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Facile separation and enrichment of polychlorinated biphenyls (PCBs) in foods has been a constantly pursuing goal in food analytical chemistry. Here, a reusable ionic liquid functionalized magnetic graphene oxide nanocomposite (3D-IL@mGO), synthesized based on our previous study, was used as adsorbent for the preconcentration of PCBs in the magnetic dispersive solid phase extraction (Mag-dSPE) procedure. Comparing the proposed 3D-IL@mGO Mag-dSPE procedure with carboxylated multiwalled carbon nanotubes d-SPE method, the 3D-IL@mGO nanocomposite could be reused at least 16 times for the extraction of 11 PCBs from seafood samples without significant sacrifice of the extraction efficiency, which is more economical. Under the optimal conditions, a simple analytical method based on Mag-dSPE and gas chromatography-triple quadrupole mass spectrometry (GC–MS/MS) has been developed for the fast determination of 11 polychlorinated biphenyls (PCBs) in seafood. The LODs for 11 PCBs were in the range of 0.012 μg·kg−1–0.054 μg·kg−1. The recoveries were ranged from 80.0% to 112% with associated intra-day and inter-day relative standard deviations (RSDs) in the range of 2.7%-6.2% and 3.6%-7.3%, respectively. Furthermore, the proposed method was applied for the analysis of 11 PCBs in 240 seafood samples. The results showed that PCB 101, PCB 153 and PCB 204 were found in 18 seafood samples with concentrations ranged from 0.862 μg·kg−1 to 12.1 μg·kg−1. It is, therefore, concluded that the Mag-dSPE procedure combined with GC–MS/MS demonstrated the applicability for food-safety risk monitoring of PCBs in seafood samples.

A novel tetraethylenepentamine-modified graphene oxide/dispersive Fe3O4 magnetic composites (TEPA-MGO-dF) has been prepared through a simple and low-cost process using ultrasound-assisted hydrothermal method. The introduction of ultrasound in the reaction system is critical for reducing the occurrence of magnetic Fe3O4 nanoparticles aggregated together as well as GO sheets stacked layer by layer. Transmission electron microscopy analysis reveals that, with ultrasound, magnetic Fe3O4 nanoparticles own quasi-monodisperse size, and evenly bonded onto the surface of monodermic GO substrates. When used as adsorbents, TEPA-MGO-dF can high-efficiently remove allergenic disperse dyes from water with much higher adsorption capacities than tetraethylenepentamine-modified graphene oxide/aggregated Fe3O4 magnetic composites (TEPA-MGO-aF) prepared without ultrasound-assisted, indicating great potential for use in water treatment. The adsorption properties of TEPA-MGO-dF for the removal of allergenic disperse dyes in wastewater were deeply investigated. The results showed adsorption efficiency was highly pH dependent and adsorption mechanism of the dyes adsorption onto adsorbents could be related with two driving force, i.e., hydrogen bonding and π-π stacking interactions. Furthermore, various isotherms have been used to fit the adsorption data, which was effectively described by the Langmuir model with all R2 > 0.99, and the adsorption kinetic of dyes onto TEPA-MGO-dF can be predicted by the pseudo-second-order model.

Developing different model age determination methods of uranium sample could get more information on insight into source and suspected use in nuclear forensic investigation. A procedure for the determination of model age of uranium sample using 231Pa/235U radiochronometer was reported. The 233Pa spike used in the procedure of 231Pa–235U model age determination was separated from in-house 237Np stock solution by using two TRU resin columns and three silica gel columns and calibrated by CRM U100. Model ages of CRM U010 and IRMM-1000b were presented. The model age of IRMM-1000b using 231Pa/235U radiochronometer were older than the literature reported results by 230Th/234U radiochronometer by amounts exceeded the expanded uncertainty.

A novel ionic liquid coupled with nano-titania coated modified magnetic GO composites (IL-Ti-Mag-GO) has been synthesized. It has been evaluated in an on-line pass-through cleanup procedure for human plasma prior to the analysis of aconitum alkaloids, i.e., mesaconitine, hypaconitine and aconitine, by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). Under optimum conditions, the level of matrix effects can be dramatically reduced by the IL-Ti-Mag-GO on-line pass-through cleanup procedure, with satisfactory recoveries ranging from 81.2% to 108%. The trueness and precision of the developed method were satisfactory, with relative errors (REs) less than 19% and within- and between-run RSDs less than 7.0%. The limits of detection (LODs) and limits of quantification (LOQs) for aconitum alkaloids were in the range of 0.01–0.028 μg L−1 and 0.034–0.092 μg L−1, respectively. The developed analytical method has been successfully applied to the analysis of mesaconitine, hypaconitine and aconitine in two cases of suspected aconite poisoning, and the concentration of aconitine and hypaconitine in one sample was determined to be 0.076 μg L−1 and 0.069 μg L−1, respectively. The results demonstrate the applicability of the developed analytical method to clinical studies.

Two parameter approach –a new technique has been devised and tested to identify and distinguish Pu–bearing particles from U-bearing particles. This technique can be used to select rare and microscopic Pu-bearing particles from environmental samples, such as in soil, water, air (aerosol) and swipe samples from the wall of buildings and surfaces of machines in nuclear factories. Some amount of Pu and U standard reference materials were respectively added to cellulose nitrate (CN) solution and dropped some quantity of the solution on mica plates and dried to from CN sheets. CR-39 track detectors were used to record tracks of α particles emitted from the Pu or U particles in CN sheets. After etching of CR-39 plates, α track stars were developed and can be seen under optical microscope. Tracks shapes of α particles in the stars were investigated. We found that at certain interval of etching time, the tip part of α tracks of Pu was very sharp, but the tip part of α tracks of U was blunted with spherical tips. The ratio Rt/Ro of the diameter (Rt) of tip point to the diameter (Ro) of the round track in center area of star is a superior parameter to identify Pu from U particles. The Rt/Ro measurements should be carried at a certain distance from the center point. The two parameter approach has been using in nuclear safeguards and nuclear forensics to analyze isotopic compositions and age of Pu samples.

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 growing use of non-steroidal anti-inflammatory drugs (NSAIDs) has seriously affected human health and ecosystems, as a result, the World Health Organization (WHO) has regarded them as emerging contaminants. NSAID’s polar nature and trace amount present in wastewater make their extraction and determination challenging in modern analytical science. Therefore, regarding the need, we herein report a rapid, sensitive and selective in-syringe solid-phase extraction (SPE) method coupled with ultrahigh performance liquid chromatography and UV detector for the determination of seven NSAIDs in environmental water samples. Specifically, the NSAIDs in water samples were directly extracted by using synthesized porous covalent organic framework functionalized poly (styrene-divinyl benzene-glycidylmethacrylate) composite (COF@PS-GMA) without further cleanup procedures. The adsorption of NSAIDs on COF@PS-GMA sorbent was investigated by using adsorption isotherms and kinetic studies. Various parameters, including amount of sorbent, pH of the samples, the volume of desorption solvent, and desorption time that were involved in in-syringe SPE were optimized. Under the optimized conditions, good linearity was observed at 0.005–5.0 μg mL−1 with method quantification limits (LOQs) estimated between 0.54–2.74 μg L−1. The recoveries of the seven NSAIDs at the level of 0.5, 5.0 and 20.0 μg L−1 were ranging from 84.3% to 99.6%.

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.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitously found in the environment and have been proved to be prospectively associated with the risk of cancer. In this study, a simple method based on pipette-tip solid phase extraction (PT-SPE) and gas chromatography-mass spectrometry (GC–MS) has been firstly developed for the determination of 16 PAHs in human whole blood. Three-dimensional ionic liquid-ferrite functionalized graphene oxide nanocomposite (3D-IL-Fe3O4-GO) was used as sorbent in PT-SPE. Compared with conventional SPE method, the PT-SPE method was solvent-saving (1.0 mL), reusable (at least 10 times) and required less blood sample (200 μL). Affecting parameters on extraction efficiency were investigated and optimized. Under the optimized conditions, a good linearity was obtained and the recoveries of 16 PAHs at three spiked levels ranged from 85.0% to 115%. The limits of quantification (LOQs) were in the range of 0.007-0.013 μg/L. Furthermore, the developed method was successfully applied to the analysis of 16 PAHs in 14 human blood samples. The results showed that the predominant PAHs in human whole blood was low-molecular-weight PAHs, with the rank order phenanthrene (PHE)> naphthalene (NAP)> fluorene (FLU)> fluoranthene (FLT)> pyrene (PYR). Because of its simplicity, accuracy and reliability, the PT-SPE method combined with GC–MS demonstrated the applicability for clinical analysis and provided more information for PAHs exposure studies.

A simple and effective method based on the PRiME (process, robustness, improvements, matrix effects, ease of use) pass-through cleanup procedure followed by ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry (UHPLC-MS/MS) was developed for analyzing fipronil and its metabolites in seafoods. Matrix effects in seafoods were effectively improved. Validation results demonstrated that this method was suitable for monitoring fipronil residues in seafoods.

In this paper, a novel three-dimensional ionic liquid functionalized magnetic graphene oxide nanocomposite (3D-IL@mGO) was prepared, and used as an effective adsorbent for the magnetic dispersive solid phase extraction (MSPE) of 16 polycyclic aromatic hydrocarbons (PAHs) in vegetable oil prior to gas chromatography-mass spectrometry (GC-MS). The properties of 3D-IL@mGO were characterized by scanning electron micrographs (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM). The 3D-IL@mGO, functionalized by ionic liquid, exhibited high adsorption toward PAHs. Compared to molecularly imprinted solid phase extraction (MISPE), the MSPE method based on 3D-IL@mGO had less solvent consumption and low cost, and was more efficent to light PAHs in quantitative analysis. Furthermore, the rapid and accurate GC-MS method coupled with 3D-IL@mGO MSPE procedure was successfully applied for the analysis of 16 PAHs in eleven vegetable oil samples from supermarket in Zhejiang Province. The results showed that the concentrations of BaP in 3 out of 11 samples were higher than the legal limit (2.0μg/kg, Commission Regulation 835/2011a), the sum of 8 heavy PAHs (BaA, CHR, BbF, BkF, BaP, IcP, DaA, BgP) in 11 samples was between 3.03μg/kg and 229.5μg/kg. Validation results on linearity, specificity, accuracy, precision and stability, as well as on application to the analysis of PAHs in oil samples demonstrated the applicability to food safety risk monitoring in China.

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 rapid and simple approach involving two-dimensional ultrahigh-performance liquid chromatography (UHPLC) combined with ion chromatography (IC) through valve-switching was developed to determine parabens and inorganic anions in cosmetics simultaneously. Compared with a conventional IC column-switching technique, the proposed method required UHPLC coupled with IC via valve-switching without refreshing the pretreatment column. In this chromatographic system, a mobile phase with 60% methanol and 40% deionized water was used to simultaneously separate parabens, namely, methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP), and to eliminate the matrix, and KOH eluent (20 mmol L−1) was utilized to separate inorganic anions, such as nitrite, sulfite, sulfate, and nitrate. Organic compound analysis, and inorganic anion pretreatment and analysis were simultaneously performed with a single injection. Under optimized conditions, matrix–calibration curves were examined by preparing and analyzing different concentrations of mixture standard solutions containing parabens and inorganic anions. Linearity was between 0.9994 and 0.9999. The limits of detection ranged from 8.0 to 80 μg L−1. Satisfactory recoveries of cosmetic samples were obtained between 93.9% and 106.2% by adding three representative standard solutions. The proposed method can be applied to routine analysis, as indicated by the validated linearity, accuracy, and precision and potential application on the analysis of MP, EP, PP, BP, nitrite, sulfite, sulfate and nitrate in eight commercial samples.

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%.

An improved method of Fission Track technique combined with Thermal Ionization Mass Spectrometry (FT-TIMS) was established in order to determine isotope ratio of uranium-bearing particle. Working standard of uranium oxide particles with a defined diameter and isotopic composition were prepared and used to review the method. Results showed an excellent agreement with certified values. The developed method was used to analyze isotope ratio of single uranium-bearing particle in swipe samples successfully. The analysis results of uranium-bearing particles in swipe samples accorded with the operation history of the origin.

To develop a rapid, effective, and accurate method for the simultaneous determination of chloramphenicol, thiamphenicol, and florfenicol in human blood by pass-through cleanup solid-phase extraction combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS), novel nano-titania-coated modified magnetic graphene oxide (TiO2-Mag-GO) is used as the PRiME pass-through cleanup solid-phase extraction sorbent for the cleanup of blood phospholipids. The chromatographic separation was performed on an Eclipse Plus C18 column (100 mm×2.1 mm, 1.8 μm) using 0.08% (v/v) aqueous ammonia solution and acetonitrile having aqueous ammonia (0.08%, v/v) as mobile phases. The tandem mass spectrometer was operated using electrospray ion source (ESI) in the multiple reaction monitoring (MRM) mode. The results showed that the linearities were in the range of 0.1-10.0 μg/L with the determination coefficients (r2) greater than 0.9990 for chloramphenicol, thiamphenicol, and florfenicol. The limits of quantification (LOQs) (S/N>10) in the blood samples were between 0.056 and 0.082 μg/L and the recoveries ranged from 90.0% to 105% at three spiked levels. Precision values expressed as relative standard deviations (RSDs) were in the range of 1.2%-6.6%. The developed method can be used for routine analyses to determine chloramphenicol, thiamphenicol, and florfenicol in clinical studies.

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 simple, cost-effective, sensitive, and quick method for the determination of nitenpyram and its metabolite 6-chloronicotinic acid in environmental samples was developed by coupling an ion chromatograph with a fluorescence detector and a post-column photochemical reactor. This developed analytical method involved a rapid sample extraction by modified and miniaturized quick, easy, cheap, effective, rugged, and safe method followed by isocratic ion chromatographic separation of nitenpyram and 6-chloronicotinic acid into an IonPac™ AS11-HC column protected by IonPac™ AG11A guard column by running 30 mM NaOH + 10% acetonitrile mobile phase. A homemade post-column photochemical reactor was also integrated with the ion chromatographic system for online transformation of both analytes into their respective highly fluorescent photoproduct in basic media without using an extra pump. The developed method was validated by following SANTE/11945/2015 guidelines on analytical quality control and validation procedures. The method showed a good linear response (r > 0.999), improved limit of detection (0.101-0.132 μg/L), minimum or no matrix effect, excellent recoveries (90.2-100.10%) and relative standard deviations were found to be ≤6.50%.

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.

A novel series of biaryl amides was identified as RORγt inhibitors through core replacement of a starting hit 1. Structure-activity relationship exploration on the biaryl moiety led to discovery of potent RORγt inhibitors with good oral bioavailability and CNS penetration. Compounds 9a and 9g demonstrated excellent in vivo efficacy in EAE mice dose dependently with once daily oral administration.

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.

An enhanced cleanup efficiency hydroxy functionalized-magnetic graphene oxide (EH-Mag-GO) fully covered porous nano-titania as coating has been designed and synthesized. It has been evaluated in PRiME (process, robustness, improvements, matrix effects, ease of use) pass-through cleanup procedure for human plasma prior to analysis of strychnine and brucine by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). Comparing with the magnetic carboxyl-graphene (Mag-CG), EH-Mag-GO is much more effective for the removal of matrix effect resulted from blood phospholipids. Under optimal conditions, the results show higher cleanup efficiency of EH-Mag-GO with recoveries in the range of 89.4%–118%. The limits of quantification (LOQs) for strychnine and brucine are 0.088 μg/L and 0.092 μg/L, respectively. Especially, the EH-Mag-GO is also evaluated for reuse (20 times) without much sacrifice of the cleanup efficiency. Validation results on linearity, specificity, accuracy and precision, as well as on the application to analysis of strychnine and brucine in six cases of suspected semen strychni poisoning demonstrate the applicability to clinical studies.

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, simple, and sensitive method based on the use of dispersive micro-solid-phase extraction (d-μ-SPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) for the determination of memantine (ME) was developed and validated over the linearity range 0.05–10.0 µg/L with 100 μL of human plasma using memantine-D6 (ME-D6) as the internal standard. The novel nanoring carboxyl-functionalized paramagnetic molecularly imprinted polymer (NR-CF-Mag-MIP) was synthesized by ultrasound-assisted suspension polymerization, using ME as a template molecule, methacrylic acid as a functional monomer, and divinylbenzene as a cross-linking agent. The NR-CF-Mag-MIP was used as the d-μ-SPE sorbent to extract ME from human plasma samples. The obtained results demonstrated the higher extraction capacity of NR-CF-Mag-MIP with recoveries between 97.6 and 101%. The limits of quantification (LOQs) for ME was 0.015 µg/L. Validation results on linearity, specificity, accuracy, precision, and stability, as well as on application to the analysis of samples taken up to 480 h after oral administration of 20 mg (two 10 mg capsules) of ME in healthy volunteers demonstrated the applicability to bioequivalence studies. Copyright © 2014 John Wiley & Sons, Ltd.

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.

A novel and effective dispersive micro-solid-phase extraction (d-µ-SPE) using ethanediamine-functionalized magnetic Fe3O4 polymer (EDA-MP) as an efficient adsorbent in wine sample was developed. Based on this, a simple and time-saving analytical method for the simultaneous determination of seven synthetic colorants (i.e., tartrazine, amaranth, carmine, sunset yellow, allura red, brilliant blue and erythrosine) in wine by reversed-phase high-performance liquid chromatography with an ultraviolet detector was established. The experimental parameters, including the chromatographic retention behavior of studied synthetic colorants, the effect of the usage amount of cross-linking monomer, the effect of the usage amount of EDA-MP on the recovery and the recyclability of the adsorbents, were studied in detail. The results showed that the EDA-MP could be reused efficiently at least six times. Under optimized conditions, the recoveries for all analytes were in the range of 88.6-105.2%, with the intraday relative standard deviations (RSDs) ranging from 2.1 to 8.2% and the interday RSDs ranging from 3.4 to 8.7%, and all the analytes had good linearities in the tested ranges with correlation coefficients (r(2)) >0.9995. The limits of quantification for seven synthetic colorants were between 0.12 and 0.45 mg L(-1). The developed method was successfully applied to wine samples, and it was confirmed that the EDA-MP particles were highly effective d-µ-SPE materials.

Novel series of N-(5-(arylcarbonyl)thiazol-2-yl)amides and N-(5-(arylcarbonyl)thiophen-2-yl)amides were discovered as potent retinoic acid receptor-related orphan receptor-gamma-t (RORγt) inhibitors. SAR studies of the RORγt HTS hit 6a led to identification of thiazole ketone amide 8h and thiophene ketone amide 9g with high binding affinity and inhibitory activity of Th17 cell differentiation. Compound 8h showed in vivo efficacy in both mouse experimental autoimmune encephalomyelitis (EAE) and collagen induced arthritis (CIA) models via oral administration.

Correction for ‘Controlled synthesis of pentachlorophenol-imprinted polymers on the surface of magnetic graphene oxide for highly selective adsorption’ by Sheng-Dong Pan et al., J. Mater. Chem. A, 2014, 2, 15345–15356.

A novel and effective dispersive solid-phase extraction (dSPE) procedure using tetraethylenepentamine-functionalized Fe 3 O 4 magnetic polymer (TEPA-MP) as an efficient adsorbent for cleaning up the matrix in wine was developed. Based on this, a simple and rapid analytical method for the simultaneous determination of nine food additives (i.e., acesulfame, saccharin, caffeine, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid and neotame) in wine by reversed-phase high-performance liquid chromatography (RP-HPLC) with an ultraviolet (UV) detector was established. The results showed that the recoveries of the acidic food additives (p K a r 2 ) higher than 0.9991. The limits of quantification (LOQs) for the nine food additives were between 0.17 and 0.92 mg/L. The developed method was successfully applied to the wine samples, and it was confirmed that the TEPA-MP particles were highly effective dSPE materials.

A series of ethylenediamine (EDA)-functionalized magnetic polymers (EDA-MPs) have been prepared via suspension polymerization with the usage amount of the functional monomer glycidylmethacrylate (GMA) varied during the suspension polymerization procedure. The EDA-MPs were characterized by transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), X-ray diffractometer (XRD), thermogravimetry and differential thermogravimetry analysis (TG-DTA), Fourier-transformed infrared spectroscopy (FTIR) and elementary analyzer (EA). The adsorption properties of the EDA-MPs for the removal of Cr(VI) in wastewater were deeply studied. The results showed the adsorption efficiency was highly pH dependent and decreased with the increasing of initial concentration of Cr(VI). The adsorption data taken at the optimized condition, i.e., 35 degrees C and pH of 2.5 were well fitted with the Langmuir isotherm. The maximum adsorption capacities (q(m)) of EDA-MPs to Cr(VI) were highly related to the contents of EDA-MPs, i.e., the q(m) of EDA-MPs to Cr(VI) calculated from the Langmuir isotherm increased from 32.15 to 61.35 mg g(-1) with the increasing of the usage amount of GMA. The adsorption kinetic data were modeled by the pseudo-second-order rate equation, and the adsorption of Cr(VI) by all the present EDA-MPs reached equilibrium in 60 min.

Four kinds of NH2-functionalized nano magnetic polymer adsorbents (NH2-NMPs) coupled with different diamino groups, i.e., ethylenediamine (EDA), diethylenetriamine (DETA), triethylentetramine (TETA), and tetraethylenepentamine (TEPA), named as EDA-NMPs, DETA-NMPs, TETA-NMPs, and TEPA-NMPs, respectively, have been prepared and characterized by transmission electron microscopy (TEM), X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), elementary analyzer (EA), Brunauer, Emmett, Teller surface area analyzer (BET), and Fourier transform infrared spectroscopy (FTIR). The sorptive characteristics of the NH2-NMPs intended for removal of chromium(VI) was investigated. Batch adsorption studies were carried out to optimize adsorption conditions. The evaluation of the adsorption kinetics, isotherm, and thermodynamics was deeply investigated. The results showed the adsorptive properties of the NH2-NMPs were highly pH dependent. Adsorption of Cr(VI) reached equilibrium within 30 min. The data of adsorption kinetics obeyed pseudo-second-order rate mechanism well. The adsorption data for Cr(VI) onto NH2-NMPs were well fitted to the Langmuir isotherm. The maximum adsorption capacities (q m) of the NH2-NMPs to Cr(VI) were 136.98, 149.25, 204.08, 370.37 mg g−1, for EDA-NMPs, DETA-NMPs, TETA-NMPs, and TEPA-NMPs, respectively. Thermodynamic parameters like ΔH θ, ΔS θ, and ΔG θ for the adsorption of Cr(VI) onto the NH2-NMPs have been estimated, which suggested that the adsorption processes of Cr(VI) onto the NH2-NMPs were endothermic and entropy favored in nature. The adsorption mechanism studies showed that the adsorption of Cr(VI) onto the NH2-NMPs could be related with electrostatic attraction, ion exchange, and coordination interactions.

Isotopic ratio of single uranium-bearing particle in swipe samples was very important for safeguards environmental sampling. For this purpose, an improved FT-TIMS method was developed in this work: (1) Uranium-bearing particles are suspended in the solution of cellulose nitrate commixed with isoamyl acetate, and then spread onto a glass surface, the solution was dried to form a transparent film; (2) After irradiating and etching, uranium-bearing particles can be found and located under microscope. The small part of the film contained one uranium-bearing particle is then cut off and transferred to a filament of TIMS; (3) Isotopic ratio of the particle is determined by TIMS. The problem of particles losing has been avoided in the process of sample preparing, particle locating and transferring. The deviation of the result from the certified value of CRM was less than 5%.

Based on the formation of tetramethylthiuram disulfide (thiram)–copper(II) complex by square-wave voltammetry on a glassy carbon electrode, a new method is proposed for determination of thiram. There is a good linear relationship between peak current and concentration of thiram in the range of 6.0×10 −6 to 8.0×10 −5 mol l −1 ( r =0.999). The method is applied to the determination of thiram residue in plant with satisfactory results, compared with results achieved by using HPLC. Two oxidation peaks and two reduction peaks are obtained by cyclic voltammetry on a glassy carbon electrode in 0.2 mol l −1 HAc–NaAc (pH 4.0) solution containing thiram–copper(II) complex. The electrode reaction process is quasi-reversible with adsorptive characteristics. The mechanism of electrode reaction is discussed.

A rapid and accurate method by liquid chromatography/tandem mass spectrometry (LC-MS/MS) using positive electrospray was established for the determination of ricinine in cooking oils. The homogenized samples, spiked with (13)C6-labelled ricinine as an internal standard, were extracted using ethanol/water (20:80, v/v) and purified by dispersive solid-phase extraction (dSPE) using primary-secondary amine (PSA) and C18 as adsorbents. The extract was separated in a short C18 reversed-phase column using methanol/water (25:75, v/v) as the mobile phase and detected in multiple reaction monitoring (MRM) mode with the absolute matrix effect of 93.2-102.2%. The alkali-metal adduct ions were discussed and the mass/mass fragmentation pathway was explained. Ricinine showed good linearity in the range of 0.5-50.0 μg/kg with the limit of quantitation 0.5 μg/kg. The recoveries were between 86.0% and 98.3% with the intra- and inter-day RSDs of 2.6-7.0%, 5.5-10.8%, respectively. This method could be applied to the rapid quantification of ricinine in cooking oils.

A reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the simultaneous determination of nine food additives, i.e., acesulfame, saccharin, caffeine, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid and neotame in red wine. The effects of ion-suppressors, i.e., trifluoroacetic acid (TFA) and ammonium acetate (AmAc) on retention behavior of nine food additives in RP-HPLC separation were discussed in detail. The relationships between retention factors of solutes and volume percent of ion-suppressors in the mobile-phase systems of acetonitrile-TFA aqueous solution and acetonitrile-TFA-AmAc aqueous solution were quantitatively established, respectively. The results showed that the ion suppressors had not only an ion suppression effect, but also an organic modification effect on the acidic analytes. The baseline separation of nine food additives was completed by a gradient elution with acetonitrile-TFA(0.01%, v/v)-AmAc(2.5 mmol L(-1)) aqueous solution as the mobile phase. The recoveries were between 80.2 - 99.5% for all analytes with RSDs in the range of 1.5 - 8.9%. The linearities were in the range of 0.2 - 100.0 mg L(-1) with determination coefficients (r(2)) higher than 0.9991 for all analytes. The limits of quantification (LOQs) were between 0.53 - 0.99 mg L(-1). The applicability of the proposed method to detect and quantify food additives has been demonstrated in the analysis of 30 real samples.

A novel and effective dispersive solid-phase extraction (dSPE) procedure with rapid magnetic separation using ethylenediamine-functionalized magnetic polymer as an adsorbent was developed. The new procedure had excellent clean-up ability for the selective removal of the matrix in red wine. An accurate, simple, and rapid analytical method using ultra-fast liquid chromatography–tandem quadrupole mass spectrometry (UFLC–MS/MS) for the simultaneous determination of nine food additives (i.e., acesulfame, saccharin, sodium cyclamate, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid, and neotame) in red wine was also used and validated. Recoveries ranging from 78.5% to 99.2% with relative standard deviations ranging from 0.46% to 6.3% were obtained using the new method. All target compounds showed good linearities in the tested range with correlation coefficients ( r ) higher than 0.9993. The limits of quantification for the nine food additives were between 0.10 μg/L and 50.0 μg/L. The proposed dSPE–UFLC–MS/MS method was successfully applied in the food-safety risk monitoring of real red wine in Zhejiang Province, China.

New selective Zn2+ fluorescent sensors, di(2-quinoline-carbaldehyde)-2,2'-bibenzoyl-hydrazone (QB1) and di(2-quinolinecarbaldehyde)-6,6'-dicarboxylic acid hydrazone-2,2'-bipyridine (QB2), have been designed and prepared. Both QB sensors exhibit an emission band centered at 405 nm (excitation at 350 nm) with low quantum yield. Zinc binding not only red-shifts the emission band to 500 nm, but also enhances the fluorescence intensity by an order of magnitude based on the deprotonization strategy via self-assembly. These probes are highly selective for Zn2+ over biologically relevant alkali metals, alkaline earth metals and the first row transition metals such as Mn2+, Fe2+, Co2+ and Ni2+ in buffered aqueous DMSO solution.

Novel triple-stranded binuclear helical complexes of silver(I) with various coordination modes are generated from the simple imine-based rigid ligand L (pyridylmethylketazine) via self-assembly in the presence of concentrate silver salts upon crystallization.