INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
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2015
·
IF 1.295
Jing Zhang,Shibo Zhang,Xue Wang,Wenchang Wang,Zhidong Chen
A convenient and sensitive method was developed for the simultaneous determination of Ponceau-4R and Allura Red using an ionic liquid modified expanded graphite paste electrode (IL-EGPE). The IL-EGPE was prepared by mixing ionic liquid-expanded graphite (IL-EG) composites with solid paraffin. Based on the advantageous functions of IL and EG, IL-EGPE showed enhanced electrocatalytic activity towards the simultaneous oxidation of Ponceau-4R and Allura Red. Under optimal experimental conditions, the IL-EGPE exhibited wide linear responses to Ponceau-4R and Allura Red ranging from 6.0 to 7.5 mg L−1 and 5.0 to 0.5 mg L−1, respectively. The detection limits for Ponceau-4R and Allura Red were 1.15 and 0.89 μg L−1 at a signal-to-noise ratio of 3, respectively. The designed electrode showed good reproducibility, stability and reusability. The proposed method was successfully applied in the simultaneous determination of Ponceau-4R and Allura Red in soft drinks. This method presented a simple, rapid and sensitive platform for simultaneous determination of Ponceau-4R and Allura Red and would become a versatile and powerful tool for food safety.
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高影响因子
ANALYTICA CHIMICA ACTA
·
2014
·
IF 4.517
Mai Luo,Donghui Liu,Lu Zhao,Jiajun Han,Yiran Liang,Peng Wang,Zhiqiang Zhou
A reliable, sensitive, rapid and environmentally friendly analysis procedure for the simultaneous determination of the analytes with a wide range of polarity in the environmental water was developed by coupling dispersive magnetic solid-phase extraction (d-MSPE) with high-performance liquid chromatography (HPLC)–diode array detector (DAD) and ultra-high pressure liquid chromatography (UHPLC)-triple quadrupole mass spectrometer (MS/MS), in this work. Magnetic ionic liquid modified multi-walled carbon nanotubes (m-IL-MWCNTs) were prepared by spontaneous assembly of magnetic nanoparticles and imidazolium-modified carbon nanotubes, and used as the sorbent of d-MSPE to simultaneously extract aryloxyphenoxy-propionate herbicides (AOPPs) and their polar acid metabolites due to the excellent π–π electron donor–acceptor interactions and anion exchange ability. The factors, including the amount of sorbent, pH of the sample solution, extraction time and the volume of elution solvent were investigated. Under the optimized conditions, the proposed d-MSPE coupling to HPLC–DAD system had a satisfactory performance, the limits of detection (LODs, defined as the signal to noise ratio of 3) and the limits of quantification (LOQs, defined as the signal to noise ratio of 10) for analytes in Milli-Q water were in the range of 2.8–14.3 and 9.8–43.2 μg L −1 respectively. Calibration curves were linear ( r 2 > 0.998) over the concentration range from 0.02 to 1 mg L −1 . The recoveries of the eight analytes ranged from 66.1 to 89.6% with the RSDs less than 8.6%. In order to extend the method in extremely low concentration analysis, d-MSPE-UHPLC–MS/MS was investigated, which showed better performance in terms of limit of detection and analysis time.
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PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Lijuan Zhao,Baizhao Zeng,Faqiong Zhao
A novel tartrazine imprinted polymer – multiwalled carbon nanotubes - ionic liquid supported Pt nanoparticles composite film coated glassy carbon electrode (MIP–MWNTs-IL@PtNPs/GCE) was presented. It was fabricated by coating a GCE with MWNTs-IL@PtNPs mixture, followed by MIP suspension. The IL functionalized MWNTs was prepared by Click chemistry, and Pt nanoparticles were then loaded on it using ethylene glycol as reducing agent. The MIP was prepared by typical free radical polymerization using 4-vinylpyridine as functional monomer. The resulting MIP–MWNTs-IL@PtNPs/GCE showed good analytical performance when it was used for the electrochemical determination of tartrazine. Under the optimized conditions, the peak current was linear to tartrazine concentration in the ranges of 0.03 – 5.0 μM and 5.0 – 20 μM with sensitivities of 0.72 μA/μM mm 2 and 0.24 μA/μM mm 2 , respectively; the detection limit was 8 nM (S/N = 3). The sensor was successfully applied to the determination of tartrazine in practical samples and the recovery for the standards added was 88 – 108%.
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高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2015
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IF 4.169
Mian Wu,Youhong Ai,Baizhao Zeng,Faqiong Zhao
Here we report a facile in situ solvothermal growth method for immobilization of metal-organic framework–ionic liquid functionalized graphene (MOF-5/ILG) composite on etched stainless steel wire. The X-ray diffraction spectra, scanning electron microscopy and transmission electron microscopy images showed that the metal organic framework possessed good crystal shape and its structure was not disturbed by the introduction of ILG. Moreover, the covalent bond established between the amino group of ILG and the carboxylic group of the metal organic framework improved the mechanical stability and structure uniformity of the microcrystals. The obtained material combined the favorable attributes of both metal-organic framework and ILG, having high surface area (820 m 2 /g) and good adsorption capability. Its adsorption properties were explored by preconcentrating chloramphenicol and thiamphenicol from aqueous solutions prior to gas chromatography-flame ionization detection. The MOF-5/ILG exhibited high enrichment capacity for the analytes as they could interact through π–π and H-bonding interaction. Under the optimum conditions, good linearity (correlation coefficients higher than 0.9981), low limits of detection (14.8–19.5 ng/L), and good precision (relative standard deviations less than 6.0% ( n = 5)) were achieved. The MOF-5/ILG composite displayed durable property. The method was applied to the determination of two antibiotics in milk, honey, urine and serum samples with acceptable relative recoveries of 82.3–103.2%.
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PubMed
高影响因子
GREEN CHEMISTRY
·
2015
·Vol. 17
·期 8
·4206-4216
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IF 8.02
Jinxia Zhou,Zhi Xia,Tingyu Huang,Peifang Yan,Wenjuan Xu,Zhanwei Xu,Jianji Wang,Z. Conrad Zhang
Increasing the glucose loading in the 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid containing a dissolved CrCl3 catalyst system led to excessive formation of humins and a serious decrease in the 5-hydroxymethylfurfural (5-HMF) yield. A biphasic system containing glycol dimethyl ether (GDE) as the extraction phase, and [BMIM]Cl/CrCl3/glucose in combination with a partitioned amount of GDE and an appropriate amount of water as the reaction phase was found to be highly efficient for the reaction; CrCl3 catalyzed the formation of 5-HMF in 64.5 mol% yield from a very high glucose concentration (80 wt% with respect to the ionic liquid) at 108 °C. This 5-HMF yield in the [BMIM]Cl–GDE–H2O ternary biphasic system nearly doubled that obtained in the single [BMIM]Cl/CrCl3/glucose reaction phase. Importantly, the GDE phase contained about 56% of the generated 5-HMF without detectable contamination by the ionic liquid or carbohydrates. GDE served multiple functions: as a hydrogen-bond acceptor, it exhibited excellent extraction performance for 5-HMF; due to its low boiling point and suitable solubility saturation point in the ionic liquid, a sustained GDE bubbling phenomenon in the ionic liquid phase was observed that promoted the rate of inter-phase mass-transfer of 5-HMF in reactions; and GDE mediated the [BMIM]Cl phase to a reduced viscosity. In addition, an appropriate amount of water in the ternary system promoted the extraction efficiency of 5-HMF and also lowered the viscosity of [BMIM]Cl/glucose. The ionic liquid–organics–water ternary biphasic system has been demonstrated for high 5-HMF productivity and separation efficiency.
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高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2015
·Vol. 38
·期 9
·1570-1576
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IF 2.737
Yuanyuan Feng,Faqiong Zhao,Baizhao Zeng
A polycarbazole film was electrodeposited on a stainless-steel wire from a solution of N , N -dimethylformamide/propylene carbonate (1:9 v/v) containing 0.10 M carbazole and 0.10 M tetrabutylammonium perchlorate. The obtained polycarbazole fiber was immersed into an ionic liquid (1-hydroxyethyl-3-methyl imidazolium bis[(trifluoromethyl)sulfonyl]imide) solution (in dimethylsulfoxide) for 30 min, followed by drying under an infrared lamp. The resulting polycarbazole/ionic liquid fiber was applied to the headspace solid-phase microextraction and determination of aromatic esters by coupling with gas chromatography and flame ionization detection. Under the optimized conditions, the limits of detection were below 61 ng/L (S/N = 3) and the linear ranges were 0.061−500 μg/L with correlation coefficients above 0.9876. The relative standard deviations were below 4.8% ( n = 5) for a single fiber, and below 9.9% for multi-fiber ( n = 4). This fiber also exhibited good stability. It could be used for more than 160 times of headspace solid-phase microextraction and could withstand a high temperature up to 350°C.
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高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Xiaojing Lv,Shuanma Yan,Yuyu Dai,Mi Ouyang,Yuan Yang,Pengfei Yu,Cheng Zhang
Ionic liquids 1-butyl-3-methyl-imidazolium tetrafluoroborate ([BMIM]BF 4 ), 1-butyl-3-methylimidazoliumhexafluorophosphate ([BMIM]PF 6 ) and conventional medium tetrabutylammonium perchlorate (TBAP) were utilized as electrolyte for the preparation of poly(4,4′,4′'-tris[4-(2-bithienyl)phenyl]amine) (PTBTPA) films and assembling of EC devices. FTIR spectra and EDX pattern demonstrate an effective doping of the anion into the PTBTPA film at the oxidation state. SEM images investigate the thickness of the polymer films and the morphologies of crimped structure at the oxidation state. The ion diffusion distance (the thickness of polymer film) plays a more critical role for the EC switching speed. According to the electrochemical impedance spectra, the improved ionic conductivity with ionic liquid [BMIM]BF 4 as the electrolyte promote ions more easily dope into the polymer film which leads to the higher optical contrast. In addition, the size of doping anion during the redox process has essential influence on the electrochemical stability.
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高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2014
·Vol. 18
·期 12
·3463-3469
·
IF 2.234
Chen Ya,Huang Yihan,Guo Dongmei,Chen Cui,Wang Qinghong,Fu Yingzi
A sensitive electrochemical method was explored for chiral recognition of 3,4-dihydroxyphenylalanine (DOPA) enantiomers based on immobilization of β -cyclodextrin ( β -CD) onto the nanocomposite comprising multiwalled carbon nanotubes (MWCNTs) and ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate (BIMIMPF 6 ) modified glassy carbon electrode ( β -CD/MWCNTs-IL/GCE). The combination of ionic liquid and carbon nanotubes could create unique nanomaterials which facilitated the electron transfer. In addition, β -CD was brought in to act as the chiral selector for DOPA enantiomers recognition. The immobilization process of β -CD/MWCNTs-IL/GCE was monitored by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy. The chiral interface ( β -CD/MWCNTs-IL/GCE) was employed to discriminate DOPA enantiomers via differential pulse voltammetry. The results indicated that the proposed sensor exhibited a stronger electrochemical response toward D-DOPA over the linear range from 4.0 × 10 −3 to 4.0 × 10 −9 mol L −1 and the detection limit was 1.2 × 10 −9 mol L −1 (S/N = 3). This work provided an available platform for enantioselective recognition of DOPA enantiomers based on the nanocomposite.
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高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Jing-Jing Lv,Jin-Xia Feng,Shan-Shan Li,Ying-Ying Wang,Ai-Jun Wang,Qian-Li Zhang,Jian-Rong Chen,Jiu-Ju Feng
A simple and facile one-pot solvothermal method is developed for preparation of flower-like PtAg alloys uniformly supported on reduced graphene oxide nanosheets (flower-like PtAg/RGOs). Ionic liquid crystal (1-hexadecyl-2,3-dimethylimidazolium bromide, [C 16 MMIm]Br) is used as a capping agent and a structure directing agent . The as-prepared nanocomposites show the larger electrochemically active surface area, better catalytic activity, higher methanol tolerant activity, and longer-term durability for oxygen reduction reaction , compared with commercial Pt black, Pt-C (10 wt %), and RGOs catalysts.
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高影响因子
FOOD CHEMISTRY
·
2013
·
IF 3.334
Miaomiao Tian,Rongmin Cheng,Juanjuan Ye,Xiaoting Liu,Qiong Jia
A new ionic liquid (IL)-calixarene coated solid-phase microextraction (SPME) fibre has been synthesized on the surface of quartz fibre by the sol–gel method. The coated fibre has been coupled with gas chromatography–flame ionisation detector (GC–FID) for the determination of triazines in fruit and vegetable samples. The operation parameters including sample volume, extraction time, extraction temperature, desorption time, and sample pH have been investigated and optimised. Under the optimum conditions, the limits of detection of atrazine, simazine, ametryn, and cyanazine based on three times of standard deviations of blank by seven replications are 3.3, 4.4, 8.8, and 13.0 μg kg −1 , respectively. The intra-day and inter-day relative standard deviations are less than 7.2% and 9.9%. The proposed method has been successfully applied to the determination of the four triazines in fruit and vegetable samples and the accuracy is assessed through recovery experiments.
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高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2015
·Vol. 38
·期 12
·2126-2131
·
IF 2.737
Lin Wang,Chuanlei Luan,Fangfang Chen,Rui Wang,Lihua Shao
A novel method has been developed for the analysis of zearalenone in maize products by vortex-assisted ionic-liquid-based dispersive liquid–liquid microextraction combined with HPLC and fluorescence detection. Maize samples were extracted with methanol/water (80:20, v/v) and the extraction solution was then used as the dispersive solvent in the microextraction procedure. The analyte was rapidly transmitted to a small volume of ionic liquid and was determined by HPLC. Various parameters affecting the recovery of the mycotoxin were investigated, such as the type and volume of the extraction solvent, the type and volume of the dispersive solvent, the pH of the aqueous phase, the salt addition, and the time of vortex and centrifugation. Under the optimal experimental conditions, a good linearity of the analyte was obtained in the range of 1.0–1000.0 μg/L with the correlation coefficient of 0.9998. The limit of detection (S/N = 3) and quantification (S/N = 10) were 0.3 and 1.0 μg/kg, and the mean recoveries ranged from 83.5 to 94.9%, with a relative standard deviation less than 5.0%. The proposed method was demonstrated to be simple, cheap, quick, and highly selective and was successfully applied to the determination of zearalenone in maize products.
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高影响因子
RSC Advances
·
2015
·Vol. 5
·期 111
·91654-91664
·
IF 3.84
Hui Mao,Yang Song,Dongmei Qian,Daliang Liu,Shuyao Wu,Yu Zhang,Yoshio Hisaeda,Xi-Ming Song
By using a one-step copolymerization of styrene (St) and 3-(1-vinyllimidazolium-3-yl)propane-1-sulfonate (VIPS), a kind of poly(St-co-VIPS) microsphere, with a hierarchical structure composed of nanospheres or nanoparticles with diameters in the range of 70–90 nm arranged on its surface and that look like a flower, has been simply prepared in the presence of polyvinyl pyrrolidone (PVP) in an aqueous alcohol system. A formation mechanism of the flower-like poly(St-co-VIPS) microspheres is proposed by investigating the influence of reaction conditions on its morphologies and observing its growth process with time. Because of the existence of zwitterionic liquid functional groups, flower-like poly(St-co-VIPS)-acid microspheres, a novel kind of heterogeneous catalyst, were successfully prepared by immobilizing heteropoly acids and H2SO4 on the flower-like poly(St-co-VIPS) microspheres, and the heterogeneous catalysts showed better catalytic activities for esterifications, acetalizations and transesterifications than with H2SO4 as the catalyst. Especially, the heterogeneous catalysts presented excellent catalytic efficiency for the acetalization of benzaldehyde and 1,2-propanediol, which could successfully reach 96.2%. Furthermore, the crosslinked flower-like poly(DVB-co-VIPS)–H2SO4 microspheres prepared under the same conditions where only St was replaced by divinyl benzene (DVB) have better reusability than that of the flower-like poly(St-co-VIPS)–H2SO4 with poor solvent resistance, and could be reused four times without significant loss of the catalytic activity, indicating that they could act as excellent recyclable heterogeneous catalysts for the synthesis of acetals and have potential application in industry.
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高影响因子
危险品化学品经营许可证（带存储）