Wu, Cho-YinCho-YinWuAsano, MakiMakiAsanoHashimoto, YoheyYoheyHashimotoRinklebe, JörgJörgRinklebeShaheen, Sabry M.Sabry M.ShaheenSHAN-LI WANGZENG-YEI HSEU2021-05-182021-05-182020-03https://www.scopus.com/pages/publications/85077310033?inwardhttps://scholars.lib.ntu.edu.tw/handle/123456789/561307Assessing the vanadium (V) fractionation and speciation to predict its bioavailability using a combined approach of geochemical extractions and micro-spectroscopic techniques is still not well studied. Therefore, we aimed to determine the bioavailability of V in rural soils using single extractants, sequential extraction procedure, and the X-ray absorption near edge structure (XANES) spectroscopy. We collected and characterized ninety four samples originated from horizons of seventeen soil profiles in Taiwan. We determined the total content of V and its geochemical fractions using the BCR sequential extraction procedure to predict its potential mobility. We also assessed the bioavailability of V in the soils using four availability indices i.e., CaCl2, HCl, ethylenediaminetetraacetic acid (EDTA), and NaHCO3 and related them to its uptake by Chinese cabbage (Brassica chinensis L.). Additionally, we determined the V speciation by vanadium K-edge XANES spectra. Moreover, we studied the elemental compositions of the soils using Electron Probe Micro Analysis (EPMA). Vanadium was mainly distributed in the residual fraction (81–98% of total V). Among the potential mobile fractions, V was mainly associated with Fe oxides, as identified by the BCR sequential extraction and EMPA. The XANES analysis indicated that V mainly existed in the soils as V(IV) and V(V). The EDTA and NaHCO3 extracted more V than CaCl2 and HCl, and both, particularly NaHCO3 were positively and significantly correlated with the total soil content and plant shoot concentrations of V; therefore NaHCO3 might be recommended as a bioavailability index for soil V. We hypothesize that the NaHCO3 may extract vanadate from soil surfaces and also vanadate transformed from vanadyl at alkaline pH during the extraction. The NaHCO3-extracted V can be predicted by a function of soil total V, CEC, and pH. Our results should be verified using different soils and plants in the future.Chinese cabbageSequential extractionSoil contaminationVanadium bioavailabilityXANES spectroscopy[SDGs]SDG3[SDGs]SDG15journal article10.1016/j.envpol.2019.113699319110082-s2.0-85077310033WOS:000519655100127