scholarly journals The influence of sample preparation quality on the results of spectral analysis

2020 ◽  
pp. 72-75
Author(s):  
M. V. Lagoyskaya
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Sample Preparation ◽  
Special Reference ◽  
Discharge Chamber ◽  
Small Samples ◽  
Central Laboratory ◽  
Comparative Tests ◽  
Reference Samples ◽  
Spectral Equipment

Сonsiders the possibility of analyzing samples of small diameters without the use of special adapters for determining the chemical composition on spectrometers. Measurements are limited to the size of the hole on the analytical table, which is 12 mm. Accordingly, all analyzed samples must have a diameter of at least 14 mm to completely cover the sample cover of the discharge chamber in order to avoid air entering the chamber. The company manufacturer of spectral equipment offers to use special adapters for the analysis of small samples. But the use of such adapters has a number of drawbacks. These include additional cash costs for the purchase of adapters, the need for additional standardization procedures, the availability of special reference samples. In the laboratory of analytical support (LAS) of the Central Laboratory of the Factory (CLF), all samples of finished rolled products (wire rods or fittings) in size from 5.5 mm to 20 mm are prepared in the form of «blades». The compressed part of the «blade» is the analyzed surface of the sample, which is further processed on a disk grinder and transmitted to the spectral analysis. The article presents the results of comparative tests of valves class U500 between samples in the form of «blades» and in the form of «columns» and concluded that the necessity of use of special adapters.

scholarly journals Influence of abrasive materials on the quality of analytical surfaces during preparation of samples for spectral analysis

2020 ◽  
pp. 112-116
Author(s):  
M. V. Lagoyskaya
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Sample Preparation ◽  
Mass Fraction ◽  
Surface Preparation ◽  
Optical Emission ◽  
Sample Surface ◽  
Standard Samples ◽  
Materials Used

The article considers the possibility of contamination of the surface of steel samples with abrasive materials when preparing samples for determining the chemical composition on optical emission spectrometers.The standards for sample preparation methods describe in detail the methods of surface treatment, the materials used, and the requirements for the quality of the analyzed surface. The sample surface can be milled or sanded using various abrasive materials. In practice, the laboratory found that the surface of samples during sample preparation is contaminated with aluminum and calcium.In order to determine how the contamination of analytical surfaces occurs, the chemical composition of all materials used in the preparation of samples was studied, and an experiment was conducted to establish a method for preparing the sample surface that does not lead to contamination of the surface with aluminum and calcium. For the experiment, three standard samples of steel composition were selected with certified values of the mass fraction of aluminum and calcium in different ranges. The surface of each sample was processed in three ways and optical emission spectral analysis was performed on each analytical surface at five points to determine the value of the mass fraction of aluminum and calcium and to estimate the spread of the results obtained. As a result of tests it was found that by grinding the sample surface by using abrasive white corundum and abrasive paper grit P40 is the surface contamination of the analyzed sample in aluminum and calcium, therefore, when determining the mass fraction of aluminium and calcium in steel are required for surface preparation to use the method of milling.

Plasma parameters in atomic-emission spectral analysis of phosphate concentrates of the fission products

2019 ◽  
Vol 85 (2) ◽  
pp. 17-22
Author(s):  
M. I. Khamdeev ◽  
E. A. Erin
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Reference Materials ◽  
Fission Products ◽  
Atomic Emission ◽  
Electric Arc ◽  
Physical Parameters ◽  
Arc Plasma ◽  
Atomic Emission Spectral Analysis ◽  
Excitation Processes

Physical parameters of electric arc plasma as well as their time dependences are calculated when analyzing phosphate precipitates of the fission products of irradiated nuclear fuel. Phosphate concentrates of the fission products are known for their complex chemical composition and high thermal and chemical stability. Hence, direct atomic emission spectral analysis of phosphate powders without transferring them into solutions is advisable. Different conditions of sample preparation and synthesis of the reference materials determine the different chemical forms of the elements to be determined. This, in turn, affects the kinetics of their evaporation in the electrode crate and excitation processes in the plasma. The known mechanisms of those processes cannot always be transferred to specific conditions of the given method of analysis thus entailing the necessity of studying the effect of the samples chemical composition on the results of determination, proper choice of spectroscopic carriers, detailed study of spectra excitation processes in spectral analysis, and analysis of the physical parameters of the electric arc plasma. We used the lines Zn I 307.206 nm and Zn I 307.589 nm to measure the effective temperature of the central hot sections of the arc in a range of4500 - 6500 K. NaCl, BaCl2 and NaCl + T1C1 were studied to reduce the effect of the sample elemental composition on excitation conditions of the spectra and their stabilization as a spectroscopic carrier. In control experiments we used carrier-free samples. The coincidence of the values of the plasma physical parameters within the measurement error not exceeding 20%, as well as the identity of the nature of the kinetic curves for samples of phosphate precipitates and synthetic reference materials prove their correctness. The result of the study substantiate correctness of the direct atomic-emission spectral procedure in analysis of phosphate concentrates of fission when using synthetic reference materials.

Structure and chemical composition of exopolysaccharides of frost-damaged sugar beet

2020 ◽  
pp. 34-39
Author(s):  
Aneta Antczak-Chrobot ◽  
Maciej Wojtczak
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Sugar Beet ◽  
Total Acid ◽  
Average Molecular Mass ◽  
Central European ◽  
Composition And Structure ◽  
Monomeric Composition ◽  
Branched Structure ◽  
Different Origin

In this research paper, development of a procedure of isolation of exopolysaccharides from frost-damaged beet and an analysis of structural and chemical composition of polymers isolated from sugar beet of different origin are presented. Total acid hydrolysis degradation integrated with HPAEC-ED analysis has been utilized to confirm the monomeric composition of the separated polysaccharides. The implementation of NMR spectral analysis and SEC chromatography of the structure of exopolysaccharides has been investigated. The results demonstrate that the chemical composition and structure of exopolysaccharides depend on their origin. Typical exopolysaccharides from Central European beet roots consist mainly of glucose monomers – and they have low branched structure – about 90% of α-1,6 linkage which is typical for dextran. The exopolysaccharides isolated from Swedish beet are characterized by 50–60% fructose monomers. They contain only about 65% α-1,6 linkages. Exopolysaccharides extracted from various origin beet differ in average molecular mass. The molecular distribution is not normal.

Analysis of Wear-Resistant Materials of Mixer - Pneumosuperchargers Blades Operating under Conditions of Abrasive Wear

2021 ◽  
Vol 316 ◽  
pp. 893-898
Author(s):  
Natalya Gabelchenko ◽  
Artem Belov ◽  
Artem Kravchenko ◽  
Oleg Kryuchkov
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Wear Resistance ◽  
Chemical Composition ◽  
Abrasive Wear ◽  
Abrasive Medium ◽  
Wear Resistant ◽  
Comparative Tests ◽  
Before And After ◽  
110G13l Steel

We conducted comparative tests of the wear resistance of metals operating under abrasive conditions. Samples were cut from the working parts of mixer-pneumosuperchargers. The chemical composition and mechanical properties were determined. To compare samples under abrasive wear conditions, we designed and assembled a carousel installation. The principle of its operation is based on mixing the abrasive medium by the samples being studied with a given speed. Wear resistance was evaluated by weight loss by samples after several test cycles. To determine changes in the structure of the metal during abrasive wear, metallographic studies of the samples were carried out before and after the tests. It is shown that the best complex of service and mechanical properties is possessed by 110G13L steel.

About the possibility of identification of articles from steels, aluminum, copper and alloys on their basis on the expanded micro-impurity elemental composition

2021 ◽  
pp. 51-56
Author(s):  
Yu. B. Sazonov ◽  
D. Yu. Ozherelkov ◽  
R. Sh. Latypov ◽  
E. E. Gorshkov
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Elemental Composition ◽  
Chemical Elements ◽  
Copper Alloys ◽  
Minimal Amount ◽  
Elementary Composition ◽  
Geometric Size ◽  
The Common

Possibility of determination of the fragments and articles made of different grades of steel aluminium and copper alloys and their affiliation to the common melt was examined via the methods of photoelectric spectral analysis based on composition of micro-impurities. Chemical elements with micro-impurities were revealed; they allow to determine affiliation of metal fragments to one melt. Ultimately possible deviations of micro-impurities within one melt were obtained. The technique allowing to establish affiliation of fragments to the common melt based on their elementary composition of micro-impurities with minimal amount of measurements was suggested based on the obtained results. The minimal geometric size of a sample available for analysis was determined; it allows to classify the examined fragments to one melt based on the results of investigation of expanded elementary composition of micro-impurities. Practical opportunities of this technique were displayed on the example of the alloys with different chemical composition.

scholarly journals Chemical Composition of Vintage Preban Absinthe with Special Reference to Thujone, Fenchone, Pinocamphone, Methanol, Copper, and Antimony Concentrations

2008 ◽  
Vol 56 (9) ◽  
pp. 3073-3081 ◽  
Author(s):  
Dirk W. Lachenmeier ◽  
David Nathan-Maister ◽  
Theodore A. Breaux ◽  
Eva-Maria Sohnius ◽  
Kerstin Schoeberl ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Special Reference
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