RU2548774C1 - Method of evaluating cadmium in liver and lungs of cattle - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: method comprises analysis of biosubstrate. The trace element analysis of the hair of cattle is carried out. The concentration of Fe and/or Ti in hair is determined and the regression equation is calculated: y=-0.3152x+0.0476, where x is content of Fe (mg/kg) in hair, y is content of Cd (mg/kg) in lungs. y=-18.672x+0.047, where x is content of Ti (mg/kg) in hair, y is content of Cd (mg/kg) in lungs.

EFFECT: method is precise, atraumatic and noninvasive, simple and easy to use.

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Description

The present invention relates to animal husbandry, veterinary medicine, ecology and is intended for use as a test for the degree of accumulation of cadmium in the lungs of cattle.

Cadmium is one of the most dangerous common environmental pollutants that can cause serious changes in the body (A. Nezavitin. Problems of agricultural ecology / A. G. Nezavitin, V. L. Petukhov, A. N. Vlasenko. - Novosibirsk: Science. Siberian Publishing Company RAS, 2000. - 255 p.). Therefore, the Russian SanPiN (Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control: SanPiN 2.1.4.1074-01. - Introduction. 2002-01-01. - M .: Ministry of Health of Russia, 2002, - p. 6) it is assigned to the 2nd hazard class - “highly hazardous substances”. Cadmium is toxic, even at low doses. The main routes of cadmium intake into the body are alimentary and respiratory (TI Bokova, Ecological Foundations of Innovative Improvement of Food Products: Monograph / TI Bokova. - Novosibirsk: Publishing House of the NSAU, 2011. - p. 25).

Studies on young ruminants show that cadmium has a negative effect on animal growth rates (Masaoka, T. Effects of sulphur, molybdenum and Cd on the growth rate and trace element status in the ruminants and pigs / T. Masaoka, M. Anke, B. Groppel, F. Akahori // 6th Int. Trace Element Symp., 1989 .-- Vol. 2 - P. 510-525). Therefore, monitoring the level of cadmium in animals must be carried out with the aim of its further correction and reduction of accumulation in the final products of animal husbandry. This in turn will contribute to the production of environmentally friendly products. The content of many chemical elements depends on the type of animal, direction and level of productivity, age, environmental conditions, season of the year and health status (Zheltikov A.I. Black-and-white cattle of Siberia / A.I. Zheltikov, V.L. Petukhov, O .S. Korotkevich - Novosibirsk: NSAU, 2010.500 s.).

There are methods for the determination of cadmium in food raw materials, which was obtained after the slaughter of animals (Food products. Method for the determination of toxic elements by the atomic emission method. - M.: Gosstandart of Russia, 1997. - S. 10-21). In addition, there is a method of determining cadmium in the muscle tissue of cattle (RF Patent No. 2426119) and pigs (RF Patent No. 2342659). The disadvantage of the first method is that blood is not the best indicator of the elemental composition of the body, since it does not differ in the constancy of the chemical composition. Both methods are time consuming for sampling and subject animals to significant stress. From the methods discussed above, our proposed method is characterized in that the chemical composition of the hair taken from live animals is determined by the method of atomic emission spectrometry with inductively coupled plasma. Set the concentration of Fe and Ti in the hair to determine cadmium in the lungs. And the regression equation is calculated:

y = -0.3152x + 0.0476, where x is the Fe content (mg / kg) in the hair,

y - the content of Cd (mg / kg) in the lungs.

y = -18.672x + 0.047, where x is the Ti content (mg / kg) in the hair,

y - the content of Cd (mg / kg) in the lungs.

The claimed method solves the problem of assessing the accumulation of cadmium in the lungs of cattle of Hereford breed. The task is achieved by determining the concentration of Ti and Fe in the hair, followed by calculating the level of cadmium in the lungs using the regression equation. The content of Fe and / or Ti in the hair determines the cadmium content in the lungs.

Execution example

Hair samples were taken from bulls of Hereford breed at the age of 18 months in the withers area. The hair was thoroughly washed for analysis. To cleanse the hair from contamination, a hair sample was placed in a flask with distilled water and then the sample was mixed for one minute with a mixer at a speed of 1000 rpm. Then the water was changed up to 10 times, repeating this procedure. Then the hair was washed in acetone grade OSCH 49-5 for two minutes, after which it was washed 3 times with deionized water. And dried at room temperature.

For analysis, a 100 mg sample was weighed and placed in a quartz cup. A sample cup was placed in a cold quartz furnace. The temperature of the furnace was raised to 250 ° C. The sample was kept at this temperature for 15 minutes. Then the temperature was raised to 450 ° C and held for 15 minutes. Then the sample was left in the oven to cool to room temperature. After carbonization, the sample was ground in quartz dishes to a black powder state. Then, a sample weighing 10 mg was taken from the prepared sample and mixed with 50 mg of graphite powder and 40 mg of spectroscopic buffer (15% NaCl and graphite powder). Directly for analysis, 20 mg were taken from the resulting mixture.

Chemical elements in the hair were determined using atomic emission spectral analysis on the basis of the analytical laboratory of the Institute of Inorganic Chemistry named after A.V. Nikolaev SB RAS. For analysis, the Fakel two-jet arc plasmatron and the Grand multi-channel atomic emission spectrometer manufactured by VMK Optoelectronics LLC (Russia) were used.

The study of lung samples was carried out on the basis of the biochemical laboratory of the Siberian Research and Design Institute of Animal Husbandry. For analysis, an atomic absorption spectrophotometer Shimadzu Perkin Elmer 360 (USA) was used.

Sample preparation for atomic absorption analysis took place in the following sequence: the dishes after washing in a soap solution were washed with tap water and rinsed with bidistilled water, then dried. Samples (weighing 100 g) were ground to a homogeneous mass, then dried in an oven at a temperature of 60-70 ° C for about 12 hours to constant weight. From the obtained dry residue, 3 g were weighed, which were ashed in a muffle furnace at a temperature of 500-550 ° C. After 10-15 hours, mineralization ended, the ash acquired a gray or white color. After this, the samples were cooled at room temperature. Next, the resulting ash residue weighing 3 g was dissolved in 3 ml of 50% hydrochloric acid, then the samples were heated on an electric stove to obtain a dry precipitate, then this residue was transferred to a flask by diluting it in 25 ml of distilled water. The resulting finished solution was investigated for elemental composition.

Based on the results presented in table 1, it can be noted that in the lungs of bulls of Hereford breed, Zn is accumulated more than other elements, and least of all, Cd. By the level of concentration of chemical elements in the lungs, it can be arranged in the form of an increasing series: Cd <Pb <Cu <Zn. At the same time, the greatest phenotypic variation is characteristic of Cd, and the smallest - for Zn.

Table 2 contains data on the content of certain chemical elements in the hair. By the level of accumulation, chemical elements can be represented as an increasing ranked series: Fe> Mn> Cu> Ti. Consequently, iron has the greatest accumulation in the hair, and titanium has the least. High phenotypic variation is observed for Mn, and low - for Cu. This is reflected broadly in extreme Mn variants, and narrow in Cu.

Table 3 shows that there are fairly high negative correlations between the studied indicators. In order to predict the level of cadmium in the lungs, regression equations were calculated. By the level of iron and / or titanium in the hair, the concentration of cadmium in the lungs can be calculated.

Thus, the proposed regression equations allow for the intravital minimally invasive assessment of cadmium content in the lungs, using only hair samples.

Claims (1)

A method for determining cadmium in the lungs of cattle, including a biosubstrate analysis, characterized in that a trace element analysis of cattle hair is carried out, the concentration of Fe and / or Ti in the hair is determined and the regression equation is calculated:
y = -0.3152x + 0.0476, where x is the Fe content (mg / kg) in the hair,
y - the content of Cd (mg / kg) in the lungs;
y = -18.672x + 0.047, where x is the Ti content (mg / kg) in the hair,
y - the content of Cd (mg / kg) in the lungs.