Determination of concentrations of sulfur compounds in different petroleum samples is a true analytical challenge. Only analytical procedures based on gas chromatography can meet the sensitivity and accuracy requirements dictated by up-to-date petroleum industry. The objective of this work is to develop the method for the quantifying of sulfur compounds in petroleum hydrocarbon streams. The opt...

A novel method combining elemental sulfur and selenium was developed, yielding crystalline sulfur-selenium compounds. The compounds were melted, and an organic comonomer added. Once the organic comonomer was consumed, the viscous compound was vitrified and allowed to cool yielding organic-inorganic hybrid polymers that are termed Organically Modified Chalcogenide (ORMOCHALC) polymers.

Four new sulfur-containing compounds, named clinamides A-C (1-3), and 2-cis-entadamide A (4), were isolated together with three known compounds from the bioactive ethanol extract of the aerial parts of Clinacanthus nutans. These secondary metabolites possess sulfur atoms and acrylamide functionalities. The structures of the isolated components were established by interpretation of their spectro...

Quantitative analysis by high-pressure liquid chromatography shows that all commercial samples of elemental sulfur besides S8 contain traces of S7 (up to 0.56%) and in some cases also S6, S9, and polymeric sulfur (S«,). Pure S8 can be obtained by recrystallization from CS2. Elemental sulfur minerals also quite often contain traces of S7 (up to 0.3%). Since neither irradiation by daylight at 20 ...

Respiratory ammonification of nitrate is the microbial process that determines the retention of nitrogen in an ecosystem. To date, sulfur-dependent dissimilatory nitrate reduction to ammonium has been demonstrated only with sulfide as an electron donor. We detected a novel pathway that couples the sulfur and nitrogen cycles. Thermophilic anaerobic bacteria Thermosulfurimonas dismutans and Dissu...

Pd(I) and Ni(II) complex compounds: [Pd(AMMT)2]Cl2 (1), [Pd(AMMT)4]Cl2 (2) and [Ni(AMMT)2(H2O)](NO3)2 (3) with 4-amino-3-mercapto-5-methyl-1,2,4-triazole (AMMT) have been synthesized. The spectral characteristics of 1, 2 were studied by 1H (13C) NMR and UV-Vis spectroscopy. X-ray diffraction studies established that all complexes contain the AMMT molecule, which are coordinated to the central m...

The monitoring of total sulfur content and speciation of individual sulfur-containing compounds in middle distillates is required for efficient catalyst selection and for a better understanding of the kinetics of the reactions involved in hydrotreament processes. Owing to higher resolution power and enhanced sensitivity, comprehensive two-dimensional gas chromatography (GCxGC) hyphenated to sul...

This report presents the chemical and physical factors governing the generation of sulfur dioxide (SO2), its transformation into other sulfur compounds, and the removal of sulfur oxides within the cement kiln system. Sulfur in cement kilns is derived from both kiln feed and from the kiln fuel. The form of the sulfur dictates the location in the kiln where the SO2 generation takes place. Sulfur ...

The prokaryotic oxidation of reduced inorganic sulfur compounds (RISCs) is a topic of utmost importance from a biogeochemical and industrial perspective. Despite sulfur oxidizing bacterial activity is largely known, no quantitative approaches to biological RISCs oxidation have been made, gathering all the complex abiotic and enzymatic stoichiometry involved. Even though in the case of neutrophi...

Wastewater from tanneries contains high concentrations of organic matter, chromium, nitrogen, and sulfur compounds. In this study, an artificial wetland is is used as the tertiary treatment in a tannery in León Gto., México. It consists of three subplots with an area of about 450 m2. Two subplots were planted with Typha sp. and the third with Scirpus americanus. Geochemical analyses along the f...