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Trace elements concentrations (As, Ba, Cd, Cr, Cu, Ni, Pb, V and Zn) were found in samples of Halodule wrightii Aschers (Cymodoceaceae) seagrass from Todos os Santos Bay, Bahia, Brazil by inductively coupled plasma mass spectrometry (ICP-MS). This bay has been impacted by the presence of industrial activity that includes chemical and petrochemical plants as well as an oil refinery and harbor activities located in the north and northeastern area. Samples were collected at 4 stations to evaluate the distribution of element concentrations in this area and under different climatic conditions. The mean concentrations, in mg kg − 1 , found in dry tissues for all the studied metals and stations were: As (1.08–5.42), Ba (3.72–32.0), Cd (0.135–1.68), Cr (1.15–10.4), Cu (2.23–13.4), Ni (1.95–9.87), Pb (0.873–5.18), V (3.39–22.4) and Zn (13.1–39.5). Statistical analysis (ANOVA) of the seagrass data showed significant inter-site differences for all elements examined except nickel and vanadium. [ABSTRACT FROM AUTHOR]

Concentrations of elements (As, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sr, V, Zn) were determined in liver, kidneys and bones of Eretmochelys imbricata and Chelonia mydas specimens found stranded along the northern coast of Bahia, Brazil. Results showed that the concentrations of Cd, Cu, Ni and Zn in the liver and kidneys of juvenile C . mydas were the highest found in Brazil. We also observed a significant difference ( p < 0.05) on the bioaccumulation of trace elements between the two species: Al, Co, Mo, Na and Se in the liver; Al, Cr, Cu, K, Mo, Ni, Pb, Sr and V in the kidneys; and Al, Ba, Ca, Cd, Mn, Ni, Pb, Se, Sr and V in the bones. This study represents the first report on the distribution and concentration of trace elements in E . imbricata in the Brazilian coast. [ABSTRACT FROM AUTHOR]

Abstract: Concentrations of elements (As, Ba, Cd, Co, Cr, Cu, Li, Mn, Ni, Pb, V, and Zn) were determined in ten species of macroalgae collected from six sites in the Todos os Santos Bay, Brazil, between May and July of 2010. An optimized microwave-assisted digestion procedure was used to digest the samples. The elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). A wide range of metal concentrations were observed between the species analysed. Somewhat higher concentrations of Cd (5.99μgg−1), Co (372μgg−1), Mn (640μgg−1), Ni (17.2μgg−1) and Zn (51.4μgg−1) were found in the brown macroalgae species Padina spp., whereas elements, such as As (19.7μgg−1) and Pb (8.27μgg−1), were mainly concentrated in the species Sargassum spp. and Bostrychia montagnei, respectively. Statistical analyses (ANOVA) of the Padina data showed significant inter-site differences for all metals examined except nickel. [Copyright &y& Elsevier]

This work proposes the application of a Doehlert design to optimize dilute HNO 3 and H 2 O 2 concentrations employed for the digestion of samples of modelling clay for children (used as toy). Inductively coupled plasma-based (ICP) methods were employed to determine 22 inorganic constituents (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Sb, Se, Sr, V and Zn) in children's modelling clay samples. The limits of quantification (LoQ) obtained were between 0.003 mg kg -1 (Cd, Co and Sb) and 0.54 g kg -1 (Ca) employing ICP-based methods. The accuracy and precision of the methods were evaluated by analysing the certified reference materials (CRMs) oyster tissue (NIST 1566b), rice flour (NIST 1568b), peach leaves (NIST 1547) and tomato leaves (NIST 1573a), along with addition and recovery tests. The children's modelling clay samples presented concentrations of As, Ba, Cd, Cr, Pb, Sb and Se in agreement with the maximum values established by National Institute of Metrology, Quality and Technology ( Instituto Nacional de Metrologia, Qualidade e Tecnologia - INMETRO). However, for other elements it were obtained concentrations within the following ranges: Al (0.83 ± 0.12–2.91 ± 0.04 g kg −1 ), Ca (16.09 ± 0.20–24.56 ± 1.00 g kg −1 ), Cu (< 0.30–30.01 ± 2.11 mg kg −1 ), Fe (< 5.3 - 13.21 ± 3.94 mg kg −1 ), K (1.31 ± 0.33–33.47 ± 0.75 g kg −1 ), Mg (0.90 ± 0.04–1.36 ± 0.05 g kg −1 ), Mn (3.32 ± 0.10–121.05 ± 1.88 mg kg −1 ), Na (12.07 ± 0.88–36.77 ± 0.50 g kg −1 ), Sr (4.23 ± 0.47–22.43 ± 6.95 mg kg −1 ), P (1.00 ± 0.13–57.43 ± 0.88 g kg −1 ), V (0.25 ± 0.07–1.15 ± 0.19 mg kg −1 ), S (3.57 ± 0.77–48.49 ± 1.02 g kg −1 ), Zn (< 4.4–11.82 ± 0.49 mg kg −1 ), Co (0.020 ± 0.002–0.060 ± 0.020 mg kg −1 ) and Ni (< 0.03–1.33 ± 0.46 mg kg −1 ). These elements have no minimum and maximum limits established by legislation for children's modelling clay so, a comparison was not possible. The ICP-based methods presented an efficient routine application in the analysis of modelling clay. [ABSTRACT FROM AUTHOR]

Highlights • Concentrations of Cd and Pb were determined in coconut water and coconut milk samples by HR-CS GF AAS. • Sample preparation procedures using dilute acid and an ultrasonic bath are simple and rapid. • Concentrations of Cd and Pb obtained in all samples were above the legal limit recommended by ANVISA. Abstract In this work, an analytical method for the determination of Cd and Pb in natural coconut water samples, industrialized coconut water samples and coconut milk using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS), after minimum treatment of the sample was developed. The analytical method was applied to 46 samples collected in Salvador, Bahia (Brazil). The ranges of concentrations obtained were: 0.42–18.72 μg L−1 Cd and <0.70–36.32 μg L−1 Pb for natural coconut water samples (n = 14); <0.06–1.49 μg L−1 Cd and 6.57–29.02 μg L−1 Pb for industrialized water coconut samples (n = 16); and <0.10–5.93 ng g−1 Cd and <0.85–22.41 ng g−1 Pb for coconut milk samples (n = 16). For all samples, Cd and Pb concentrations were below the maximum tolerated values recommended by Brazilian Health Surveillance Agency (Agência Nacional de Vigilância Sanitária, ANVISA). [ABSTRACT FROM AUTHOR]

Highlights: [•] Factorial and Doehlert designs for ultrasound-assisted extraction optimisation. [•] The sample preparation is rapid, easy, inexpensive and reproducible. [•] Information about micronutrient concentrations in coconut milk samples is provided. [Copyright &y& Elsevier]

Abstract: A plasticised PVC membrane containing pyrochatecol violet as complexing reagent has been used to extract and pre-concentrate Cu2+ ions from aqueous solution, aiming at their determination by Laser Induced Breakdown Spectroscopy. The membrane was prepared from a THF cocktail solution on a cellulose acetate support by the dip-coating technique, providing a homogeneous distribution of the complexing reagent and a thickness of 3μm. The extraction was straightforwardly performed by immersing the membrane in the Cu2+ sample solution buffered at pH 6.0 with sodium acetate. The extraction time defined the working analytical range (from μgL−1 to mgL−1) and a 50-min extraction provided a detection limit of 15μgL−1 for Cu2+ ions. The membrane is stable for at least 2months when stored in a desiccator, allowing in-field extractions, that avoid sampling, storage and transport of the aqueous sample to the laboratory. [Copyright &y& Elsevier]

Abstract: The aim of this work was to evaluate the microemulsification as sample preparation procedure for determination of Cu, Fe, Ni and Zn in vegetable oils samples by High-Resolution Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS). Microemulsions were prepared by mixing samples with propan-1-ol and aqueous acid solution, which allowed the use of inorganic aqueous standards for the calibration. To a sample mass of 0.5g, 100μL of hydrochloric acid and propan-1-ol were added and the resulting mixture diluted to a final volume of 10mL. The sample was manually shaken resulting in a visually homogeneous system. The main lines were selected for all studied metals and the detection limits (3σ, n =10) were 0.12, 0.62, 0.58 and 0.12mgkg−1 for Cu, Fe, Ni and Zn, respectively. The relative standard deviation (RSD) ranged from 5% to 11 % in samples spiked with 0.25 and 1.5μgmL−1 of each metal, respectively. Recoveries varied from 89% to 102%. The proposed method was applied to the determination of Cu, Fe, Ni and Zn in soybean, olive and sunflower oils. [Copyright &y& Elsevier]

Abstract: The efficiency of diluted nitric acid solutions for digesting regular coffee samples was evaluated employing two closed vessel procedures: one was based on microwave-assisted heating and the other was based on conductive heating using pressurized Parr bomb. The efficiency of digestion was evaluated by determining residual carbon content (RCC) and residual acidity. The digestion was effective using both procedures, i.e. there were no solid residues after the decomposition reactions when using up to 3.5molL−1 nitric acid solutions. It was demonstrated that the digestion procedures are critically dependent on reactions occurring in liquid and gas phase and that the formation of NO and its conversion to NO2 by O2 exerts a major effect in the oxidation of organic matter. These processes are more effective in closed vessels heated by microwave radiation due to the greater volume of these flasks and the temperature gradient that exists during the first step of the digestion process. The proposed model for the digestion processes in diluted nitric acid solution is corroborated by data about consumption of acid during the digestion and by measuring the pressure during the whole process. [Copyright &y& Elsevier]

Abstract: Biological samples can be acid-digested using open or closed reaction vessels. Each one has advantages and limitations related to sample mass, contamination, operational temperature range, and losses of analytes. The latter may be critical when working with thermolabile chemical compounds. In the present work, focused-microwave and cavity-microwave ovens were employed for acid digestion of marine invertebrate samples (oyster, mussel and clam). The aim of this study was to evaluate losses of volatile species containing As, Cd, Pb, Se, and Zn, in both microwave systems, after an acid digestion procedure using nitric and sulfuric concentrated acids. The elemental determinations were performed by inductively coupled plasma optical emission spectrometry (ICP OES) with axially viewed configuration. Using a focused-oven, losses of volatile elements were always higher than 12%, when compared to cavity-microwave oven. High losses were observed for Pb and Cd, while Zn was not affected by volatilization in marine invertebrate samples. Standard reference material (Oyster tissue, NIST SRM 1566b) was used to check the accuracy. [Copyright &y& Elsevier]

Honey is a food of nutritional, medicinal and commercial importance. The physicochemical characteristics, pollen spectrum and mineral composition of eighteen honey samples obtained from regions (Cachoeira, Coqueiros, Maragojipe and Santiago do Iguape) near the Paraguaçu River, Bahia, Brazil were evaluated. Botanical families Asteraceae, Leguminosae, Malvaceae, Myrtaceae and Palmae were most frequently found. Five samples had water contents above the maximum limit established by the Brazilian legislation (> 20%). The mineral composition was determined by ICP OES, after microwave digestion. Ca, K, Mg and Na were measured (mg Kg-1) in the range from: 18.85 to 79.61; 366.74 to 1214.98; 12.46 to 44.59 and 11.56 to 85.39, respectively. Cu, Fe, Mn and Zn had variable concentration ranges, between 0.05 and 6.13 mg Kg-1. Al, Ba, Cd, Co, Cr, Ni, Pb, Se and V showed values below the LOD. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) demonstrated that there are no similarities of mineral composition among honey samples.