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1.
Fluorescence spectroscopy and circular dichroism (CD) spectroscopy were used to investigate the interaction of coumarin-3-carboxylic
acid with human serum albumin (HSA) and bovine serum albumin (BSA) under physiological conditions in a buffer solution of
pH 7.4.
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2.
Dmitriy A. Golovko Virender K. Sharma Olga. V. Pavlova Elena. A. Belyanovskaya Igor. D. Golovko Victoria. I. Suprunovich Radek Zboril 《Central European Journal of Chemistry》2011,9(5):808-812
A new amperometric titration method was developed for quantitative determination of ferrate(VI) (FeVIO4
2−) in the 7.06×10−5−5.73×10−3 M concentration range. Chromium(III) hydroxide solution was used as the titrant. The diffusion current (Id) had a linear
relationship with the concentration of ferrate(VI) and slopes were dependent on the concentration of NaOH. The amperometric
titration could detect a lower concentration of ferrate(VI) than could potentiometric and colorimetric titrations. The method
was applied successfully to determine concentrations of ferrate(VI), generated electrochemically, in strong alkaline solutions.
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3.
Ksenija R. Kumrić Tatjana M. Trtić-Petrović Ljubiša M. Ignjatović Jožef J. Čomor 《Central European Journal of Chemistry》2008,6(1):65-69
Lutetium has been determined by differential pulse anodic stripping voltammetry in an acidic solution containing Zn-EDTA.
Lutetium (III) ions liberated zinc (II), which was preconcentrated on a hanging mercury drop electrode and stripped anodically,
resulting in peak current linearly dependent on lutetium (III) concentration. Less than 0.4 ng mL−1 lutetium could be detected after a 2 min deposition.
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4.
Nikolai N. Kolesnikov Elena B. Borisenko Dmitrii N. Borisenko Boris A. Gnesin 《Central European Journal of Chemistry》2011,9(4):619-623
In the present study newly produced semiconductor ceramic nanopowder materials made of CdTe and Cd1−xZnxTe (CZT) are considered. Common features and differences in microstructures, phase transformations, grain growth and properties
of the ceramic materials of the binary and ternary compositions are studied.
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5.
Sylwia Smarzewska Sławomira Skrzypek Barbara Bachowska Piotr Bałczewski Witold Ciesielski 《Central European Journal of Chemistry》2011,9(5):840-845
Electrochemical oxidation of methylthiomethyleneisoquinolinium chloride (MTMIQ), the first alkylthiomethyl substituted ammonium
salt, which is fully miscible with water has been investigated by voltammetric (SWV) method using glassy carbon electrode.
On the electrode, MTMIQ undergoes oxidation at the potential near Ep = 0.07V (vs. Ag/AgCl/3 M KCl). The influence of the pH
of buffers, amplitude, frequency, step potential on the received signal was studied. The best results were obtained with a
citrate buffer at a pH of 5. The oxidation peak current used for MTMIQ voltammetric determination was in the range of 2–8×10−5 mol L−1, LOD = 3.7×10−6, LOQ = 1.2×10−5. The product of the oxidation was accumulated at the working electrode and was investigated by spectroscopic method. Mechanistic
pathways of the oxidation have been proposed.
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6.
Nitin A. Mirgane Sandip B. Kotwal Anil V. Karnik 《Central European Journal of Chemistry》2010,8(2):356-360
Ionic liquids (IL) are gaining importance as green solvents. Imidazolium ionic liquid [bmim]+[Cl]−, an environmentally benign solvent, was found to promote the Diels-Alder reaction between anthrone and maleimides at room
temperature with excellent yields. The ionic liquid played a dual role as solvent and catalyst.
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7.
Mónica Díaz-Pérez Manuel Aboal-Somoza Pilar Bermejo-Barrera Adela Bermejo-Barrera 《Central European Journal of Chemistry》2008,6(4):520-525
Preliminary results of development of a direct and fast method of determination of antimony in samples of tap water using
GFAAS are presented. The found levels of antimony were lower than permitted for human consumption. A mixture of Pd and Mg(NO3)2 (concentrations in the injected solution: 8.6 μg mL−1 and 5.8 μg mL−1 respectively) was used as the chemical modifier. The pyrolysis and atomization temperatures were 1000 and 1700°C, respectively
and the mean analytical recovery 98.2%.
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8.
Panayot K. Petrov Jožica Majda Serafimovska Sonja Arpadjan Dimiter L. Tsalev Trajče Stafilov 《Central European Journal of Chemistry》2008,6(2):216-221
The influence of EDTA, carboxylic acids, amino-and hydroxocarboxylic acids, monosaccharides and humic substances on the generation
of arsines in hydride generation atomic absorption spectrometry (HGAAS) was investigated. EDTA (0.02 mol L−1), ascorbic acid (0.02 mol L−1) and glucose or fructose (0.2 mol L−1) are useful additives for levelling sensitivities for As(III), monomethylarsonate (MMA) and dimethylarsinate (DMA). The presence
of glycine, malonic, tartaric acids, BICIN and soil humin extracts leads to differences in analytical signal response between
these arsenic species. An analytical application to the determination of the sum of As(III), monomethylarsonate (MMA) and
dimethylarsinate (DMA) as well as the sum of toxicologically relevant hydride forming arsenic fraction As(III) + As(V) + MMA
+ DMA in EDTA soil/sediment extracts using continuous flow HGAAS was demonstrated. The limit of detection was 0.2 mg kg−1 As. Within-day and between-day precision were in the range 3–7% and 4–10%, respectively, for arsenic contents of 0.7–25 mg
kg−1, with recoveries 95–103%.
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9.
Mi?osz Mi?tkiewski Beata Powa?a Bartosz Staniszewski Maciej Kubicki W?odzimierz Urbaniak Cezary Pietraszuk 《Central European Journal of Chemistry》2011,9(4):728-736
Selected β-diketones bearing unsaturated derivatives have been demonstrated to undergo homo-metathesis and cross-metathesis with selected
olefins in the presence of Grubbs catalysts. The reactions led to respective homo- and cross-metathesis products mainly with
good yields and selectivities.
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10.
Ismail M. M. Rahman Yoshiaki Furusho Zinnat A. Begum Akhmad Sabarudin Shoji Motomizu Teruya Maki Hiroshi Hasegawa 《Central European Journal of Chemistry》2011,9(6):1019-1026
A simple flow-based method was developed for the simultaneous separation of certain transition metal ions (Co, Ni, Cu, Zn,
Cd) from aqueous systems, which ions show ecotoxic effects when present at elevated concentrations. A silica-gel-bonded macrocycle
system, commonly known as molecular recognition technology (MRT) gel, was used for solid phase extraction (SPE) of the target
analytes. The collection behavior of the MRT-SPE system was studied based on pH. Fortified deionized water samples containing
250 μg L−1 of each of the elements were treated at the flow rate of 1 mL min−1. The collected analytes were then eluted by 3 M HNO3 and analyzed using inductively coupled plasma spectrometry. Detection limits of the proposed technique were in the range
of 0.004–0.040 μg L−1 for the studied metal ions. The validity of this separation technique was checked with spiked ‘real’ water samples, which
produced satisfactory recoveries of 96–102%. The non-destructive nature and highly selective ion-extraction capability of
the SPE material are the most important aspects of the proposed method and they are the main focus of this paper.
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11.
This article describes the simple hydrodehalogenation of halogenated anilines and their derivatives by the action of Raney
aluminium-nickel alloy in aqueous alkaline solution at room temperature. The reaction course was monitored by means of 1H
nuclear magnetic resonance (NMR) spectroscopy and GC-MS spectra.
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12.
Aleksandra Prichodko Kristina Jonusaite Vida Vickackaite 《Central European Journal of Chemistry》2009,7(3):285-290
A hollow fibre liquid phase microextraction for gas chromatographic determination of some p-hydroxybenzoic acid esters has
been developed. Chlorobenzene containing tetradecane as internal standard was used for the extraction. Optimized extraction
was carried out at room temperature for 40 min in the presence of 0.4 g mL−1 NaCl in the sample solution. Calibration was linear up to 30 mg L−1. Correlation coefficients were 0.996–0.998. Enrichment factors were 21, 95 and 154, and detection limits were 0.20, 0.03
and 0.01 μg mL−1 for methylparaben, ethylparaben and propylparaben, respectively. Reproducibility was acceptable with relative standard deviations
up to 11.7%. The technique was tested for water and urine analysis.
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13.
Morteza Bahram Khalil Farhadi Abbas Afkhami Donya Shokatynia Farzin Arjmand 《Central European Journal of Chemistry》2009,7(3):375-381
A partial least squares (PLS-1) calibration model based on kinetic—spectrophotometric measurement, for the simultaneous determination
of Cu(II), Ni(II) and Co(II) ions is described. The method was based on the difference in the rate of the reaction between
Co(II), Ni(II) and Cu(II) ions with 1-(2-pyridylazo)2-naphthol in a pH 5.8 buffer solution and in micellar media at 25°C.
The absorption kinetic profiles of the solutions were monitored by measuring the absorbance at 570 nm at 2 s intervals during
the time range of 0–10 min after initiation of the reaction. The experimental calibration matrix for the partial least squares
(PLS-1) model was designed with 30 samples. The cross-validation method was used for selecting the number of factors. The
results showed that simultaneous determination could be performed in the range 0.1-2 μg mL−1 for each cation. The proposed method was successfully applied to the simultaneous determination of Cu(II), Ni(II) and Co(II)
ions in water and in synthetic alloy samples.
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14.
Jaromíra Chýlková Renáta Šelešovská-Fadrná Jaroslava Machalíková 《Central European Journal of Chemistry》2007,5(2):479-495
The optimal process of pre-treatment and activation of gold rotating disc electrode (AuRDE) before voltammetric determination
of mercury is proposed. This treatment encompasses polishing of the electrode surface, electrochemical cycling, and activation.
This procedure both increases determination sensitivity as well as improves determination reproducibility. The detection limit
on the working electrode achieved using this approach amounted to 8.26·10−10 mol L−1for direct mercury determination in water solution (applying 200 s running accumulation). The procedure of the quantitative
mercury isolation from complicated sample matrix was developed as well. It provides better selectivity and significant increase
of sensitivity of mercury determination. In case of mercury isolation from one liter of water the detection limit is 6.23·10−11 mol L−1 (analyzing a greater sample volume the determined concentration could be lower).
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15.
This paper describes the preparation and characterization of poly(ethyl cyanoacrylate) colloidal particles loaded with the
organic fluorophore Rhodamine 6G. We studied the physicochemical properties of the colloidal particles: morphology, size-distribution,
ζ-potential, fluorescent properties and photobleaching upon UV-light illumination. The properties of the obtained colloidal
particles, as well as the dye loading efficiency, were found to depend on the concentrations of ethyl cyanoacrylate monomer
and Rhodamine 6G in the polymerization medium. The fluorophore release from the colloidal particles in aqueous buffer is also
studied.
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16.
Cecylia Wardak 《Central European Journal of Chemistry》2008,6(4):607-612
A new all plastic sensor for Co2+ ions based on 2-amino-5 (hydroxynaphtyloazo-1′)-1,3,4 thiadiazole (ATIDAN) as ionophore was prepared. The electrode exhibits
a low detection limit of 1.5 × 10−6 mol L−1 and almost theoretical Nernstian slope in the activity range 4.0 × 10−6–1 × 10−1 mol L−1 of cobalt ions. The response time of the sensor is less than 10 s and it can be used over a period of 6 months without any
measurable divergence in potential. The proposed sensor shows a fairly good selectivity for Co(II) over other metal ions.
The electrode was successfully applied for determination of Co2+ in real samples and as an indicator electrode in potentiometric titration of Co2+ ions with EDTA.
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17.
Zholt Kormosh Iryna Hunka Yaroslav Bazel Andriy Laganovsky Iryna Mazurenko Nataliya Kormosh 《Central European Journal of Chemistry》2007,5(3):813-823
The potentiometric response characteristics of a diclofenac selective electrode, based on ion association in different plasticizers,
were compared. The sensitivity, working range, detection limit and selectivity of membrane sensors demonstrated significant
dependence on the type of plasticizers. The potentiometric unit presented a linear response toward diclofenac concentrations
between 1 × 10−5 − 5 × 10−2 mol L−1, with slopes of approximately 60 mV dec−1, and exhibited a response time of 3 s. The potentiometric analysis of sodium diclofenac in pharmaceutical formulations was
perfomed by the membrane electrode proposed and compared with the results of potentiometric titration given by the Pharmacopoeia
of Ukraine.
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18.
Leandro Rodrigues de Lemos Luis Henrique Mendes da Silva Maria do Carmo Hespanhol da Silva Jorge AmimJr Jane Sélia dos Reis Coimbra Luis Antonio Minim 《Central European Journal of Chemistry》2010,8(2):258-263
This work proposes a method for determination Cu(II) concentrations, based on the formation of a copper-1-nitroso-2-naphthol
complex, in the presence of micelles; formed by a triblock copolymer, made up of two blocks of polyethylene oxide (PEO), and
one block of polypropylene oxide (PPO). The insoluble copper complexes, are concentrated inside the hydrophobic micelle core;
formed by the PPO block. For a solution containing 0.200 mg L−1 Cu(II), the proposed method had a relative standard deviation of 2.0% (n = 3); an absolute error from 0.11 to 0.39 mg L−1; and a linear calibration range, from 0.200 to 0.800 mg L−1. Detection and quantification limits, were 43.1 mg L−1 and 144 mg L−1, respectively. We show that there is excellent agreement, between the results obtained using our novel method; and those
obtained using flame atomic absorption spectrometry: In the determination of Cu(II) concentrations, in Brazilian sugar-cane
spirits. The proposed method, is the first to apply macromolecular micelle systems, to the determination of copper concentrations;
and improves upon the results obtained using molecular surfactants. This method is environmentally friendly (since it does
not use any organic solvents for extraction), and the triblock copolymer is biodegradable and non-toxic.
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19.
Ardeshir Shokrollahi Mojtaba Shamsipur Fahimeh Jalali Hamid Nomani 《Central European Journal of Chemistry》2009,7(4):938-944
A simple, sensitive and selective flotation method is described for the preconcentration and atomic absorption spectrometric
determination of zinc ion in water and blood samples. At a solution pH of 5.2, 4-(2-pyridylazo-resorcinol) and Triton X-114
were used as hydrophobic ligand and non-ionic surfactant, respectively. The chemical variables affecting the preconcentration
process were optimized. Under the optimized experimental conditions, the selective preconcentration and determination of as
low zinc concentration as 6.5 μg L−1 can be made. The proposed method was successfully applied to the preconcentration and low-level determination of zinc in
different water and blood serum samples.
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20.
M. H. Sorouraddin M. Iranifam A. Imani-Nabiyyi 《Central European Journal of Chemistry》2009,7(1):143-147
A simple and selective method for penicillin V potassium (PVK) determination by chemiluminescence (CL) was developed. Oxidation
of PVK by alkaline hydrogen peroxide produces CL, which is greatly enhanced by N, N-dimethyl formamide (DMF) and N-cetyl-N,N,N-trimethylammonium
bromide (CTMAB). Optimum conditions were established using luminometry. There is a linear relationship between the chemiluminescent
peak height and the amount of PVK within the range 0.5–129.5 mg L−1, with a detection limit of 0.2 mg L−1. The coefficient of variation was 1.2% for 40 mg L−1 PVK solution (n = 7). The method is very simple, has high sensitivity and good selectivity, and is usable for process control.
It was successfully utilized for the determination of PVK in pharmaceuticals and spiked human urine.
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