Research on the Feasibility and Key Influencing Factors of Rapid Determination of Heavy Metals in Soil by Portable X-ray Fluorescence Spectrometer

This study used 4 different brands of portable X-ray fluorescence spectrometers (p-XRF) to determine 26 elements in 18 actual soil samples from 10 regions in China and 6 standard soil samples. By comparing with the laboratory ICP-MS method, the elements that could be accurately quantified were screened out, and the effects of soil particle size and moisture content on the determination results were analyzed. The results show that p-XRF could accurately quantify 15 elements (Sb, As, Ba, Cd, Cr, Cu, Pb, Ni, Sn, Zn, Mn, Rb, Sr, Th, Ti) with relative errors less than 20% and precision H values not exceeding 2. The method detection limit ranged from 0.03 to 40.0 mg·kg^-1. When the optimal soil particle size was 100 mesh and the moisture content was below 10% the determination accuracy was higher. Compared with the laboratory method, p-XRF showed a good linear relationship (with the coefficient of determination ranging from 0.877 9 to 0.996 3) in the determination of 7 major heavy metals (Cr, Ni, Cu, Zn, As, Pb, Cd). p-XRF could be used as an effective auxiliary tool for rapid detection of heavy metals in soil, and the optimized test conditions could provide a reference for its application in environmental management.