METHOD OF DETERMINING SPECIFIC ACTIVITY OF STRONTIUM-90 AND CAESIUM-134 OR CAESIUM-137 RADIONUCLIDES IN MILK OR MILK WHEY Russian patent published in 2013 - IPC G01N33/04 

FIELD: chemistry.

SUBSTANCE: method of determining specific activity of strontium-90 and caesium-134 or caesium-137 radionuclides in milk or milk whey involves preparing a starting sample for analysis by mixing milk or milk whey with a sorbent, depositing radionuclides on the sorbent, separating the sorbent from the milk or milk whey, washing and drying the sorbent, measuring specific activity of the radionuclides in the sorbent, the method being characterised by that the sorbent added to milk or milk whey is manganese dioxide, and specific activity of strontium-90 and caesium-134 or caesium-137 radionuclides in milk or milk whey is determined using the equations: Q₁=A_meas.·m_s/M_pr.·K_Sr-90, Q₂= A_meas.·m_s/M_s·K_{Sr-134 or 137}, where: Q₁ is the specific activity of the strontium-90 radionuclide in milk or milk whey, Bq/g, Q₂ is the specific activity of the caesium-134 or caesium-137 radionuclide in milk or milk whey, Bq/g, A_meas. is the specific activity of the strontium-90 or caesium-134, 137 radionuclides in the sorbent, Bq/g; m_s is the mass of the washed and dried sorbent after contact with milk or milk whey, g; M_s is the mass of the milk or milk whey sample in contact with the sorbent, g; K_Sr-90 is the sorption coefficient of strontium-90 from milk or milk whey on the manganese dioxide sorbent, K_{Cs-134 or Cs-137} is the sorption coefficient of Cs-134 or Cs-137 from milk or milk whey on the manganese dioxide sorbent, wherein the sorption coefficients of strontium-90 or caesium-134 or caesium-137 from milk are equal to 0.4-0.6 and 0.8-0.9, respectively; and the sorption coefficients of strontium-90 and caesium-134 or caesium-137 from milk whey are equal to 0.8-0.9 and 0.8-0.98, respectively.

EFFECT: method enables fast and accurate calculation of activity of strontium-90 and caesium-134 or caesium-137 radionuclides in milk or milk whey.

4 tbl, 2 ex