Validación del método de espectrometría gamma en matrices con densidad de 0.8 a 1.2 g/cm3 en el rango de 200 a 1600 keV del espectrómetro gamma “Software Spectra Line Gamma Precision (GP)” Modelo GCD-40180X del Laboratorio de Vigilancia Ambiental Radiactiva de la SCAN.

Abstract

The objective of the research was to validate the gamma spectrometry method in matrices with a density of 0.8 to 1.2 g/cm3 in the range of 2000 to 1600 keV of the gamma spectrometer “SOFTWARE SPECTRA LINE GAMMA PRECISION (GP)” model GCD-40180x of the Surveillance Radioactive Environmental Laboratory of the Sub-secretary of Control of Nuclear Applications (SCAN) of Ecuador. The validation was carried out by making several experimental readings using two certified samples: a multinucleate standard and radioactive water contained in polyethylene bottles, which when analyzed generated an energy spectrum and two text files called general report and specific report. The information of each analysis was divided into three groups according to the evaluation criteria of the Analytical Chemistry Guide in Europe (EURACHEM). With the first group the standard deviation was calculated, method detection limit (MDL) and relative error, the second group worked to obtain the limit of repeatability and with the third group the limit of reproducibility of the method. The margin of error when comparing the data obtained with those found in the factory certificate and the evaluation of the relative standard uncertainty of the measurements with the Kragten calculation sheet was less than 10%, which according to the guide has an index of acceptance (A). Therefore it was verified that the measurements with the gamma spectrometer “SOFTWARE SPECTRA LINE GAMMA PRECISION (GP)” model GCD-40180x comply with the EURACHEM guidelines and the requirements of Standard ISO/ IEC 17025, for which it is concluded that he method is validated for the aforementioned gamma spectrometer. It is recommended to verify the values stated in the certificates for the reference materials used, because they do not necessarily correspond to values obtained by means of the gamma spectrometry technique.