What to Expect for the New Year?

In this work, an analytical method for determination of Ba, Cu, Ni, V, and Zn, in medicinal herbs, through direct solid sample analysis by energy dispersive X-ray fluorescence spectrometry (EDXRF), was applied. Accuracy and precision (intra and inter day) of the analytical method were confirmed through analysis of certified reference material, tomato leaves (CRM NIST 1573a). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) allowed to observe the formation of two groups. Group I was composed by highest levels of Cu and Zn, and the group II with highest concentrations o...