Accuracy and precision of EDS analysis for identification of metal-bearing minerals in polished and rough particle samples

Abstract

The study was carried out in order to estimate reliability of EDS analysis for identification of various naturaland anthropogenic metal-bearing phases in polished and rough particle samples of stream sediments. For thispurpose, the accuracy and precision of EDS analysis were assessed. Results of the precision measurements showedthat the overall relative standard deviation of EDS measurements was 8 % for polished samples and 24 % for roughparticle samples and was within acceptable limits for most of major elements and some of the elements present inminor or trace contents in the analysed metal-bearing phases. The random analytical fluctuations were considerednegligible and phase compositions could be determined with sufficient reliability in individual grains of each phase.The overall average relative error for all elements amounted to about 12 %, which was within acceptable limits foraccuracy in EDS analysis of polished samples. Chemical formulae and identification of mineral species of metalbearingphases were thus calculated from atomic ratios between constituent elements with sufficient accuracy. Acomparison between EDS measurements in polished and rough particle samples using the Welch’s t-test showedthat about 38 % of studied metal-bearing phases could be identified with sufficient reliability by EDS analysis ofrough particle samples. The results of this study demonstrated that elemental composition of metal-bearing phasesin polished and rough particle samples was mostly determined with sufficient precision and accuracy using EDSanalyses.

Keywords

• EDS analysis
• accuracy
• precision
• polished samples
• rough particle samples
• metal-bearing phases