Determination of amino acids, vitamins, and drug substances in aqueous solutions using new potentiometric sensors with Donnan potential as analytical signal

2010 ◽  
Vol 46 (11) ◽  
pp. 1252-1262 ◽  
Author(s):  
O. V. Bobreshova ◽  
A. V. Parshina ◽  
M. V. Agupova ◽  
K. A. Polumestnaya
Keyword(s):  
Amino Acids ◽  
Aqueous Solutions ◽  
Analytical Signal ◽  
Potentiometric Sensors ◽  
Donnan Potential ◽  
Drug Substances

Donnan-Potential Sensors Based on Zirconia-Modified Nafion Membranes Treated under Different Conditions for the Determination of Amino Acids with Several Nitrogen-Containing Groups

2017 ◽  
Vol 57 (13) ◽  
pp. 1250-1257 ◽  
Author(s):  
E. Yu. Safronova ◽  
A. V. Parshina ◽  
E. A. Ryzhkova ◽  
D. V. Safronov ◽  
O. V. Bobreshova ◽  
...  
Keyword(s):  
Amino Acids ◽  
Donnan Potential ◽  
Nafion Membranes

Potentiometric Sensors Based on MF-4SC Membranes and Carbon Nanotubes for the Determination of Nicotinic Acid in Aqueous Solutions and Pharmaceuticals

2020 ◽  
Vol 2 (4) ◽  
pp. 256-264
Author(s):  
A. V. Parshina ◽  
E. Yu. Safronova ◽  
G. Z. Habtemariam ◽  
E. I. Ryzhikh ◽  
I. A. Prikhno ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Nicotinic Acid ◽  
Potentiometric Sensors

scholarly journals THE METHOD OF DETECTION OF BIOMOLECULES FOR THE CREATION OF SENSORS BASED ON NANO-STRUCTURED Si.

2019 ◽  
pp. 521-528
Author(s):  
Keyword(s):  
Amino Acids ◽  
Porous Silicon ◽  
Aqueous Solutions ◽  
Key Words ◽  
Active Oxygen ◽  
Distilled Water ◽  
Photoluminescence Intensity ◽  
Photoluminescence Spectra ◽  
Detection Of Biomolecules

In the work, the modification of photoluminescence spectra in the processing of porous silicon in aqueous solutions with different oxygen contents and aqueous solutions of amino acids was studied in order to further create a sensor sensitive to chemically active oxygen near the surface of porous silicon in the presence of various amino acids. he growth of the photoluminescence intensity at the processing of porous silicon in distilled water and the sensitivity of the intensity of photoluminescence to the oxygen content in water are revealed. It is proposed to use a change in the intensity of luminescence to study the properties of biomolecules, namely the determination of the amount of chemically active oxygen near the surface of porous silicon in the presence of various amino acids. Changing the sizes of nanocrystals is the main reason for increasing the intensity of photoluminescence when processing porous silicon in aqueous solutions. After applying to the surface of samples of porous silicon aqueous solutions of glycine, alanine, phenylalanine, the intensity of photoluminescence varies for all samples. Changing the sizes of nanocrystals is the main reason for increasing the intensity of photoluminescence when processing porous silicon in aqueous solutions. After applying to the surface of samples of porous silicon aqueous solutions of glycine, alanine, phenylalanine, the intensity of photoluminescence varies for all samples. Key words: photoluminescence, nanostructured porous silicon, biosensors.

Imaging polymers, proteins and dna in aqueous solutions with the atomic force microscope

1989 ◽  
Vol 47 ◽  
pp. 32-33
Author(s):  
S.A.C. Gould ◽  
B. Drake ◽  
C.B. Prater ◽  
A.L. Weisenhorn ◽  
S.M. Lindsay ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Sequencing ◽  
Aqueous Solutions ◽  
Atomic Force Microscope ◽  
Piezoelectric Crystal ◽  
Atomic Force ◽  
Structure Of Molecules ◽  
Optical Lever

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.

Dc arc emission analysis of rare earth metals and their oxides with sorption preconcentration of impurities

2018 ◽  
Vol 84 (11) ◽  
pp. 9-14
Author(s):  
E. S. Koshel ◽  
V. B. Baranovskaya ◽  
M. S. Doronina
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Analytical Signal ◽  
Graphite Powder ◽  
Atomic Emission ◽  
Standard Samples ◽  
Emission Analysis ◽  
Sorption Preconcentration ◽  
Sample Shape

The analytical capabilities of arc atomic emission determination of As, Bi, Sb, Cu, Te in rare earth metals (REM) and their oxides after preparatory group concentration using S,N-containing heterochain polymer sorbent are studied on a high-resolution spectrometer “Grand- Extra” (“WMC-Optoelectron-ics” company, Russia). Sorption kinetics and dependence of the degree of the impurity extraction on the solution acidity are analyzed to specify conditions of sorption concentration. To optimize the procedure of arc atomic emission determination of As, Bi, Sb, Cu, and Te various schemes of their sorption preconcentration and subsequent processing of the resulted concentrate with the addition of a collector at different stages of the sorption process have been considered. Graphite powder is used as a collector in analysis of rare earth oxides due to universality and relative simplicity of the emission spectrum. Conditions of analysis and parameters of the spectrometer that affect the analytical signal (mass and composition of the sample, shape and size of the electrodes, current intensity and generator operation mode, interelectrode spacing, wavelengths of the analytical lines) are chosen. The evaporation curves of the determinable impurities were studied and the exposure time of As, Bi, Sb, Cu, and Te in the resulted sorption concentrate was determined. Correctness of the obtained results was evaluated using standard samples of the composition and in comparisons between methods. The results of the study are used to develop a method of arc chemical-atomic emission analysis of yttrium, gadolinium, neodymium, europium, scandium and their oxides in a concentration range of n x (10-2 - 10-5) wt.%.

LUMINESCENT DETERMINATION OF SUGAR IN NATURAL HONEY

2020 ◽  
Vol 0 (4) ◽  
pp. 29-32
Author(s):  
B.M. GAREEV ◽  
◽  
A.M. ABDRAKHMANOV ◽  
G.L. SHARIPOV ◽  
◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laboratory Test ◽  
Aqueous Solutions ◽  
Analytical Method ◽  
Sugar Content ◽  
Carbon Quantum Dots ◽  
Photoluminescence Intensity ◽  
Sucrose Content ◽  
Natural Honey

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.

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