 1%.The developed method is simple, less interference and specificity, and is suitable for the simultaneous rapid determination of trace acetaldehyde, acrolein, methacrylaldehyde, crotonaldehyde in air of work place.

Ultra-fast liquid chromatography-tandem mass spectrometry method was developed for the analysis of contamination degree of biotoxins in seafood in Ningbo City from 2017 to 2019 and the assessment of dietary exposure was conducted.Samples were extracted and purified with optimized pretreatment process and then injected for analysis. According to the result of the measurements, an international point estimate model was used to evaluate the dietary exposure of the population.For tetrodotoxin and 16 shellfish toxins monitored routinely, gonyautoxin5(GTX5), tetrodotoxin and homo-yessotoxin(hYTX) had higher detection rate, other toxins including okadaic acid(OA), dinophysistoxin1(DTX1), decarbamoyl gonyautoxin2(dcGTX2) and decarbamoyl gonyautoxin3(dcGTX3) were detected sporadically. The detection rates of TTX、GTX and hYTX were 27%, 52% and 12%, respectively. The concentration ranges of TTX, GTX and hYTX in polluted samples were 0. 003-0. 535, 0. 008-0. 189 and 0. 032-0. 110 mg/kg. The exposure risk indices(ERI) of TTX, GTX5, hYTX, dcGTX2 and dcGTX3 were 2. 5, 0. 026, 0. 0080, 0. 79 and 0. 32, respectively.Marine biotoxins have a lower dietary health risk to the population. It is must be given great attention that in the season of toxic red tide, the detection rates of higher toxic toxins, dcGTX2 and dcGTX3 increased significantly with high risks to human. Moreover, the dietary health risk of tetrodotoxin in routine surveillance in 2019 was higher.

A rapid and efficient QuEChERS-based preparation method was established for the simultaneous determination of 43 mycotoxins in chestnut and jujube (Chinese date). The contaminants were extracted using acetonitrile and subjected to dispersive solid-phase extraction for further clean-up. Central composite design was conducted to overcome the limitations of conventional optimization methods, and assess the interaction effects between variables and reach the true optimal conditions. Quantitative analysis was performed on UHPLC-MS/MS with the aid of stable isotope internal standards and matrix-matched curves, whereas qualitative identification was carried out by using high-resolution MS based on exact masses and fragmentation patterns. In addition to the mycotoxins that are routinely monitored (like aflatoxins, ochratoxin A, etc.), this study also revealed a non-negligible contamination of zearalenone (56/170), beauvericin (52/170), enniatin B (43/170), and alternariol monomethyl ether (42/170) in chestnut and jujube, especially the chestnut flour.

The heterogeneous catalytic process has been under development for aqueous pollutant degradation, yet electron transfer efficiency often limits the effectiveness of catalytic reactions. In this study, a novel composite material, manganese doped iron–carbon (Mn–Fe–C), was tailor designed to promote the catalytic electron transfer. The Mn–Fe–C composite, synthesized via a facile carbothermal reduction method, was characterized and evaluated for its performance to activate persulfate (PS) and degrade Rhodamine Blue (RhB) dye under different pH, catalyst dosages, PS dosages, and pollutant concentrations. Electron spin resonance, along with quenching results by ethanol, tert-butanol, phenol, nitrobenzene and benzoquinone, indicated that surface bounded SO4•− was the main contributor for RhB degradation, while the roles of aqueous SO4•− and •OH were very minor. Through characterization by XRD, XPS and FTIR analysis, it was determined that the electron transfer during activation of PS was accelerated by the oxygen functional groups on catalyst surface and the promoted redox cycle of Fe3+ and Fe2+ by Mn. Finally, the Mn–Fe–C composite catalyst exhibited an excellent reusability and stability with negligible leached Fe and Mn ions in solutions. Results of this study provide a promising design for heterogeneous catalysts that can effectively activate PS to remove organic pollutants from water at circumneutral pH conditions.

a novel and rapid analytical method was established for the extraction of N-nitrosodimethylamine in large-volume water samples.Pretreatment was on the basis of ultrasonic-assisted-dispersed solid phase extraction. Coco housing activated carbon was incorporated into the water samples, and the rapid enrichment of N-nitrosodimethylamine was realized by implementing ultrasonic-assisted dispersion. After that, the suspension was filtered by suction, and the residue was eluted by dichloromethane. The eluate was collected and then concentrated to dry using rotary evaporation. Ultra-high performance liquid chromatography tandem mass spectrometer, which equipped with atmospheric pressure chemical ionization source was employed for determination under the multiple reaction monitoring mode.Limit of detection and quantification for N-nitrosodimethylamine in 500 mL water was 2. 0 ng/mL and 6. 0 ng/mL, respectively. Throughout the validation, good linearity with R~2gt;0. 999 were achieved with the range from 0. 5 ng/mL to 150. 0 ng/mL. Satisfactory recovery(95. 7%-100. 8%) and inter-day reproducibility(lt;4. 2%) were obtained by three-level spiking experiments in different water matrices. Finally, the established method was applied for analysis of 48 real samples, the detectable concentrations of positive samples were in the range oflt;2. 0 ng/L to 14. 4 ng/L.Compared with the traditional solid-phase extraction method, this method ology showed the characteristics of rapid and more efficient, and could save at least 50% of the pretreatment time. Meanwhile, the result of method ology validation were satisfactory.

Pressurized vertical electro-osmotic dewatering (PVEOD) is an emerging mechanical technology for deep dewatering of wastewater sludge. In this study, the influence of main operation variables including sludge dosage, voltage, mechanical pressure on electro-osmotic dewatering was investigated. Response surface method (RSM) was applied to evaluate and optimize the interactive effects of the three major operating variables. The results indicated the optimum conditions to be 2.70 MPa of mechanical pressure, 18.33 V of voltage and 0.0169 kWh/kg water of energy consumption. Layered distribution study was conducted between anode side and cathode side to investigate the vertical changes of moisture content, zeta potential, three-dimensional excitation emission matrix (3D-EEM) spectra of extracellular polymeric substances, the concentration of proteins and polysaccharides. The morphology changes of sludge observed by microscope images unveiled the possible mechanisms of enhancing the sludge dewaterability in the PVEOD process. The electrochemical at electrodes and electro-osmosis are important for interpreting the dryer sludge at anode layer.

The novel quaternary ammonium modified magnetic carboxyl-carbon nanotubes (QA-Mag-CCNTs) have been synthesised and characterized. QA-Mag-CCNTs were applied in magnetic dispersive solid phase extraction (Mag-dSPE) for preconcentration of perchlorate from tea leaves prior to liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS) analysis. The Mag-dSPE procedure for preconcentration of perchlorate succeed in overcoming the flaw (containing target analyte randomly) of commercially available SPE cartridge. Under optimal conditions, the results showed higher extraction efficiency of QA-Mag-CCNTs, with recoveries between 85.2% and 107%. And the satisfactory precision with inter-day and intra-day RSD values were lower than 8.0%. Furthermore, QA-Mag-CCNTs were evaluated for reuse up to 20 times. The limit of quantification (LOQ) for perchlorate was 8.21 ng kg−1. The developed method was successfully applied in tea leaves for food-safety risk monitoring in Zhejiang province, China. The results showed the concentrations of perchlorate in 229 out of 240 collected samples were in the range of 0.082–988 μg kg−1. It was confirmed that QA-Mag-CCNTs were highly effective materials used for preconcentration of perchlorate.

A novel double layer pipette tip magnetic dispersive solid phase extraction (DPT-MSPE) based on polyamidoamine-functionalized magnetic carbon nanotubes (PAMAM@Mag-CNTs) was developed for the purification of fifteen toxic alkaloids in meat dishes and vegetable dishes. PAMAM@Mag-CNTs were synthesized through direct reaction between the carboxy group on the surface of the Mag-CNTs and the peripheral amino group of the polyamidoamine (PAMAM) dendrimers. The magnetism of PAMAM@Mag-CNTs simplified the post-processing during preparation of the sorbent, and reinforced the interaction between the sorbents and the analytes during the cleanup procedure. An ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) coupled with DPT-MSPE method has been developed to determine fifteen alkaloids in meat dishes and vegetable dishes. Under the optimal conditions, satisfactory recoveries, i.e., 83.4–125% for meat dishes and 84.2–122% for vegetable dishes, were obtained due to the high cleanup efficiency of the DPT-MSPE. Furthermore, the method, which displays good linearity (r ≥ 0.9991), acceptable precision (RSD < 8%), and low limits of quantification (0.054–1.058 ng g−1), has been successfully applied to several food samples, and it was confirmed that PAMAM@Mag-CNTs DPT-MSPE was a highly effective extraction method for alkaloids in cooked food samples.

Two analytical approaches, including ultra-high performance liquid chromatograph linked with photo-diode array/fluorescence detector, and ultra-high performance liquid chromatography-tandem mass spectrometry, have been proposed for simultaneous determination of five Alternaria toxins in cereals, which both based on QuEChERS strategy. After QuEChERS extraction and salting out, the collected supernatant was subjected to an extra dispersive liquid–liquid microextraction step prior to quantitative analysis. Response surface methodology based on central composite design was employed to optimize the micro-extraction conditions. During photo-diode array/fluorescence detector method validation, satisfactory analytical characteristics, in terms of selectivity, recovery (72.7%–109.1%), precision (inter-day RSDs −1 to 120.0 μg kg −1 ) and linearity ( R 2 all higher than 0.9984), were achieved. Mass spectrometry method was employed as a certified method for accuracy. The two methodologies were successfully applied to 71 samples including three different matrices and the quantitative results were compared. As the result of non-parametric test shown, the established two analytical approach exhibited comparable quantitative accuracy to each other.

To establish a rapid and accurate method for determination of 25-hydroxyl vitamin D2, 25-hydroxyl vitamin D3 and 3-epi-25-hydroxyl vitamin D3 in serum by isotope dilution ultra-fast liquid chromatography-tandem mass spectrometry(UFLC-MS/MS).The serum sample was extracted by nhexane after methanol/acetonitrile precipitation protein, and then the extract was concentrated by nitrogen and volumed with the primary mobile phase. The chromatographic separation was carried out on a Phenomenex Kinetex F5 column(2. 1 mm × 150 mm, 1. 7 μm) by using 0. 1%(V/V) formic acid and 0. 1%(V/V) formic acid/methanol solution as the mobile phase with the gradient elution. Detection was performed in positive multi-reaction monitoring(MRM) mode with the isotope internal labeling method for quantification.The baseline separation was obtained within 6 min for the epimer 25-hydroxyl vitamin D3 and 3-epi-25-hydroxyl vitamin D3, and the accurate qualification was obtained for the simultaneous determination of 25-hydroxyl vitamin D2, 25-hydroxyl vitamin D3 and 3-epi-25-hydroxyl vitamin D3. The three analytes showed good linear relationship within the range of 0. 5-50. 0 μg/L with a correlation coefficient r0. 9995. The limits of detection(LODs) and the limits of quantitation(LOQs) of the method were 0. 15 μg/L and 0. 5 μg/L, respectively. The recoveries of the method were84. 3%-109. 0%(n = 11) at the three spiked levels of 1. 0, 10. 0 and 30. 0 μg/L, and the relative standard deviations(RSDs) were between 0. 8%-6. 8%. At the same time, the certified standard reference materials(SRM) of the America National Institute of Standards and Technology(NIST) Level 1, Level 2, Level 3 and Level 4(SRM 972 a)were used as the quality control samples for verification, the relative deviations of the measurement result were less than 5% compared with the reference values.The developed method has the characteristics of simplicity, rapidity, sensitivity and accuracy, and is suitable for the simultaneous rapid determination of 25-hydroxyl vitamin D2, 25-hydroxyl vitamin D3 and 3-epi-25-hydroxyl vitamin D3 in serum.

Bimetallic oxide CuFeO2 as a new heterogeneous catalyst has shown much higher catalytic ability for activating peroxide than single-metal oxides. The present work demonstrated a synergistic microwave (MW) enhanced Fenton-like process with CuFeO2 for rapid decolorization of azo dye Orange G (OG). The MW irradiation dramatically enhanced the OG degradation efficiency, achieving 99.9% decolorization within 15 min at pH 5. The XRD analysis of reused CuFeO2, together with metal leaching tests, indicated merits of recycling for CuFeO2. The subsequent surface element analysis by XPS for fresh and used CuFeO2 showed a complex network for reactions between copper-iron redox pairs and surface hydroxyl groups, leading to a synergistic Fenton-like system accelerated by MW irradiation. In the CuFeO2 initiated Fenton-like reactions, several oxidant species (i.e., OH, O2 −, electron hole, and FeIV O) responsible to the OG oxidation were identified by quenching experiments, showing the MW generated high temperature and “hot spots” enhanced the yield of OH by generation of electron-hole pairs. Further, the 26 detected degradation products confirmed the OH dominant oxidation of OG. This study shows that the MW-enhanced Fenton-like reaction using CuFeO2 has potential applications for rapid decolorization of dye effluent.

This study developed a method to perform the simultaneous determination of 58 (ultra) trace human and veterinary drugs in river water. The analytes included 24 steroid hormones, 22 sulfonamides and 12 quinolones. The easy-to-handle magnetic dispersive solid-phase extraction (Mag-dSPE) procedure was performed using three-dimensional interconnected magnetic chemically modified graphene oxide (3D-Mag-CMGO) as the adsorbent, and an enrichment factor of 100 times was obtained. Under the optimal conditions, the results showed higher extraction capacity of 3D-Mag-CMGO with recoveries between 78.0 and 109%. The limits of quantification (LOQs) for 58 (ultra) trace analytes are in the range of 0.10–2.09 ng L−1. Validation results on linearity, specificity, accuracy, and precision, as well as the application to the analysis of 58 (ultra) trace analytes in ten real samples demonstrated the applicability to environment monitoring analysis.

In this paper, a monodisperse, well-defined core–shell magnetic molecularly-imprinted polymer (MD-CS-MMIP) was controllably synthesized via modified precipitation polymerization and used as a magnetic solid-phase extraction adsorbent for the simultaneous determination of six trace mycotoxins in rice samples. The as-prepared MD-CS-MMIP was fully characterized by SEM, TEM, XRD, and TG-DTG. This study is particularly concerned with the influence of the amount of oleic acid used for MD-CS-MMIP synthesis on the material morphology, components, and adsorption efficiency. The results reveal that the modification of oleic acid on the Fe3O4 surface could improve the monodispersion of core–shell MD-CS-MMIP. Moreover, MD-CS-MMIP was used as a magnetic solid-phase extraction adsorbent for the determination of six mycotoxin residues in rice samples, and the adsorption and desorption conditions of MD-CS-MMIP toward mycotoxins were optimized to obtain the highest adsorption capacity, selectivity, and desorption efficiency. Under optimal conditions, the limits of quantitation (LOQs) of the developed method toward the six mycotoxins range from 0.003 μg kg−1 to 0.01 μg kg−1. The developed method was successfully used for the determination of mycotoxins in rice samples, with recoveries in the range of 86.3 to 103.1%.

In China, air pollution is getting worse, and the adverse effect of formaldehyde on human health has been attracting more and more attention. The present work proposes a novel, fast and sensitive analytical method for the determination of formaldehyde in the air of public places. This method was based on the determination of the 3-methyl-2-benzothiazolinone hydrazone (MBTH)–formaldehyde condensation product of the derivatization between formaldehyde and MBTH. The actual formaldehyde concentration in air was determined by leading the test atmosphere through a bubble absorption tube containing the MBTH absorption solution and subsequent liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS) analysis. Recoveries of spiked formaldehyde samples were in the range of 92.2–106% with relative standard deviations (RSDs) less than 5.0%. The limit of detection (LOD) of formaldehyde in air samples was 0.05 μg m−3, which was much lower than that of the state standard method of China for the determination of formaldehyde in the air of public places (5.6 μg m−3). The satisfactory validation results and the application to the analysis of formaldehyde in the air of a hotel and subway station demonstrated the applicability to air quality monitoring analysis.

A new facile, rapid, inexpensive, and sensitive method for the analysis of six trace trichlorophenols in seawater samples was developed by magnetic micro-solid-phase extraction coupled to liquid chromatography with tandem mass spectrometry. Core-shell covalently functionalized ferroferric oxide coated with aminated silicon dioxide and decorated with multiwalled carbon nanotubes was applied as an adsorbent to perform the extraction process. The effect of factors including solution pH, contact time, adsorbent amount, and ionic strength were investigated in detail. The obtained results revealed that the proposed adsorbent was a highly effective and low-cost magnetic micro-solid-phase extraction material for the enrichment of 2,3,4-trichlorophenol, 2,3,5-trichlorophenol, 2,3,6-trichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, and 3,4,5-trichlorophenol from seawater. Under the optimized conditions, the recoveries ranged from 88.0 to 99.5% at the three spiking levels, the limits of detection and the limits of quantification were 0.002 and 0.007 μg/L for the six trichlorophenols, respectively. The intra- and interday relative standard deviations were 2.0-6.7 and 4.5-8.9%, respectively. The calibration curves showed a good linearity in the range of 0.02-5.0 μg/L. The routine run analyses showed that the developed method was fast, simple, accurate, solvent-saving and high resolution, and it was suitable for the determination of trace trichlorophenols in seawater.

The objectives of this study were to determine the suitability of total serum lipid (TSL) concentrations, which were calculated by three different formulae, for pregnant women and to optimize the improved matrix solid-phase dispersion (MSPD) method. The results showed that the TSL predicted by the three formulae were significantly correlated to our measured values (sums of the total cholesterol, triglycerides and phospholipids contents). In particular, one of formulae was the most statistically suitable for pregnant women. Meanwhile, an improved MSPD method was developed to extract 22 POPs. The developed MSPD method was compared with SPE and EPA (8081 & 8082) to evaluate the performance of each extract method. The method validation showed that the results obtained using the improved MSPD method were closest to the actual concentration (adjusted by lipids), and the dispersion of the data was minimal.

A novel magnetic metal-organic framework composite was prepared by a self-assembly approach. The material properties were characterized by Fourier-transform infrared spectroscopy, vibrating sample magnetometry, thermogravimetry and differential thermogravimetric analysis, and X-photoelectron spectroscopy. Then, the as-prepared material was used as an adsorbent and indicated great enrichment ability toward glyphosate, glufosinate, bialaphos, and their main metabolites aminomethylphosphonic acid and 3-methylphosphinicopropionic acid. Based on this, an efficient magnetic solid-phase extraction method combined with ultra high performance liquid chromatography with high-resolution mass spectrometry for the pretreatment and determination of five target compounds in environmental waters was established. Parameters that could impact on the adsorption performance had been studied in detail. The proposed method was successfully applied for the simultaneous determination of glyphosate, glufosinate, bialaphos, and their main metabolites aminomethylphosphonic acid and 3-methylphosphinicopropionic acid in environmental water with recoveries in range of 86.2-104.6% with relative standard deviations less than 10%. Desired linearity was achieved varying from 1 to 100 μg/L for five target analytes, respectively. The limits of detection were between 0.01 and 0.03 μg/L.

To develop a method for determination of imidacloprid, acetamiprid, chlorobenzamide and indoxacarb in tea samples using Qu ECh ERS-based pretreatment method and ultra-fast liquid chromatography-tandem mass spectrometry( UFLC-MS/MS).Tea samples were firstly extracted by acetonitrile-water solution( 4∶ 1, V/V) by vortex and ultrasound, and then 1 g Na Cl and 4 g Mg SO4 were added into the mixture, following by vortex and centrifugation at 8500 r/min for 5 min. Finally the supernatant was purified by Mg SO4 and PSA power, and then the chromatographic separation process was performed on a Waters ACQUITY UPLC BEH C18 column( 2. 1 mm × 100 mm, 1. 7 μm) with a linear gradient elution procedure ofacetonitrile and 0. 1%( V/V) formic acid-5 mmol/L ammonium acetate in water as elution solvent. The multiple reaction monitoring( MRM) in positive mode was used for quantification by internal standard method.The four insecticides including imidacloprid, acetamiprid, chlorobenzamide, and indoxacarb showed good linearity in the range of 0. 20-50. 0 μg/L with coefficients( r) higher than 0. 9998. The limits of detection( LODs) varied from 0. 1 μg/kg to 0. 3 μg/kg. The recoveries of spiked tea samples in the range of 88. 4%-98. 8% at the three concentrations of 1. 0 μg/kg, 40. 0μg/kg and 80. 0 μg/kg, while the relative standard deviations( RSD) were all less than10%.The proposed method is simple, fast, sensitive and accuracy, and can be used for qualitative and quantitative analysis of imidacloprid, acetamiprid, chlorobenzamide, andindoxacarb in tea samples.

An effective method has been developed for the simultaneous determination of four bisphenols (bisphenol A, S, F and B) in various foodstuffs. The contaminants were extracted by QuEChERS-based strategy and subjected to ion-exchange solid-phase extraction for further clean-up. The critical variables were screened by Plackett-Burman design and then optimized by central composite design. Under the optimized conditions, satisfactory accuracy (recoveries 76%-116%) and precision (RSDs 12%) were achieved. The established method was then used to assess the contamination status of 379 real samples. Bisphenol A was demonstrated to be the predominant bisphenol with highest incidence (79.7%) and average concentration (14.3 μg/kg). The positive rates (mean concentration) of bisphenol S, F and B were 37.7% (1.6 μg/kg), 26.9% (1.4 μg/kg) and 0.0% (not detected), respectively. Finally, the daily dietary intakes of ∑

A method was developed for the determination of pentachlorophenol( PCP) in food by ultrafast liquid chromatography-tandem mass spectrometry after solid phase extraction.The sample was extracted in 8%triethylamine/acetonitrile( 70/30, V/V) and purified on a MAX-SPE cartridge. The UFLC separation was performed on a Shim-pack XR-ODS Ⅲ column( 150 mm × 2. 0 mm, 2. 2μm) with a linear gradient elution program of acetonitrile and 5 mmol/L ammonium acetate( 0. 1% formic acid) as the mobile phase. Electrospray ionization was applied and operated in the negative ion mode.The limit of quantitation( LOQ) and limit of detection( LOD) for PCP were 0. 4-0. 5 μg/kg and 0. 12-0. 15 μg/kg. The calibration curve showed good linearity between 0. 5-50. 0 μg/L, and the correlative coefficients( r) were more than 0. 999. The recovery was between 82. 0%-108. 0%, and the RSD was between 1. 89%-5. 09%( n = 6).The method is sensitive, reproducible, and adapts to determination of PCP in variety of foods.

A novel triethylenetetramine-functionalized magnetic graphene oxide composite was prepared and used as a magnetic solid-phase extraction adsorbent for the fast detection of ten trace-level phenolic environmental estrogens in environmental water. The synthesized material was carefully characterized by scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, and X-ray photoelectron spectroscopy to confirm the structure and components. The adsorption and desorption conditions of the adsorbent toward phenolic environmental estrogens were optimized in detailed to obtain the best extraction recovery and elution efficiency. Under the optimum conditions, the limits of detection of the method for ten phenolic environmental estrogens were in range of 0.15-1.5 ng/L, which was lower than the reported methods for phenolic environmental estrogens detection in literatures. This could be contributed to the unique structure and property of the as-prepared material. The developed method was successfully applied for the determination of environmental water samples with recoveries ranging from 88.5 to 105.6%.

The present work demonstrates the application of the combination of hydrodynamic cavitation (HC) and the heterogeneous Fenton process (HF, Fe(0)/H2O2) for the decolorization of azo dye Orange G (OG). The effects of main affecting operation conditions such as the inlet fluid pressure, initial concentration of OG, H2O2 and zero valent iron (ZVI), the fixed position of ZVI, and medium pH on decolorization efficiency were discussed with guidelines for selection of optimum parameters. The results revealed that the acidic conditions are preferred for OG decolorizaiton. The decolorization rate increased with increasing H2O2 and ZVI concentration and decreased with increasing OG initial concentration. Besides, the decolorization rate was strongly dependent on the fixed position of ZVI. The analysis results of degradation products using liquid chromatography-ESI-TOF mass spectrometry revealed that the degradation mechanism of OG proceeds mainly via reductive cleavage of the azo linkage due to the attack of hydroxyl radical. The present work has conclusively established that the combination of HC and HF can be more energy efficient and gives higher decolorization rate of OG as compared with HC and HF alone.

Microcystins (MCs), a group of cyclic heptapeptide heaptoxins and tumor promoters, are generated by cyanobacteria occurring in surface waters, such as eutrophic lakes, rivers, and reservoirs. In this present study, a novel double-sided magnetic molecularly imprinted polymer modified graphene oxide (DS-MMIP@GO) based magnetic solid-phase extraction (MSPE) method was developed for fast, effective and selective enrichment, and recognition of trace MCs in environmental water samples combined with high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The synthesized novel DS-MMIP@GO was used as the adsorbents in this work and was carefully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectra. The adsorption and desorption conditions of DS-MMIP@GO toward MCs were optimized in detail to obtain the highest binding capacity, selectivity, and release efficiency. Under the optimum conditions, the enrichment factors of the method for eight target MCs were found to be 2000. The limits of quantitation (LOQs) of the method for eight MCs were in range of 0.1-2.0ngL(-1). The double-sided MMIP modified structure provided DS-MMIP@GO with abundant adsorption sites and permitted it to exhibit excellent enrichment and selectivity toward trace-level MCs. The proposed method was successfully applied for the analysis of environmental water samples with recoveries ranging from 84.1 to 98.2%. Compared to conventional methods for MCs detection reported in literatures, the one developed in this work based on DS-MMIP@GO and LC-MS/MS showed much faster, more sensitive, and more convenient.

Background: In order to search for effective control and prevention measures, the status of metal pollution in Ningbo, China was investigated. Methods: Nine of the most common contaminating metals including lead (Pb), cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), chromium (Cr), nickel (Ni), zinc (Zn), and mercury (Hg) in samples of vegetables, rice, soil, irrigation water, and human hair were detected using inductively coupled plasma-mass spectrometry (ICP-MS). Three different districts including industrial, suburban and rural areas in Ningbo were studied through a stratified random sample method. Results: (1) Among all of the detected vegetable samples, Cd exceeded the standard limit rates in industrial, suburban and rural areas as high as 43.9%, 27.5% and 5.0%, respectively; indicating the severity of Cd pollution in Ningbo. (2) The pollution index (PI) of Cd and Zn in soil (1.069, 1.584, respectively) suggests that soil is slightly polluted by Cd and Zn. Among all samples, metal contamination levels in soil were all relatively high. (3) A positive correlation was found between the concentrations of Pb, Cd and Cu in vegetables and soil; Pb, Cu, Cr and Ni in vegetables and irrigation water, as well as, Cu and Ni in rice and irrigation water; and, (4) Higher Pb and Cd concentrations were found in student scalp hair in both industrial and suburban areas compared to rural areas. (5) Hg and Pb that are found in human scalp hair may be more easily absorbed from food than any of the other metals. Conclusions: In general, certain harmful metal pollutions were detected in both industrial and suburban areas of Ningbo in China.

An in situ controllable approach for fabrication of a well-designed graphene oxide-based ternary magnetic molecularly imprinted polymer hybrid (T-MMIP hybrid) was developed. The GO sheet was firstly modified with Fe3O4 microspheres via a one-pot solvothermal method to prepare GO-Fe3O4. Then, the synthesized GO-Fe3O4 was used as the desired substrate for further in situ co-polymerization in the presence of a functional monomer (acrylamide, AM), cross-linking agent (divinylbenzene, DVB), and template molecule (microcystin-LR, MC-LR), followed by elution of the template molecule. The morphologies and structures of the T-MMIP hybrid were verified by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer analysis (VSM), thermogravimetry analysis (TGA), Brunauer–Emmett–Teller analysis (BET), and fluorescence spectroscopy. The obtained T-MMIP hybrid showed an outstanding affinity towards eight similar structural microcystins (MC-RR, MC-YR, MC-LR, MC-LW, MC-LY, MC-LA, MC-LF, and MC-WR) in aqueous solution under the optimum conditions, and the enrichment factors of this material for the eight MCs were found to be above 2000. Compared with the literature, it showed that the synthesized T-MMIP hybrid binding with the optimal original template MC-LR had a significant improvement on the affinity and selectivity for a group of structurally related compounds.

In this work, a reliable, accurate, and sensitive method based on a simple extraction with trichloroacetic acid at 5% and a clean-up step by means of a Strata-X SPE cartridge prior to the analysis of 14 biogenic amines (BAs) and metabolites by ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) was developed. The 14 BAs and metabolites could be separated by using a LC column under conditions of gradient elution within 6.0 min and simultaneously determined without interference from contaminants in biological samples. The results showed that the Strata-X SPE cartridge used in this method is more effective than C18 SPE and HLB SPE cartridges for cleanup of BAs and metabolites in bullfrog blood. The obtained results demonstrated the higher extraction capacity of the Strata-X SPE cartridge with recoveries between 73.2 and 102%. The limits of quantification for the 14 BAs and metabolites ranged from 0.20–34.3 μg L−1. The developed Strata-X cartridge SPE UFLC-MS/MS method had been successfully applied to 15 real samples, and it was confirmed that the Strata-X SPE cartridge was highly effective for clean-up of BAs and metabolites.

A novel fluoroquinolone molecularly imprinted polymer (MIP) on the surface of ethylenediamine-functionalized magnetic carbon nanotubes (EDA@Mag-CNTs–MIP) was synthesised. The properties of the EDA@Mag-CNTs–MIP were characterized by using a transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). With using EDA@Mag-CNTs–MIP as the adsorbent, a simple and sensitive method based on the use of a magnetic molecularly imprinted polymer matrix solid phase dispersion extraction (Mag-MIP-MSPD) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) was developed to determine 12 fluoroquinolones in river water. Fluoroquinolones adsorbed with EDA@Mag-CNTs–MIP could be simply and rapidly isolated through a magnetic field, and the main factors, i.e., the pH value and sample volume, affecting the extraction were investigated in detail. Under optimal experimental conditions, the enhancement factor of the Mag-MIP-MSPD procedure was 100 times. The obtained results demonstrated the higher extraction capacity of EDA@Mag-CNTs–MIP with recoveries between 80.2 and 116%. The limits of quantification (LOQs) for the fluoroquinolones were between 0.26 and 1.78 ng L−1. The developed Mag-MIP-MSPD UFLC-MS/MS method had been successfully applied to sixty real samples, and it was confirmed that the EDA@Mag-CNTs–MIP was a kind of highly effective Mag-MIP-MSPD material for fluoroquinolone analyses.

A novel hydrophilicity nano-titania coating modified magnetic graphene oxide (HTC-Mag-GO) has been synthesized. It has been evaluated in PRiME (process, robustness, improvements, matrix effects, ease of use) pass-through cleanup procedure for human blood prior to analysis of fipronil and its metabolites, i.e., fipronil sulphone, fipronil sulphide and fipronil desulfinyl by liquid chromatography-tandem quadrupole mass spectrometry (LC–MS/MS). Compared with the Oasis PRiME HLB cartridge, HTC-Mag-GO is much more effective for the removal of matrix effect. Furthermore, it is beneficial to protect the chromatographic column and ESI source by the HTC-Mag-GO PRiME pass-through cleanup procedure, resulting from the much cleaner blood samples. Under the optimum conditions, the results show higher cleanup efficiency of HTC-Mag-GO with recoveries in the range of 92.4%–108%. Especially, the HTC-Mag-GO is also evaluated for reuse (20 times) without much sacrifice of the cleanup efficiency. The limits of quantification (LOQs) for fipronil, fipronil sulphone, fipronil sulphide and fipronil desulfinyl are 8.9 ng/L, 7.2 ng/L, 8.0 ng/L and 42 ng/L, respectively. The developed method has also been successfully applied to monitoring fipronil and its metabolites in 120 blood samples, and fipronil sulphone is detected in six samples with concentrations in the range of 12.1 ng/L–106 ng/L. Further, the well validation results and the application to analysis of fipronil and its metabolites in real samples demonstrate the applicability to toxico kinetic studies and clinical studies.

The dewatering of waste activated sludge by integrated hydrodynamic cavitation (HC) and Fenton reaction was explored in this study. We first investigated the effects of initial pH, sludge concentration, flow rate, and H2O2 concentration on the sludge dewaterability represented by water content, capillary suction time and specific resistance to filtration. The results of dewatering tests showed that acidic pH and low sludge concentration were favorable to improve dewatering performance in the HC/Fenton system, whereas optimal flow rate and H2O2 concentration applied depended on the system operation. To reveal the synergism of HC/Fenton treatment, a suite of analysis were implemented: three-dimensional excitation emission matrix (3-DEEM) spectra of extracellular polymeric substances (EPS) such as proteins and polysaccharides, zeta potential and particle size of sludge flocs, and SEM/TEM imaging of sludge morphology. The characterization results indicate a three-step mechanism, namely HC fracture of different EPS in sludge flocs, Fenton oxidation of the released EPS, and Fe(III) re-flocculation, that is responsible for the synergistically enhanced sludge dewatering. Results of current study provide a basis to improve our understanding on the sludge dewatering performance by HC/Fenton treatment and possible scale-up of the technology for use in wastewater treatment plants.

In this study, novel benzenesulfonic acid groups modified magnetic microspheres (Fe3O4@SiO2@poly(4-VB)) were synthesized and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectrometry (FTIR), and vibrating sample magnetometer (VSM). The as-prepared Fe3O4@SiO2@poly(4-VB) was employed as a magnetic-phase extraction (MSPE) adsorbent for rapid determination of paraquat (PQ) and diquat (DQ) in human urine samples coupled with ultra-high performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). Moreover, this paper had expounded systematically the mass spectrum cracking mechanisms of PQ and DQ. And a zwitterionic functionalized SIELC Obelisc R column was employed for separation and retention of the above two polar herbicides using 50 mmol/L ammonium formate (pH = 3.7)-acetonitrile as the mobile phase. Besides, the adsorption and desorption conditions of Fe3O4@SiO2@poly(4-VB) toward PQ and DQ were optimized in spiking urine samples to obtain the best adsorption and desorption efficiencies. And the adsorption mechanisms of Fe3O4@SiO2@poly(4-VB) toward PQ and DQ referred to synergetic effect of electrostatic attraction and π-π interaction. Under the optimal conditions, the inter-day and intra-day spiking recoveries of the proposed method were in the range of 86.7–109.9% with RSDs less than 10%. The limits of detection (LODs) were obtained by spiking in blank urine samples at a series of low concentrations and were found to be 0.12 μg/L and 0.14 μg/L for PQ and DQ, respectively, which were lower than the comparing literatures. The developed analytical method was proven to be simple, rapid, sensitive, and accurate for clinical poisoning analysis.

A novel core–shell covalently functionalized Fe 3 O 4 coated SiO 2 decorated multi-walled carbon nanotubes (Fe 3 O 4 @SiO 2 –MWCNTs) adsorbent was synthesized and characterized by scanning electron microscopy, transmission electron microscopy, Fourier Transform Infrared Spectrum (FTIR), Thermogravimetry, X-ray diffraction and magnetic measurements. The pentachlorophenol (PCP) adsorption effect factors of initial concentration, contact time, solution pH and temperature were investigated in detail. It was found the absorption capacity was strongly depended on pH, and the maximum adsorption value for PCP (96.4 mg/g) was obtained at pH 2.5. The equilibrium was attained within 30 min, and the adsorption kinetics was better described by pseudo-second-order kinetic model. The data pointed out excellent fit to Freundlich isotherm model. Thermodynamic parameters such as standard enthalpy (Δ H θ ), standard entropy (Δ S θ ) and standard free energy (Δ G θ ) showed that the adsorption of PCP onto Fe 3 O 4 @SiO 2 –MWCNTs was spontaneous, endothermic and random within the temperature range of 288–318 K. The results indicate that the Fe 3 O 4 @SiO 2 –MWCNTs adsorbent is a potential low-cost effective material for PCP removal from contaminated wastewater.

A novel planar-structure amine-functional magnetic polymer modified graphene oxide nanocomposite (NH2-MP@GO) was synthesized. The properties were characterized by transmission electron microscopy (TEM) and Fourier-transform infrared spectrometry (FTIR). The obtained adsorption results showed that the NH2-MP@GO had great adsorptive ability toward five chlorophenols (CPs), including 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and pentachlorophenol (PCP). Based on these, an effective magnetic solid-phase extraction (MSPE) procedure coupled with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the preconcentration and determination of the five CPs in environmental water samples was developed. Various experimental parameters that could affect the extraction efficiencies had been investigated in detail. Under the optimum conditions, the enrichment factors of the method for the target CPs were found to be 1000. The proposed method was successfully applied for the analysis of environmental water samples with recoveries ranging from 86.4 to 99.8% with correlation coefficients (R) higher than 0.9994. Good linearities were obtained ranging from 10 to 500ng/L for 2-CP, 5 to 500ng/L for 2,4-DCP, 2 to 500ng/L for 2,4,6-TeCP and 2,3,4,6-TeCP, and 1 to 500ng/L for PCP, respectively. The limits of quantitation for the five CPs were 0.6-9.2ng/L. It was confirmed that the planar-structure NH2-MP@GO was a kind of highly effective MSPE materials used for the trace CPs analyses.

A novel amphiphilic polymeric ionic liquid membrane containing a hydrophilic bromide anion and a hydrophobic carbonyl group was synthesized in dimethylformamide (DMF) systems using the ionic liquid 1-butyl-3-vinylimidazolium bromide (BVImBr) and the methylmethacrylate (MMA) as monomers. The prepared amphiphilic ploy-methylmethacrylate-1-butyl-3-vinylimidazolium bromide (MMA-BVImBr) was characterized by a scanning electron microscope and an infrared spectrum instrument. The results of solid-phase micro-extraction membrane (SPMM) experiments showed that the adsorption capacity of membrane was about 0.76μgμg(-1) for aniline. Based on this, a sensitive method for the determination of trace aniline, as a degradation product of azo dye Orange G under sonication, was developed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The calibration curve showed a good linearity ranging from 0.5 to 10.0μgL(-1) with a correlation coefficient value of 0.9998. The limit of quantification was 0.5μgL(-1). The recoveries ranged from 90.6% to 96.1%. The intra- and inter-day relative standard deviations were less than 8.3% and 10.9%. The developed SPMM-LC-MS/MS method was used successfully for preconcentration of trace aniline produced during the sonication of Orange G solution.

a b s t r a c t A novel, simple and sensitive method was developed for the simultaneous determination of 22 sulfona- mides (SAs) in chicken breast muscle by using the dispersive micro-solid-phase extraction (d-� -SPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS). The excellent core-shell nanoring amino-functionalized superparamagnetic molecularly imprinted polymer (CS-NR-Mag-MIP) was used as sorbent, and the main factors affecting the extraction efficiency were investigated in detail. All target compounds showed good linearities in the tested range with correlation coefficients (r) higher than 0.9980. The mean recoveries were in the range of 85.0-112.2% at low, medium and high concentration levels (0.1, 1.0 and 5.0 ng/g). The intra-day and inter-day relative standard deviations (RSDs) were lower than 6.0% and 8.9%, respectively. The limits of quantification for the 22 SAs were between 0.013 and 0.099 ng/g. The developed d-� -SPE-UFLC-MS/MS method had been successfully applied to the chicken breast muscle samples for food-safety risk monitoring in Zhejiang Province, China. The results showed sulfamethazine, sulfamethoxazole and sulfaquinoxaline in five out of three hundred collected samples were detected with concentrations of 0.418-2.28, 16.4 and 2.93 ng/g, respectively. It was confirmed that the CS-NR-Mag-MIP was a kind of highly effective d-� -SPE materials used for the SAs analyses.

A novel, simple and sensitive method based on the use of magnetic dispersive solid-phase extraction (M-dSPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC–MS/MS) was developed to determine seven synthetic pigments (tartrazine, amaranth, carmine, sunset yellow, allura red, brilliant blue and erythrosine) in wines and soft drinks. An amino-functionalized low degrees of cross-linking magnetic polymer (NH 2 -LDC-MP) was synthesized via suspension polymerization, and characterized by transmission electron microscopy (TEM). The NH 2 -LDC-MP was used as the M-dSPE sorbent to remove the matrix from the solution, and the main factors affecting the extraction were investigated in detail. The obtained results demonstrated the higher extraction capacity of NH 2 -LDC-MP with recoveries between 84.0 and 116.2%. The limits of quantification (LOQs) for the seven synthetic pigments were between 1.51 and 5.0 μg/L in wines and soft drinks. The developed M-dSPE UFLC–MS/MS method had been successfully applied to the real wines and soft drinks for food-safety risk monitoring in Zhejiang Province, China. The results showed that sunset yellow was in three out of thirty soft drink samples (2.95–42.6 μg/L), and erythrosine in one out of fifteen dry red wine samples (3.22 μg/L), respectively. It was confirmed that the NH 2 -LDC-MP was a kind of highly effective M-dSPE materials for the pigments analyses.

An ionic liquid-based ultrasonic-assisted dispersive liquid–liquid microextraction (IL-USA-DLLME) method was proposed for highly effective extraction of trace bromadiolone and brodifacoum in environmental water samples. The ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate [C6mim][PF6] was quickly disrupted by ultrasonication and dispersed in water as fine droplets. At this stage, the analytes were extracted into the fine ionic liquid droplets. After centrifugation, the concentration of the enriched rodenticides in the sedimented phase was determined. Extraction conditions including extraction solvent, dispersive solvent volume, pH, ultrasonic time and centrifugation time were investigated thoroughly. Compared with the conventional solvent extraction, the proposed approach exhibited higher efficiency, which indicated the IL-USA-DLLME method was an efficient, rapid and simple sample preparation technique. Under optimized extraction conditions, the enrichment factors were up to 122–137 times, achieving the limits of quantitation, which based on the signal-to-noise ratio (S/N) of 10 were 0.005 μg L−1 for both. The linearities for both analytes were in the range of 0.005–1.0 μg L−1 with a correlation coefficient >0.999, and the recoveries were between 88.8–98.3% with relative standard deviations (RSDs) between 1.1% and 9.3%. The proposed method shows high reproducibility, and it is suitable for analysis of trace bromadiolone and brodifacoum in environmental water samples.