首页期刊导航|Journal of analytical chemistry
期刊信息/Journal information
Journal of analytical chemistry
Consultants Bureau
Journal of analytical chemistry

Consultants Bureau

1061-9348

Journal of analytical chemistry/Journal Journal of analytical chemistryISTPSCIEIAHCI
正式出版
收录年代

    Introduction to this Issue

    Rusanova, T. Yu.
    3页
      原文链接:
    • NSTL
    • Pleiades Publishing Inc

    Surface-Enhanced Raman Spectroscopy for the Determination of Medical and Narcotic Drugs in Human Biofluids

    Markina, N. E.Goryacheva, I. Yu.Markin, A. V.
    18页
    查看更多>>摘要：The review is devoted to an analysis of the capabilities, limitations, and special features of the application of surface-enhanced Raman spectroscopy (SERS) to the determination of drugs and narcotics in human body fluids (blood, urine, and saliva). An analysis of the literature demonstrated that the most efforts of researchers were aimed at overcoming the main disadvantage of SERS as an analysis method-low selectivity, which is especially important in the case of complex objects such as biological fluids. In this regard, the main positive results in the SERS analysis of human biological fluids are currently associated with the development of procedures that minimize the level of a background signal. The procedures are based on various combinations of SERS with separation and preconcentration methods, the use of sample preparation, and the application of chemometrics to take into account the background component of an analytical signal. Significant progress is also associated with the development of multifunctional SERS-active materials, which make it possible to improve the selectivity of analysis. However, it is the analytical part of most works that is the weakest point, which requires further research, including the verification of SERS analysis procedures using control reference methods.
      原文链接:
    • NSTL
    • Pleiades Publishing Inc

    Comparative Evaluation of the Concentration of Free Phenolic Compounds and the Antioxidant Activity of Various Buckwheat Samples

    Aleksenko, S. S.Kazimirova, K. O.Shtykov, S. N.
    9页
    查看更多>>摘要：In many countries, buckwheat is considered an alternative gluten-free food product with a unique set of proteins and amino acid composition, and also the high antioxidant activity (AOA). This study deals with the assessment and comparison of the AOA and the total concentration of free phenolic compounds in various buckwheat products purchased from supermarkets in four countries. It is shown that the optimal extractant of free phenols from buckwheat grain is a 50% water-ethanol solution; vortexing without heating is sufficient for extraction. Using high-performance liquid chromatography with a diode array detector, fluorescence and MS detectors, the dominant components are quantitatively determined in all buckwheat samples: rutin ((6.7-14.1) x 10(-2) g/kg), flavan-3-ols (catechin (1.8-8.7) x 10(-2) g/kg and epicatechin (2.5-11.6) x 10(-2) g/kg). Protocatechuic and gallic acids, as well as unbound vitexin and quercetin, are detected in minor amounts mainly in heat-treated buckwheat grains. Linear correlations between the total concentration of phenolic compounds, estimated by the Folin-Ciocalteu method, and AOA, as well as between the sum of concentrations of three components (rutin, catechin, and epicatechin) and AOA are obtained. The chromatographic profiles and AOA of buckwheat, wheat, barley, corn, and rice are compared.
      原文链接:
    • NSTL
    • Pleiades Publishing Inc

    Photometric Determination of Novocaine with Preconcentration in Surfactant Micelles

    Sokolova, T. A.Doronin, S. Yu.
    6页
    查看更多>>摘要：The work deals with the extraction and preconcentration of novocaine using mixed surfactants of nonionic (Triton X-114) and anionic (sodium dodecyl sulfate) types with the photometric registration of an analytical signal. The method is based on the condensation reaction of novocaine with p-dimethylaminobenzaldehyde (pH 2.5-3.5) and the subsequent micellar extraction of the colored analytical form, the Schiff base. For the effective extraction of this form, the parameters of micellar extraction (concentrations of reagents: c(NaCl) = 0.5-1 \M, c(Triton X-114) = 2 x 10(-3)-1 x 10(-2) M; conditions: centrifugation time 5 min at 3000 rpm) are optimized. The proposed method makes it possible to determine novocaine in the concentration range 38-4800 ng/mL (RSD <= 7%, limit of detection 19 ng/mL), which is several orders of magnitude lower than in the known spectrophotometric versions. The Bouguer-Lambert-Beer law is obeyed in the range 8 x 10(-7)-4 x 10(-5) M. The developed extraction-photometric method was tested in the determination of novocaine in 0.5% ampoule solutions for injection.
      原文链接:
    • NSTL
    • Pleiades Publishing Inc

    Potentiometric Sensors Sensitive to Some Cephalosporin Antibiotics: Properties and Applications

    Kulapina, E. reKulapina, O. I.Cherdakova, E. N.Ankina, V. D....
    11页
    查看更多>>摘要：We developed unmodified and modified solid-contact potentiometric sensors (tubular and screen-printed) for determining some cephalosporin antibiotics in aqueous media, biological fluids, and pharmaceutical preparations. Tetraalkylammonium compounds with silver(I)-beta-lac [Ag(beta-lac)(2)] complex compounds were used as active membrane components; carbon nanotubes, polyaniline, and copper oxide and NiZnFeO nanoparticles were used as modifiers. The main electroanalytical and operational characteristics of the studied sensors in aqueous solutions of antibiotics and oral fluid were determined. The sensors ensure the determination of antibiotics in a wide analytical range of 1 x 10(-4) (1 x 10(-5))-1 x 10(-2) (0.1) M; the values of c(min) = n x 10(-5) (1 x 10(-6)) M. The modifiers stabilize the electrode potential and act as electron transfer mediators, improving the electroanalytical characteristics of the sensors. Solid-contact sensors can be used to determine the main substances in drugs from various manufacturers and model aqueous solutions and oral fluid with added antibiotics and as consistuents of "electronic tongue" multisensor systems for the separate determination of cephalosporin antibiotics in two-component mixtures.
      原文链接:
    • NSTL
    • Pleiades Publishing Inc

    Test Systems Based on Nanofibers Produced by Electrospinning for the Determination of Nickel Ions

    Komova, N. S.Danchuk, A. I.Galushka, V. V.Pavlov, A. M....
    7页
    查看更多>>摘要：Test systems based on polymer nanofibers obtained by electrospinning are developed for the determination of nickel ions in natural and waste waters. The detection of the analytical signal of test systems can be carried out both visually and by colorimetry. Polyacrylonitrile and fluoroplastic are used as a polymer matrix, and rubeanic acid, pyridylazonaphthol, dimethylglyoxime, and alpha-furyldioxime are used as reagents. The immobilization of the reagents into the matrix is carried out by adding them to the polymer spinning solution before the start of the fiber manufacturing process. The optimal conditions for obtaining test systems (composition of the spinning solution, electrospinning parameters, the nature of the polymer and the reagent) and for recording the analytical signal (pH, color parameter, and signal recording time) are chosen. The parameters of calibration dependences for the determination of nickel ions using various test systems are determined, and their selectivity with respect to ions of other heavy metals is studied. It is shown that a test system based on polyacrylonitrile (mass fraction of polymer in the spinning solution 12%) and rubeanic acid (reagent concentration in the spinning solution 0.05 M) ensures the determination of nickel ions in the concentration range 1 x 10(-6) M-0.01 M. The developed test systems are used to determine nickel ions in natural, tap and waste waters. An advantage of the proposed test systems is the simplicity of test fabrication, the absence of sample preparation, and the possibility of conducting analysis in the field.
      原文链接:
    • NSTL
    • Pleiades Publishing Inc

    Rapid Determination of Beta-Lactam Antibiotics

    Kosyreva, I. V.Tumskaia, A. V.
    6页
    查看更多>>摘要：Rapid methods for the determination of the antibacterial compounds amoxicillin and cephalexin from the beta-lactam group based on visual-colorimetric and colorimetric evaluation using a smartphone camera were developed. The reaction of ninhydrin with the amino groups of antibiotics was chosen as an indicator. The interaction of immobilized ninhydrin with gentamicin on the surface of a solid matrix was evaluated using diffuse reflectance spectroscopy. The stability and the effects of temperature and heating time of the test agents on the course of the reaction were studied. Color scales for the visual-colorimetric determination of amoxicillin and cephalexin were obtained. Linear dependences of the intensities of the Green channel of the RGB color model on the logarithm of antibiotic concentration were plotted. The procedures developed were applied to the analysis of drug samples.
      原文链接:
    • NSTL
    • Pleiades Publishing Inc

    Kinetic and Analytical Characteristics of the Peroxidase Oxidation Reaction of Sodium Triphenyl-4-Sulfonate

    Burmistrova, N. A.Pidenko, S. A.Moskvicheva, I. S.
    6页
    查看更多>>摘要：We studied a possibility of the enzymatic oxidation of sulfo derivatives of di- and triarylamines with hydrogen peroxide in the presence of horseradish peroxidase (HRP). The product of the enzymatic oxidation of sodium triphenylamine-4-sulfonate (TPAS) is more stable than sodium diphenylamine-4-sulfonate. The effects of various factors, such as the nature of buffer solutions, reagent concentrations, and the presence of cationic Ir(IV) and Rh(III) complexes in the reaction medium, on the TPAS oxidation rate were studied. The kinetic regularities of the TPAS enzymatic oxidation were studied, the kinetic parameters (k(cat), K-M) were estimated, and an assumption was made about the process activation mechanism in the presence of catalytically active Ir(IV) and Rh(III) complexes. The reaction of the enzymatic oxidation of TPAS can be used for the determination of HRP (5.0 x 10(-2) nM), hydrogen peroxide (0.6 mM), and cationic complexes of Ir(IV) (5 nM) and Rh(III) (60 nM).
      原文链接:
    • NSTL
    • Pleiades Publishing Inc

    Micellar Thin-Layer Chromatography and Preconcentration of L-Carnitine with Magnetite Nanoparticles

    Sumina, E. G.Shtykov, S. N.Reshetnikova, I. S.Yurasov, N. A....
    7页
    查看更多>>摘要：Thin-layer chromatography (TLC) is used to study the chromatographic behavior of L-carnitine in aqueous-organic mobile phases (MPs) and aqueous MPs in the presence of the cationic surfactant cetylpyridinium chloride (CPC) on plates with a normal stationary phase based on silica. Among aqueous-organic MP, the best results are obtained for MP of the composition propanol-2-acetone-water-acetic acid (4 : 5 : 2 : 2). The best chromatographic characteristics are obtained for aqueous-micellar MPs containing 0.001 M CPC. The adsorption of L-carnitine on magnetite nanoparticles modified with cetyltrimethylammonium bromide is studied for the first time. It is found that the quantitative adsorption of the analyte with the recovery of L-carnitine 89% proceeds in 40 min. An eluent is found-ethanol, which allows 95% desorption of L-carnitine. It is found that the use of 3 mg of nanomagnetite for preconcentration makes it possible to reduce the lower limit of the L-carnitine determination by five times. A procedure for the densitometric determination of L-carnitine using micellar TLC in the "XXI POWER L-Carnitine" sports drink is developed.
      原文链接:
    • NSTL
    • Pleiades Publishing Inc

    Effect of Plasmon Resonance of Silver Nanoparticles on the Fluorescent Properties of Doxycycline

    Smirnova, T. D.Zhelobitskaya, E. A.Danilina, T. G.
    5页
    查看更多>>摘要：Silver nanoparticles modified with Eu3+ ions increase the intensity of the fluorescence signal by a factor of 125 in an analytical system containing doxycycline as a result of a combination of resonance and exchange-resonance mechanisms of excitation energy transfer. Using a model system, a complex of doxycycline with Tb3+ ions, the role of energy transfer from silver nanoparticles to the doxycycline ion in the formation of an analytical signal was revealed and evaluated. A fluorimetric procedure for the determination of 1.0 x 10(-8)-1.0 x 10(-5) M of doxycycline was developed based on the formation of an antibiotic complex with Eu3+ ions in the presence of silver nanoparticles. The calibration equation is y = 5.0 x 10(7)x + 10; R-2 = 0.996.
      原文链接:
    • NSTL
    • Pleiades Publishing Inc