Application of chemometric tools for homogeneity and stability evaluation during the preparation of a powdered milk laboratory reference material for inorganic analysis
Powdered milk and its derivatives are widely consumed worldwide, which require the development of reference materials for the evaluation of analytical methodologies that are developed for the analysis of these samples. In this work, the homogeneity and stability of a powdered milk laboratory reference material candidate were evaluated using chemometric tools as an alternative to analysis of variance (ANOVA). Elements Ca, Fe, K, Mg, P, Na and Zn were quantified by inductively coupled plasma optical emission spectrometry (ICP OES) after the acid digestion procedure using microwave-assisted radiation. The results obtained through not only ANOVA, but also PCA and HCA allow us to state that the material can be considered homogeneous and stable. However, the application of the chemometric tools (PCA and HCA) allowed the extraction of more information compared to ANOVA, besides confirming the homogeneity and stability of the powdered milk laboratory reference material candidate.