Spectrophotometric determination of boron in plant and soil samples by a new solvent extraction procedure

A routine method has been developed for the determination of boron in plant and soil samples. The boron in the prepared samples is converted into BF₄- in a H₂SO₄-HF system, then extracted as a coloured complex with Azure-C (or mthylne blue) into dichloroethane and finally determined spectrophotometrically. Satisfactory recoveries (±7%) were obtained for plant tissue analyses.