Abstract: A flow injection hydride generation graphite furnace atomic absorption spectrometric (FI-HG-GFAAS) method was applied to the determination of Se in Se-doped and undoped cereals and bakery products. For the purpose of doping, the soils used for the cultivation of the cereals were dosed with Se- doped foliar fertilizers. The samples were dissolved in a mixture of HNO(3) and H(2)O(2) solutions using micro-waveassisted digestion. The decomposition of H(2)Se generated from the sample solutions and the trapping of elemental Se were performed at a temperature of 300 degrees C on an Ir-pretreated integrated graphite platform of a transversally heated graphite atomizer(THGA). For release of the trapped Se within a fairly short atomization time (5s), an atomization temperature of 2200 degrees C was observed to be optimal. The overall efficiency of hydride generation, transport and trapping was similar to 86%. The upper limit of the linear dynamic range of calibration was 10 mu gL(-1), which corresponds to 0.5 mu g g(-1) for solid samples. Recovery of the samples spiked with Se(VI) solutions was found to be 93 +/- 6% on average. The relative standard deviation of the determinations was less than 8%. The limit of detection was found to be 0.06 mu gL(-1), corresponding to 3 ng g(-1) for solid samples. The accuracy of the method was verified with the use of IAEA-155 ( whey powder) certified reference material. End-capped THGA tubes resulted in an extension of the linear calibration range compared to that of standard THGAs. The Se content in bakery products made of undoped cereals ranged from 7.7 to 68 ng g(-1) ( wet weight) in 18 samples, whereas the Se content of the corresponding cereals was found to be below 100 ng g(-1) ( wet weight). The Se level of cereals grown on soils treated with Se- doped fertilizers ranged from 128 to 1046 ng g(-1) ( wet weight), and it depended linearly on the Se concentration of the corresponding foliar fertilizer.

Abstract: Differential-pulse stripping voltammetry is applied to measure zinc, cadmium, lead and copper by anodic stripping and selenium(IV) by cathodic stripping in rain water at pH 2; subsequently, at pH 9,1, manganese is measured by anodic stripping on the same portion, and cobalt and nickel are measured in the adsorptive mode after formation of their dimethylglyoximates. The instrumental parameters are optimized. The linear ranges, mutual interferences and detection limits are studied. Excellent accuracy is demonstrated; the standard deviation is around 15% at 2.550 μg l−1 levels. The method is shown to be applicable for rain water.

Abstract: Magnetic state of Fe-57 implanted and doped ZnO samples have been reported and studied by Mossbauer spectroscopy at different temperatures. The Mossbauer spectra mainly showed four doublets and three sextets, but some ambiguous identification remains regarding the probe site location and influence of defects in the hyperfine and magnetic parameters. In the present work some possible implantation configurations are suggested and evaluated using Monte Carlo simulation and electronic structure calculations within the density functional theory. Various implantation environments were proposed and studied considering the presence of defects. The obtained Fe-57 hyperfine parameters show a good agreement with the reported experimental values for some of these configurations. The possibility of Fe pair formation, as well as a Zn site vacancy stabilization between he second and third neighborhood of the implantation site, is supported. (C) 2014 Elsevier Ltd. All rights reserved.

Abstract: The direct reagentless electrochemical detection of recombinant firefly luciferase binding with a gold electrode modified with nickel complex of 1,16-di[4-(2,6-dihydroxycarbonyl)pyridyl]-1,16-dioxa-8,9-dithiahexadecane has been carried out.

Abstract: In November 1984 in Makasar and the Flores Basin water samples were collected (T, S, dissolved O2, total CO2), bottom samples (sediment composition) and suspended matter (particle composition, particle size). A sediment trap was moored in the Flores Basin at 4600 m depth for nearly four months, covering the dry season. In the Flores Basin there are indications for bottom flow resuspending bottom material or preventing suspended material from settling; in Makasar Strait there is probably inflow of deep water both from the south and from the north, resulting in a very slow bottom water flor. Bottom deposits in Makasar Strait and the Flores Basin are predominantly terrigenous, with an admixture of organic carbonate and silica (mostly coccoliths). Volcanic material is primarily present near to the volcanoes in the south and reaches the deeper basins by slumping. In the suspended matter no volcanic particles and little planktonic material were found, although the latter form 10 to 15% of the top sediment and of the material deposited in the sediment trap. In suspension particles with a large concentration of tin (Sn) were found associated mainly with iron. They probably come from northern Kalimantan or northern Sulawesi. Suspended matter concentrations were mainly less than 0.5 mg·dm−3, only off the Mahakam river mouth were concentrations higher than 1 mg·dm−3. Particle size was erratic because of the variable composition of the coarser particles in suspension. Organic matter concentrations in suspension (in mg·dm−3) roughly follow the distribution of total suspended matter but organic content (in %) of the suspended matter does not show any trends. All organic matter in suspension is of marine origin except in the Mahakam river and estuary. Deposition rates, as estimated from the sediment trap results, are 150 mg·cm−2·a−1 for the total sediment, 26 mg·cm−2·a−1 for carbonate and 13 mg·cm−2·a−1 for organic matter. Flocs and fibres in suspension were only found in and below the Mahakam river plume that reaches ca 400 km from the river mouth to the southeast, and in surface waters associated with plankton (diatoms). The formation of these flocs (broken-up macroflocs or marine snow) is primarily related to particle concentration, turbulence, and the presence of organisms that produce sticky material or glue particles together.

Abstract: The alkaline aluminate waste, of which 10002000 tonnes are dumped a few times a year off the Belgian coast in the Southern Bight of the North Sea, contains 5·4% NaCl, 1·8% dissolved Al and 7·4% NaOH, in addition to traces of heavy metals and some aniline- and phenol-derivatives. The pH rises locally to 8-5 and the total Al-concentration reaches 120niglitre−1(corresponding to an initial waste dilution factor of only 150) in the 10-m wide track just beyond the discharging barge, but these decay quickly to pH 8·1 and 1 mg litre-1 in the 30-m wide track, 500m behind the barge. The relation between the waste concentration and seawater pH was studied. The white precipitate that forms immediately in the sea was identified as Mg6Al2CO3(OH)164H20 (hydrotalcite-manasseite like). No trace of it was found in the local sediments.

Abstract: The spatial distribution and temporal concentration variation of a set of gaseous air components (e.g., CO2, CO, H2CO, H2O) have been monitored with a multi-channel photoacoustic gas-analyzer in an urban church ( Saint Catherine's, Cracow) and a mountain church ( Saint Michaels Archangel, Szalowa) of Poland, in order to assess the likely effects of air pollution indoors under the influence of provisory electrical infrared (IR) heaters and without heating. Likewise, the ventilation characteristic and the leakage of these buildings with different constructions (i.e., plastered stone and wooden structures) with the assistance of decay curves of SF6 tracer gas was evaluated and compared. The wooden building in Szalowa, due to its more open structure, developed about one order higher ventilation rates (e.g., 0.9-1.3 h(-1)) than the stone church in Cracow (e.g., 0.1 h(-1)). The IR-heating affected only modestly the ventilation rate of the wooden church (e.g., 1.2-1.6 h(-1)), but it increased significantly that of the plastered stone church (e.g., 0.27 h(-1)). The ventilation rates were also assessed with the use of the CO2 curve decay method, and satisfactory agreement was found with those observed by the use of SF6 tracer. The spatial distribution of the studied gaseous pollutants (CO2, H2O) was found to be in some occasions nonhomogeneous in both buildings, due to the active usage of the IR-heating, especially, during a couple of consecutive liturgical services. Besides the pollution events due to ingress of gaseous air pollutants, present at enhanced levels outdoors, increased CO, CO2 and H2CO peaks were observed indoors too, which, in most cases, could be associated with incense burning. (C) 2018 Elsevier Masson SAS. All rights reserved.

Abstract: A first-principles study of the electric field gradient (EFG) calculated for ideal and In-111(Cd-111) implanted ZnO samples is reported in the present work. The study was made for ZnO ideal hexagonal structures and supercells were introduced in order to consider the possible implantation environments. The calculation was done using the “WIEN2k” code within the density functional theory, the exchange and correlation effects were determined by the GGA approximation. Three possible In-111(Cd-111) implantation configurations were studied, one substitutional incorporation at cation site and two interstitials. The obtained EFG values for the ideal structure and the substitutional site are in good agreement with the experimental reports measured by perturbed angular correlation (PAC) and high precision nuclear magnetic resonance (NMR). Thus, the ascription of substitutional incorporation of In-111(Cd-111) probe atom at the ZnO cation site after annealing was confirmed. (C) 2011 Elsevier Ltd. All rights reserved.

Abstract: Tetra-tert-butylphthalocyanine aluminum (III) chloride was studied by voltammetric and potential-resolved spectroelectrochemical methods in a non-coordinating solvent o-dichlorobenzene. Five redox transitions were found including two oxidation waves at 0.18 and 0.90 V and three reduction waves at −1.28, −1.65, and −2.63 V vs. Fc+/Fc. Electrochemical reversibility of the first oxidation and reduction processes was assessed by using the diagnostic criteria of cyclic voltammetry. First comprehensive spectroelectrochemical characterization of oxidation of the aluminum phthalocyanine is reported. Moreover, potential-resolved spectroelectrochemical titration revealed strong influence of aggregation on the UV–vis spectra and the half-wave potentials of the first oxidation transition and disclosed the presence of the partially oxidized complex in the initial solution, which noticeably affected the spectrum of the neutral form.