MICROCHIMICA ACTA
·
2015
·Vol. 183
·期 1
·441-448
·
IF 3.741
Cao Gen-Xia,Wu Xiu-Ming,Dong Yu-Ming,Li Zai-Jun,Wang Guang-Li
We describe a colorimetric assay for the quantitation of melamine (MA). It relies on the observation that MA reverses the inhibition of the light-triggered activity of horseradish peroxidase (HRP) functionalized gold nanoclusters (HRP-Au NCs) by Hg(II) ions. The HRP-Au NCs catalyze the oxidation of the substrate 3,3’,5,5’-tetramethylbenzidine (TMB) by dissolved oxygen if exposed to visible light provided by a 300 W Xe lamp (λ ≥ 400 nm). The addition of Hg(II) suppresses the enzymatic activity due to the metallophilic interaction between Hg(II) and Au(I) present on the surface of the HRP-Au NCs. MA with its triazole ring can restore the catalytic activity of the HRP-Au NCs by inhibiting the metallophilic interaction. As a result of these findings, a colorimetric “turn-on” assay for MA was worked out that can be used to determine MA in the 0.2 to 15 μmol·L −1 concentration range and with a 72 nmol·L −1 detection limit, which is much lower than the established safety limit. The method was successfully applied to the quantitation of MA in (spiked) raw milk and milk powder, with recoveries ranging from 98.5 % to 101.5 %.
We describe a colorimetric assay for the quantitation of melamine (MA). It relies on the observation that MA reverses the inhibition of the light-triggered activity of horseradish peroxidase (HRP) functionalized gold nanoclusters (HRP-Au NCs) by Hg(II) ions.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2013
·Vol. 18
·期 1
·105-113
·
IF 2.279
Li Hongying,Wang Xueliang,Yu Zhangyu
An electrochemical sensor for simultaneous determination of dopamine (DA), uric acid (UA), guanine (G), and adenine (A) has been constructed by copolymerizing melamine monomer and Ag ions on a glassy carbon electrode (GCE) with cyclic voltammetry. The poly-melamine and nano Ag formed a hybridized film on the surface of the GCE. The morphology of the film was characterized by scanning electron microscope. The electrochemical and electrocatalytic properties of this film were characterized by cyclic voltammetry, linear sweep voltammetry, and square wave voltammetry (SWV). In 0.1 M phosphate buffer solution (pH 4.5), the modified electrode resolved the electrochemical response of DA, UA, G, and A into four well-defined voltammetric oxidation peaks by SWV; the oxidation peak current of DA, UA, G, and A increased 13-, 6-, 7-, and 9-fold, respectively, compared with those at the bare GCE and the SWV peak currents of DA, UA, G, and A with linear concentrations in the ranges of 0.1–50, 0.1–50, 0.1–50, and 0.1–60 μM, respectively. Based on this, a method for simultaneous determination of these species in mixture was setup. The detection limits were 10 nM for DA, 100 nM for UA, 8 nM for G, and 8 nM for A.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Yuqin Zhu,Hang Gao,Lei Huang,Yang Lv,Pingle Liu
In the present study, the catalyst modified with alkaline oxide can enhance the selectivity to primary amines. However, the addition of alkaline oxide inevitably reduces catalytic activity. In this study, NiCo-NC@BaO-MFC catalyst derived from zeolitic imidazolate framework-67, Ba(CH 3 COO) 2 , and melamine formaldehyde (MF) resin was prepared and used for the hydrogenation of adiponitrile (ADN) to hexamethylene diamine (HDMA). The carbon layer obtained from the MF resin effectively prevents the interaction between barium (Ba) and the active center, thus improving target product selectivity without decreasing catalytic activity. The results of the density functional theory (DFT) calculation and characterization indicated that the effect of synergy between nickel (Ni) and cobalt (Co) bimetals induces an electron density growth on the Ni surface, bringing the d-band center toward the Fermi surface. Meanwhile, the high electron density of the active center compensates for the electron-deficient state of the carbon atom in –C N, thus improving the catalytic activity. Furthermore, it was found that the introduction of Ba promotes the formation of nucleophilic hydrogen anions, which facilitates the hydrogenation of 6-aminohexylimine (AHIM) to HDMA and inhibits the intramolecular condensation of AHIM, hence improving the selectivity to HDMA. The NiCo-NC@BaO-MFC catalyst gives 98.6 % ADN conversion and 97.2 % selectivity to HDMA in an alkali-free system.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Lin Gu,Wei Xia,Yifan Zhao,Shuhai Ding,Cong Kong,Junyu Zhang,Longlong Wang,Peng Wang,Guangxin Yang
Antibiotic pollution, particularly the overuse of tetracycline antibiotics (TCs), poses a significant threat to aquatic environments. Solid-phase extraction (SPE) is widely used for water sample pretreatment, and developing cost-effective, easily synthesized packing materials remains an active area of research. In this study, a novel filler material (SAS-MFP) was developed by combining commercial melamine-formaldehyde prepolymer (MFP) with a silica aerogel sponge (SAS), offering excellent water permeability, simple fabrication, and low cost. Characterization results revealed that the two materials were well integrated, with MFP evenly distributed across the surface of the silica aerogel. The adsorption mechanism of SAS-MFP was investigated through adsorption experiments. The results fit the Langmuir isotherm and pseudo-second-order kinetic models, indicating that SAS-MFP primarily adsorbs via chemisorption. Optimized SPE conditions led to the highest recovery (97.6 %) for four TCs under pH 7, using 400 mg of sorbent, a flow rate of 120 s·mL −1 , 5 % acetonitrile as the rinsing solvent, and 5 mL of 1 M oxalic acid–acetonitrile (1,4, v v −1 ) as the eluent. Furthermore, the limit of detection for TCs in blank water samples ranged from 0.09 to 0.12 μg·L −1 , with inter-day and intra-day relative standard deviations ranging from 2.46 % to 7.38 % and 4.58 % to 9.31 %, respectively, demonstrating the method's sensitivity and reproducibility for practical applications.
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Jinhan Lu,Xuan Sun,Zhilin Chen,Peng Jiang,Luming Li,Maohai Wang
The flammability of wood composite materials inevitably limits its broadly applications, inspired by the sandwich structure, we propose an intumescent flame-retardant vinyl acetate-ethylene based adhesive reinforced by melamine amino trimethyl phosphate and sodium lignosulfonate compounds (IFRs), then being incorporated in adhesive layer to prepare fire-proofing plywood. The formaldehyde-free adhesive incorporated with 23 wt% IFRs in plywood (FR plywood) resulted in a significant reduction in the peak heat release rate (pHRR, −51 %) and a great delay in time to pHRR (219 s) compared with that of the sample neat plywood. Additionally, the shear strength and bending strength of sample FR plywood present significant increase of 150 % and 73 %, respectively, compared to that of the neat plywood. By incorporating the IFRs into the plywood adhesive layers, low-flammability gasses can be released under heat to dilute flammable volatile gasses together with the wood decomposition in the gaseous phase, simultaneously, generated polyphosphoric acids to facilitate the charring of wood under heat, leading to a cohesive and dense phospho-carbonaceous structure in the condensed phase. Thus, this work provides an efficient and simple strategy to prepare fire-proofing plywood with excellent mechanical performance, is worth commercializing in plywood industry.
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2012
·
IF 3.655
Minwei Zhang,Xianyi Cao,Hongkun Li,Fengrui Guan,Jiajia Guo,Fei Shen,Yeli Luo,Chunyan Sun,Ligong Zhang
A simple, rapid and sensitive fluorescent assay for determination of melamine has been developed based on inner filter effect (IFE) of gold nanoparticles (AuNPs) on the fluorescence of CdTe quantum dots (QDs). When thioglycolic acid-capped CdTe QDs was mixed with citrate-stabilized AuNPs , the fluorescence of CdTe QDs was significantly quenched via the IFE of AuNPs. With the presence of melamine, melamine could induce the aggregation and corresponding absorbance change of AuNPs, which then resulted in the recovery of IFE-decreased emission of CdTe QDs. Under the optimum conditions, the detection limit for melamine in raw milk was 0.02 mg L −1 . The application of this method in samples of melamine-spiked raw milk suggested a recovery between 103% and 104%. Therefore, the obvious merits provided by the present assay, such as simplicity, rapidity, low cost, and high sensitivity, would make it promising for on-site screening of melamine adulterant in raw milk.
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2025
·
IF 9
Yang Peng,Xianqing Zhu,Qian Shen,Yun Huang,Ao Xia,Jingmiao Zhang,Xun Zhu,Qiang Liao
Co-hydrothermal carbonization (co-HTC) of microalgae and lignocellulosic biomass can boost co-hydrochar yield and nitrogen retention rate, but the co-hydrochar still suffers from low nitrogen content and porosity. Accordingly, in this study, FeCl 3 , NH 4 Cl and melamine were employed as additives to intensify the co-HTC process of microalgae (CP) and corn stalk (CS), and their impacts on the co-hydrochar yield, physicochemical properties and nitrogen transformation pathways were firstly investigated comprehensively. The results indicated that adding FeCl 3 increased co-hydrochar’s specific surface area, but the oxidation power of Fe 3+ facilitated nitrogen into the aqueous-phase products, leading to the nitrogen distribution in aqueous-phase products reaching up to 83.51 %. Melamine incorporation increased the nitrogen content of co-hydrochar (6.95 %) and oil-phase products, while reduced co-hydrochar’s porosity. NH 4 Cl was the most effective additive for nitrogen-doped hydrochar production, simultaneously increasing the yield (40.24 %), nitrogen content (8.93 %) and specific surface area (9.12 m 2 g −1 ) of co-hydrochar. The nitrogen transformation mechanism during NH 4 Cl-assisted co-HTC process could be divided into two stages. At the first stage (200 ℃–240 ℃), the NH 4 + in NH 4 Cl could react with hydrolysis intermediates (Maillard and Mannich reactions) to generate heterocyclic nitrogen compounds entering the oil-phase, which would further react with the oxygen-containing functional groups to facilitate the nitrogen enrichment in the co-hydrochar. At the second stage (240 ℃–280 ℃), a portion of hydrochar would undergo secondary degradation and formed water-soluble nitrogen-rich small molecules, which were transferred to the aqueous-phase products again. This study demonstrated the high feasibility of additive-assisted co-HTC for producing high-quality nitrogen-rich carbon materials.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Peige Qin,Dengke Chen,Mengyuan Li,Dan Li,Yanmei Gao,Shiping Zhu,Mengyao Mu,Minghua Lu
In this work, a magnetic carbon nanotube-decorated nitrogen-doped carbon (CNT/Fe@N-C) composite was successfully prepared by carbonization of melamine and MIL-101(Fe) under inert atmosphere at 900 °C. In order to study the removal performance of adsorbents for the organic dyes, different mass ratios melamine/MIL-101-derived CNT/Fe@N-C were prepared. The results show that the as-prepared CNT/Fe@N-C material delivers a high performance for removal of organic dyes (Rhodamine B, malachite green, and methyl orange) with mass ratio of MIL-101(Fe) and melamine at 1:3. The experimental parameters including amount of adsorbent, pH, contact time, and initial concentration of organic dyes were investigated. Under the optimized conditions, the maximum adsorption amount of CNT/Fe@N-C for three dyes are in the range of 182.1–196.5 mg/g. The adsorption process of three dyes on the CNT/Fe@N-C material was consistent with Langmuir isotherm model and pseudo-second-order model. The results indicate that the adsorption may be the monolayer chemisorption process. The adsorption mechanism of organic dyes on the adsorbent material is may be due to the electrostatic interactions and π-π stacking interaction. Finally, the CNT/Fe@N-C material can be reused 5 times without a significant reduction in the removal rate. The results indicate that the CNT/Fe@N-C material is a promising sorbent for removing organic dyes. This work provides a new strategy to prepare CNT/metal@N-doped carbon material with excellent adsorption properties from nitrogen-free raw MOF materials by calcining a mixture of MOF and melamine at high temperature.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Bionic Engineering
·
2021
·Vol. 18
·期 5
·1168-1178
·
IF 2.682
Liao Chenchen,Xia Yurou,Keshen A. Yinaer Nu,Dai Boya,Zhao Song’an,Hu Ziqing,Zheng Zaihang,Liu Yan
Inspired by nature, a superhydrophobic and magnetic melamine sponge (BFSM-MF) was fabricated by a one-step dip-coating method. Aiming at replacing nano-Fe 3 O 4 particles with a complex preparation process and high cost, the commercial and cheap Fe 3 O 4 originated from magnetite was employed as a magnetic substance. To acquire superhydrophobicity, the hierarchical mirco/nano-sized structure with low surface energy was mainly contributed by bonding hydrophobic Fe 3 O 4 and graphene with silicone resin onto the surface of the melamine sponge. The results demonstrated that the water and oil static contact angle values of BFSM-MF were 160° and 0°, revealing that BFSM-MF was superhydrophobic and super-oleophilic. Moreover, the self-cleaning ability, magnetic-driven oil absorption ability and continuous oil–water separation performance of BFSM-MF have also been evaluated. As expected, BFSM-MF possessed magnetic-driven oil absorption ability and the oil–water separation efficiency for light oil reaches 98% ± 1%. In addition, the adsorption capacity and recycling performance of different organic solvents were systematically investigated. Therefore, the development of biomimetic, fluorine-free and superhydrophobic foam with magnetic-driven effect has potential application value in marine oil spill treatment and separation of domestic oil pollution.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2020
·
IF 3.99
Jie Yue,Meng Yuan,Xuan Zhang,Guochang Wen,Guina Ren,Bo Ge,Limin Zhao,Xin Shao
Due to its porous structure, hydrophobic modified three dimensional melamine sponge (MS) was commonly used for high efficiency oil/water separation. Nevertheless, it does nothing to water-soluble pollutants. In order to deal with residual pollutants, the direct Z-scheme BiOI/CdS composites was constructed and loaded onto the melamine sponge which easily achieved efficient degradation and selective deoiling. Furthermore, traditional hydrophobic methods (such as grafting mercaptan, silanes and so on) had several drawbacks, hence a novel metal organic frame material ZIF-8 was adopted in order to attain the purpose of superhydrophobic . In this work, it has shown that the cyclic photodegradation efficiency of superhydrophobic BiOI/CdS/ZIF-8 melamine sponge (BCZ MS) could still achieve 92% after performing 4 cycles of degradation and the results indicated that BCZ MS has preeminent stability. Besides, it was verified by the capture experiment that the main active species was O 2 − .
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2020
·Vol. 43
·期 14
·2842-2849
·
IF 2.878
Liping Sun,Sufang Wang,Tao Zhu
In this study, the new and efficient three-dimensional network porous aromatic frameworks materials called Silica-PAFs-a, Florisil-PAFs-a, Silica-PAFs-b, and Florisil-PAFs-b were first synthesized. The properties of materials were analyzed by five characterization methods. The materials were used as adsorbents in pipette-tip solid-phase extraction for the effective determination of carbendazim and thiabendazole in spinach sample. Meanwhile, the obtained materials were tested by static adsorption and dynamic adsorption. The result showed that the specific surface area of materials greatly increased after introducing three-dimensional network porous aromatic frameworks. Microstructural modification exposed a large number of amino reactive groups that made them have a better adsorption amount for the two targets. The calibration graphs of carbendazim and thiabendazole in methanol were linear over 0.10–300.0 µg/mL, and the limits of detection and quantification were 0.00546 and 0.0182 µg/mL, and 0.00741 and 0.0247µg/mL respectively. A reliable analytical method was developed for recognition targets in spinach sample by Silica-PAFs-b with satisfactory extraction recoveries (96.25 and 100.51%). The proposed method using the material was applied for trace analysis of the carbendazim and thiabendazole residue.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
·
2018
·
IF 1.372
Yanfang Zhao,Lubin Xu
In this work, a low-cost melamine-formaldehyde polymer with large-surface-area mesoporous structure was prepared and applied as an efficient solid sorbent for pre-concentration of five kinds of chlorinated herbicides including fomesafen, atrazine, pyrithiobac-sodium, benazolin and acifluorfene from water samples. Extraction parameters such as pH of the sample solution, amount of mesoporous melamine-formaldehyde polymer (mMFP), extraction time, type of desorption solv-ent and volume of the sample were systematically investigated. Combining dispersive solid-phase extraction with high-performance liquid chromatography (HPLC), the detection limits (S/N = 3) of the five herbicides were ranged from 0.04 to 0.18 μg L−1 with good linearity (R2 ≥ 0.9908). Then the tap water and river water samples were analysed by the developed method, and the obtained results indicated that this method provides acceptable recoveries and precisions. mMFP can be prepared through one-pot catalyst-free polymerisation from low-cost starting materials, so that they could be easily scaled up for the sample pre-treatment and have the powerful potentiality in purification of contaminated water.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）