RU2629605C1 - Method for lead level determination in cattle muscular tissue - Google Patents

Abstract

FIELD: veterinary medicine.

SUBSTANCE: method consists in determination of strontium or zinc concentration in hair. The regression equation is then calculated. The concentration of lead in the muscular tissue is determined by the strontium or zinc content, y=0.0019x+0.0376, where x is the Sr content (mg/kg) in the hair, y is the Pb content (mg/kg) in the muscular tissue; y=0.0011x+0.0142, where x is the Zn content (mg/kg) in the hair, y is the Pb content (mg/kg) in the muscular tissue.

EFFECT: method is atraumatic, accurate and non-invasive, convenient and easy to use.

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Description

The present invention relates to ecology, veterinary medicine, animal husbandry and is intended for use as a test in vivo determination of the concentration of lead in muscle tissue of cattle of meat direction.

To obtain environmentally friendly livestock products, soils, plants, organs and tissues of cattle and other animals are monitored.

Lead is considered one of the most significant environmental pollutants. Its content in meat and slaughter products is strictly regulated (SanPiN 2.3.2.1078-01) due to its high toxicity.

The main routes of lead into the human body from environmental objects is inhalation, along with inhaled air and the alimentary route, with drinking water and food [4]. Most of the metal, from 44 to 100%, enters the body through the gastrointestinal tract along with food. About 0.01-0.024 mg / day is ingested with drinking water.

The toxic effect of lead is largely due to its ability to form bonds with a large number of ligand anions, which include sulfhydryl groups, cysteine derivatives, imidazole and carboxyl groups, phosphates [1]. As a result of the binding of anhydrins to lead, protein synthesis and enzyme activity, such as ATPase, are inhibited. Lead disrupts heme and globin synthesis, affects porphyrin metabolism, induces erythrocyte membrane defects, and reduces antibody production [3]. Long-term accumulation of lead can cause the formation of eosinophilic inclusions inside the nucleus [2].

A known method for the determination of heavy metals, including lead in the organs of cattle (Patent No. 2421726, No. 2426119). These methods are designed to determine lead in internal organs such as the liver, lungs, spleen, and kidneys.

From the methods discussed above, our proposed method is characterized in that the chemical composition of cattle hair is determined by inductively coupled plasma atomic emission spectrometry. Set the concentration of Sr or Zn in the hair to determine the level of lead in muscle tissue and calculate the regression equation:

y = 0.0019x + 0.0376, where x is the Sr content (mg / kg) in the hair,

y - the content of Pb (mg / kg) in muscle tissue;

y = 0.0011x + 0.0142,

where x is the content of Zn (mg / kg) in the hair,

y - the content of Pb (mg / kg) in muscle tissue.

The claimed method solves the problem of assessing the accumulation of lead in muscle tissue of cattle of Hereford breed. The task is achieved by determining the concentration of Sr or Zn in the hair, followed by calculating the level of lead in muscle tissue using the regression equation.

Execution example

Hairballs of Hereford breed at the age of 18 months were taken hair samples weighing 100 mg in the withers. The hair was thoroughly washed. Then, they were degreased in OSCH grade 49-5 acetone for two minutes, after which it was washed with dionized water. Then the sample was dissolved in 2 ml of nitric acid OSH 27-5. After that, it was decomposed in the MARS-5 microwave oven ("СЕМ) for 40 minutes at temperatures up to 180 ° C. The resulting solution was diluted to 10 and 100-fold according to calibration solutions of multi-element standards. The content of chemical elements in the hair was carried out by atomic emission spectrometry in the analytical laboratory of the Institute of Inorganic Chemistry named after A.V. Nikolaev of the Siberian branch of the Russian Academy of Sciences, on the ICAP-6500 spectrometer of ThermoScientific firm (USA).

The concentration of strontium and zinc in organs and tissues was determined on the basis of the biochemical laboratory of the Siberian Research Institute of Animal Husbandry on a Perkin Elmer 360 atomic absorption spectrophotometer (USA). A portion of muscle tissue weighing 100 g was ground to a homogeneous mass and dried in an oven at a temperature of 60-70 ° C for 12 hours. 3 g were taken from the obtained dry residue, then they were ashed in a muffle furnace at a temperature of 500-550 ° C for 2-3 hours. After cooling the samples at room temperature, the ash residue was dissolved in 3 ml of 50% hydrochloric acid, and then evaporated to a dry residue on an electric stove. The resulting residue was transferred to a volumetric flask by diluting it in 25 ml of distilled water. The resulting finished solution was investigated for elemental composition.

In cattle in muscle tissue, the highest concentration among the studied trace elements is characteristic of copper, and the smallest - for cadmium (table 1). The distribution of chemical elements in livestock muscles can be arranged in the form of a ranked series: Cd <Pb <Mn <Cu, in a ratio of 1: 3.6: 14.3: 44.8. Minimal phenotypic variation was recorded in copper. Cadmium and copper are characterized by high individual variability, which reflects the broad ratio of extreme variants of these elements.

Table 2 shows data on the level of accumulation of chemical elements in the hair. The ranked number of chemical elements in the hair is as follows: Sr <Fe <Zn <P. Consequently, the maximum concentration of phosphorus is revealed in the hair, and the minimum - strontium. Indices of phenotypic variation in hair in zinc and phosphorus were significantly lower than in strontium.

Table 3 shows that there are high positive correlations between the studied indicators. In order to predict the level of lead in muscle tissue, regression equations were calculated. By the level of strontium and / or zinc in the hair, the concentration of lead in muscle tissue can be calculated.

Thus, using the proposed regression equations, it is possible to conduct a non-invasive and intravital assessment of the interior of beef cattle by the content of lead in muscle tissue, using only livestock hair samples.

Bibliographic list

1. Avtsyn P.A. Microelementoses of a person / P.A. Avtsyn, A.A. Zhavoronkov, M.A. Rish, L.S. Strochkova - M .: Medicine, 1991.- S. 496.

2. Skalny A.V., Rudakov I.A. Bioelements in medicine. - M.: Mir, 2004 .-- S. 272.

3. Abdel-Mageed A.A review on biochemical roles, toxity and interactions of zinc, copper and iron / A. Abdel-Mageed, F.W. Oehme // Vet. Human Toxicol. - 1990. - No. 32 (5). - P. 456-458.

4. Jin A. Blood lead levels in children aged 24 to 36 months in Vancouver / A. Jin, C. Herzman, S.H. Peck // Can. Med. Assoc. J. - 1995. - V. 152. - No. 7. - P. 1077-1086.

Claims (5)

A method for determining the level of lead in cattle muscle tissue, including a biosubstrate analysis, characterized in that a microelement analysis of Hereford cattle hair is performed, the concentration of strontium or zinc in the hair is determined, and the regression equation is calculated: y = 0.0019x + 0.0376, where x is the Sr content (mg / kg) in the hair, y is the Pb content (mg / kg) in muscle tissue; y = 0.0011x + 0.0142, where x is the Zn content (mg / kg) in the hair, y is the Pb content (mg / kg) in muscle tissue.