Diffuse reflectance spectroscopy for monitoring potentially toxic elements in the agricultural soils of Changjiang River Delta, China

► Binding forms of Cd, Cr, Pb, Cu, Hg and As in soils determined by DRS. ► Cr, Cu, and As had stronger correlation with DRS than Cd, Pb and Hg. ► Correlation bands attributed to the absorption features of iron oxides, clays and TOC. ► Univariate and PLS models of Vis/NIR spectra showed better prediction than MIR.