RU2421726C1 - Method to detect lead content in organs of cattle - Google Patents

Abstract

FIELD: veterinary science. ^ SUBSTANCE: potassium and copper content is detected in an animal hair by method of atomic emission spectrometry. Afterwards a regression equation is calculated, at the same time, using the parameter of potassium concentration, lead content is detected in animal liver and kidneys, and using copper concentration, lead content is detected in spleen. ^ EFFECT: method causes minimum level of stress in animals, ensures non-invasive sampling, convenience in their storage and transportation. ^ 3 tbl, 1 ex

Description

The alleged invention relates to animal husbandry, veterinary medicine, ecology and is intended for in vivo determination of the degree of accumulation of lead in the parenchymal organs of cattle.

The concentration of elements in the hair is less subjected to strict homeostatic control, in contrast to the liquid internal environments of the body. Hair samples are an integral indicator of the body's mineral metabolism. The content of elements in the hair reproduces the mineral status of the body, which makes it possible to use the analysis of hair elements for early detection of pathological processes that occur in the body (Skalny A.V., Lakarova E.V., Kuznetsov V.V., Skalnaya M.G. Analytical methods in bioelementology .-- SPb .: Nauka, 2009. - P.22-28).

Lead is one of the most toxic elements for humans and animals. Exposure to animals of elevated concentrations of lead leads to its accumulation in the body. The difference in the toxicity of lead compounds is explained by their different solubility in body fluids, for example, in gastric juice. It is known that in the chemical analysis of the hair composition, one can trace the effect and dynamics of lead accumulation in humans and animals (D. Oberlis D., Harland B., Skalny A. The biological role of macro- and microelements in humans and animals. - St. Petersburg: Science, 2008. - P.473-479; Skalny A.V., Lakarova E.V., Kuznetsov V.V., Skalnaya M.G. Analytical methods in bioelementology. - St. Petersburg: Nauka, 2009. - P.22- 28).

With lead poisoning in the body as a result of its interaction with calcium, magnesium and sodium, pathochemical shifts occur.

Known methods for determining the concentration of lead in food raw materials, including muscles and other organs that can be used only after slaughtering animals (GOST 30178-96. Atomic absorption method for the determination of toxic elements for raw materials and food products. - Minsk: Interstate Council for Standardization, Metrology and certification, 2003. - C.1-6; GOST 30538-97. Methodology for the determination of toxic elements by the atomic emission method in food products. - Minsk: Interstate Council for Standardization, Metrology and Certification, 2001. - S.11-16) .

However, existing methods cannot evaluate the degree of lead contamination of organs and tissues during life and eliminate the toxic effect of lead on the animal. Human consumption of cattle by-products contaminated with lead can pose a health hazard.

The technical problem is the determination of lead in organs in vivo.

This method of determining the content of lead in the organs of cattle involves analysis of the biosubstrate of the animal. The elemental composition of the hair is determined by inductively coupled plasma atomic emission spectrometry or by atomic absorption spectrophotometry, the potassium concentration is determined to determine the lead in the liver and kidneys, and the copper level in the hair is determined to determine the lead content in the spleen and the following linear regression equation is calculated:

y = -3.0644 + 0.5069x, where x is the concentration of Cu (mg / kg) in the hair, y is the content of Pb (mg / kg) in the liver;

y = -0.05 71 + 0.0122x, where x is the concentration of Cu (mg / kg) in the hair, y is the content of Pb (mg / kg) in the spleen;

y = -1.3619 + 0.0276x, where x is the concentration of K (mg / kg) in the hair, y is the content of Pb (mg / kg) in the liver;

y = 0.0195 + 0.0005x, where x is the concentration of K (mg / kg) in the hair, and y is Pb (mg / kg) in the kidneys.

The above method solves the problem of assessing the accumulation of lead in the liver, kidneys and spleen of cattle.

The concentration of lead in the liver and kidneys is calculated by the level of potassium in the hair, and also by the concentration of copper in the liver and spleen.

From the existing methods in which the determination of the concentration of lead in the organs and tissues of the animal is possible only after slaughter, the claimed method differs in that the content of potassium and copper in the hair is established and the accumulation of lead in the liver, kidneys and spleen is estimated by it. The lead content in the liver and spleen can be determined by the concentration of copper in the hair.

The determination of lead in parenchymal organs of the proposed method provides a reduction in animal stress, ease of storage and transportation of samples.

Execution example

The concentration of macroelements in the samples was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) in the laboratory of analytical geochemistry of the Joint Institute of Geology, Geophysics and Mineralogy SB RAS. Samples of parenchymal organs and muscle tissue were studied on an IRIS Advantage spectrometer manufactured by Thermo Jarrell Ash.

Lead concentration was determined by atomic absorption spectrophotometry. Samples were studied on a Perkin-Elmer Zeeman / 3030 spectrophotometer.

Hair samples were taken in the area of the scapula, washed with detergents and degreased with acetone. Then it was washed with distilled water and dried at a temperature of 70 ° C for 24 hours. Ashing of samples was carried out with a gradual increase in temperature from 200 to 450 ° C.

Mineralization was considered complete when the ash became white or slightly grayish in color. This usually happened in 10-15 hours. Then the samples were cooled at room temperature. 5 ml of nitric acid were added to quartz cups with samples, covered with a fluoroplastic lid on top and left for 12 hours. Then the samples were heated on an electric stove until a dry precipitate was obtained. Then, 1 ml of perchloric and 5 ml of nitric acid were added to each sample, and a fluoroplastic cap was placed on top. The contents of the cups were evaporated on a hot plate. When the solution became clear, 5 ml of 1: 1 hydrochloric acid was added to each dish. This was repeated until a wet precipitate of yellowish salts was obtained. Then 5 ml of 5% hydrochloric acid was added to each sample. Heated on a hot plate until the precipitate dissolved. The resulting samples were allowed to cool at room temperature. To each sample, 2 ml of scandium was added; the final concentration of scandium in solution was 2 μg / ml. Gently poured the resulting solution into test tubes. After it was diluted with bidistilled water to 10 ml.

The method of plasma spectrometry is one of the universal and progressive methods of elemental analysis of matter; its use makes it possible to simultaneously determine a large set of chemical elements, including those with low detection limits, from a single sample.

Analyzing the data of table 1, it should be noted that the highest concentration of lead in the studied animals was in the heart and liver. According to the level of lead accumulation, the organs were arranged in the following order: heart> liver> lungs> kidneys> spleen.

Table 1 The content of lead in the organs of cattle, mg / kg Organ

σ Lim Liver 0.64 ± 0.249 1.27 ± 0.176 0.15-6.73 Kidney 0.05 ± 0.006 0.03 ± 0.004 0.01-0.14 Spleen 0.03 ± 0.005 0.02 ± 0.03 0.01-0.09 Heart 0.82 ± 0.115 0.58 ± 0.08 0.01-1.99 Lungs 0.17 ± 0.018 0.09 ± 0.01 0.06-0.47

The content of some elements in the hair of gobies of black-motley breed was studied (Table 2). The level of calcium, sodium, phosphorus, potassium, magnesium and copper according to the degree of accumulation in the hair can be arranged in the following order: Na> Ca> Mg> P> K> Cu. Individual phenotypic variability of elements was relatively low in calcium, copper, magnesium, sodium. The relatively high calcium content in the hair does not indicate its excess in the body, but reflects the enhanced circulation of this element in the body.

table 2 The content of certain chemical elements in the hair, mg / kg Element

σ Cv Lim Ca 4952.15 ± 168.31 858.2 ± 119.2 17.3 ± 2.4 3636-6556 Mg 829.1 ± 30.09 157.7 ± 20.2 19.0 ± 2.7 589.8-1264 Na 4986.69 ± 211.76 1079.7 ± 149.9 21.6 ± 3 3591-8553 K 72.35 ± 7.36 37.6 ± 5.2 51.9 ± 7.2 39.47-220 P 348.57 ± 19.54 99.6 ± 13.8 28.6 ± 3.9 204-739 Cu 7.30 ± 0.2 1.03 ± 0.14 14.1 ± 2.0 5.07-9.59

It is shown that between the studied indicators there are medium and high positive correlations. In order to predict the level of lead in parenchymal organs, the regression equations were calculated. The accumulation of lead in the liver and spleen can be determined by the concentration of copper in the hair. The concentration of potassium in the hair determines the level of lead in the liver and kidneys.

Table 3 The relationship of the level of copper and potassium with the concentration of lead in the organs and tissues of animals Pairs of items r + s _r y = a + bx R ² Cu Hair - Pb Liver 0.41 ± 0.16 * y = -3.0644 + 0.5069x 0,301 Cu hair - Pb spleen 0.52 ± 0.14 ** y = -0.0571 + 0.0122x 0.271 K hair - Pb liver 0.81 ± 0.06 *** y = -1.3619 + 0.0276x 0.667 K hair - Pb kidney 0.54 ± 0.14 ** y = 0.0195 + 0.0005x 0,301 * P <0.05; ** P <0.01; *** P <0.001.

The most informative indicator is the concentration of potassium in the hair. With it, you can set the level of lead in the liver and kidneys.

Thus, the use of regression equations allows the intravital non-invasive method to predict the concentration of lead in parenchymal organs by the level of potassium and copper in the hair.

Claims (1)

The method for determining the lead content in cattle organs, including the analysis of the biosubstrate of the animal, characterized in that the hair of the animal is used as the biosubstrate, the content of potassium and copper in it is determined by atomic emission spectrometry, after which the regression equation is calculated, and the concentration index is calculated potassium determine the lead content in the liver and kidneys of animals, and the concentration of lead in the spleen is determined by the concentration of copper:
y = -3.0644 + 0.5069x, where x is the concentration of Cu (mg / kg) in the hair,
y - the content of Pb (mg / kg) in the liver;
y = -0.0571 + 0.0122x, where x is the concentration of Cu (mg / kg) in the hair,
у is the content of Pb (mg / kg) in the spleen;
y = -1.3619 + 0.0276x, where x is the concentration of K (mg / kg) in the hair,
y - the content of Pb (mg / kg) in the liver;
y = 0.0195 + 0.0005x, where x is the concentration of K (mg / kg) in the hair,
y - Pb (mg / kg) in the kidneys.