Utilização de planejamento fatorial no preparo de amostras de detergente em pó para a determinação de fósforo por análise em fluxo

Abstract

Prof. Luiz Freire, s/n, 50740-550 Recife-PE, Brasil Recebido em 31/8/09; aceito em 7/1/10; publicado na web em 23/4/10 EVALUATION OF SAMPLE PREPARATION OF THE DETERGENT POWDER USING FACTORIAL DESIGN. The decomposition of detergent powder samples in a microwave oven and autoclave was evaluated. To establish the best experimental conditions a 2 5 factorial design was performed, varying the conditions in autoclave and microwave digestion and flow system parameters for the determination of phosphorus. The best composition was: 0.2 mL sulfuric acid; 500 W power and a 2 min time interval; 6 mmol L-1 of ascorbic acid and 16 mmol L-1 of molybdate to flow system. This factor levels use less reagents than the reference method. No statistically significant differences were found between the autoclave and microwave oven responses at the 95% confidence level.