HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY COUPLED WITH ARRAY INDUCTIVELY-COUPLED PLASMA OPTICAL-EMISSION SPECTROMETRY FOR THE SEPARATION AND SIMULTANEOUS DETECTION OF METAL AND NONMETAL SPECIES IN SOYBEAN FLOUR

Biological samples (soybean flour extracts) were subjected to a separa tion/detection process using size-exclusion chromatography (SEC) coupl ed with ICP-OES with the aim of obtaining information about possible b inding forms of selected trace metals, An array ICP-OES instrument wit h a segmented charge coupled device detector was used which simultaneo usly monitors element emission lines and the spectral background, In a ddition to the trace metals, the non-metals P and S were included to o btain further information about the binding sites of the trace metals in the matrix, Two SEC columns with different packing materials couple d with ICP-OES were compared in terms of performance and influence on native species composition, Recoveries of the eluting metals were eval uated by a post-column injection technique, In the soybean flour extra ct, Cu and Zn were predominantly present in the 10-16 kDa fraction, Tw o Mn and P signals were located in the 17-31 kDa range, S was eluted w ith the exclusion volume of both SEC columns (100 and 70 kDa, respecti vely) as well as in the 20 kDa range, The effects of chromatographic t echnique and column type on recoveries and species composition are dis cussed.