In this paper, the effect of the extraction method on the concentrations of selected elements in yerba mate (Ilex paraguariensis) infusions is presented. Seven pure yerba mate samples (without additives) were selected, representing various types and countries of origin. An extensive sample preparation procedure was proposed: ultrasound-assisted extraction using two types of extractants (deionized and tap water) at two different temperatures (room and 80 °C). In parallel, the above extractants and temperatures were carried out for all samples by the classical brewing method (without ultrasound). In addition, microwave-assisted acid mineralization was carried out to determine the total content. All the proposed procedures were thoroughly investigated with certified reference material (tea leaves, INCT–TL–1). For the total content of all the determined elements, acceptable recoveries (80–116%) were obtained. All digests and extracts were analyzed by simultaneous ICP OES. For the first time, it was assessed how tap water extraction affects the percentage of extracted element concentrations.

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In this work, a methodology for determination of As(III), As(V), dimethylarsinic acid (DMA), Fe(II) and Fe(III) in fifty-eight samples (forty-nine products of thirteen brands from three countries) commercial yerba mate (Ilex paraguariensis) was performed. The hyphenated high performance liquid chromatography inductively coupled plasma optical emission spectrometry (HPLC-ICP OES) technique was used. Arsenic was determined below the quantification limit in 38 samples of yerba mate. As(III) was found at the level 0.09 and 0.08 mg kg−1. The As(V) content was in the range: 0.21 to 0.28 mg kg−1. The content of DMA was found the highest of the three arsenic species in the range: 0.21 to 0.47 mg kg−1. The content of Fe(II) and Fe(III) was found in the range: 0.61 to 15.4 mg kg−1 and 0.66 to 43.1 mg kg−1, respectively and the dominance of Fe(III) was observed. Moreover, total and extractable content of 16 elements were determined. The results have been subjected to statistical analysis in order to establish relationships between samples of the same origin (country), kind (type) and composition (purity).

The optimization and application of a new hyphenated procedure for iron ionic speciation, i.e., high performance liquid chromatography (HPLC) with short cation–exchange column (50 mm × 4 mm) coupled to high resolution inductively coupled plasma optical emission spectrometry (ICP hrOES), is presented in this paper. Fe(III) and Fe(II) species were separated on the column with the mobile phase containing pyridine–2,6–dicarboxylic acid (PDCA). The total time of the analysis was approx. 5 min, with a significantly low eluent flow rate (0.5 mL min−1) compared to the literature. Additionally, a long cation-exchange column (250 mm × 4.0 mm) was used as reference. Depending on the total iron content in the sample, two plasma views were chosen, e.g., an attenuated axial (<2 g kg−1) and an attenuated radial. The standard addition method was performed for the method’s accuracy studies, and the applicability was presented on three types of samples: sediments, soils, and archaeological pottery. This study introduces a fast, efficient, and green method for leachable iron speciation in both geological and pottery samples.

Consumers around the world are choosing sustainable and unprocessed foods. Roe deer meat, due to the natural origin, is a source of organic and healthy meat. The selection of suitable storage conditions and times plays an important role in a deterioration of the meat's functional and nutritional values. The knowledge about oxidation processes in roe deer meat stored and packed deploying different methods is limited. The main aim of this study was therefore to investigate the effect of storage method on the physicochemical properties of musculus longissimus thoracis et lumborum (LTL), musculus biceps femoris (BF), and musculus vastus lateralis (VL) of roe deer. The muscles were stored either dry (DRY-AGED), vacuum--packed (VAC), or packed under modified atmosphere (MAP) for 21 days. The quality of roe deer meat was assessed based on chemical composition, technological properties, pH values, water activity, colour, and oxidation processes of proteins and lipids. Roe deer meat had high protein (216.5-228.6 g/kg) and low fat content (17.1-25.8 g/kg). Both DRY-AGED and VAC contributed to improving meat tenderness during storage, while the Warner-Bratzler shear force of the MAP muscles increased. The high-oxygen conditions during MAP storage strongly induced the oxidation processes; an average increase of 1,263% for thiobarbituric acid reactive substance (TBARS) level and 155% for protein carbonyl content on day 21. Vacuum packaging and dry-ageing are recommended methods for storing roe deer meat. The high oxygen atmosphere negatively affected the quality of this game species. It carries the risk of increased oxidation of proteins and lipids which may promote the formation of potentially detrimental compounds.