JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2014
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IF 2.063
Xiaoshan Sun,Haijian Ou,Changfeng Miao,Ligang Chen
In this study, magnetic carbon nanotubes (MCNTs) have been synthesized by hydrothermal synthesis of Fe 3 O 4 nanoparticles onto carbon nanotubes, and characterized by Fourier transform infrared spectroscopy, transmission electron microscope and physical property measurement system. They were used as adsorbents for the removal of sudan I, sudan II, sudan III, and sudan IV from aqueous solution. The effects of experimental parameters on adsorption were fully studied. The results showed that 5 mg MCNTs can remove sudan dyes sufficiently from 20 mL aqueous solution within 60 min at pH in the range of 4–7. Moreover, the existence of NaCl favored the adsorption. The sorbents can be reused more than ten times with 2% acetic acid ethanol as desorption solution. The equilibrium, kinetic and thermodynamic studies were investigated. The resultant kinetic data were well described by the pseudo-second-order model. The Freundlich model fitted sudan dyes sorption isotherms better than the Langmuir model. The thermodynamic data calculated from the temperature dependent sorption isotherms demonstrated that sudan dyes sorption on the MCNTs was a spontaneous process.
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Analytical Methods
·
2014
·Vol. 6
·期 11
·3751-3757
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IF 1.938
Xiao-Yan Xu,Xing-Guo Tian,Liang-Gen Cai,Zhen-Lin Xu,Hong-Tao Lei,Hong Wang,Yuan-Ming Sun
The demanding task of monitoring illegal dyes in foodstuffs requires sensitive detection methods. Here, a surface plasmon resonance (SPR) sensor, combined with a 75 ± 5 nm thick molecularly imprinted polymer (MIP) nanofilm as a recognition element, is used for the selective detection of Sudan dyes. The MIP-SPR sensor chip was fabricated by anchoring the MIP nanofilm of Sudan I on a gold chip via surface-initiated in situ polymerization. The surface morphology and thickness of the MIP films were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The adsorption properties of the sensor chip were studied through application as an SPR sensor. The MIP-SPR sensor exhibited excellent adsorption capacity, and high sensitivity and selectivity for Sudan dyes. The SPR response was linearly proportional to the concentration of Sudan I over the range 50–400 ng mL−1. Based on a signal-to-noise ratio of three, a detection limit of 30 ng mL−1 was established with a 400 s response time. Non-imprinted SPR sensors were compared in terms of selectivity with MIP-SPR sensors and it was found that all the recognition coefficients (α) for Sudan I–IV were greater than 1. The MIP-SPR sensor also showed reproducible response over three equilibration–adsorption–regeneration cycles.
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ANALYTICAL LETTERS
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2013
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IF 0.965
Xiuying Liu,Bing Bai,Qian Zhou,Yingchao Yu,Shujuan Ji
Molecularly imprinted polymers grafted on to the surface of carboxyl-modified multiwalled carbon nanotubes were developed using methacrylic acid as a functional monomer and trihydroxymethylpropyl trimethylacrylate as a crosslinker for application to rhodamine B determination. The synthesis, characteristics, and evaluation of the molecularly imprinted polymer are described. The apparent morphology of the polymers was characterized by scanning electron microscopy. To evaluate the binding ability of the molecularly imprinted polymers, equilibrium binding experiments were conducted and revealed the maximal binding capacity to be 561.54 µg g−1. The introduction of nanomaterials into the polymer composite made important contributions to the affinity enhancement and recognition properties of the molecularly imprinted polymers. Moreover, the polymers were preliminarily applied as an adsorbent for separation and extraction of Rhodamine B from dried chili powder samples, based on solid phase extraction technology. The calibration curve was linear in the range of 0–7 µg mL−1. For all tested samples, recoveries were reliable and in the range of 101.75–109.73%. The relative standard deviation ranged from 6.43–14.32%, which demonstrated that the polymer has potential for preconcentration of Rhodamine B from chili powder samples.
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ELECTROCHIMICA ACTA
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2013
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IF 3.777
Hong Dai,Lingshan Gong,Guifang Xu,Shupei Zhang,Shuanyan Lu,Yuwei Jiang,Yanyu Lin,Longhua Guo,Guonan Chen
A simple and sensitive electrochemical sensor which was constructed with alkoxy silane and carbon nanohorns was first utilized to detect some food borne contaminants, including malachite green, sudans, triclosan, bisphenol A. Due to the large surface area, good conductivity, admirable electrochemical activity of carbon nanohorns and excellent immobility of alkoxy silane, the synergistic effect root from the easily controlled composition of organic–inorganic hybrid film was achieved. The present work demonstrated this functional film brings advantageous features such as stable and strong adherence to electrode matrix and excellent electrochemical catalysis, to electrochemical sensor to achieve advanced application. By choosing triclosan and malachite green as object, their kinetic parameters on this modified electrode were calculated and the relative quantitive protocols were established. Compared with previous reports, the designed sensor presented lower detection limit, higher sensitivity and more broad linear range. This electrochemical platform offered a useful tool for the on-site determination of food born contamination.
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ELECTROCHIMICA ACTA
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2015
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IF 4.504
Junhua Li,Haibo Feng,Jun Li,Yonglan Feng,Yaqian Zhang,Jianbo Jiang,Dong Qian
In this paper, we are presenting a facile, green and in situ synthesis strategy for the convenient preparation of well-dispersed gold nanoparticles (AuNPs)-decorated reduced graphene oxide (RGO) without the use of any template molecules and poisonous reductant. The as-synthesized nanocomposite has been detailedly characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis as well as electrochemical technologies. The morphological and structural characterizations illustrate that AuNPs can be efficiently decorated on RGO with the Au content of 20.33 wt% in the matrix and the size of the embedded AuNPs vary between 25 and 40 nm. The electrochemical investigations confirm that the small-sized AuNPs on the RGO film can remarkably boost the electrocatalytic activity for the oxidation of Sudan I, which can be used as an enhanced electrochemical sensing platform for the sensitively detection of the toxicant Sudan I. Moreover, the kinetic parameter studies demonstrate that the Sudan I electro-oxidation at the AuNPs/RGO electrode is a diffusion-controlled process which involves two-electron and two-proton transfer. Under the optimal conditions, a wide linear range of Sudan I detection from 0.01 to 70 μmol L −1 with good linearity ( R 2 = 0.9965, 0.9942) and a low detection limit (1.0 nmol L −1 , S/N = 3) were obtained. In comparison with the existing analogues ever reported, the AuNPs/RGO eletrode exhibits overwhelmingly superior comprehensive properties for the sensitive detection of Sudan I. Finally, the newly developed sensor was applied to quantitative determination of Sudan I in food samples such as chilli powder and ketchup sauce with satisfactory sensitivity, selectivity and reversibility.
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NANO
·
2015
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IF 1.09
Yu Cao,Zhihui Fang,Duanguang Yang,Yong Gao,Huaming Li
We reported a sensitive voltammetric sensor for Sudan I determination by modifying glassy carbon electrode (GCE) with single-walled carbon nanotubes (SWCNTs)/β-cyclodextrin conjugate. The cyclic voltammetry results showed that the modified GCE exhibited strong catalytic activity toward the electro-reduction of Sudan I with a well-defined cyclic voltammetric peak at -673 mV. Differential pulse voltammetry measurement showed that the response current exhibited a linear range between 50 nM and 5 μM, and the detection limit was as low as 2.22 nM (S/N = 3). The enhanced electrochemical performance of the fabricated sensor was attributed to the combination of the excellent electrocatalytic properties of SWCNTs and the molecular recognition ability of β-cyclodextrin to Sudan I. The sensor was successfully applied to determine Sudan I in real food samples with satisfactory results.
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SENSORS AND ACTUATORS B-CHEMICAL
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2015
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IF 4.097
Ling Wang,Ran Yang,Jianjun Li,Lingbo Qu,Peter de B. Harrington
In this work, a very sensitive electrochemical sensor for Sudan I was established based on nanohybrids of graphene-ZnSe quantum dots . Positively charged cetyltrimethyl-ammonium bromide (CTAB) functionalized graphene was used as a template-directed building block to self-assemble negatively charged ZnSe quantum dots (QDs). The hybrids of ZnSe-CTAB-graphene exhibited strong enrichment effect on Sudan I and gave superior electrocatalytic activity towards the oxidation of Sudan I. Applying differential pulse voltammetry (DPV), the peak current of Sudan I is proportional to its concentration in the range from 0.004 to 2.0 μM and 2.0 to 15.0 μM. This report is the first on applying graphene-ZnSe hybrids for electrochemical sensing.
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Analytical Methods
·
2014
·Vol. 6
·期 20
·8129-8135
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IF 1.938
Jinjiao Shi,Ligang Chen
A sensitive and simple method for high-performance liquid chromatography (HPLC) determination of Sudan dyes in lipstick samples after preconcentration by cloud point extraction (CPE) has been developed. The nonionic surfactant Triton X-114 was chosen as the extraction medium. Various experimental conditions were investigated to optimize the extraction and preconcentration process. Under optimum conditions, 3% Triton X-114 (v/v), ultrasonication for 20 min, pH 7, the satisfied recoveries of Sudan dyes were obtained. For the preconcentration of Sudan dyes by cloud point extraction, the solution was incubated in a thermostatic water bath at 60 °C for 10 min, and 22.5% sodium chloride (m/v) was added to the solution to facilitate the phase separation and increase the preconcentration factor. The limits of detection for the analytes are 0.11, 0.10, 0.07 and 0.08 μg g−1, respectively. The intra-day and inter-day precisions of four Sudan dyes are in the range of 4.6–6.4% and 4.4–6.7%, respectively. The recoveries of four Sudan dyes are 89.3%, 90.3%, 91.8% and 92.0%, respectively. The results demonstrate that this method is simple, rapid, sensitive and low cost. Moreover, it does not require the large consumption of organic solvents and is a non-toxic and eco-friendly method.
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INTERNATIONAL JOURNAL OF COSMETIC SCIENCE
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2016
·Vol. 38
·期 5
·481-486
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IF 1.542
F. M. Zibetti,A. C. A. Cardoso,G. C. Desmarais,K. B. de Almeida,L. M. do Nascimento,L. F. Rolim,M. S. Rocha,N. G. D. Duarte,P. H. R. A. Azevedo,J. L. Araújo,S. C. Mourão,D. Q. Falcão
en This link goes to a English section fr This link goes to a French section Objectives The aim of this study was to evaluate by central composite design the influence of colouring agents in lipstick colour, expressed by L* , a* , b * parameters (CIELab system) where L* indicates lightness, and a* and b* are the chromaticity coordinates. The a* indicates colour direction from red to green and b* from yellow to blue. Methods Lipsticks were formulated as described by (Recent Adv. Prosp. Potent Med. Plants, 2009 and 39). The combined effect of three variables (dye, pigment and opacifier) was evaluated by different formulations in a central composite design. Colour parameters ( L* , a* , b *) were analysed by reflectance spectrophotometry. Lipsticks were characterized by visual analyses and melting point. Results All formulations were integrate and homogeneous. The pigments and dye do not influence in colour transfer neither in melting point of lipsticks. On the other hand, results indicated that variables studied show influence only in parameter b *, whereas for L * and a * values there was no significant difference ( P < 0.05). Conclusion It was possible to verify that only the colour parameter b * was influenced by the variation in colouring agent's concentrations in lipstick formulation, leading to the production of the colour ranging between violet and light red. Such results are useful for developing new lipstick formulations to obtain the desired colour in the final product. Résumé en This link goes to a English section fr This link goes to a French section Objectif L'objectif de cette étude était d'évaluer par Composite Central Design l'influence des agents colorants dans les rouges à lèvres, exprimée par les paramètres L *, a *, b * (système CIELab) où L * indique la clarté, et a * et b * sont les coordonnées chromatiques. a * indique la direction de la couleur du rouge au vert et b * du jaune au bleu. Méthodes Des rouges à lèvres ont été formulées comme décrit par Dwivedi et al. (2009). L'effet combiné de trois variables (colorant, pigment et opacifiant) a été évalué par différentes formulations dans un Composite Central Design. Les paramètres de couleur ( L *, a *, b *) ont été analysés par spectrophotométrie d'absorption. Les rouges à lèvres ont été caractérisés par des analyses visuelles et leur point de fusion. Résultats Toutes les formulations étaient visuellement homogène. Les pigments et colorants n'influencent pas le transfert de couleur ni le point de fusion des rouges à lèvres. D'autre part, les résultats indiquent que les variables étudiées n'ont qu'une influence sur le paramètre b *, alors que les valeurs L * et a * n'avaient pas changés de manière significative ( P < 0.05). Conclusion Il était possible de vérifier que seul le paramètre de couleur b * a été influencée par la variation de la concentration des agents colorants dans la formulation de rouge à lèvres, pour toute couleur comprise entre le violet et le rouge clair. Ces résultats sont utiles pour le développement de nouvelles formulations de rouges à lèvres afin d'obtenir la couleur désirée dans le produit final.
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高影响因子
TALANTA
·
2016
·
IF 4.035
Wenhua Ji,Mingming Zhang,Tao Wang,Xiao Wang,Zhenjia Zheng,Junjie Gong
In this research, the successfully developed molecularly imprinted solid-phase extraction (MISPE) method based on SH-Au modified silica gel for Sudan dyes determination has been described. Gold nanoparticles (Au NPs) were organized onto the surface of silica gel through the covalent binding between sulfydryl and Au. Subsequently, molecularly imprinted polymers (MIPs) were prepared via the graft polymerization using Au NPs as the functional monomer . The composition and morphology of MIPs were characterized by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TG). Binding property was systematically evaluated through adsorption isotherm , adsorption kinetics , and selective recognition capacity. MISPE pretreatment was successfully established after optimizing various parameters. Under optimized conditions, good linearity for six investigated Sudan dyes was ranged from 0.005 to 10.0 μg g −1 (R 2 >0.999) with low limits of detection and quantification (1.5–4.7 and 5.2–15.5 ng g −1 , respectively). The recoveries at three different spiked levels (0.05, 0.5, and 2.0 μg g −1 of each Sudan dye) were ranged from 87.2% to 94.7% with RSD below 6.1% (n=3). The results demonstrated one reliable, sensitive and accurate MISPE pretreatment technique with excellent reproducibility for the determination of six Sudan dyes in chili powder samples.
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ACS Sustainable Chemistry & Engineering
·
2016
·
IF 5.267
Zhenkang Li,Zhiping Wang,Qiwei Yang,Zhiguo Zhang,Yiwen Yang,Qilong Ren,Huabin Xing
Ionic liquid (IL)-mediated extraction methods have drawn much attention due to their reduced environmental impact and improved extraction efficiencies compared to traditional separation methods. However, one long-standing challenge in the application of IL-based extraction processes is the difficulty in recovering high-boiling solutes from the IL phase due to the negligible vapor pressure of ILs and the strong interaction between solutes and ILs. In this study, a new CO2-assisted back-extraction method was developed for the recovery of high-boiling solutes from the IL phase based on the reversible chemical absorption and/or strong physical interaction of CO2 with ILs. We found the distribution coefficient (D) of the typical solute δ-tocopherol in the [P4444][Pro]/DMSO–hexane biphasic system significantly decreased from 10.38 to 2.42 after the introduction of CO2, which greatly reduced the required solvent consumption and the number of back-extractions required for tocopherol recovery. For example, the number of back-extractions required for the recovery of 90% of the tocopherols from the [P4444][Pro]/DMSO–hexane biphasic phase decreased from 24 to 5 with the aid of CO2 absorption, along with a decrease in solvent consumption by approximately 80%. The effects of the structure of the IL, the loading of CO2, the type of cosolvents, and the temperature of the CO2-assisted back-extraction processes were investigated in this study. This proof-of-concept study demonstrates the great potential of CO2-assisted back-extraction as a green method for the efficient recovery of high-boiling solutes from the IL phase.
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MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 12
·3275-3283
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IF 4.831
Yao Youzhi,Liu Yunchun,Yang Zhousheng
The authors describe a method for room temperature preparation of reduced graphene oxide (rGO) decorated with Ag-Cu nanoparticles (NPs). The nanocomposite (Ag-CuNP/rGO) was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. A glassy carbon electrode (GCE) modified with this nanocomposite dispersed is shown to be a viable electrode for determination of Sudan I (best at a working voltage of −112 mV vs. Ag/AgCl), with remarkably increased electrochemical response to Sudan I compared to that of a plain GCE. The calibration plot is linear in the 1.0 nM to 10 µM concentration range, with a 0.4 nM detection limit (at a signal-to-noise ratio of 3). The method was successfully applied to the determination of Sudan I in ketchup and chili powder.
The nanocomposite of reduced graphene oxide (rGO) decorated with Ag-Cu nanoparticles (Ag-CuNP/rGO) was prepared using NaBH 4 as a reductant at room temperature. A glassy carbon electrode (GCE) was coated with a Ag-CuNP/rGO nanocomposite to form a modified electrode that can detect trace concentrations of Sudan I.
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危险品化学品经营许可证（带存储）