Analysis of micronutrients and heavy metals in portuguese infant milk powders by wavelength dispersive x-ray fluorescence spectrometry (WDXRF)

Abstract

Concentrations of trace mineral nutrients such as Cu, Fe, and Zn have been analyzed by WDXRF in eight different infant milk powders, representing the majority of the milk powder brands commercialized in Portuguese pharmacies. Results suggest that the concentrations of some of elements analyzed are not consistent with the values labeled by manufacturers. However, all fall inside the concentration ranges defined by the Portuguese and European legislations, except for Al. The presence of aluminum was detected in all analyzed formulations in an average concentration of 8.25 to 19.75 mg Kg−1. This study also reveals the feasibility of WDXRF for the quantitative analysis of trace mineral nutrients in milk powder samples. Moreover, the approach described herein, using the WDXRF technique in helium mode, presents a new methodological advantage over similar published studies. This technique may represent an option for quality control of milk powder formulations, particularly at their production site.