On-site Analysis of Heavy Metals in Soil Using a Handheld XRF Spectrometer

A rapid sample preparation method and a correction method achieving accurate quantification were developed for the on-site determination of heavy metals (Cr, As, Se, Cd, and Pb) in soil using a handheld X-ray fluorescence spectrometer. A soil sample was roughly crushed using a tablet crusher and a glass rod. The crushed sample was filled in a plastic container (28 mm of diameter and 10 mm of height), and a surface of the sample was covered with a polyester film. The sample was analyzed using a handheld X-ray fluorescence spectrometer after fixing the sample container to an acrylic jig. The moisture content in soil was measured by a refractive index-type mobile soil-moisture meter, and the concentrations of heavy metals obtained using the handheld X-ray fluorescence spectrometer were corrected to that in dried soil by a quantitative correction using the moisture content. The proposed method does not require a power supply in any analytical step, and is applicable to rapid and accurate determinations of heavy metals in soil.