DIRECT DETERMINATION OF FE AND ZN IN DIFFERENT COMPONENTS OF COW MILKBY FAAS WITH A HIGH-PERFORMANCE NEBULIZER

Methods for the direct determination of iron and zinc in different com ponents of cow milk (whole milk, non fat milk and whey milk) by flame atomic absorption spectrometry (FAAS) were performed using two nebuliz ers (nebulizer of platinum with a glass impact bead and a high perform ance nebulizer). The non fat milk and the whey milk were obtained by p hysical procedures (centrifugation and ultracentrifugation) in absence of chemical treatment. A limit of detection of 0.024 and 0.007 mu g m l(-1) for iron and zinc, respectively, were obtained by using a high p erformance nebulizer. The precision obtained varied between 1.4-4.0% a nd 0.4-1.9% for iron and zinc, respectively. The accuracy of the metho ds was studied with the analysis of SRM-1549 and A-ii non fat milk ref erence materials. The methods were applied to ten cow milk samples. Da tes about the distribution of iron and zinc into the different compone nts of cow milk were present, (C) 1997 Elsevier Science B.V.