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Bimetallic oxide CuFeO 2 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 CuFeO 2 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 CuFeO 2 , together with metal leaching tests, indicated merits of recycling for CuFeO 2 . The subsequent surface element analysis by XPS for fresh and used CuFeO 2 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 CuFeO 2 initiated Fenton-like reactions, several oxidant species (i.e., OH, O 2 − , electron hole, and Fe IV 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 CuFeO 2 has potential applications for rapid decolorization of dye effluent. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A novel, well-designed magnetic graphene oxide sheet embedded with core-shell molecularly imprinted polymer microspheres (MGO@MIP) was controllably synthesized via a reflux-precipitation polymerization and surface imprinting technique. The as-prepared MGO@MIP was fully characterized and the results reveal that the specific selectivity and remarkable adsorption capacity to pentachlorophenol (PCP) are closely related to the synergetic effect of hydrogen bonding and π-π interactions, which are strongly associated with the solution pH and the distribution of magnetic microspheres on the surface of GO sheets. Under the optimal conditions, i.e., pH of 4.0 and a ratio of monomers to Fe3O4 of 15, the maximum adsorption capacity and the imprinting factor (α) of MGO@MIP towards PCP were 789.4 mg g-1 and 4.36, respectively. The newly synthesized MGO@MIPs has proved to be a great adsorbent for PCP in environmental water. [ABSTRACT FROM AUTHOR]

ABSTRACT A poly(methyl methacrylate) (PMMA)- b-poly[2-( N,N-dimethylamino) ethyl methacrylate] (PDMAEMA) block copolymer was successfully synthesized by a reversible addition-fragmentation chain-transfer method. The resulting copolymer was used to prepare poly(vinylidene fluoride) blend membranes via a phase-inversion technique. The polymorphism, structure, and properties of the blend membranes were investigated by Fourier transform infrared spectrometry, scanning electron microscopy (SEM), ζ potential analysis, and filtration. The results indicate that PMMA- b-PDMAEMA could migrate onto the surface of the membrane during the coagulation process, and more of the β-crystal phase appeared with the increase of the block copolymer in the membranes. The surface morphology and cross section of the membranes were also affected by the copolymer, as shown by SEM. The ζ-potential results show that the surface charges of the membrane could be changed from positive to negative at an isoelectric point as the pH increased. The blend membrane also exhibited good pH sensitivity, and its water flux showed a great dependence on pH. The filtration experiment also indicated that the blend membrane had good hydrophilicity and antifouling properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40685. [ABSTRACT FROM AUTHOR]

Abstract: A novel and effective dispersive solid-phase extraction (dSPE) procedure using tetraethylenepentamine-functionalized Fe3O4 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 (pKa <7.0) were highly dependent on the pH, and the TEPA-MP could be reused efficiently at least six times. Under optimized conditions, the recoveries for all analytes were between 80.1 and 97.1%, the intra-day RSDs were in the range of 1.7–8.5% and the inter-day RSDs were between 1.7 and 9.8%, and all the analytes had good linearities in the tested ranges with determination coefficients (r 2) higher than 0.9991. The limits of quantification (LOQs) for the nine food additives were between 0.17 and 0.92mg/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. [Copyright &y& Elsevier]

A new analytical method is proposed for simultaneous determination of twenty organic acids in juices and beverages by eluent generator reagent free ion chromatography with electrospray ionization mass spectrometry (ESI-MS) in the negative selected ion monitoring mode (SIM). Twenty organic acids showed good linear relationship in the ranges of 0.5 ∼ 20.0 mg/L. The correlation coefficients were more than 0.998, the detection limits were between 0.05 ∼ 0.5 mg/L, and the average recoveries were between 88.0% ∼ 106.0%. The relative standard deviations (RSDs) were less than 7.6%. The method has been applied to juice and beverage samples with satisfactory results. [ABSTRACT FROM AUTHOR]

This paper describes a simple method for the simultaneous determination and confirmation of the indandione rodenticides in serum. After samples were extracted with 10% (v/v) methanol in acetonitrile and cleaned by solid-phase extraction, chromatographic separation was performed on an IonPac® AS11 analytical column (250 × 4.0 mm) using gradient KOH eluent with 10% (v/v) methanol as organic modifier. Confirmation was depended on the extensive fragmentation of the indandione molecule under MS/MS conditions which provides sufficient structural information. Quantification was performed by negative electrospray ionization in multiple reaction monitoring mode. All the method parameters were validated. It was confirmed that this method could be used in clinical diagnosis and forensic toxicology. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Valone has a chronic and toxic anticoagulant rodenticide that has widely used in China and has resulted in some accidental and intentional intoxication in recent years. The literature reported so far lacks sensitive and selective method for the confirmation of valone. The purpose of this study was to establish a novel assay for the identification and quantification of valone in serum by ion chromatography–electrospray ionization tandem mass spectrometry (IC–MS/MS). After serum sample was extracted with methanol/acetonitrile (10:90, v/v) and cleaned by Oasis® HLB solid-phase extraction cartridge, chromatographic separation was performed on an Ionpac® AS11 column with an eluent of methanol/30mmol/L KOH (10:90, v/v). The overall extraction efficiency was >81.0%, and the limit of quantification was 0.5ng/mL for valone. Regression analysis of the calibration data revealed good correlation (r 2 >0.99) for valone. Intra- and inter-day precisions for quality-control samples were less than 8.0 and 13.7%, respectively. The proposed method enables the identification and quantification of valone in both clinical and forensic specimens. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

Abstract: The effect of ultrasound on the leaching process, in which Geniposide is leached from the Gardenia fruit by deionized water at 20°C, was investigated. The phase equilibrium and the dynamics were measured at static, stirring, and ultrasonically assisted conditions, respectively. The experimental results show that the extraction yield of Geniposide with ultrasound at 0.1533Wcm−2, is increased by 16.5%, in comparison with that without ultrasound when the ratio of the solvent volume to the fruit weight is 40ml/g. A model for mass transfer, based on the intraparticle diffusion and the external mass transfer, was developed. And the dynamic curves calculated by the model are in a good agreement with the experimental data. The external mass transfer coefficient k f /R and intraparticle diffusion coefficient D e /R 2 were obtained by fitting of the experiment data. The external mass transfer coefficient with ultrasound at 0.1533Wcm−2 is 1.63 times higher than that in static process, and the intraparticle diffusion coefficient with ultrasound at 0.1533Wcm−2 is 3.25 times higher than that in static process. [Copyright &y& Elsevier]

In this work, the decolorization of azo dye Orange G (OG) in aqueous solution by aluminum powder enhanced by ultrasonic irradiation (AlP-UI) was investigated. The effects of various operating operational parameters such as the initial pH, initial OG concentration, AlP dosage, ultrasound power and added hydrogen peroxide (H2O2) concentration were studied. The results showed that the decolorization rate was enhanced when the aqueous OG was irradiated simultaneously by ultrasound in the AlP-acid systems. The decolorization rate decreased with the increase of both initial pH values of 2.0-4.0 and OG initial concentrations of 10-80mg/L, increased with the ultrasound power enhancing from 500 to 900W. An optimum value was reached at 2.0g/L of the AlP dosage in the range of 0.5-2.5g/L. The decolorization rate enhanced significantly by the addition of hydrogen peroxide in the range of 10-100mM to AlP-UI system reached an optimum value of 0.1491min(-1). The decolorization of OG appears to involve primarily oxidative steps, the cleavage of NN bond, which were verificated by the intermediate products of OG under the optimal tested degradation system, aniline and 1-amino-2-naphthol-6,8-disulfonate detected by the LC-MS., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Measurement of indandione rodenticides is important in the diagnosis and treatment of accidental rodenticide ingestion. Current assays lack effective measurements for simultaneous analysis of the indandiones, especially the isomers. The intent of this study was to establish a novel and selective method for the simultaneous determination of indandione-type rodenticides (diphacinone, chlorophacinone, valone, and pindone) in human serum by liquid chromatography-electrospray ionization-tandem mass spectrometry. After addition of internal standard, the sample was extracted with 10% methanol in acetonitrile and cleaned by solid-phase extraction (SPE). The analytes were separated on a C(18) rapid column and infused into an ion trap mass spectrometer in the negative electrospray ionization mode. The multiple-reaction monitoring ion pairs were m/z 339 --> 167, m/z 373 --> 201, m/z 229 --> 145, m/z 229 --> 172, and m/z 307 --> 161 for diphacinone, chlorophacinone, valone, pindone, and IS, respectively. Recoveries were between 81.5 and 94.6%, and the limits of quantification were 0.2 to 0.5 ng/mL. Intra- and interday RSDs were less than 7.9 and 11.5%, respectively. The assay was linear in the range of 0.5-100.0 ng/mL with coefficients of determination (r(2) > 0.99) for all analytes. The proposed method enables the unambiguous confirmation and quantification of the indandiones in both clinical and forensic specimens.

Valone is a chronic anticoagulant rodenticide that has come into wide use in China. Current literature lacks analytical methods for the determination of valone. In this paper, a sensitive and selective assay was established for the identification and quantification of valone in serum by liquid chromatography-tandem mass spectrometry. After addition of the internal standard, warfarin, serum samples were extracted with 10% methanol in acetonitrile and cleaned using Oasis HLB solid-phase extraction (SPE) cartridges. The compounds were separated on an Agilent SB C18 column with a mobile phase of methanol/acetic acid-ammonium acetate (5 mmol/L, pH 6.3) (75:25, v/v). Detection was performed by electrospray ionization ion trap mass spectrometry in the negative multiple reaction monitoring mode. The transition ions of m/z 229 --> 145 and m/z 307 --> 161 were selected for quantification of valone and the internal standard, respectively. The overall extraction efficiency was between 81.1% and 91.1%. The limit of quantification was 0.5 ng/mL. Regression analysis of the calibration data revealed good correlation (r(2) > 0.99) for valone. Intra- and interday precisions for quality-control samples were less than 7.8% and 12.8%, respectively. This method combines a rapid SPE procedure with an extremely fast chromatographic analysis, which is especially advantageous or clinical laboratories.

A sensitive method has been developed and validated for the simultaneous determination of triptolide, tripdiolide, and tripterine in human serum using hydrocortisone as an internal standard (IS). After triptolide, tripdiolide, and tripterine in human serum were extracted with ethyl acetate, the extracts were separated on an XDB C(18) column (30 mm x 2.1-mm i.d., 3 microm) using a mobile phase of acetic acid/ammonium acetate (5 mmol/L, pH 4.5)/acetonitrile/methanol in gradient elution. Detection was performed by high-performance liquid chromatography coupled with atmospheric-pressure chemical ionization ion trap mass spectrometry in negative multiple reaction monitoring mode. The transition ions m/z 359 --> 340, m/z 375 --> 357, m/z 449 --> 405, and m/z 419 --> 329 were selected for the quantification of triptolide, tripdiolide, tripterine, and IS, respectively. The linear range was 1.0-100.0 ng/mL, the absolute recoveries were between 78.3 and 89.2%, the relative recoveries were between 88.1 and 94.6%, and the limits of quantification in human serum were 0.5-1.0 ng/mL for the three target compounds. The intra- and interday relative standard deviations were less than 11.9% and 13.0%, respectively. This method was found to effectively and simultaneously determine trace triptolide, tripdiolide, and tripterine in human serum and can be suitable for clinical and toxicological studies.