Authors: Flávia Regina de Amorim Milton Batista Franco Clésia Cristina Nascentes José Bento Borba da Silva
Publish Date: 2010/03/12
Volume: 4, Issue: 1, Pages: 41-48
Abstract
A fast and efficient method to determine molybdenum Mo in milk and other infant food by atomic absorption spectrometry with electrothermal atomization employing slurry sampling was developed Slurries were prepared in ultrapure water with 5 to 20 min of sonication in concentrations of 10 w/v The injection of 50 µL of a 01 v/v cetyl trimethyl ammonium chloride solution before the temperature program reduced the effect of buildup of carbonaceous residues within the atomizer Europium chemical modifier and niobium permanent modifier were chosen for use from several potential modifiers The parameters of merit were obtained in the optimized conditions T a = 2700 ºC T p = 2000 ºC tp = 20 s and Eu 50 μg + permanent Nb 5000 μg These parameters were linear working range up to 1000 μg/L limit of detection 11 ± 01 μg/L aqueous calibration and standard addition curves with r 2 09900 and relative standard deviation of 06 to 87 The accuracy was evaluated by recovery tests and by certified material analysis the agreement among these numbers validated the method The powdered sample concentrations were between 39 and 1570 µg/kgThe authors are grateful for the financial support of the Conselho Nacional de Pesquisa e Desenvolvimento CNPq and Fundação de Amparo à Pesquisa do Estado de Minas Gerais FAPEMIG and for the technical support of the Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN
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