Possibilities of low-power X-ray fluorescence spectrometry methods for rapid multielemental analysis and imaging of vegetal foodstuffs

In the present contribution the possibilities and drawbacks of two analytical strategies based on the use of low power X-ray fluorescence systems (EDXRF and μ-XRF) have been explored for rapid multielemental analysis and chemical imaging of different edible vegetal species. The proposed methodologies allow analysis of vegetation material without complex sample treatments providing relevant advantages in terms of simplicity and costs compared to classical destructive methods. As study cases, we have focused on the analysis of different parts of several vegetal species (Daucus carota, Spinacia oleracea, Cynara scolymus, Raphanus staivus, Coriandrum sativum) collected in agricultural soils irrigated with municipal treated wastewater samples. EDXRF and μ-EDXRF data revealed that content of some major elements such as P and S increased if crops are irrigated with municipal treated wastewater although the distribution of these elements is not depending of the type of water used for irrigation purposes. On the contrary, trace element content is not significantly higher in comparison to vegetables irrigated with fresh water, except for bromine. The findings of this contribution can contribute to expand the knowledge about the impact of the use of reclaimed wastewaters for irrigation on vegetal composition but the use of the aforementioned XRF techniques could be also extended to other food safety and nutritional studies.