Keywords: gamma-, ray spectrometry, gypsum, phosphate fertilisers, radium, nitric acid, barium sulfate
Determination of radium-226 in phosphate fertilisers and gypsum by gamma-ray spectrometry
The 226Ra isotope was determined in 17%, 20% and 46% phosphate fertilisers and in gypsum. The fertiliser samples were dissolved in 10% nitric acid solution. The barium sulfate method was used for the precipitation of 226Ra. An alkaline fusion method was used to separate the 226Ra from the gypsum. The 226Ra concentrations present in these materials were between 10-4 and 10-5µg g-1. Neutron activation analysis was also used to verify the presence of uranium in the fertilisers and gypsum; the uranium concentration in gypsum was 4.85 ± 1.72 ppm.