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A possibility of using a monitor calibrator for the determination of luminescent compounds is shown on an example of quinine. The determination is based on the irradiation of a sample with broadband radiation in the visible and near UV spectral regions from a built-in source exciting phosphor molecules and the simultaneous registration of the radiation incident on the detector. Measurement conditions are selected. Quinine can be determined in the range of 60-750 [micro]M, the limit of detection is 20 [micro]M. The determination is not affected by common inorganic ions, as well as sweeteners and acidity regulators present in many beverages. The developed method of determination is applicable to the analysis of carbonated drinks and drugs. Compared to a traditional spectrofluorimeter, monitor calibrator is characterized by compactness, mobility, ability of detecting luminescence in cuvettes of various sizes and shapes, and lower cost., Author(s): M. V. Gorbunova [sup.1] , T. A. Terentev [sup.1] , V. V. Apyari [sup.1] , S. G. Dmitrienko [sup.1] , Yu. A. Zolotov [sup.1] [sup.2] Author Affiliations: (1) grid.14476.30, [...]

Single-drop microextraction (SDME) and hollow-fiber membrane microextraction (HFME) belong to methods of the liquid-phase microextraction preconcentration of organic compounds. These methods are characterized by the low consumption of organic solvents, high preconcentration factors, simplicity, low cost, ease of combination with various chromatographic methods; processes of preconcentration and sample injection are combined in a single device. Since the emergence of SDME (1996) and HFME (1999), a large number of versions have been developed that differ in the preconcentration technique, nature of the extractants used, and combinations with methods for the subsequent determination of the preconcentrated substances. The popularity of these methods among the analysts is evidenced by many reviews that we have summarized in this publication., Author(s): S. G. Dmitrienko [sup.1], V. V. Apyari [sup.1], V. V. Tolmacheva [sup.1], M. V. Gorbunova [sup.1] Author Affiliations: (1) grid.14476.30, 0000 0001 2342 9668, Department of Chemistry, Lomonosov Moscow [...]

Published data on various versions of the homogeneous liquid-liquid microextraction (HLLME) of organic compounds are generalized and systematized, and a classification of these versions is given. The main HLLME procedures are discussed. Examples of the application of HLLME to the separation of organic compounds in the analysis of environmental samples, food products, and biological fluids are given., Author(s): S. G. Dmitrienko [sup.1], V. V. Apyari [sup.1], M. V. Gorbunova [sup.1], V. V. Tolmacheva [sup.1], Yu. A. Zolotov [sup.1] [sup.2] Author Affiliations: (1) grid.14476.30, 0000 0001 2342 9668, [...]

Dispersive liquid-liquid microextraction (DLLME) is one of the most promising methods of the microextraction preconcentration of organic compounds. This method is eco-friendly, simple, and universal; in comparison with conventional extraction, the consumption of the reagents and solvents, the time of extraction, and the cost of analysis in this method are reduced. For a short time from the moment of the appearance of DLLME in 2006, analysts developed numerous versions, differing by the method of dispersion, the nature of the extractant and by combinations with other methods of sample preparation and methods of the subsequent determination of the preconcentrated substances. The popularity of the method among the analysts is attested in a great number of reviews summarized in this publication., Author(s): S. G. Dmitrienko [sup.1], V. V. Apyari [sup.1], V. V. Tolmacheva [sup.1], M. V. Gorbunova [sup.1] Author Affiliations: (1) grid.14476.30, 0000 0001 2342 9668, Department of Chemistry, Lomonosov Moscow [...]

The use of hypercrosslinked polystyrene for the group sorption preconcentration of catecholamines is proposed. The conditions for the preconcentration of noradrenaline, adrenaline, and dopamine are optimized: a microcolumn (10 x 6 mm), mass of adsorbent 0.03 g, 25 mL of solution (pH ~ 8.5), and transmission rate of the solution 1.0 mL/min. Compounds were desorbed with 1 mL of 6 M acetic acid and determined in the eluate by reversed-phase HPLC with an amperometric detector (E = 0.8 V). Adsorption preconcentration ensures the reduction of the limits of detection for catecholamines by more than 20 times. The limits of detection were 0.7 ng/mL for dopamine and 1 ng/mL for noradrenaline and adrenaline. The procedure was applied to the analysis of model mixtures based on urine., Author(s): V. V. Tolmacheva [sup.1] [sup.2], D. I. Yarykin [sup.1], M. V. Gorbunova [sup.1], V. V. Apyari [sup.1], S. G. Dmitrienko [sup.1], Yu. A. Zolotov [sup.1] [sup.2] Author Affiliations: (1) [...]

Gold nanorods (AuNRs) stabilized by cetyltrimethylammonium bromide (CTAB) were synthesized and an interaction of catecholamines (CAs) with silver ions in the presence of the obtained AuNRs was studied. The reaction results into formation of core-shell Au@Ag nanorods (Au@AgNRs) and leads to a hypsochromic shift of the long-wave surface plasmon resonance (SPR) band in the absorption spectrum of AuNRs. The influence of a CA structure, excess of CTAB, interaction time, pH, concentration of AuNRs, silver ions and CAs on this interaction was studied. Based on correlation of the NRs spectral characteristics with the concentration of CAs, a method for spectrophotometric determination of dobutamine, epinephrine, norepinephrine and dopamine with detection limits 27, 18, 16 and 13 μg L(-1), respectively, has been developed. The method can be applied to the analysis of medicines., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Based on a study of the function of the enzymes participating in red blood cell transmembrane transport (K+, Na+ATPase, Mg2(+)-ATPase and Ca2(+)-ATPase) in the newborn with pneumonias it was established that there was a decrease in the activity of the enzymes at the height of the clinical manifestations of disease, especially in septic pneumonias. The changes discovered were in agreement with the disease gravity and the intensity of certain clinical symptoms and depended as well on the initial vegetative tone. The activity of the membrane enzymes also depended on the changes in the physicochemical constants of cellular membranes, namely on red blood cell deformability and the phospholipid ratio. The results of the studies demonstrate that the use of the drugs favouring the improvement of reparative functions of cellular membranes and inhibiting the transmembrane calcium flow is advisable in the newborn as part of multimodality treatment.