EVALUACIÓN DE LA PRECISIÓN INTRALABORATORIO PARA LA DETERMINACIÓN SIMULTÁNEA DE OCHO ELEMENTOS EN MUESTRAS GEOLÓGICAS APLICANDO LA ESPECTROMETRÍA DE EMISIÓN ATÓMICA CON PLASMA ACOPLADO

Abstract

In this work the intralaboratory precision for the  simultaneous determination of Al, Si, Fe, Mg, Ni,
Co, Cr and Mn in lateritic ores employing coupled plasma atomic emission spectrometry is evaluated. The task was realized in the Laboratory of Minerals from Geominera Orient Company and the standard deviations of the relative differences obtained from 58600 duplicates determinations at 15 levels of concentration were determinate. The value obtained was ± 2,8 % independently of the analyzed element or its concentration level in the sample. This result is agree with the values reported by specialized literature for this type of analysis, but contradicts in part the quality control system established in the laboratory, which utilize different precisions according to the element and  concentration level. It is recommended that the laboratory modifies the form which evaluate the quality of the analytical results when the simultaneous quantification is employed, in order to avoid reject correct results with precisions not reached by the analytical system and will be originate a increasing in the total of samples to be
controlled, with the unnecessary spent of humans and materials recourses.
Keywords: intralaboratory, precisión, ICP-AES, laterites, multielemental analysis.