Sodium metaarsenite

As a crucial component of soil, organic matter significantly influences the accuracy of quantitative detection of heavy metals in soil using X‐ray fluorescence (XRF) spectroscopy. In view of this problem, this study first analyzes the variations of soil XRF spectra corresponding to changes in organic matter content, and it was found that organic matter content had a linear positive correlation with the net area of the Compton scattering peak (R2 = 0.987). Based on this, heavy metals such as lead (Pb) and arsenic (As) were used as the target elements, and a correction method for the influence of organic matter on the detection of Pb and As in soil by XRF using the Compton scattering peak as the internal standard was established. The results demonstrated that the established method, when used to detect Pb (48.43–94.78 mg/kg) and As (75.86–122.07 mg/kg) coexisting in 34 soil samples with different organic matter contents (0%–49.5%), the relative errors of Pb and As were 0.05%–3.94% and 0.22%–3.87%, and the average relative errors were 0.99% and 0.97%, respectively, which were significantly lower than those of 2.77%–46.20% and 0.25%–9.05% before correction for the influence of organic matter. Moreover, the applicability of this established method was verified with 33 soil samples with different organic matter contents (1.5%–49.5%). The relative errors of Pb (11.35–21.04 mg/kg) and As (50.08–70.39 mg/kg) obtained by this method were 0.39%–12.95% and 0.69%–14.22%, with average relative errors of 4.94% and 4.01%, respectively, which were also significantly reduced compared to the relative errors of 6.69%–131.65% and 0.46%–15.79% before correction for organic matter effect. Therefore, this method could effectively improve the accuracy of XRF quantitative analysis of Pb and As in soils under the influence of organic matter. This study provides an important methodological foundation for the rapid and accurate on‐site detection of heavy metals in soil by XRF.