Study of minerals and trace element species in soybean flour

The total concentrations of Na, Mg, P, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Se and Mo in soybean flour and in extract of soybean flour were determined by ICP - AES and ICP - MS. The highest element extractability was found in case of potassium (66 +/- 7%) and nickel (66 +/- 7%). The soybean flour extract was submitted to fractionation by size exclusion chromatography on a Fractogel EMD Bio SEC (S) column with 0.2 mol/L Tris-HNO3 buffer pH 7.5, Sixty 2 mt fractions of effluent were collected and contents of elements were determined by ICP-MS and ICP-AES. Iron and selenium were predominantly present in fractions corresponding to molecular weight 380 kDa, while cobalt, nickel, copper, zinc and molybdenum were mostly found in low-molecular fractions (2-3 kDa). Most of phosphorus was found in the 7 kDa fraction. Sodium and potassium were present in fractions corresponding to molecular weights < 1 kDa.