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An analytical method for determination of inorganic arsenic species in retorted oil shale slurry by atomic absorption spectrometry coupled to hydride technique with ultrasound assisted acidic extraction is reported. Trivalent arsenic measurement employed sample stabilization with a pH 4.5 prior to reaction with the reducing agent and analysis. In contrast, total inorganic As depended upon the pre-reduction of As(V) to As(III) with KI and ascorbic acid in 6.0 M HCl and of As(V) was estimated by the difference of the total inorganic As and As(III) concentrations. The limit of quantification was 3.7 mg kg−1 for As(III) and 1.3 mg kg−1 for itAs. [ABSTRACT FROM AUTHOR]

Plastics in the ocean create the "plastisphere", a diverse habitat hosting various life forms. Other than the pollution induced by plastics, the co-occurrence of primary producers, symbiotic organisms, decomposers, and pathogens within the plastisphere raises questions about how they influence the dynamics of marine ecosystems. Here, we used a shotgun DNA-sequencing approach to describe the species thriving on floating plastics collected in two Mediterranean sites. Our findings revealed many species of bacteria, eukaryotes, viruses, and archaea on each plastic. Proteobacteria was dominant (70% of reads in the entire dataset), with other groups such as Ascomycota fungi (11%) and Bacteroidetes (9%) also being represented. The community structure was not affected by the polymeric composition or the plastic shape. Notably, pathogenic Vibrio species, including V. campbelli, V. alginolyticus, and V. coralliilyticus, were among the most abundant species. Viruses, despite showing lower relative abundances, occurred in all samples, especially Herpesvirales, Caudovirales, and Poxviridae groups. A significant finding was the presence of the White Spot Syndrome virus (WSSV). This pathogen, responsible for devastating outbreaks in aquaculture systems, had not been previously reported in the marine plastisphere. Our study emphasizes the need for further investigation into the ecological and economic impacts of plastisphere organisms in the ocean. [ABSTRACT FROM AUTHOR]

Synthesis of bis-arylsulfenyl-benzo-2,1,3-thiadiazoles was accomplished using a Pd-G3 XantPhos as a simple and inexpensive catalyst. Numerous benzene thiols reacted well with 4,7-dibromo-benzo-2,1,3-thiadiazole in DMF, using K2 CO3 as the base, obtaining high product yields in a short reaction time. All the synthesized compounds showed remarkable fluorescence properties with emission wavelengths in the visible range. Due to their unique properties, these compounds have potential for application as image probes in fluorescence microscopy. The study found that these compounds have a wide range of potential uses in the area of sensors, as well as displaying other useful photophysical properties. [ABSTRACT FROM AUTHOR]

Ceramics manufactured in Brazil and in other countries were analyzed by laser induced breakdown spectroscopy (LIBS). The LIBS spectra were employed to identify the origin of the tableware as produced in Brazil or abroad using soft independent modeling of class analogy (SIMCA) and linear discriminant analysis (LDA). Three sets of spectral variables were evaluated aiming at discrimination of the ceramics: the entire LIBS spectrum, a set of selected spectral ranges, and the maximum of emission intensity of the elements Al, Ca, Mg, Si, Na and Ti. The results for the three sets of variables show good performance, achieving correct classification from 88.6 to 94.3%, and 86.7 to 100% for the external training and test, respectively. [ABSTRACT FROM AUTHOR]

This work presents a study involving the determination of Cd, Cr and Pb in ceramic tableware by graphite furnace atomic absorption spectrometry (GF AAS) using a simple and practical slurry sampling method. A central composite design (CCD) was used to optimize the slurry sampling conditions. The obtained results were confronted by the ultrasonic acid decomposition, evaluating the instrumental parameters relevant to the accuracy and precision. In addition, recovery measurements of the analytes were performed and ranged between 90% and 111% for both methods. The concentrations obtained were in the range from 0.04 to 184; 67 to 1395 and 42 to 5305 μg g−1 for Cd, Cr and Pb, respectively. These concentrations were higher for some ceramic samples, which may be related to the raw material used for their manufacture and also due to the pigment used during the decoration process. In addition, the leaching study observed concentrations in the range from 0.07 to 1.68; 0.1 to 5.0 and 0.6 to 46.3 μg g-1 for Cd, Cr and Pb, respectively, and there is a possibility of migration of these toxic metals from the ceramic materials to the food. [ABSTRACT FROM AUTHOR]