AVALIA O DE QUATRO TIPOS DE ABERTURAS DE AMOSTRAS NA DETERMINA O DE CROMO, COBRE E ZINCO EM áGUAS RESIDUáRIAS

Studies that verified the level of certain chemical elements in various samples are very common in laboratory analysis of environmental quality, food pharmaceutical, among others. In general, the samples require a previous prepared, often difficult and prolonged, varying with the type of the sample and the concentration of each element analyzed. In this case, the preparation is called digestion of samples, and the openings by dry nitro-percloric and by mixing wet are the most common. This study aimed to examine the effectiveness of four sample digestion techniques, including among classical methods, a technique that uses the microwave oven for detect the presence and concentration of the elements chrome, copper and zinc in different samples of wastewaters. The wastewaters consisted of sewage sludge, pig manure and wastewater from starch. The results showed that microwave technique is more efficient to detect concentrations of these elements in the samples, characterized as a practical procedure.