Potato starch and its mixt. with chitosan (10% by mass) were extruded in a single screw lab. extruder. The extrudates were stored in Cu, Pb and Zn ion solns. for 1-10 days and then mineralized and studied for content of the metals. The addn. of chitosan to starch resulted in an increase in sorption power of starch (by 49% for Cu and only by 8% for Zn).