ÉDER C. LIMA, FRANCISCO J. KRUG, JOAQUIM A. NÓBREGA and ELISABETE A. N. FERNANDES
A procedure for ytterbium determination in digesta and faeces of animals by ETAAS with a transversally heated graphite atomizer and Zeeman-effect background correction is described. Up to 2500 mg l-1 of Na, K, P or Si, 1000 mg l-1 of Ca or Mg and 500 mg l-1 of Fe, Cu, Al, Zn or Mn did not interfere significantly with the atomization of 10.0 µg l-1 Yb. The characteristic mass was 3.0 pg and a detection limit of 0.15 µg l-1 for a 20 µl sample volume was calculated. Digesta and faeces were dry-ashed in a muffle furnace and the resulting ash was treated with hydrochloric acid. Application of the t-test to the results obtained by the proposed procedure and by instrumental neutron activation analysis demonstrated that there was no significant difference at the 5% probability level.