Browsing by Author "Idrovo Gallegos, Marcela Margarita"

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    Evaluación de la extracción de plomo y cadmio de vajilla cerámica vidriada
    (Universidad de Cuenca, 2016-06) Flores Zamora, Marittza Eleanor; Idrovo Gallegos, Marcela Margarita; Flores Zamora, Damián Vicente
    This article assesses if a single extraction, by applying a standardized test method, which simulates extreme conditions of use, determines the total content of lead and cadmium in ceramic ware pieces that come into contact with food, and their implication in the analytical result. The test method was applied several times on ceramic reference materials with different initial concentrations of lead and cadmium as to quantify the successive liberation of both metals. The leachate at each application was analyzed by atomic absorption. Results showed that a single application of the test method does not extract all of the lead and cadmium in glazed tableware pottery. Subsequent liberations for all tested ceramic pieces with different initial concentration were noticed. For cadmium the following variation in extractions were recorded: 40 to 95% in the first extraction, 0 to 28% in the second, 0.2 to 21% in the third, and 1 to 40% in the fourth leachate test. For lead, the subsequent values were recorded: a leachate varying between 50 and 93% in the first test, between 2 and 24% in the second, between 2 and 18% in the third and between 2 and 17% in the fourth extraction. The results reveal that the total amount of lead and cadmium released in a single standard test do not reflect the total content of lead and cadmium that ceramic pieces after long-term use liberate.
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    Obtención de pectinasas microbianas a partir de residuos de fruta
    (2004-11-11) Gutierrez Jara, Silvia R.; Idrovo Gallegos, Marcela Margarita; García Alvear, Nancy Beatriz