G. N. Anoshin

Analysis of geologic reference materials for REE and HFSE by inductively coupled plasma-mass spectrometry (ICP-MS)

A variant of the ICP-MS technique was developed for the analysis of geological materials for REE and HFSE (Zr, Nb, Hf, and Ta) and is illustrated by analyzing geological reference materials (GRM) of various composition. The chemical preparation of the samples, including their sintering/fusing with highly purified Li metaborate and the stabilization of the solution, ensures the complete transfer of the elements to be analyzed into solution. The use of an ELEMENT high-sensitivity mass spectrometer with an U-5000AT+ ultrasonic nebulizer made it possible to improve the detection limits of REE and HFSE. A combination of an external calibration with internal standard for the calculation of the concentrations allowed us to take into account the effect of the matrix and variations in the plasma parameters on the analytical signal. The accuracy of the method is illustrated by the comparison of the results obtained on the most reliably certified GRM with the values assumed for them. The relative standard deviation of the analysis amounts to 2–5% on average, depending on the concentrations.

Determination of Platinum-Group Elements and Rhenium in Standard Geological Samples by Isotope Dilution with Mass-Spectrometric Ending

A method is proposed for determining platinum-group elements, Ru, Pd, Os, Ir, Pt, and Re in geological samples by isotope dilution with mass spectrometric ending after sample decomposition with a mixture (1: 3) of conc. HCl + HNO3 in a microwave system and the chromatographic separation of the analytes from the matrix on an AG 50W × 8 cation exchanger. The concentrations and isotope ratios are determined on high-resolution mass spectrometers ELEMENT and ELEMENT2. The attained detection limits range from 0.005 ng/g (Ir) to 0.2 ng/g (Pd) in solid samples. The use of isotope dilution improves the accuracy of determination and takes into account the matrix effect and changes in plasma parameters on the analytical signal. The method is tested in the analysis of standard samples of spinel lherzolite (GP-13) and serpentinite (UB-N). The relative standard deviation of the results of analysis is 5–22%, depending on the element and its concentration level (Ru, Pd, Re, Pt). In determining Os and Ir, a certain decrease in the accuracy and repeatability of the results is noticed.

Geochemical Characteristics of the Modern State of Salt Lakes in Altai Krai

A complex of analytical methods (atomic absorption spectroscopy AAS, synchrotron radiation X-ray fluorescence SR-XRF, and instrumental neutron activation analysis INAA) were used for analyses of 40 trace elements. In compliance with the conventional biogeochemical methods, enrichment factors EF were calculated for plankton relative to the average concentrations of elements in continental clay (shale) preliminarily normalized to Sc. In order to understand the concentration specifics of trace elements in living organisms inhabiting aquatic ecosystems of variable salt composition and geochemical characteristics, chemical speciation of elements was calculated for the brines of salt lakes by the WATEQ4F and Selektor-S computer programs. The enrichment of plankton in Hg in Lake Bol’shoe Yarovoe is caused not only by the chemistry of the mineralized brine (bittern), as follows from the Hg speciation in it, but also by anthropogenic contamination (Hg-bearing wastes from the Altaikhimprom chemical plants in the town of Yarovoe).

Distribution of mercury and its species in the zone of sulphide tailing

The waste is not fixed; during the entire period of the tailing’s existence it is regularly diluted by rainwa� ter and flood water. The ravine’s swampy territory below the tailings down to the Ur river (a confluent of the Inya river) is covered with the derived waste matter (Fig. 2); the area’s vegetation has been destroyed due to the acid mine drainage influence. The derived mat� ter lays over the peat, with swamp hassocks still present. Down in the ravine, in the valley of the river Ur, the waste covers the splinters of limestone.

Anomalous concentrations of zinc and copper in highmoor peat bog, southeast coast of Lake Baikal

When examining the peat deposit discovered in Vydrinaya bog, South Baikal region, the authors encountered anomalous Zn and Cu concentrations for highmoors being up to 600–500 ppm on a dry matter basis in the Early Holocene beds (360–440 cm) formed 11 000–8500 years ago. It has been demonstrated that Zn and Cu are present inside the plant cells of peat moss in the form of authigenic sulfide minerals of micron size. Apart from Zn and Cu, native Ag particles (5–7 um) have been encountered in the peat of the Vydrinaya bog at a depth of 390–410 cm; these particles formed inside the organic matter of the plasma membrane of peat moss containing Ca, Al, S, and Cu. This study suggests probable patterns of the formation of zinc sulfides, copper sulfides, and native silver in peat moss. The results obtained indicate that biogenic mineral formation plays a significant role in this system, which is a very important argument in the discussion on the ore genesis, in which physicochemical processes are normally favored, while the role of living matter is quite frequently disregarded.