The preconcentration experiments were carried out with the aid of dosing pumps Tec-nopon DMC 100. Elemental analysis was performed on an EA 1110CHNS-O analyzer from CE Instruments using 2.2 mg of material.Specific surface area was determined using a Micromeritics ASAP2010 apparatus (Micromeritics Instrument Corporation) with 2.0 g of minced cassava roots husks