SU532291A1 - Method of radioactive extraction from animal fish meat - Google Patents

Description

extraction of cesium -137 with hydrochloric acid from alumina-silica gel 90-100%.

An example. A sample of ca (1 kg) is passed through the m cutter. Ground water is poured with tap water (water volume 2 l), mixed and a nylon bag with silica-gel KSM or ShSM GOST 3936-54 grades (the weight of silica-gel 0 g; grain size 0.5-1 mm) is lowered into this vessel and then boiled t. Boiling time from the moment of boiling 30 min. After that, the bag with the alumina-silica gel is taken out, washed with water from the remains of meat and the alumina silica gel is transferred with water into a glass. Water is drained. Silica gel is poured about 200 ml of 1.0 n. hydrochloric acid and left for 3 hours. The acid is poured into a beaker, silica gel is re-treated with 1N. hydrochloric acid is poured into the same beaker and the carrier is added.

As a carrier, 1 ml of a cesium titrated solution containing 106 mg / l of cesium antimony salt is introduced.

After the carrier was added to the eluate, 5 ml of a 0.1 M nickel nitrate solution and 5 ml of a 0.1 M potassium ferrocyanide solution were added. Stir for 5-10 minutes. The precipitate formed is left to stand for a few hours with a solution (preferably overnight), then the main part of the p & s leaf is decanted and filtered off. The filter with the precipitate is calcined for 1 h in a muffle furnace at 300-400 0. The calcined precipitate is transferred to a beaker, poured with a small amount of 2N. hydrochloric acid and boil. The undissolved residues are filtered off and discarded. A 0.3 m saturated solution of antimony trichloride is added to the filtrate and then with stirring, dry potassium iodide is added in small portions with stirring. The solution is stirred to form a precipitate of antimony n-isoiodide cesium salt. After one to two hours of settling, the main part of the solution is separated by decantation, and the precipitate is transferred to a small diameter filter by washing off the sediment with glacial acetic acid. The precipitate is washed with alcohol.

The filter with the precipitate is dried under a lamp yli at room temperature on the table. The dried precipitate of cesium antimony salt | iodide salt is transferred to a 1 pre-weighed substrate, the weight of the precipitate is determined and the output of the carrier is calculated, equal to the ratio of the obtained weight of the precipitate to 106 mg. The precipitate is moistened with several drops of ethanol, evenly distributed over the substrate, and dried. The result is a thin-layer preparation of the cesium salt, which also contains the radioactive cesium-137 extracted from the sample. The beta activity of the obtained thin-layer preparation was measured on a low-background UFM-1500 installation with a SVT-13 counter having a background count rate of 4-5 pulses / min. From the; scientific counting rate of a thin-layer preparation, the speed is taken away.

bills background. The counting rate of the drug without background is used to determine the activity of the sample.

Sample activity is calculated by the formula:

A g (pc ") P",

p-ad1

where n is the drug count rate,

imp / min

PF - background counting rate, imp / min, P - carrier output in units, K - coefficient of transition from the counting rate of the drug to its rate of activity, P sp-min. Min.imp 7

2.22 - the number of disintegrations per 1 min, per 1 cucurie,

split

min.pcurie

The coefficient of transition from the counting rate of a drug to its activity is equal to the ratio, the number of disintegrations in a preparation per unit of time to the number of pulses (without background) recorded by the counter for the same unit of time from this preparation. The magnitude of the transition coefficient is determined by measuring the count rate from a calibrated thin-layer drug cesium -137 (i.e., a drug whose number of decays is known per unit of time) on the same counter in the same measurement geometry. With the measurement geometry used by us, the conversion coefficient is 15 min.

5 3

min.imp

At the same time, the degree of extraction of cesium 137 from the sample of ground meat is 60-80%.

Claims (1)

Invention Formula 1. A method of extracting radioactive isotopes from the meat of animals and fish, which involves pouring water on the initial sample of ground and boiling, boiling, separating the liquid phase and precipitating isotopes from it, characterized in that, in order to speed up the process, before boiling the crushed portion of meat is placed on an alumina-silica gel packaged in a liquid-permeable fabric, and after boiling, before precipitation, the alumina-silica gel is separated from the portion of meat by a subsequent washout from 5, 5322916 tops with aluminosilicacle mononormal 4. Method pop. 1, a distinctive solution of hydrochloric acid and with the fact that as a pack2. The method according to claim 1, distinguishes between aluminosilicage and cap1 D and with the fact that alumina silica gel fabric . enter in the amount of 15-20 g per 1 kg of sources of information, m sa.f taken into account during expection 3. Method pop. 1, otlichayu-kova and others. Radiobiologists and radioads and with the fact that hydrochloric acidologists and agricultural workers live in an amount of 200-300 ml per 15 gs, M., Atomiadat, 1973, aluminosil-icagel. . 207. 1. Ktsiga edited by B.N. Ann