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The development of multiplex assays to simultaneously monitor multiclass chemical contaminants that commonly coexist in foods, such as heavy metal ions, antibiotics, and estrogen residues, is gaining attention. Here, a microfluidic chip (MC)-based multianalysis method coupled with magnetic encoded aptamer probes was used for simultaneous detection of kanamycin, 17β-estradiol, and lead ion (Pb2+). Using this innovative strategy, the magnetic bead (MB)-based encoded probes labeled with aptamer hybrid chains were first used to selectively capture multiple targets, followed by generating single-stranded primers. The primers triggered a multibranched hybridization chain reaction (mHCR). Finally, three kinds of complementary strands (C-DNAs) with different lengths were hybridized with the arms of the mHCR products to form three types of multibranched DNA nanostructures. The decrement signals of C-DNAs were employed for qualification of targets. As the signal tags corresponded to different targets, the DNA nanostructures realized "one target for the decrease of massive C-DNAs" to improve sensitivity. The use of MB-based encoded probes could achieve magnetic separation to eliminate interference in the complex. The detection limits of this method were 1.76 × 10-4 nM (kanamycin), 1.18 × 10-4 nM (17β-estradiol), and 1.29 × 10-4 nM (lead ion). Furthermore, the MC platform is reusable and can be used for more than 4000 samples. The assay combining the MC with MB-based encoded probes with multibranched DNA signal tags offers a universal, reusable, and high-throughput detection platform for screening multiclass chemical contaminants in food samples with complex matrices.

Correction for ‘In situ controllable synthesis of graphene oxide-based ternary magnetic molecularly imprinted polymer hybrid for efficient enrichment and detection of eight microcystins’ by Sheng-Dong Pan et al., J. Mater. Chem. A, 2015, 3, 23042–23052.

There are some problems faced in the teaching model of the Chemical Engineering and Technology major in higher education. In traditional teaching model, cultivation of professional talents mainly focused on teaching theoretical knowledge, while neglecting engineering education and the connection with industry enterprises. Under the background of engineering education professional certification and "Double first-class plan", speciality development faces new challenges and opportunities. In this paper, we introduce a systematic student-centered teaching model for undergraduates majoring in Chemical Engineering and Technology. Preliminary practical results have been presented for discussion and criticism.

It is challenging to greatly increase of the extraction selectivity and efficiency by stir bar sorptive extraction of ultra-trace polychlorinated biphenyls (PCBs) in complex environmental matrix, e.g., soils. To fulfill this purpose, one of the critical works is to prepare some coatings with high selectivity, adsorptive capacity and reusability. It is also important to develop some green, simple methods for preperation the coatings. In this work, a kind of highly efficient and bioactive coating based on hyperbranched aptamer (HB-Apt) was constructed via hybridization chain reaction (HCR). Then, the HB-Apt was coated on a magnetic stir bar and applied to headspace extraction of PCB72 and PCB106 in soils. The core-shell gold magnetic particles (Fe3O4@AuNPs, AuMNPs for short) was employed as the substrate to immobilize the HB-Apt. The extracted PCBs on the stir bar could be easily eluted in ethanol by stirring, and then sampled in gas chromatography-mass spectrometry (GC-MS) for qualification. The ultra-low detection limit (0.003–0.005 ng•g−1), good linearity (0.01–500 ng•g−1, R2≥0.994) and reproducibility (RSD: 4.58–6.53%) were obtained. Compared with the common aptamer coating, the HB-Apt coating exhibited good selectivity and higher extraction capacity. The results might be related to the fact that there are more aptamer fragments grated on the HB-Apt coating than those of the common aptamer coating. The magnetic stir bar can not only be employed for easy headspace extraction, but also facilitate separation and elution. Moreover, the coating could be recycled for at least 60 times before recoveries of the PCB72 and PCB106 in the spiked samples drop below 90%. All these indicated that the assay is simple, robust, environment friendly and promising for detection of trace PCBs in complex environmental samples.

The major of Chemical Engineering and Technology is one of the oldest specialties in higher education. In the traditional education model for training of engineering students, there are still some problems, such as paying too much attention to theoretical knowledge, ignoring the connection between engineering education and industry enterprises. In this paper, taking the construction of a talent training model and practice in the major of the Chemical Engineering and Technology in our institute, as an example. We introduce a practical way for training of engineering students and preliminary results for idea exchange and criticism by peers.

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.

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.

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.

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.

In this work, a systematic approach to develop the teaching of general education courses via flipped classroom strategy is discussed. A series course of general chemistry is taken as examples for discussion. A conceptual framework for organizing and executing three-in-one combination teaching and studying systems, i.e., in-out class studying, on-off line studying, theoretical-practical studying, is presented. Problem based learning (PBL) and cooperative learning (CL) methods are applied. Overall, a student-centered environment is proposed which aims to train students’ innovative and critical thinking capabilities.

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 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.

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.

This article has been retracted at the request of the Editor after the corresponding author pointed the Editor to comments from an anonymous reader. The article reports electron micrographs of different preparations while showing identical images as used in previous publications by the same authors. The particles in Fig. 4C (SEM image of Fe3O4@SiO2) are identical to each other and the corresponding author confirmed that these have been copy-pasted. In addition, these particles have previously been communicated as different substances in Fig. 1B from Pan et al., J. Mater. Chem. A, 2015,3, 23042-23052 (DOI: 10.1039/C5TA05840F) and Fig. 3F from Pan et al., Anal. Methods, 2017,9, 5281-5292 (DOI: 10.1039/C7AY01444A). Furthermore, the curves in Fig. 7, especially the baseline, shows a remarkable similarity to Fig. 8 from Pan et al., J. Mater. Chem. A, 2015,3, 23042-23052 (DOI: 10.1039/C5TA05840F) and Fig. 5F from Pan et al., J. Mater. Chem. A, 2014,2, 15345-15356 (DOI: 10.1039/c4ta02600d). The manipulation of images and data in this way is a serious offense to the integrity of the scientific community and casts doubts on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).

A novel, simple and sensitive method was developed for the simultaneous determination of eight phenolic environmental estrogens in blood by using the dispersive micro-solid-phase extraction (d-µ-SPE) procedure combined with ultra-fast liquid chromatography–tandem quadrupole mass spectrometry (UFLC–MS/MS). The excellent nanomaterials tetraethylenepentamine-functionalized magnetic polymer was used as an adsorbent, 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 0.999. The mean recoveries were in the range of 85.0–105.0%. The intra-day and inter-day relative standard deviations (RSDs) were lower than 4.9% and 5.2%, respectively. The limits of quantification for the eight phenolic environmental estrogens were between 0.075 and 0.42 µg L−1. The developed method can be applied to the routine analyses for the determination of the eight phenolic environmental estrogens in blood samples.

Spinel Li 4 Ti 5− x Zr x O 12 (0 ⩽ x ⩽ 0.25) materials were prepared by a solid-state reaction method using Li 2 CO 3 , ZrO 2 and TiO 2 as raw material, and the structure and electrochemical performance of the material were investigated by TG–DTA, XRD, SEM, CV, EIS and charge–discharge tests. The Zr-doped Li 4 Ti 5 O 12 materials show much improved rate capability and specific capacity compared with pristine Li 4 Ti 5 O 12 . Especially, the pristine Li 4 Ti 5 O 12 offers about 111 mA h g −1 , but Li 4 Ti 4.9 Zr 0.1 O 12 delivers a remarkable capacity of 172 mA h g −1 at 2 C charge–discharge rate. Li 4 Ti 4.9 Zr 0.1 O 12 sample delivers a capacity of 155 mA h g −1 even after 150 cycles at 5 C charge–discharge rates, implying the possibility for high power applications, such as HEV and PHEV. The rate capability of the anode material made from the modified powder is significantly improved when discharged at high current rates due to the reduced charge transfer resistance and fast lithium insertion/extraction kinetics.

Nb-doped LiMn2O4 materials were synthesized by a solid state process, and the structure and kinetic performance were characterized by TG-DTA, XRD, SEM, CV, and EIS. TG-DTA shows that the decomposition reaction has almost completed and all reactions have finished at the temperature of 590 °C. XRD indicates that the all samples are in accordance with the standard spinel LiMn2O4. However, it can be found that little Nb5+ ions do not completely substitute Mn3+ ions of LiMn2−1.667xNbxO4 (x=0.02, 0.03, 0.04). SEM reveals that the average particle size of all samples is about 1 μm. CV exhibits that the improved reversibility and dynamic behaviors of LiMn2O4 can be attributed to the Nb doping. EIS demonstrates that Nb doping decreases the charge transfer resistance of LiMn2O4, and then reduces the cell impedance. Nb doping results in lower electrode polarization and a high lithium ion diffusion coefficient, and can effectively improve the kinetic performance of LiMn2O4.

A systematic approach to develop the teaching of instrumental analytical chemistry is discussed, as well as a conceptual framework for organizing and executing lectures and a laboratory course. Three main components are used in this course: theoretical knowledge developed in the classroom, simulations via a virtual laboratory, and practical training via experimentation. Problem-based learning and cooperative-learning methods are applied in both the classroom and laboratory aspects of the course. In addition, some reflections and best practices are presented on how to encourage students to learn actively. Overall, a student-centered environment is proposed that aims to cultivate students’ practical abilities and individual talents.

The structural and thermal stability are essential to understand the safety of Li 4 Ti 5 O 12 , but it is not fully understood. Here, the structural and thermal stability were investigated by the density functional theory (DFT) plane-wave pseudopotential technique and experimental method. Sub-micro Li 4 Ti 5 O 12 particles were synthesized by a solid-state reaction. The calculated results of lattice parameters are highly coincident with the experimental values. XRD and Raman spectra demonstrate the formation of pure phase Li 4 Ti 5 O 12 . There is an amorphous phase and no phase transition when discharged to 0 V, which confirms that there is a certain reversible intercalation processes cycled below 1 V instead of a reduction–decomposition reaction. SEM shows that Li 4 Ti 5 O 12 powder has a uniform, nearly cubic structural morphology with a narrow size distribution of about 500 nm. The low formation enthalpy (−6061.45 ± 4) indicates that Li 4 Ti 5 O 12 has a high thermodynamic stability. The superior cycling performance at high rates cycled between 0 and 2.5 shows that Li 4 Ti 5 O 12 has a very high structural stability. The high thermodynamic stability of Li 4 Ti 5 O 12 is related to the strong covalent bonding characteristic between Ti and O according to the electron density difference diagram. DSC reveals that PF 5 is the main species which damages the SEI layer.

A series of mercapto-functionalized core–shell structured nano-magnetic Fe 3 O 4 polymers (SH-Fe 3 O 4 -NMPs) with different amount of magnetic core were synthesized and characterized by XRD, EA, VSM, TG–DTG and XPS. Their applications as adsorbents for Hg(II) removal from aqueous solutions were intensively investigated. The adsorption process of Hg(II) by SH-Fe 3 O 4 -NMPs was found highly pH dependent and related to the content of Fe 3 O 4 magnetic core in the adsorbents. The optimized content of magnetic core for SH-Fe 3 O 4 -NMPs was found to be at 5.88%. Kinetic studies showed that the adsorption of Hg(II) by SH-Fe 3 O 4 -NMPs followed pseudo-second-order model, suggesting a chemisorption process. Activation energy ( E a ) for the Hg(II) removal was found to be 22.1 kJ mol −1 , indicating that the diffusion process might be the rate-controlled step. Thermodynamic studies suggested that the adsorption processes of Hg(II) onto the SH-Fe 3 O 4 -NMPs were endothermic and entropy favored in nature with the enthalpy changes (Δ H θ ) at 7.26–16.54 kJ mol −1 and the entropy changes (Δ S θ ) at 27.60–56.78 J mol −1 K −1 . The adsorption processes fit the Langmuir isotherms well with the maximum adsorption capacities of Hg(II) onto the SH-Fe 3 O 4 -NMPs at 129.9–256.4 mg g −1 with the content of Fe 3 O 4 in SH-Fe 3 O 4 -NMPs varying from 0% to 22.37%. The selective adsorption of Hg(II) by SH-Fe 3 O 4 -NMPs can be achieved when Ca 2+ , Mg 2+ , Na + or Cu 2+ ions coexisted. XRD and XPS analyses results of the adsorbents before and after Hg(II) adsorption suggested that Hg(II) ions had been successfully adsorbed onto SH-Fe 3 O 4 -NMPs via coordination interactions, and Hg(II) might be partially reduced to Hg 2 Cl 2 through solid state redox reaction via charge transport on the surface of the SH-Fe 3 O 4 -NMPs, in which the Fe 3 O 4 magnetic core in the adsorbents might play an important role.

A series of NH 2 -functionalized nano-magnetic polymer adsorbents (NH 2 -NMPs) coupled with different multi-amino groups, i.e ., ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA), named as EDA-NMPs, DETA-NMPs, TETA-NMPs and TEPA-NMPs have been prepared and used for the investigation of the adsorption mechanism of Cu(II) and Cr(VI) co-existing water system. Three approaches, e.g. by adsorbing Cu(II), Cr(VI) from water simultaneously, or adsorbing Cr(VI) followed by adsorbing Cu(II), and vice versa , were applied for the adsorption mechanism investigation. The results showed that the adsorption of Cu(II) or/and Cr(VI) on NH 2 -NMPs was competitive as well as cooperative. The adsorption mechanisms of Cu(II), Cr(VI) co-existing system could be related with coordination interactions, electrostatic attraction, and ion exchange. New adsorbents can be obtained via adsorption of Cu(II) or Cr(VI) by NH 2 -NMPs, named as Cu-NH 2 -NMPs, i.e. , Cu-EDA-NMPs, Cu-DETA-NMPs, Cu-TETA-NMPs, Cu-TEPA-NMPs; and Cr-NH 2 -NMPs, i.e. , Cr-EDA-NMPs, Cr-DETA-NMPs, Cr-TETA-NMPs, Cr-TEPA-NMPs, respectively. Cu-NH 2 -NMPs and Cr-NH 2 -NMPs can be reused for the adsorption of Cr(VI) or Cu(II), with high selectivity, broad pH applicable range and comparable adsorption properties with NH 2 -NMPs themselves.

In this paper, a novel and recyclable amino-functionalized nano-composite material (NCM) using tetraethylenepentamine (TEPA) as a coupling agent was synthesized. The properties of the TEPA-NCM were characterized by transmission electron microscopy (TEM), Fourier transform infrared analysis (FTIR), thermogravimetric analysis (TGA) and elemental analysis (EA). An effective dispersive solid-phase extraction (dSPE) procedure using the TEPA-NCM was developed, and comparative studies were carried out among Carbon/NH2 SPE, primary secondary amine (PSA) dSPE and TEPA-NCM dSPE. The results showed that TEPA-NCM dSPE was faster, easier and more effective to clean and enrich than the Carbon/NH2 cartridges, and the TEPA-NCM was much more effective to remove the pigments in vegetable samples than the PSA materials. The TEPA-NCM could be reused at least five times without much sacrifice of the cleanup efficiency. Furthermore, a gas chromatography–triple quadrupole mass spectrometry (GC–QqQ-MS/MS) method was established for the simultaneous determination of 29 pesticides (such as organochlorine and organophosphorus pesticides) in vegetables by dSPE using acetonitrile as an extraction solvent and TEPA-NCM as an adsorbent instead of PSA. The recoveries were in the range of 75–114% for all analytes except for trans-chlordane. The RSDs were in the range of 2–17%. The linearities were in the range of 0.4–100.0 μg/kg with determination coefficients (r2) higher than 0.986 for all compounds. The limits of detection (LODs) for all pesticides were less than 0.29 μg/kg and the limits of quantification (LOQs) were between 0.17 and 0.95 μg/kg. The developed method was applied to fifteen real vegetable samples, and it was confirmed that the TEPA-NCM was one of a kind of highly effective dSPE materials used for the pesticides analyses.

M(Salen)-functionalized Fe3O4 polymer magnetic composites (Fe3O4-poly(MMA -DVB-GMA)-M(Salen), where M = Ru(III), Cu(II), Fe(III)) of approximately 20 nm in size were synthesized and characterized by IR, AAS, EA, TGA, XRD, TEM and VSM. These magnetic composites were air-stable, efficient catalysts for the selective oxidation of alcohols to aldehyde and ketones.

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.

In this study, a novel NH2-functionalized nano-sized magnetic polymer (TEPA-NMP) adsorbent coupling with tetraethylenepentamine (TEPA) had been prepared. Its application for the removal of Cr(VI) from industrial wastewater was investigated. Batch adsorption studies were carried out to evaluate the effects of pH value, initial concentration, adsorption isotherm, adsorption kinetics, and desorption characters etc. The adsorption of Cr(VI) reached equilibrium rapidly within 30 mins. The adsorption efficiency of the TEPA-NMP on Cr(VI) was dependent on pH value and the initial Cr(VI) concentration. The adsorption efficiency of Cr(VI) decreased with the increasing of the initial Cr(VI) concentration and pH value. The adsorption data were well fitted with the Langmuir isotherm. The maximum adsorption capacity calculated from the Langmuir isotherm was 370.4 mg/g at temperature of 35 °C and pH of 2.0. Regeneration studies indicated that the adsorbent could be reused for 8 times with only 3.4 % lost of adsorption efficiency. The adsorption mechanism study results suggested that the adsorption of Cr(VI) could be related with electrostatic attraction, ion exchange and coordination interactions.

The selective oxidation of alcohols with molecular oxygen was efficiently completed in high conversion and selectivity using HPW/MCM-41 as a heterogeneous photocatalyst in ionic liquids, [bmim]PF6, [omim]BF4 and [hmim]BF4. Comparative studies on the catalytic properties of HPW/MCM-41, HPW to MCM-41 were carried out. Some important variables, e.g. the loading amount of HPW on MCM-41 and the effects of different ionic liquids were discussed in this work.

The selective oxidation of alcohols with molecular oxygen was efficiently completed in high conversion and selectivity using copper-bisisoquinoline-based catalysts under mild reaction condition. The effects of various parameters such as reaction temperature, reaction time, oxidant, ligands, etc, were studied. Solvent effect has been as well studied in ionic liquids [bmim]PF6, [omim]BF4 and [hmim]BF4, comparing to traditional volatile organic solvent. The use of ionic liquids was found to enhance the catalytic properties of the catalysts used.

Magnetic Fe3O4-C18 composite nanoparticles of approximately 5-10 nm in size were synthesized and characterized by IR spectroscopy, atomic absorption spectroscopy, X-ray diffraction, and transmission electron microscopy. The magnetic Fe3O4-C18 composite nanoparticles were applied for cleanup and enrichment of organophosphorous pesticides. Comparative studies were carried out between magnetic Fe3O4-C18 composite nanoparticles and common C18 materials. Residues of organophosphorous pesticides were determined by gas chromatography in combination with a nitrogen/phosphorus detector. The cleanup and enrichment properties of magnetic Fe3O4-C18 composite nanoparticles are comparable with those of common C18 materials for enrichment of organophosphorous pesticides, but the cleanup and enrichment are faster and easier to perform.

The selective oxidation of alcohols with molecular oxygen was efficiently completed in high conversion and selectivity using polymer-bound ruthenium complexes under mild reaction condition. The syntheses and characterization of the polymer-bound ruthenium complexes have been reported. The present catalyst was able to be reused for at least 10 times.

Studies on determination of eight kinds of phthalates, e.g. di-ethyl phthalate (DEP), di-propyl phthalate (DPP), di-isobutyl phthalate (DIBP), di-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di-cyclohexyl phthalate (DCHP), di-(2-ethylhexyl) phthalate (DEHP), di-octyl phthalate (DOP), in 25 kinds of plastic products for food use, including packaging bags, packaging film, containers, boxes for microwave oven use, sucking tubes, spoons, cups, plates, etc. by gas chromatography in combination with mass spectrometry detector (GC-MS) in electronic ionisation mode (EI) with selected-ion monitoring (SIM) acquisition method (GC-MS (EI-SIM)) have been carried out. Methods have been developed for both qualitative and quantitative analysis of phthalates. Extraction, clean-up and analysis procedure have been optimized. Determination of samples were performed after frozen in liquid nitrogen and sonication-assisted extraction with hexane, clean-up with LC-C18 SPE and analyzed by GC-MS methods. The base peak (m/z=149) of all the phthalates was selected for the screening studies. The characteristic ions, 121, 177, 222 for DEP; 191, 209 for DPP; 57, 223 for DIBP; 104 for DBP; 91, 132, 206 for BBP; 55, 167 for DCHP; 113, 167, 279 for DEHP; 279 for DOP were chosen for quantitative studies. These techniques are possible to detect phthalates at the level of 10.0mug/kg. Overall recoveries were 82-106% with R.S.D. values at 3.8-10.2%. Only one of the 25 examined samples was free from phthalates. The rest 24 samples were found to contain at least three or more of these phthalates. The predominant phthalate detected in the studied samples was DEHP.

Studies on screening, determination and confirmation of chloramphenicol (CAP) in 10 kinds of matrices, including seafood, meat, honey, etc. by enzyme-linked immunosorbent assay (ELISA), high-performance liquid chromatography (HPLC) with UV detector (HPLC–UVD) and gas chromatography in combination with electronic capture detector (GC–ECD) and mass spectrometry detector (GC–MS) in both electronic ionization mode (EI) and the negative ion chemical ionization mode (NCI) with selected-ion monitoring (SIM) acquisition method (GC–MS–EI–SIM and GCMS–NCI–SIM) have been carried out. Methods have been developed for both qualitative and quantitative detection of chloramphenicol (CAP). Extraction, clean-up, derivatization and analysis procedure have been optimized. The ELISA was carried out for screening, HPLC, GC and GC–MS were applied to determine and confirm CAP residue concentration in suspect samples. The ELISA procedure was carried out on an aqueous extract of the samples. Determination and confirmation of suspect samples were performed after extraction with phosphoric buffer solution (PBS, pH = 6.88)/ethyl acetate, defatting with hexane, analyzed by HPLC or GC–ECD, GC–MS–EI, GC–MS–NCI method. Samples for GC analysis, were further clean-up with solid-phase extraction using LC-Si and LC-C18 cartridges and derivatized to form volatile derivatives by derivatization agent. These techniques are able to detect chloramphenicol residues at the level of 0.1–10 μg/kg. Overall recoveries were 75–120% with R.S.D. values at 5.4–8.1%.

Alkylation of phenol with tert -butyl alcohol (TBA) was carried out in ionic liquids [bmim]PF 6 , [omim]BF 4 , and [hmim]BF 4 . Comparative studies on the catalytic properties of ionic liquids, H 3 PO 4 and some solid acidic catalysts, such as HZSM-5, H-β, HPW, and HPW/MCM-41, were carried out under identical reaction conditions. Solvent effect has been as well studied. The use of ionic liquids was found to enhance the catalytic properties of the catalysts used.

We have investigated the use of room temperature ionic liquids as catalytic and environmentally benign solvents for the facile homogenous synthesis of benzyl salicylate by the nucleophilic displacement reaction between sodium salicylate and benzyl chloride. The reaction was found to proceed under relatively mild conditions with excellent conversion (up to 96%) without the use of PTCs. The ionic liquids were recycled and reused. The effect of temperature was also investigated. No by–products were observed after 1H NMR and GC analysis.

Four new tetranuclear complexes, [Cu(en)2]3Ru(ox)3Cl3 (1), [Ni(en)2]3Ru(ox)3Cl3 (2), [Cu(bpy)2]3Ru(ox)3Cl3 (3) and [Ni(bpy)2]3Ru(ox)3Cl3 (4), have been prepared and characterized by elemental analyses, infrared and electronic spectra. The copper(II) complexes have been further characterized by ESR. The cyclic voltammograms of the four complexes have been studied. Magnetic investigation of (1) shows that this compound presents an antiferromagnetic interaction (J=−5.73 cm−1) between oxalate-bridged Cu(II)-Ru(III) units.

Two new Schiff base ligands (3-MeSGH and 4-MeSGH) derived from methyl-substituted salicylaldehyde (MeS) and D-glucosamine (GA), and ten of their metal complexes ML2 (M= Cu(II), Zn(II), Fe(II), Co(II), Ni(II); HL=3-MeSGH or 4-MeSGH) were prepared and characterized by elemental analyses, infrared and electronic spectra, molar conductivity measurements and magnetic moments at room temperature. The Schiff base ligands and the zinc(II) complexes were further characterized by 1H and 13C NMR. The copper(II) complexes were also characterized by ESR. All the complexes are non-electroly tes and superoxide free radical scavengers.

Cu(II), Zn(II), Fe(III), Co(III), and Ni(II) complexes of D-glucosamine (GluH2·HCl) were synthesized. These complexes, Cu (II)(GluH)(OAc)(H2O)·H2O (1), Zn(II)(GluH)(OAc)(H2O)·H2O (2), Fe(III)(Glu)(OAc)(H2O)·H2O (3), Co(III)(Glu)(OAc)(H2O)·H2O (4), and Ni(II)(GluH)(OAc)(H2O)·H2O (5), were characterized by elemental analyses, conductivity and magnetic susceptibility measurements, and infrared and electronic spectra. Cu(II)(GluH)(OAc)(H2O)·H2O was further characterized by ESR. The ligand (GluH2·HCl) and Zn(II) (GluH)(OAc)(H2O)·H2O were also characterized by 1H NMR and 13C NMR. It is suggested that all of the complexes have pseudo-tetrahedral structures and are nonelectrolytes. These complexes are superoxide free radical (O2 −·) scavengers.

Four novel binuclear Ln(III) complexes containing the dianion of phthalic acid (phth) as a bridging ligand have been synthesized, namely [Ln2(phth)(phen)4](CIO4)4.xH2O and [Ln2(phth)(NO2-phen)4](CIO4)4.xH2O (Ln = Dy, Nd; phth = dianion of phthalic acid; phen = 1,10-phenanthroline; NO2-phen = 5-nitro-1,10-phenanthroline). The complexes have been characterized by elemental analyses, IR, electronic spectra and conductances. The variable-temperature magnetic susceptibility (4-300K) of the complex [Dy2(phth)(NO5-phen)4](CIO4)4.6H2O has been determined, and the data were fit to the susceptibility equation derived from the spin Hamilton, Ĥ=δ[Lcirc]z 2+gβH·Ĵi+2Z′J′+MJ(Ĵz), by the least square method. The exchange interaction parameters are Z′J′ = -5. 94 × 10−4 cm−1 indicating that there is a weak antiferromagnetic spin exchange interaction between the lanthanide ions in the complex.

A hydrogen-bonded complex Ru(bpy)2(OX)·4H2O has been synthesized. Its structure consists of a unique three-dimensional network in which Ru(bpy)2(OX)·4H2O units are alternatively linked by tetracyclic and octacyclic rings. The cyclic voltammogram of the titled compound has been studied.

Cu(II), Fe(II), Co(II), Ni(II), Mn(II) complexes of azido-l, 4-bis(imidazol-l-yl-methyl)benzene (bix) or 1, 4-bis(imidazol-l-yl-methyl)-2.5-dimethyl-benzene) (Mebix) were synthesized by the spontaneous self-assembly method. The compounds [Cu2(bix)3(N3)4-2H2O. Ni2(bix)3(N3)46H2O. Co2(bix)3(N3)4·6H2O, Cu2(Mebix)3(N3)4·4H2O, Mn2(Mebix)3(N3)4·6H2O, Ni2(Mebix)3(N3)4·4H2O] were characterized by element analyses, infrared and electronic spectra. Cu2(bix)3(N3)4·2H2O was further characterized by ESR. It is suggested that all the complexes have ID structures, in which bix or Mebix functions as bridging ligand and N3' as terminal ligand. The coordination environment is distorted octahedral for each metal ion.

Cu(II), Zn(II), Fe(II), Fe(III), Co(II), Co(III). Ni(II) complexes with the Schiff basc derived from D-glucosamine and 2-hydroxynaphthaldehyde (NGH2) were synthesized. These compounds [Cu(II)NG 2H2O, Zn(II)(NGH)2. H2O, Fe(II)NG .2H2O, Fe(III)NG(OAc) .H2O, Co(II)NG .2H2O, Co(III)NG(OAc).H2O and Ni(II)(NGH)2 .4H2O] were characterized by element analyses, conductivity measurements, infrared and electronic spectra. The Schiff base ligand (NGH2) and Zn(II)(NGH)2. H2O were further characterized by 1H NMR and 13C NMR. Cu(II)NG 2H2O was also characterized by ESR. It is suggested that all the complexes have pseudo-tetrahedral structures. All the complexes are non-electrolytes. These complexes are superoxide free radical (O2) scavengers.