Abstract Herein we report for the first time the levels of phenylpropanoids and iridoids in extracts and infusions of V. minutiflora consumed in Brazil to treat urinary and infectious disorders. An in house validation study demonstrated good accuracy and precision to determine the bioactive compounds in V. minutiflora by HPLC-DAD. Phenylpropanoids varied in the extracts (leaves 139.70 to 221.20 mg g-1, flowers 106.43 to 227.22 mg g-1, stems 42.18 to 56.48 mg g-1). Verbascoside occurred in higher concentration in extracts of leaves (87.66 – 136.16) mg g-1 and flowers (58.12 – 148.96) mg g-1 than in stems (19.24 – 24.62) mg g-1. Iridoids in extracts were as follows: leaves (46.60 − 54.79) mg g-1, flowers (55.88 − 93.87) mg g-1 and stems (40.05 to 61.74) mg g-1. High levels of iridoids (314.70 − 415.10) μg mL-1, phenylpropanoids (1996.39 − 2674.13) μg mL-1 and verbascoside (1029.38 − 1456.42 μg mL-1) in infusions support the popular consume of V. minutiflora.

The bioaccessibility of Zn during in vitro gastrointestinal digestion from yogurt was investigated. In addition, the methodologies of sample preparation (dry and wet digestion, and slurry sampling) for the determination of total concentration of Zn in yogurt by flame atomic absorption spectrometry were also compared in this work. In comparison with digestion procedures, the proposed slurry sampling is simple and less time-consuming procedure. The limit of quantification determined was 1.3 µg g-1. The concentrations of Zn in the Brazilian yogurt ranged from 3.40 to 5.62 µg g-1. The percentage of the bioaccessible fraction of Zn from the samples ranged from 10 to 26%. This corresponds to an average daily intake of less than 2% of the metal for adults and children, suggesting that the Brazilian yogurt contributes with a low amount of Zn for the human diet.

17α-methyltestosterone (17α-MT) is a hormone used in medicine and aquaculture which can be found in natural waters. It is considered an emerging organic pollutant and its accurate and precise analysis is required. Therefore, this study presents the in-house validation of a new voltammetric methodology for 17α-MT analysis in natural waters. A hanging mercury drop electrode and NaOH 5.0×10-3 mol L-1 solution as the electrolyte were employed in the voltammetric determinations. To confirm the presence of 17α-MT in water samples quantitative analysis was performed by ESI-MS/MS. The methodology exhibited good selectivity, linearity, accuracy (recovery of between 100.4 and 108.8%) and precision (RSDs for repeatability of 2.85% and for intermediate precision of 14.10%, with n = 5, respectively). LOD and LOQ were 3.07 µg L-1 and 10.78 µg L-1, respectively. The methodology was suitable for determination of 17α-MT in natural waters due to low-cost, good performance and no sample pre-treatment required.

Arsênio total, As(III), As(V) e ácido dimetilarsínico (DMA) foram determinados seletivamente em águas naturais pela técnica da geração de hidretos - espectrometria de absorção atômica, em diferentes meios de redução. Para as amostras de água de rio investigadas os resultados mostraram ser arsenato a forma arsenical predominante. Os limites de detecção encontrados para As(III) (tampão citrato), As(III) + DMA (ácido acético ) e As(III) + As(V) (ácido clorídrico) foram, respectivamente, 0.6, 1.1 e 0.5 mg As L-1. O estudo da estabilidade das formas arsenicais em amostras de águas naturais revelou serem os próprios meios reacionais convenientes para uma preservação adequada das amostras.

Total arsenic, arsenite, arsinate and dimethylarsinic acid (DMA) were selectively determined in natural waters by hydride generation - atomic absorption spectrometry, using sodium tetrahydroborate(III) as reductant but in different reduction media. River water samples from the north region of Paraná State, Brazil, were analysed and showed arsenate as the principal arsenical form. Detection limits found for As(III) (citrate buffer), As(III) + DMA (acetic acid) and As(III) + As(V) (hydrochloric acid) were 0.6, 1.1 and 0.5 mg As L-1, respectively. Sample storage on the proper reaction media revealed to be a useful way to preserve the water sample.

A fast and direct method for the determination of Cr in milk and cane sugar suspensions using graphite furnace atomic absorption spectrometry with Zeeman-effect background correction is described. No sample pre-treatment was necessary, minimizing the risk of contamination. The concentration of chromium in cane sugar was evaluated using Cr reference solutions prepared in 1% v/v HNO3 solution. The milk samples were introduced into the furnace with a mixture of amines for avoiding the autosampler blockage and foaming of milk. Chromium determination in milk was based on the standard additions method (SAM). The limit of detection and characteristic mass for cane sugar sample (30 muL) were 0,13 ng/ml and 4,3 pg, and for milk sample (10 muL) were 0,23 ng/ml and 7,8 pg, respectively. The graphite tube lifetime was 300 firings for sugar-cane sample and 100 firings for milk sample. The heating program was implemented in 68 s.