title: Determination of ytterbium in animal faeces by tungsten coil electrothermal atomic absorption spectrometry.
abstract: A method for ytterbium determination in animal faeces by tungsten coil electrothermal atomic absorption spectrometry (TCAAS) was developed. Faeces were dry-ashed in a muffle furnace, the ashes were treated with hydrochloric acid, and 10 mul of sample solution were delivered into 150-W tungsten coil atomizer. A matrix-matching procedure employing a 66-s heating program proved to be efficient for obtaining accurate results. Characteristic mass and detection limit were 7.1 pg and 0.35 mug g(-1) Yb, respectively. The tungsten coil atomizer lifetime exceeded 300 firings with digested solutions and R.S.D. of measurements was 1.9% after ten consecutive injections of 10.0 mug l(-1) Yb. Accuracy of the proposed method was assessed by employing a graphite furnace atomic absorption spectrometric procedure. Application of the paired t-test did not reveal any significant difference for ytterbium contents determined by both methods at 95% confidence level. It was demonstrated that the proposed procedure can successfully be used for evaluation of kinetic passage rate of feed through digestive tract of animals.
authors.affiliation: Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Postal Box 96, 13400-970, Piracicaba SP, Brazil.
authors.forename: E C
authors.initials: EC
authors.lastname: Lima
authors.forename: F J
authors.initials: FJ
authors.lastname: Krug
authors.forename: J A
authors.initials: JA
authors.lastname: Nóbrega
authors.forename: A R
authors.initials: AR
authors.lastname: Nogueira