Determination of specific concentrations of ⁴⁰K, ²³⁸U and ²³²Th in mineral fertilizer samples

The use of fertilizer is an established practice worldwide to promote agricultural productivity increased without increasing the planted area, resulting in native forests protection and increase of the food availability. Some kinds of fertilizer have in their chemical composition some radionuclides due the origin of its feedstock, such as ²³⁸U, the ²³²Th, and their descendants, beyond ⁴⁰K. Knowledge of the radioactivity levels in the environment is great importance to know the gamma radiation dose that the human being is exposed. For identification and quantitation of radionuclides, it was used gamma spectrometry where HPGe detector was used to obtain the spectra, and LabSOCS software for calculating the detection efficiency for each energy. The values of ²³²Th specific concentrations ranged from 4.1 to 368.1 Bq.Kg^-1, the values of ²³⁸U specific concentrations ranged from 16.0 to 647.7 Bq.Kg^-1 and ⁴⁰K specific concentrations ranged from 19.1 to 12713 Bq.Kg^-1. Concentrations of values are consistent with those found in literature. (author)