Inorganic Geochemistry of Crude Oils of Northern Eurasia after ICP-MS Data as Clear Evidence for Their Deep Origin

The emergence of mass-spectroscopy with inductively-coupled plasma (ICP-MS) made it possible to study the microelement composition of crude oil and its derivatives with the limit of detection (LOD) at the ppt level. We have studied the crudes from West Siberian (Shaimsky, Sredneobsky and Oktyabrsky regions) and Tatarstan Romashinskoye oilfields with the ICP-MS method to detect 50 rare, rare-earth, and other microelements. The elemental composition is reasonably comparable to their concentrations in ultrabasites whereas the contents of most of the elements are low to the limit. On the diagrams of rare-earth elements, one can see the prevalence of light lanthanides and positive europium anomaly. Increased content of platinoids was found in Tatar oils; in some cases, the concentration of ruthenium reaches 0.06 g/t. The study shows that studied crudes have a specific microelement composition. Based on the elevated contents of transit elements and platinoids, a conclusion was made about the “ultrabasic” geochemical–metallogenic specialization of studied petroleum systems and the assumption about its origin was proposed.

Luminescence of Eu3+ in Some Scandium Phosphates

Lanthanide ions are very efficient activators. Due to the presence of shielded 4f shell, the energy levels can be predicted with relative ease. Interaction with the surrounding lattice is minimum and luminescence efficiency is high. For this reason, many important phosphors having various applications have been discovered which use lanthanide activators. For obtaining efficient phosphors, it is important to find a suitable host for lanthanide activators which can accommodate these ions without concentration quenching. The hosts must be transparent to the emitted light. Lanthanides, most commonly occur as trivalent. Thus, hosts constituted by trivalent metals can be suitable. Yttrium compounds have been extensively studied as hosts. Scandium is another trivalent metal. Compared to the yttrium compounds, Scandium compounds have been very scarcely studied as hosts. We are investigating Scandium compounds as luminescence hosts. Synthesis and photoluminescence properties of Sr9 Sc (PO4)7 : Eu3+ and Sr8MgSc(PO4)7:Eu3+ phosphor are described in this work. The phosphors were prepared by solid state reaction. Usually, these phosphors are reduced and results on Eu2+ photoluminescence are reported. However, we have recorded photoluminescence before reduction and thus new results on Eu3+ emission could be obtained.

Separation of Rare Earth Elements (REE) by Ion Interaction Chromatography (IIC) Using Diglycolic Acid (ODA) as a Complexing Agent

The possibility of rare earth elements (REE) separation by ion interaction chromatography (IIC) employing their complexes with diglycolic acid (ODA) in anion exchange mode has been studied theoretically and experimentally. Calculations, assuming that only trivalent complex is significantly uptaken by the stationary phase, indicated that at at pH 4–6, the retention in the lanthanide series should increase from La to the Tb–Dy–Ho region with yttrium showing apparent atomic number (App.At.No.) of 67½ and then decrease with further increase of atomic number. Chromatographic experiments in the system: Column: Eternity C18—mobile phase 5 mM ODA/8.6 mM TBAOH/0.6 mM HNO3; pH 4.60 confirmed theoretically predictions. It was found that scandium at pH ≥ 4.0 elutes in front of the whole REE group but at low pH enters the region of light lanthanides. The non-monotonical change of affinity of the REE with the increase of atomic number results in quite unusual order of elution of REE namely: Sc < La < Ce < Lu < Pr < Yb < Nd < Tm < Sm < Eu < Er≈Y < Gd < Ho < Tb≈Dy.

Occurrence of XoxF-type methanol dehydrogenases in bacteria inhabiting light lanthanide-rich shale rock

This study analyzed the occurrence of lanthanide-dependent (XoxF type) methanol dehydrogenases in the bacterial community inhabiting shale rock. The studied bacterial community was dominated by Proteobacteria, including Alpha-, Beta-, and Gammaproteobacteria classes. Four taxonomic groups known from the literature as capable of producing XoxF were detected among Proteobacteria, including: (i) only methylotrophic species (1.4% of Proteobacteria); (ii) both methylotrophic and nonmethylotrophic species (15.65%), (iii) species performing methylotrophic co-metabolism (5.74%), and (iv) only nonmethylotrophs (18.47%). In total, 22 sequence matches of XoxF enzymes were identified in the metaproteome of the bacterial community. This enzyme was produced by Alpha- and Betaproteobacteria represented by five orders such as Rhizobiales, Rhodobacterales, Rhodospiralles, Burkholderiales, and Nitrosomonadales. The dominant number of sequences came from Rhizobiales. Among the identified XoxF proteins, seven belonged to XoxF1 clade and 15 to XoxF5 clade. In the studied bacterial community, Ca-dependent methanol dehydrogenases were not detected. This study is the first to show the occurrence of XoxF proteins in the metaproteome of environmental lithobiontic bacterial community colonizing an underground rock rich in light lanthanides. The presented results broaden our understanding of the ecology of XoxF producing bacteria as well as the distribution and diversity of these enzymes in the natural environment.

Sorption Behaviors of Light Lanthanides(III) (La(III), Ce(III), Pr(III), Nd(III)) and Cr(III) Using Nitrolite

The sorption of light lanthanides(III) (La(III), Ce(III), Pr(III), Nd(III)) and chromium(III) ions from acidic solutions on Nitrolite was studied at varying ions concentrations, pH, contact time and temperatures. The sorption capacity of lanthanides(III) and chromium(III) ions were examined in the ranges 2–9 and 2–5, respectively. The adsorption capacities of all metals are increase with the increasing pH (up to initial pH 9), despite the potential precipitation of metals at higher pH values. Therefore, an initial pH 9 of lanthanides gives the highest adsorption capacities. The kinetics of sorption chromium(III) and light lanthanides(III) were investigated. The experimental data were analyzed using the pseudo-first-order, pseudo-second-order forms, Elovich, and intra-particle diffusion models. The sorption kinetics of investigated ions was described by pseudo-second-order model the best. The results indicate the endothermic process of Cr(III), La(III), Ce(III), Pr(III) and Nd(III) ions sorption. The sorption capacities of La(III) 4.77 mg/g, Ce(III) 4.45 mg/g, Pr(III) 4.30 mg/g, Nd(III) 4.13 mg/g and Cr(III) 2.39 mg/g were calculated from the Langmiur model, which describes adsorption better than Freundlich and Dubinin–Radushkevich.

ANOMALIES OF RARE ELEMENTS IN MANGANESE MICRONODULES FROM ETHMODISCUS OOZES IN THE BRAZIL BASIN OF THE ATLANTIC OCEAN

The composition of manganese micronodules from miopelagic clays and Ethmodiscus oozes of the central part of the Brazil Basin (station 1537, R/V Akademik Sergei Vavilov) is considered. Micronodules were recovered from >50 μm fraction of sediments from the depth intervals of 300 to 305, 405 to 410 and 442 to 452 cm below seafloor. The composition of micronodules was determined in separate size fractions of 50–100, 100–250 and 250–500 μm after dissolution in 0.5N NH2OH × HCl + 25% CH3COOH. The contents of Co, Ni, Cu, Ce, Pb, W, Th, and Bi in micronodules of miopеlagic clays were found to be higher than in micronodules from Ethmodiscus oozes. In the latter, the positive anomalies of Li, As, Mo, Cd, Tl, and U were revealed. The REE composition of micronodules in miopelagic clays is similar to the composition of hydrogenous crusts with a maximum in middle REE and a positive cerium anomaly. Micronodules of Ethmodiscus oozes have a positive Ce anomaly 2.8–3.8 and a deficiency of light lanthanides, similar to the composition of dissolved REEs in pore and bottom ocean waters. High accumulation of redox-sensitive elements in micronodules (As, Mo, V, and Cd) indicates an anaerobic stage in the post-sedimentary period in Ethmodiscus ooze caused by high biological productivity of waters. The formation of micronodules began during the period when the reducing conditions changed to oxidizing ones. Elements with low mobility (As, Mo, V, and Cd) accumulated in sediments and pore water during the anaerobic stage were then sorbed on Mn oxyhydroxides during the oxidation stage.