Use of Doehlert design for optimizing the digestion of beans for multi-element determination by inductively coupled plasma optical emission spectrometry

Journal of the Brazilian Chemical Society

Wagna Piler C. Dos Santos¹  Diogenes R. Gramacho¹  Alete P. Teixeira¹  Antônio Celso S. Costa¹  Maria Das Graças A. Korn¹ 

[1] ,Universidade Federal da Bahia Instituto de Química Núcleo de Excelência em Química AnalíticaSalvador BA ,Brazil

关键词: experimental design;    essential and non-essential elements;    bean;    sample digestion;    ICP OES;    response surface methodology;    Doehlert design;   

DOI  :  10.1590/S0103-50532008000100002

来源: SciELO

【 摘 要 】

In this work, the optimization of a fast and inexpensive acid wet digestion procedure for beans was developed. Essential (Ca, Cu, Fe, K, Mg, Mn, Ni, P, Zn) and non-essential (Al, Ba, Sr) elements were determined in beans degestates by inductively coupled plasma optical emission spectrometry (ICP OES). Experimental designs for five factors (HNO3 and H2O2 volume, digestion time, block temperature and particle size) were used for optimization of the digestion procedure, adopting a factorial experiment with 2(5-1) design. The factor block temperature was found to be the most important parameter and Doehlert designs were applied in order to determine the optimum conditions. Decomposition conditions were attained using 3.5 mL of concentrated HNO3 and lasts 45 min. The accuracy of the results was demonstrated using one certified reference material (spinach leaves NIST 1570a) and comparison with recommended official method. A paired t-test showed a good agreement for all analytes at 95% confidence values.

【 授权许可】

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