Abstract Soil is the major resource that provides the appropriate conditions for organisms and humans as the main components of the environment. Soil pollution threatens plant communities and other living organisms. One of the pollution cases is the abnormal accumulation of heavy metals in the soil, which has become an environmental problem due to its long-term stability in the soil and harmful ecological effects. The measurement of the concentration of heavy elements in soil has been done so far with methods such as magnetic absorption, pXRF analysis, and chemical methods all over the world. This research aims to eva‎luate the efficiency of the pXRF technique in estimating the concentration of heavy elements and compare its efficiency with the magnetic susceptibility technique. The studied area is a part of Dasht Afzer in Fars province. In this study, 300 soil samples were taken from the surface layer (0-30 cm depth) and were transferred to the laboratory for laboratory analysis. The magnetic susceptibility of the samples was measured using the Bartington MS2 Dual Frequency Sensor and the MS2B sensor at two frequencies. A portable X-ray fluorescence device was used to measure the X-ray fluorescence spectrum. The concentration of heavy elements including Mn, Fe, Cr, Cu, Ni, and Cd was determined by chemical method and then by atomic absorption spectroscopy (model Analyst 200). The results showed that there is a positive and significant correlation between magnetic susceptibility at high frequency and the concentration of copper, iron, manganese, zinc, chromium, and nickel metals. However, higher correlation coefficients were obtained between the pXRF method and the concentration of elements using the chemical method. The highest correlation coefficient is related to the elements of iron (r = 0.785), zinc (r = 0.716), manganese (r = 0.693), nickel (r = 0.598) and copper (r = 0.561). However, the chrome element has a low correlation (r = 0.05) with pXRF data as compared to the magnetic susceptibility technique. Magnetic susceptibility provided more efficiency in predicting Cr content compared to pXRF. The pXRF method does not require any chemical reagents, so it is environmentally friendly, as well as this technique is cost-effective and does need not a large number of laboratory operations. The concentration of the elements measured by the chemical method had the highest correlation with the concentration measured by the pXRF method, and the highest correlation is related to the elements of iron, zinc, manganese, nickel, and copper, respectively. Due to the relative ease of sample preparation, reasonable analysis cost, stability and ease of measurement, performing quantitative and qualitative analysis, the pXRF method has high proficiency for elemental analysis of soil samples. Since the changes in the chemical composition of the soil reflect different conditions such as the type of parent material, the state of weathering, and the degree of soil formation, and these conditions are the reason for the variety of soil characteristics, including the texture, color, and mineralogical composition of the soil. pXRF can explore soil characteristics across the landscape. It is suggested that the potential of this technique to measure heavy elements and even soil nutrients should be studied in other regions of the country. Keywords: Magnetic susceptibility, X-ray fluorescence spectrum, heavy elements, atomic absorption, soil pollution.

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