RESUMO
On page 168, the left column, line 26 to 29, the sentence,Working standard solutions (1, 5, 7.5, and 10 ng mL(-1)) were prepared from the iodine stock solution by dilution with 7.0% (v v(-1)) nitric acid, 5.0% (v v(-1)) acetic acid and 1.2% (v v(-1)) hydrogen peroxide.should readWorking standard solutions (1, 5, 7.5, and 10 ng mL(-1)) were prepared from the iodine stock solution by dilution with 7.0% (v v(-1)) nitric acid and 5.0% (v v(-1)) acetic acid.
RESUMO
A method for quantifying iodine in infant formula is described. Nitric acid and hydrogen peroxide converted iodine into iodate in microwave-assisted digestion and prevented iodine volatilization and memory effects. Acetic acid as a carbon source was added to both the sample and standard solutions as a countermeasure against carbon charge transfer to iodine and the addition of acetic acid helped to enhance the sensitivity. The instrument limit of quantification was 0.1 ng mL(-1) and the relative standard deviation was less than 3%. The spike recoveries were between 94.8 and 106%. Good agreement with the values obtained using the tetramethylammonium hydroxide method was obtained for infant formula sold in several countries. This method permitted the simultaneous determination of iodine and 12 other important elements (Na, Mg, P, K, Ca, Cr, Mn, Fe, Cu, Zn, Se and Mo) in infant formula.
