Development and validation of portable X-ray fluorescence spectrometry for elemental routine measurement in geological samples

Abstract

A pressed pellet technique was developed for quantitative analysis of elements in geological samples by portable X-ray fluorescence spectrometry (pXRF). Validation of analytical method was done using eight geological reference materials (BCR-2: basalt, COQ-1: carbonatite, GSP-2: granodiorite, JA-1: andesite, JB-2: basalt, JG-1a: granodiorite, JG-2: granite and JSy-1: Syenite). Minimum concentrations of Al, Ca, Cu, Fe, K, Mn, Pb, Rb, Si, Sr, Ti, Y, Zn and Zr in geological reference materials for pXRF detection were 6.60%, 0.50%, 19 mg/kg, 0.06%, 0.35%, 120 mg/kg, 5.36 mg/kg, 7.37 mg/kg, 1.62%, 17.92 mg/kg, 0.09%, 24.90 mg/kg, 13.60 mg/kg and 51.20 mg/kg, respectively. The accuracy of the developed method was acceptable with the mean error below 18%. The geological samples received from the Department of Mineral Resources (DMR) were also tested using this method. The results showed that the concentration values obtained by the studied method were in good agreement with those obtained by the DMR for K, Mn, Pb, Rb, Si, Sr, Ti, Y and Zn with concentrations ranging of 3.70-4.20%, 90-400 mg/kg, 64-89 mg/kg, 296-404 mg/kg, 24.44-32.17%, 50-180 mg/kg, 0.22-0.28%, 34-47 mg/kg and 30-41 mg/kg, respectively. This method is suitable for elemental routine measurement in geological samples.