WD‐XRF Determination of Gold in Geological Samples: An Eco‐Friendly Pre‐Concentration Method

Abstract

This study proposes a novel approach for gold analysis in soil and rock samples using wavelength dispersive X‐ray fluorescence. The method offers advantages over traditional techniques like fire assay and MIBK extraction by being less labor‐intensive, environmentally friendly, and achieving lower limits of detection of 20–70 μg/kg depending on matrix of sample. The method involves pre‐concentration steps including aqua regia digestion, evaporation of filtrate and pressed pellet preparation, followed by WD‐XRF analysis to quantify gold content. The instrumental parameters for optimal signal‐to‐background ratio were determined. To ensure precise measurements, the calibration curve was created using specially made pressed pellets of gold‐spiked hematite ore samples. These samples contained known amounts of gold and matched the matrix of the pellets being analyzed. The proposed method demonstrates good accuracy and precision, making it a viable alternative for gold exploration and mining activities.