Resumen

COSTA, Letícia M. et al. Factorial design employed for microwave-assisted digestion of bean samples. Quím. Nova [online]. 2006, vol.29, n.1, pp. 149-152. ISSN 0100-4042.  http://dx.doi.org/10.1590/S0100-40422006000100026.

The use of factorial design was evaluated for optimization of focused-microwave-assisted digestion of bean samples. Calcium, Fe, Mg, Mn and Zn percentual recoveries were determined in digestates after focused-microwave-assisted digestion according to factorial design procedures. A cavity microwave digestion was carried out to certify the elemental compositions obtained. The accuracy was checked using a standard reference material, the NIST SRM 8433 - Corn Bran. Results are in agreement with certified values at the 95% confidence limit when the Student t-test was used. Volumes of nitric and sulfuric acid, temperature, and the interplay between HNO₃ and H₂SO₄ initial volumes were significant variables according to P-values in the analysis of variance (ANOVA).

Palabras llave : factorial design; bean; focused-microwave-assisted digestion.