المصدر: حل هذه المسالة في منتدى : قسم الكيمياء To a sample of a protein hyrolysate , an analyst added 1.00 mg of tryptophan ,which was labeled with C14 and exhibited a counting rate of 584 cpm above background .After this labeled compound was thoroughly mixed was passed through an ion –exhange column .The fraction of effluent containing only tryptophan was collected and from it an 18.0 mg sample of pure tryptophan was isolated .The isolated sample had a countring rate of 204cpm in the counter .What was the weigh of tryptophan in original sample ?
