The leaching of V(V) with PO4 in the speciation analysis of soil

The leaching of V(V) from soil by two phosphate reagents, viz. (NH₄)₂HPO₄ and Na₃PO₄ has been studied. (NH₄)₂HPO₄ (1 M) and Na₃PO₄ (0.01 M) were efficient enough to extract all V(V) species from samples. The results were compared with that extracted by Na₂CO₃. Statistical evaluations show that the proposed method is similar to the established method utilizing Na₂CO₃.The method was applied in the analysis of soil samples from contaminated area of the vanadium mine where many grazing cattle died.Validation of the method was also done by comparing the sum of V(IV) and V(V) and the total vanadium obtained from the samples by an independent method. It was found that the sum of V(V) and V(IV) is in good agreement with the total content of vanadium in all samples after HF-H₂SO₄-HClO₄ digestion. From the results of the investigation, it follows that the use of phosphate fertilizers in V(V)-rich soil may enhance the mobility and availability of V(V) to plants. The plants, in turn, are consumed by animals that may die depending on the level of poisoning.