Dimethylformamide Medium Research Articles

Unprecedented synthesis of indole-linked tetra-substituted alkenes by catalyst-free domino reaction

Herein, we report a simple, efficient catalyst-free green domino reaction of indole, arylglyoxal, and cyclic 1,3-dicarbonyls such as barbituric acid derivatives/dimedone at 100oC in dimethylformamide medium in open air condition. In this reaction, one C-C and one C=C bonds have been formed in one-pot without using any additive or metal based reagent. Considering the presence of indole, benzoyl and cyclic 1,3-dicarbonyl moieties in the products, it is expected that they will exhibit interesting medicinal properties. All the synthesized products were characterized by recording FTIR, 1H NMR, 13C NMR, and HRMS. Moreover, a single crystal XRD of compound 4i was recorded to confirm the structure of the product. Operational simplicity, gram-scale synthesis, mild reaction conditions, good yields, and wide substrate scope are the salient features of this methodology.

Metal Ion‐Endows Orange‐Red Light Fluorogenicity of an Imine‐Linkage Probe Embracing Simple Electron Donor‐Acceptor Units

AbstractSelectively tracking and quantifying Al3+ ions is a significant concern to the scientific communities. In the present article, an imine‐linkage electron donor‐acceptor system, DSAN, (E)‐5‐(diethylamino)‐2‐(((2‐hydroxy‐4‐nitrophenyl)imino)methyl)phenol has been introduced which shows Al3+ ions endows red light fluorogenicity which could be utilized for sequential and detection of Al3+ ions and picric acid (PA) in both solid and liquid phases. Upon addition of Al3+ ions into the DSAN solution, an orange‐red fluorescence is noticed at 604 nm caused by the formation of Al3+ ions chelated DSAN complex having detection and quantification limit 0.2 μM and 0.62 μM respectively in dimethylformamide (DMF) medium. The complex formation is found to be a 1 : 1 stoichiometric ratio as evident from Job's plot analysis. Also, the binding affinity value is found to be 3.24×104 M−1 demonstrating a high affinity of DSAN towards Al3+ ions. This orange‐red fluorescence of Al3+ ions chelated DSAN complex solution is quenched due to the introduction of PA. A super handy paper‐strips‐based detection tool also been fabricated utilizing DSAN which could be employed to track trace amounts of Al3+ ions in the solid state. The mechanism involved in the detection of Al3+ ions is elucidated by density functional theoretical analysis.

ПОЛУЧЕНИЕ ИСКУССТВЕННЫХ ПОЛИМЕРОВ НА ОСНОВЕ ЦЕЛЛЮЛОЗЫ

The production of artificial polymers with a complex of useful physical and chemical properties is based on three main methods of their synthesis is polymerization, polycondensation and modification. At the same time, the modification of polymers has now found wide application, including for the production of cellulose ethers, among which cellulose nitrate ester is one of the large-scale products. Through reactions of functional groups, cellulose nitrate can be converted into new compounds in nucleophilic substitution reactions. The interaction of 4,4',5,5'-Tetranitro-2,2'-bi-1H-imidazole (TNBI) with cellulose nitrate C6H7O2(OH)0,87(ONO2)2,13 in the medium of dimethylformamide at a temperature of 70-72 oC and different reaction times 1, 2, 3 and 4 hours was studied. The main directions of the reaction were identified, namely, nucleophilic substitution nitrate groups of cellulose nitrate for a fragment of a THБИ; partial hydrolysis of nitrate groups; depolymerization and destruction of the polymer chain with the breaking of β-glycosidic bonds and joining at the ends of the polymer chain in the positions C1 and C4 of the fragment of a TNBI molecule. Based on the results of experimental data and physical and chemical studies, the chemical composition and structure of the reaction products obtained are determined and the scheme of interaction of cellulose nitrate with TNBI is presented. It was found that the product of interaction of cellulose nitrate with TNBI, obtained at the maximum reaction time 4 hours at a temperature of 70 oC has the lowest degree of substitution of nitrate groups. A further increase the reaction time does not lead to a significant increase in the content of the TNBI fragment in the products, since there is a strong degradation of the initial polymer, which makes it difficult to isolate high-molecular products was found. The possibility of a directed change in the composition of chemically modified cellulose nitrates at different stages of synthesis to obtain products with controlled composition and properties has been established.

Lanthanum and some lanthanides 2,4-dichlorophenoxyactetates: Structure and luminescent properties

The exchange interaction of lanthanum and some lanthanides salts (neodymium, samarium, europium, gadolinium, terbium and dysprosium) with sodium salt of 2,4-dichlorophenoxyacetic acid (HL) in dimethylformamide medium produced lanthanum and lanthanide carboxylates. The compounds were studied by elemental and thermal analysis, infrared spectroscopy and X-ray structure analysis. It was found that the complexes form two isostructural series: [Ln2L6(DMF)3]∙Solv (Ln = La, Nd, Sm, Eu) and [LnL3(H2O)2]∙2DMF∙Solv (Ln = Gd, Tb, Dy). Both series have a one-dimensional polymer structure in which the central atoms are connected by bridging carboxylate anions. The crystal structures of the complexes have a branched network of noncovalent D-H…A and Cl…Cl interactions. An analysis of the photophysical properties of all compounds revealed a bright luminescence with a quantum yield up to 39.5 % and an excited state lifetime of 1330 μs for the europium polymer enhanced by 2,4-dichlorophenoxyacetate ligands.

Development of a method for the quantitative determination of glibenclamide in tablets

Aim. To develop and validate a spectrophotometric technique for quantitative determination of glibenclamide in tablets by reaction with 2,3-dichloro-1,4-naphthoquinone. Materials and methods. In the study, the substance glibenclamide of pharmacopoeial purity was used, tablets – “Maninil” 5 mg and “Glibenclamid-Zdorovye” 5 mg, 2,3-dichloro-1,4-naphthoquinone of the “CFA” qualification was chosen as a reagent, as a solvent – dimethylformamide (DMF) “CFA”. The following analytical equipment was used for the research: spectrophotometer “Specord-200” (Analytic Jena AG, Germany), water bath “MEMMERT WNB7”, laboratory electronic scales RADWAG XA 210. 4Y, measuring laboratory vessels of class A. Results. A new, simple spectrophotometric method of quantitative determination of glibenclamide in tablets by reaction with 2,3-dichloro-1,4-naphthoquinone in DMF medium was developed. The absorption maximum was at 489–491 nm. The value of the detection limit is 10.9 μg/ml, which indicates sufficient sensitivity of the reaction. Subordination to the basic law of light absorption is within the limits of concentrations of 13.7–27.4 mg/100 ml. In the process of developing the methodology, the following validation characteristics were determined: specificity, linearity, precision, correctness, and robustness. Conclusions. The methodology for the quantitative determination of glibenclamide was developed and validated according to the requirements of the State Pharmacopoeia of Ukraine. It has been proven that the method is simple, accessible, and validated for such characteristics as linearity, convergence and robustness and can be used for application in laboratories for quality control of medicinal products.

Побочные продукты окислительной десульфиризации судового маловязкого топлива — перспективные ингибиторы коррозии

The studies described in the article show that the by-product of oxidative desulfurization of low-viscosity marine fuel is a promising inhibitor of acid corrosion, showing anticorrosive activity in dimethylformamide medium with respectto carbon steel grade St3sp with a degree of protection of 75.5%. This will not only simplify the material support of the proposed alternative technological process of desulfurization of fuel and solve environmental problems, but also reduce the need of the domestic industry for expensive imported reagents.

Synthesis of 1-nicotinoylo-3-(meta-nitrophenyl)- thiourea derivatives with anti-inflammatory activity

Thiourea derivatives are used in many industries: medicine, agriculture, engineering, rubber industry, organic synthesis. On their basis, various preparations for the needs of the national economy were obtained. The latest studies of thiourea derivatives, carried out at the present time, are prompted not only by theoretical, but also by practical needs. From this point of view, thiourea derivatives are of undoubted interest in substances with different biological activities. They are widely used in agriculture and have been used as herbicides, fungicides, insecticides, bactericides, dyes, growth stimulants, etc. Of particular interest is the use of these compounds in medicine as antitumor, antiviral, anti-inflammatory, antiarrhythmic, vasodilator and other drugs. Today, most of the derivatives of thiourea, urea, the search for new highly effective low-toxic biologically active compounds based on them is constantly ongoing, as can be judged by the large number of publications in the world scientific and patent literature. This article proposes a simple and convenient method for the preparation of 1-nicotinoyl-3-(m-nitrophenyl)-thioureas based on heterocyclic thioisocyanate with nitroaniline in a dimethylformamide medium, in rather high yields. And also studied the anti-inflammatory activity of the synthesized drug.

СИНТЕЗ И ДОКЛИНИЧЕСКАЯ ОЦЕНКА ВИЗУАЛИЗАЦИОННЫХ ВОЗМОЖНОСТЕЙ 99mТс-ДТПА-ГДОФ КАК НОВОГО ОТЕЧЕСТВЕННОГО ГЕПАТОТРОПНОГО ПРЕПАРАТА ДЛЯ СЦИНТИГРАФИЧЕСКИХ И ОФЭКТ-ИССЛЕДОВАНИЙ

Purpose: Was to obtain a radiopharmaceutical (RPH) ‒ 99mTc bound with DTPA-GDOF (2-(2-carboxymethyl-(4-hexa-decyloxyphenyl-carbamoyl-methyl)-aminoethyl)-aminoethyl-(4-hexadecyl-oxyphenyl-carbamoyl methyl)-aminoacetic acid) and evaluate in an in vivo experiment on laboratory rats the possibility of using as hepatotropic RPH for scintigraphy and SPECT. Material and methods: The synthesis of DTPA-GDOF was carried out according to the original method of M.L. Belyanin e.a. at the N.M. Kizhner Center of TPU, by the interaction of 4-hexadecyloxyaniline with diethylenetriaminopentaacetic acid (d-DTPA) anhydride in dimethylformamide medium. Then 2 mg of GDOF-DTPA powder was mixed with 0.5 ml of 5 % sodium bicarbonate solution and heated to 100 oC until completely dissolved. 2 mg of tin dichloride powder were added to the solution, stirred and incubated at 25 oC for at least 20 minutes. The resulting solution was mixed with 99mTc eluate with an activity of 3 MBq and incubated for 10 min at 25 oC. Control of the labelling efficiency of 99mTc with DTPA-GDOF was carried out by chromatography on paper, according to the method of Zimmer and Pavel (1977). An in vivo study of the absorption kinetics of 99mTc-DTPA-GDOF was performed on male rats of the Wistar line (n = 12) 300–350 g. 99mTc-DTPA-GDOF at a dosage of 0.025 mmol/kg, 3 MBq was injected into the femoral vein. All scans are performed using the SPECT/CT Siemens Symbia T. Dynamic planar study included recording 4 sec/frame for the first two minutes, 128 × 128 pixels, and then up to 20 min – as 15 s/frame, followed by a SPECT/CT of the whole body. The value of the fraction of extraction (retention) of RPH in the liver was calculated. The values of the organ accumulation of RPH were determined as the organ fraction of uptake of the agent relative to the total dose administered to the animal Results. The labeling efficiency of DTPA-GDOF with 99mTc in fresh eluate of a standard molybdenum generator was in all cases more than 94 % (on average 95.6 ± 2.1 %, thus the proportion of free technetium was up to 4‒4.5 %). When storing 99mTc-DTPA-GDOF at room temperature on a shelf for up to 5 hours, the release of 99mTc-from the complex with DTPA-GDOF did not exceed 3.1 ± 0.3 %. The extraction fraction of 99mTc-DTPA-GDOF in the liver is as high as 0.78 ± 0.04. The fraction of the injected dose taken up by the liver is up to 70 % (68.9 ± 8.9). The quota of the spleen uptake is 14.1 ± 4.2 %. The level of accumulation of 99mTc-DTPA-GDOF in the liver was then maintained steadily without a significant decrease for up to 16‒18 hours. Conclusion: The 99mTc-DTPA-GDOF complex is a original RFP, with a high 99mTc labeling efficiency, long-lasting stability after labelling, and providing in vivo highly specific long-term imaging of the liver and spleen with gamma scintigraphy and SPECT.

Studying spectroscopic, cyclic voltammetry, and electrical properties of novel 4-amino antipyrine derivative for photonic applications

The present work aims to synthesize a new antipyrine derivative and then study its optical properties in the form of thin films with the aim of using the obtained results in the fabrication and designing of new optoelectronic devices. A N1,N3-bis(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)malonamide, dpdp novel organic compound has been successfully synthesized in dimethylformamide (DMF) medium by the chemical reaction between 4-aminoantipyrine and malonyl chloride. The obtained dpdp compound is characterized quantitatively and qualitatively by using micro elemental analysis, FTIR spectroscopy, 1H– & 13C–NMR, and thermogravimetric measurements. Two steps weight loss of 84 % (calcd. mass loss 37.25 %) is recorded in the temperature range of 25 °C to 800 °C. Thin films of the novel organic dpdp were successfully grown by the thermal evaporation technique. FSEM images show the surface topology of the as-deposited thin film which is characterized by high quality, continuous, and crystalline granular surface with an average particle size of 70 nm. The cyclic voltammetric analysis showed that the energy difference between the HOMO and LUMO equals 2.43 eV. The calculated values of the optical band gap transitions deduced from the diffuse reflectance spectra are found to be 2.27 eV, and 3.44 eV for the powder and the as-deposited dpdp thin films, respectively. The photoluminescence spectra analysis showed that the as-deposited film dpdp is characterized by a main green peak centered at 530 nm. The optical transflection spectra showed that the calculated values of the indirect optical band gap transitions are found to be 3.53 eV for the as-deposited thin film which slightly increased to 3.63 eV after annealing at 373 K and 423 K for 4 h. Spectral variations of the refractive index and the specific polarizability showed one peak around 400 nm which fades by annealing treatment at 373 K and 423 K. The dc electrical resistivity activation energy of the free charge carriers was estimated.

Freezing for the Future: Obtaining Fibroblast Samples from Deceased Wild Mammals for the Brazilian Cerrado Germplasm Bank.

We isolated and further characterized fibroblasts obtained from postmortem skin biopsies of three different Brazilian wild species (Chrysocyon brachyurus-maned wolf, Cerdocyon thous-crab-eating fox, Mazama gouazoubira-brown brocket deer). The effects of two cryoprotectants, 10% dimethyl sulfoxide (DMSO) and 5% dimethylformamide (DMF), were assessed to determine the most efficient cryopreservation protocol. Such an investigation promotes the creation of germplasm banks, using samples that would otherwise be rejected and permanently lost following the death of the animals. We utilized animal corpses that were involved in highway accidents, found dead in the natural environment, or referred to us from the veterinary hospital at the Brasília Zoo. Fibroblasts from C. brachyurus specimens presented a delay in cell growth in Dulbecco's modified Eagle's medium in relation to other species. This observation is a limiting factor for the future storage of cells from this species. Differences in cellular morphology were observed between C. brachyurus, C. thous, and M. gouazoubira, presenting branched, fusiform, and spherical forms, respectively. The cryoprotective solution containing 10% DMSO was more efficient than 5% DMF medium in preserving the viability of fibroblasts of the three species (p < 0.05). After defining the best cryopreservation solution, a germplasm bank was successfully formed. This biological reservoir is configured as the first germplasm bank containing somatic cells and gametes of wild mammals of the Cerrado biome of Brazil. This material will be used for future characterization of the species and multiplication by means of nuclear transfer cloning.

Synthesis, characterization and Ion-exchange properties of 4, 4 oxy-dianiline, 2,6 diamino-pyridine with formaldehyde terpolymer

Abstract A new terpolymer ligand (DAPR) was synthesized based on condensation polymerization techniques. DAPR was named by 4,4 oxy-dianiline and 2,6 diamino-pyridine with formaldehyde. The taken monomers mole ratio is 1:1:2 in the reaction medium of Dimethylformamide (DMF). The solubility behaviour of the terpolymer samples have been studied in various solvents. The prepared terpolymer ligand was characterized by elemental analysis, FTIR, 1H & 13C NMR and TGA studies. The synthesized terpolymer ligand molecule formula identified by elemental analysis and the most probable structure confirmed by the spectral studies of FTIR, 1H & 13C NMR. The SEM image used to establish the outward of the ligand. The thermal decomposition and thermal strength of DAPR ligand was carried out by thermo gravimetric analysis (TG-DTA). The chelation ion exchange studies of the terpolymer for the definite metal ions were also carried out by batch equipoise way under the estimation of metal ion uptake at diverse electrolytes.

In Situ Transformed Cobalt Metal-Organic Framework Electrocatalysts for the Electrochemical Oxygen Evolution Reaction.

The development of an active and efficient electrocatalyst for the oxygen evolution reaction remains indispensable for the smooth running of an electrolyzer. Herein, we have synthesized two cobalt metal-organic frameworks (Co-MOFs) with the formulas [C6H6CoN2O4] (compound 1) and [C12H10CoN2O4] (compound 2) using pyrazine and 4,4'-bipyridine as linkers in dimethylformamide medium by a solvothermal method. Both Co-MOFs shows strong antiferromagnetic interactions with Θp = -70 and -61 K for compounds 1 and 2, respectively. The in situ transformation of both compounds catalyzes the OER efficiently in alkaline medium, affording a current density of 10 mA/cm2 at overpotentials of 276 ± 3 and 302 ± 3 mV by compounds 1 and 2, respectively. Moreover, compound 1 shows a very high turnover frequency (15.087 s-1), lower Tafel slope (56 mV/dec), and greater Faradaic efficiency of 95.42% in comparison to compound 2. The transformations of the Co-MOFs have been accessed by employing powder X-ray diffraction (PXRD), high-resolution transmission electron microscopic (HRTEM) analysis, and X-ray photoelectron spectroscopy, which reveal the formation of uniform hexagonal Co(OH)2 plates. Therefore, the as-developed Co-MOF is found to be an efficient pre-electrocatalyst for the OER in alkaline medium. These results not only reveal the preparation of OER electrocatalysts from a Co-MOF but also establish a method to derive a potentially active electrocatalyst to substitute for the traditional noble-metal-based materials.

Solvent Switched Weak Interaction of a 4-Quinazolinone with a Cavitand Derivative.

Interaction of 4-quinazolinone with tetrakis (3,5-dicarboxylatophenoxy)-cavitand derivative has been studied in methanol and dimethylformamide media using fluorescence spectroscopy and molecular modeling methods. Results show temperature dependent complex formation: either the entropy gain or the high enthalpy changes are responsible for the formation of stable complexes in two separated temperature regions. However, different thermodynamic parameters are associated to different conformations of the complexes: while the high entropy gain associated to the formation of deeply included guest in methanol, the high entropy gain is associated with the formation of weakly included guest in dimethylformamide solvent. This finding highlights the importance of dynamic properties of the species interacted in different solvents.

Cs2CO3-Mediated Rapid Room-Temperature Synthesis of 3-Amino-2-aroyl Benzofurans and Their Copper-Catalyzed N-Arylation Reactions.

Cs2CO3 in dimethylformamide (DMF) is a perfect combination for the rapid room-temperature synthesis of 3-amino-2-aroyl benzofuran derivatives from the reaction of 2-hydroxybenzonitriles and 2-bromoacetophenones in good to excellent yields. Using this one-pot C–C and C–O bond-forming strategy, we prepared a series of 3-amino-2-aroyl benzofuran derivatives within a very short time (10–20 min). This method was also found suitable for gram-scale synthesis. Benzofurans (3) obtained by this Cs2CO3-mediated methodology were then further explored for the development of a tunable base- and ligand-free copper-catalyzed N-arylation methodology using arylboronic acids for the easy access of either mono- or bi-N-aryl derivatives of aminobenzofurans at ambient temperature. The reaction of 3 with malononitrile in DMF medium under microwave heating conditions provided highly fluorescent conjugated alkenes and novel pyridine-fused benzofurans.

Femtosecond laser ablation-assisted synthesis of silver nanoparticles in organic and inorganic liquids medium and their antibacterial efficiency

Laser ablation from a solid target assists the synthesis of nanoparticles (NPs) as an alternative physical process. This work is attempt to investigate the morphological properties of silver nanoparticles (AgNPs) synthesized by femtosecond pulsed laser ablation in different liquid medium; Double Distilled Water (DDW), Deionized Water (DIW), Tetrahydrofuran (THF), and Dimethylformamide (DMF). XRD diffraction peaks that corresponds to (111), (200), (220) and (311) planes confirm the synthesized of AgNPs. The absorption spectra confirm the existence surface plasmon resonance (SPR) peak of AgNPs. The direct optical energy band gap (Eg) values have been calculated according to Tauc's equation and equal to 3.97, 3.82, 3.86, and 3.88 eV for synthesized AgNPs by Fs PLAL at different medium; DDW, DIW, THF, and DMF, respectively. Also, the influence of different liquid medium on the antibacterial efficiency was studied. In vitro Antibacterial activity of synthesized AgNPs was carried out against four types of bacteria employing agar plate technique. The experiments demonstrated that ablation efficiency, stability, and antibacterial efficiency of AgNPs in DIW medium are higher than those prepared in DDW, THF, and DMF medium.

Utility of chromogenic property of 2, 2-dihydroxyindane-1, 3-dione for quantification of Memantine hydrochloride in pure, pharmaceutical preparation and application to uniformity testing.

Accurate, simple, sensitive, and fast spectrophotometric assay was applied for the quantification of certain anti-Alzheimer drug namely; Memantine hydrochloride, in its bulk and pharmaceutical preparation. The described assay has been established on the reaction between the primary amino moiety of the cited drug and 2,2-dihydroxyindane-1,3-dione reagent in N,N'-dimethylformamide medium in boiling water bath. Which give Ruhemann's purple color that can be determined at λmax = 595 nm. Beer's law has been obeyed within drug concentration range from 10-120 μg per milliliter. Detection limit and quantitation limit have been 1.6 & 4.9 μg per milliliter respectively. Developed procedure has been validated in agreement with International Conference of Horizon recommendations and applied successfully for detection of cited drug in bulk, pharmaceutical dosage form and content uniformity testing.

Polyoxometalate-Promoted Electrocatalytic CO2 Reduction at Nanostructured Silver in Dimethylformamide.

Electrochemical reduction of CO2 is a promising method to convert CO2 into fuels or useful chemicals, such as carbon monoxide (CO), hydrocarbons, and alcohols. In this study, nanostructured Ag was obtained by electrodeposition of Ag in the presence of a Keggin type polyoxometalate, [PMo12O40]3- (PMo). Metallic Ag is formed upon reduction of Ag+. Adsorption of PMo on the surface of the newly formed Ag lowers its surface energy thus stabilizes the nanostructure. The electrocatalytic performance of this Ag-PMo nanocomposite for CO2 reduction was evaluated in a CO2 saturated dimethylformamide medium containing 0.1 M [ n-Bu4N]PF6 and 0.5% (v/v) added H2O. The results show that this Ag-PMo nanocomposite can catalyze the reduction of CO2 to CO with an onset potential of -1.70 V versus Fc0/+, which is only 0.29 V more negative than the estimated reversible potential (-1.41 V) for this process and 0.70 V more positive than that on bulk Ag metal. High faradaic efficiencies of about 90% were obtained over a wide range of applied potentials. A Tafel slope of 60 mV dec-1 suggests that rapid formation of *CO2•- is followed by the rate-determining protonation step. This is consistent with the voltammetric data which suggest that the reduced PMo interacts strongly with CO2 (and presumably CO2•-) and hence promotes the formation of CO2•-.

Synthesis and characterization of carboxylic cation exchange bio-resin for heavy metal remediation

A new carboxylic bio-resin was synthesized from raw arecanut husk through mercerization and ethylenediaminetetraacetic dianhydride (EDTAD) carboxylation. The synthesized bio-resin was characterized using thermogravimetric analysis, field emission scanning electron microscopy, proximate & ultimate analyses, mass percent gain/loss, potentiometric titrations, and Fourier transform infrared spectroscopy. Mercerization extracted lignin from the vesicles on the husk and EDTAD was ridged in to, through an acylation reaction in dimethylformamide media. The reaction induced carboxylic groups as high as 0.735mM/g and a cation exchange capacity of 2.01meq/g functionalized mercerized husk (FMH). Potentiometric titration data were fitted to a newly developed single-site proton adsorption model (PAM) that gave pKa of 3.29 and carboxylic groups concentration of 0.741mM/g. FMH showed 99% efficiency in Pb(II) removal from synthetic wastewater (initial concentration 0.157mM), for which the Pb(II) binding constant was 1.73×103L/mol as estimated from modified PAM. The exhaustion capacity was estimated to be 18.7mg/g of FMH. Desorption efficiency of Pb(II) from exhausted FMH was found to be about 97% with 0.1N HCl. The FMH simultaneously removed lead and cadmium below detection limit from a real lead acid battery wastewater along with the removal of Fe, Mg, Ni, and Co.

Modification of poly(vinyl chloride) with sodium salts of triazoles

New copolymers containing reactive vinyltriazole units and polyvinylene blocks with conjugation system promising as materials with special electrical, physical, catalytic, and sorption properties have been prepared by the reaction of poly(vinyl chloride) with sodium salts of 1,2,4-triazole and 1,2,3-benzotriazole in a dimethylformamide medium.

Hybrid of ZnONPs/MWCNTs for electrochemical detection of aspartame in food and beverage samples

An electrochemical sensor for the detection of aspartame using differential pulse voltammetry (DPV) was developed by modifying a glassy carbon electrode (GCE) with zinc oxide nanoparticles (ZnONPs) dispersed over multiwalled carbon nanotubes (MWCNTs) in dimethylformamide medium. The ZnONPs/MWCNTs/GCE surface area of 12.17mm2 was able to oxidize aspartame at a potential of 1.70V in a phosphate buffer of pH2.0 showing two anodic peaks at 0.398V and 1.491V. The characterization of nanocomposite was carried out using transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and cyclic voltammetry (CV). The sensitivity and detection limits obtained with the modified electrode was four-fold greater than that of the unmodified electrode and the concentration of aspartame was found to be 40.36μM, 27.92μM and 44.30μM in Coke zero, Huletts and Sprite zero respectively. The developed method was successfully applied for the determination of aspartame in food samples with a 96% confidence level.