scholarly journals Determination of zinc by atomic absorption in automobile tire rubber as a source of ecotoxicants in atmospheric air

2021 ◽  
Vol 2131 (3) ◽  
pp. 032059
Author(s):  
A A Fedoseenko

Abstract Annotation. A methodology for determining zinc in tires (as a source of ecotoxicants in the atmospheric air) by atomic absorption with microwave pre-treatment as a product of motor vehicle wear in St. Petersburg was developed. In the article, the author gives different ways of sampling for testing. One of the rubber samples was taken from one area no larger than 5x5 cm on one tyre (first sampling option), the second sample was taken cumulatively from all tyre sides around its circumference (second sampling option). Tests of selected samples were carried out allowing conclusions to be drawn about the optimal sampling method. A comparative analysis has been made of the test results of samples taken by different methods from the car tyre surface. Based on the comparative analysis conclusions were made about the homogeneity of the tire composition. Various physical and chemical methods of sample preparation for the heavy metals determination are presented. In the course of the work the author selected the optimal conditions for sample preparation for testing allowing to obtain the maximum possible extraction of the analyte at the stage of sample preparation. The atomic absorption method was used to determine the zinc content in automobile tire samples. On the basis of the results obtained conclusions about the optimal sampling methods and sample preparation were made and the test conditions of the samples were optimized.

2021 ◽  
Vol 937 (2) ◽  
pp. 022045
Author(s):  
A A Fedoseenko

Abstract Annotation. A methodology for determining zinc in tires (as a source of ecotoxicants in the atmospheric air) by atomic absorption with microwave pre-treatment as a product of motor vehicle wear in St. Petersburg was developed. In the article, the author gives different ways of sampling for testing. One of the rubber samples was taken from one area no larger than 5x5 cm on one tyre (first sampling option), the second sample was taken cumulatively from all tyre sides around its circumference (second sampling option). Tests of selected samples were carried out allowing conclusions to be drawn about the optimal sampling method. A comparative analysis has been made of the test results of samples taken by different methods from the car tyre surface. Based on the comparative analysis conclusions were made about the homogeneity of the tire composition. Various physical and chemical methods of sample preparation for the heavy metals determination are presented. In the course of the work the author selected the optimal conditions for sample preparation for testing allowing to obtain the maximum possible extraction of the analyte at the stage of sample preparation. The atomic absorption method was used to determine the zinc content in automobile tire samples. On the basis of the results obtained conclusions about the optimal sampling methods and sample preparation were made and the test conditions of the samples were optimized.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 660
Author(s):  
Qingqing Liu ◽  
Di Gao ◽  
Wei Xu

According to the old surface coating process of European and American furniture, the surface of modified poplar is first differentiated pre-treatment, and then the bottom color modification and material color modification are respectively applied to the modified poplar after the surface differentiation treatment. The visual physical quantity and physical and chemical properties were measured and compared with mahogany, which is commonly used in old furniture in Europe and America to explore the effect of colorants and coloring steps, as well as different surface pretreatments on the coloring effect. Finally, it is concluded that continuous coloring operations can narrow the difference in brightness and red color value in the coloring layer of modified poplar and mahogany. Continuous coloring operations increase the difference between the yellow-green color values of modified poplar and mahogany. Therefore, the coloring difference between modified poplar and mahogany was affected by the colorant and coloring steps. Through color accumulation, the gap between the two in the target color coloring effect can be reduced, thereby reducing the difference between the coloring effect of modified poplar and mahogany.


2017 ◽  
Vol 270 ◽  
pp. 107-111
Author(s):  
Zuzana Andršová ◽  
Pavel Kejzlar

Many of currently manufactured components intended for automotive, must not only meet the requirements on functionality, but also considerable demands on the visual appearance. Parts are subjected to thorough inspection and suppliers are forced to deal with causes of a very slight visual defects. When examining the defects, it is necessary to use a whole range of advanced analytical methods and procedures previously used only for identification of the physical and chemical properties and structure of the material. This paper deals with several examples which have been solved. It focuses especially on the use of demanding metallographic sample preparation from components with surface defects, examining the defects on the cross-section using mainly microscopic techniques and determining the causes of their generation. These results then serve as a basis for modification of the technology and thus they are the tool for significant reduction of amount of NOK parts.


Author(s):  
NE Fedorova ◽  
MV Egorova ◽  
AS Rodionov

Introduction. Various copper compounds are most widely used as plant protection agents in agriculture. From a hygienic point of view, information on excessive accumulation of copper in plants related to the use of a specific formulation of copper-containing pesticides is of interest. Our objective was to assess feasibility of increasing statistical significance of results of determining low residue levels of a copper-containing pesticide in apple samples by flame atomic absorption spectrometry using a high-resolution spectrometer in combination with developed approaches to sample preparation of plant-based foods, including homogenization with dry ice and microwave mineralization. Materials and methods: We analyzed 30 samples of apples collected in three different agro-climatic zones by flame atomic absorption spectrometry and electrothermal atomization atomic absorption spectrometry. Both methods were validated on 10 samples with added copper at levels 1-5 of the lower limit of quantitation. A statistical calculation was performed based on a simple Student’s test to assess the significance of differences between the results of measurements by flame and electrothermal techniques. Homogeneity of variances was estimated using the Fisher test to clarify the possibility of comparing two data sets. Results: The use of a technique of cryo-grinding and microwave decomposition in a microwave reactor in combination with a high-resolution continuum source atomic absorption spectrometry demonstrated a decrease in scattering and the limit of detection and better repeatability in the analysis of parallel samples. Results of statistical calculations confirmed the homogeneity of variances in data samples obtained for electrothermal and flame techniques, and the further Student’s t-test showed insignificant differences between the results of measurements obtained by FAAS and ET-AAS. Conclusion: Our findings prove that modern methods of sample preparation in combination with highly sensitive equipment allow a significant reduction in the limit of detection and scattering of test results.


2013 ◽  
Vol 37 (5) ◽  
pp. 1128-1135 ◽  
Author(s):  
Gener Tadeu Pereira ◽  
Zigomar Menezes de Souza ◽  
Daniel De Bortoli Teixeira ◽  
Rafael Montanari ◽  
José Marques Júnior

The sampling scheme is essential in the investigation of the spatial variability of soil properties in Soil Science studies. The high costs of sampling schemes optimized with additional sampling points for each physical and chemical soil property, prevent their use in precision agriculture. The purpose of this study was to obtain an optimal sampling scheme for physical and chemical property sets and investigate its effect on the quality of soil sampling. Soil was sampled on a 42-ha area, with 206 geo-referenced points arranged in a regular grid spaced 50 m from each other, in a depth range of 0.00-0.20 m. In order to obtain an optimal sampling scheme for every physical and chemical property, a sample grid, a medium-scale variogram and the extended Spatial Simulated Annealing (SSA) method were used to minimize kriging variance. The optimization procedure was validated by constructing maps of relative improvement comparing the sample configuration before and after the process. A greater concentration of recommended points in specific areas (NW-SE direction) was observed, which also reflects a greater estimate variance at these locations. The addition of optimal samples, for specific regions, increased the accuracy up to 2 % for chemical and 1 % for physical properties. The use of a sample grid and medium-scale variogram, as previous information for the conception of additional sampling schemes, was very promising to determine the locations of these additional points for all physical and chemical soil properties, enhancing the accuracy of kriging estimates of the physical-chemical properties.


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