The tracer packet technique is an efficient tool to evaluate simultaneously the behavior of some closely associated elements. The present study has been performed to determine the binding affinity of various toxic heavy and micronutrient elements with the proteins extracted from Erythrina variegata Linn. (Family: Leguminosae) seed by means of ‘tracer packet’ technique. Effects of buffer and pH dependence on the binding affinity of the elements of interest have also been examined.