Several commercial soft drinks and respective plastic bottles were analyzed for their multielement contents employing the synchrotron radiation total reflection X-ray fluorescence spectrometry technique (SRTXRF). The SRTXRF method has been developed and validated, and about 20 elements were detected in the investigated samples, including some trace elements, which can be toxic for human beings, such as Ti, Cr, Sb, As, and Pb in soft drinks and Al, Sb, As, and Pb in poly(ethylene terephthalate) (PET) containers. Statistical analysis was performed using chemometric techniques (principal component analysis and cluster analysis), and similarities were verified in the multielement contents of the samples. The results demonstrated that the SRTXRF offers a good multielemental approach for the quality control of food products. Moreover, on the basis of enrichment factors, the possibility of the trace elements in the PET container may be leached to the beverages under normal commercial situations and other results were discussed.

Based on the energy-dispersive x-ray fluorescence (EDXRF) technique, the concentrations of elements (22 ≤ Z ≤ 30) were assessed in five kinds of commercial tea from six commercial suppliers: Matricaria chamomilla L. (camomile), Mentha piperita L. (mint), Cymbopogon citratus (DC) Stapf. (herb 'cidreira'), Malus domestica Borkh. (apple tea) and Camellia sinensis (L.) O. Kuntze (black tea). The samples were excited by an x-ray tube with an Mo anode (25 kV and 10 mA), with a Zr filter, and the characteristic x-ray were detected by an Si(Li) detector coupled to a multichannel analyzer. Using standard samples, the relationship between the detection limit and the atomic numbers of Fe, Co, Ni, Cu and Zn was determined. In some tea samples Ti was detected, but it is not an essential microelement for the plant growth. Fe, Ni and Cu were detected in all tea samples analyzed; Ti, Cr, Co and Zn were detected in Matricaria chamomilla and Malus domestica; Ti, Co and Zn in Mentha piperita and Ti, Mn, Co and Zn in Cymbopogon citratus.The inorganic constitution profile of this matrix type and the fingerprints in the production process can be evaluated by employing the EDXRF quality control of the commercial products.

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A comparative study of classical and ultrasound-assisted extractions of steroids and triterpenoids from stem, leaves and flowers of Chresta exsucca, C. scapigera and C. sphaerocephala is described. The direct analysis of crude apolar and medium-polar extracts has been conducted by high-resolution gas chromatography followed by co-injections of the crude extract with certified standards on capillary columns of different polarities. The use of ultrasound decreased significantly the total time of treatment and in addition, this extraction method was more effective for the steroids and most of the triterpenes.