An analytical method for multi-elementary determination in powder refreshment, based on sample digestion using dilute mineral acids and detection by inductively plasma coupled optical emission spectrometry (ICP OES) is proposed. Chemometric tools, such as fractional factorial design and principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to optimize the sample preparation conditions in closed block digester, and Doehlert design for spectrometer operation. Addition and recovery tests and analyses of certified reference material were performed to evaluate the precision and accuracy, and the results confirm the reliability of the proposed method. Limits of quantification (LOQ) between 0.02 and 36 µg g−1 were obtained. The analytical method was applied for determination of 24 inorganic constituents in 20 powder refreshment samples. Calcium, K, Mg, Na, P, S and Ti presented the highest concentrations. The analytical method was adequate for the determinations of inorganic constituents in powder refreshment samples by ICP OES.

The concentrations of trace metals Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Zn and V were measured in gills, muscle and hepatopancreas of G. cruentata caught from South of Bahia in order to assess the potential health risk by the consumption of mangrove crabs. The highest metal concentrations in gills, and hepatopancreas were Cu, and Zn in muscles, while the lowest metal concentration in three tissues was Cd and Mo. With the results, it is possible to suggest that the high concentrations of some elements, especially of the Cu, may present risks to the Aratu consumers of the mangrove areas studied, or to other populations where these animals may be transported, same for other cities. The mean concentration of Pb in gills in Una and Jequitinhonha is above the value allowed by the legislation, 3,08 μg g-1 and 3,49 μg g-1, respectively. The concentration of Mn in the females in the three estuaries studied was 1.5 to 4.2 times higher than in the males. In general, detected mean metal concentrations in crab tissues were (in decreasing order) gills > hepatopancreas > muscles. Through the PCA analysis, differentiation between the tissues studied was observed due to its elemental composition. The target hazard quotient (QR) of all trace metals in muscle was less than 1.0 of the provisional tolerable daily intake (IDE) adopted by the USEPA. These results imply that G. cruentata caught from South of Bahia do not have an adverse impact on the consumer health.

Assessment of phosphorus in fruit juices is of great interest due to its essentiality and nutritional properties. This study applied sample treatment strategies to determine phosphorus in fractions of juices. Firstly, total phosphorus (Ptotal) was determined from digestion and sample suspension exploring direct analysis by inductively coupled plasma optical emission spectrometry, which presented no significant difference, for 95% of confidence level. Then, free phosphorus (Pfree) was determined by spectrophotometry and represented 30-90% of Ptotal with an inverse relationship respecting Ptotal concentration. Fractioning according to particle size evidenced highest fraction of Pfree in samples after filtration. Fractioning of phosphorus based on its charge was also performed and the high percentages of P in the anionic fraction (from 91.2 to 95.9%) are related to free inorganic phosphate in equilibrium with its protonated forms. Thus, it is more assailable after consumption, giving this food great functionality on human diet.

A cloud-point extraction (CPE) method using the surfactant (30)p-tert-octylphenol polyoxyethylene (OPEO30) was proposed as the preceding step for the determination of polycyclic aromatic hydrocarbons (PAHs) by gas chromatography-mass spectrometry (GC-MS). Given the need for surfactant derivatization before the chromatographic analysis, the reaction conditions of coacervate derivatization were studied. The extraction process was also optimized, where surfactant concentration, temperature and time were analyzed as variables. The limits of detection obtained were between 0.02 and 0.05 µg L-1, and the recoveries of analytes were between 70 and 98%, with coefficient of variation better than 10.3%. The analytical method developed provides an efficient, precise and accurate method for the determination of the 16 priority PAHs, generating results in accordance with the USEPA 3510C method. The method was applied to the analysis of groundwater samples collected from artesian wells located at retail fuel stations.