A. R. Tsygankova

Analysis of high-purity germanium dioxide by atomic absorption spectrometry

To ensure analytical support for the growth of bismuth orthogermanate single crystals, we have developed an electrothermal atomic absorption technique for analysis of germanium dioxide with the separation of the host through reactive evaporation in the form of germanium tetrachloride. The technique allows Cd, Co, Cu, Cr, Mn, Ni, and Pb to be determined with detection limits in the range 1 × 10−8 to 1 × 10−8 wt %.

Analysis of Europium, Yttrium and Lanthanum Compounds by Atomic Emission Spectrometry with Inductively Coupled Plasma

The paper presents a multi-element analysis of europium, yttrium and lanthanum compounds by atomic emission spectrometry with inductively coupled plasma (ICP-AES). The plasma power was optimized, the choice of analytical lines of the impurities to be determined and the concentration of matrix element were substantiated. The method allows to determine up to 40 trace elements with the limits of detection (LODs) ranging from 10–6 to 10–3 wt %.

ICP-AES analysis of silicon, germanium, and their oxides

The techniques of atomic emission spectrometry with inductively coupled plasma (ICP-AES) for quantitative determination impurities in silicon, germanium, and their dioxides are developed. Analytical lines for silicon-matrix (29 trace elements) and germanium-matrix (42 trace elements) are selected. Matrix interferences caused by the presence of silicon and germanium in the solutions are studied. The optimal concentrations of matrix are determined. LODs for trace elements are in the range from n × 10–7 to n × 10–5 wt %; RSD < 20%. The accuracy of the results is confirmed by the method of “introduced–found.” The developed techniques are express, simple, and can determine a broad range of trace elements.

A procedure of ICP-AES analysis of silicon using microwave digestion and preconcentration

A combined procedure has been developed for the analysis of high-purity silicon with preliminary vapor-phase digestion and preconcentration in a microwave oven using inductively coupled plasma atomic emission spectrometry (ICP-AES). Liners for high-pressure vessels of microwave oven ensuring the simultaneous distillation of matrices from 3–4 samples without their contact with the acid solution have been designed and manufactured. The procedure ensures the determination of up to 30 elements: Ag, Al, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hf, In, K, Li, Mn, Mo, Na, Nb, Ni, P, Rb, Sb, Sn, Sr, Ta, V, W, Zn, and Zr with the limits of detection 10−8 −10−6 wt %.

ICP-AES analysis of high purity bismuth oxide

Two ICP-AES techniques for analysis of high-purity bismuth oxide are described. The direct techniques enables determination of 46 impurities in bismuth oxide with limits of detection (LODs) at the level of 10−8–10−5 wt %, and the method with separation matrix allows determination of 22 impurities with LODs at the level of 10−9-10−6 wt %.

ICP-AES analysis of high-purity silicon

An ICP-AES procedure for analyzing high-purity silicon, which is implemented on up-to-date standard equipment and intended to determine 44 impurities with detection limits of n × 10−8−n × 10−6 wt % in silicon, is described. The procedure is compared with ICP-AES procedures, conforming to GOST (State Standard) and published in the literature, in quantity of determined impurities and their detection limits.

Using of Fractional Separation for the Analysis of MoO3 by Atomic Emission Spectrometry with Inductively Coupled Plasma and Electrothermal Vaporization

The introduction of various forms of molybdenum into an inductively coupled plasma was studied in the vaporization of solutions from a graphite tube. A temperature program is selected that enables the separated vaporization of analytes and molybdenum (matrix) for atomic emission spectrometry with inductively coupled plasma and electrothermal vapoization (ETV–ICP–AES) analysis. The limits of detection for analytes in the ETV–ICP–AES analysis of molybdenum trioxide are evaluated using the fractional separation of analytes and the matrix.

Phase relations in the Nd2S3-SnS system and properties of the γ-Nd9.5Sn1.8S16 solid solution

The Nd2S3-SnS system has been studied at a temperature of 1100°C. The Nd2S3 solubility in molten SnS at this temperature is determined to be 4.4 mol %. The neodymium is present in the SnS melt in the form of Nd3+ ions. Its diffusion coefficient in molten SnS is estimated at 1.2 × 10−8 m2/s. Nd2S3 dissolution in SnS has a negligible effect on the SnS vapor pressure over saturated liquid solution in comparison with pure molten SnS. Using solvent evaporation, we have grown γ-Nd9.5Sn1.8S16 crystals and determined their chemical and phase compositions, structure, density and optical band gap.

Possibilities of inductively coupled plasma atomic emission spectrometry with electrothermal vaporization in the analysis of high-purity reagents

Possibilities of electrothermal sample vaporization in inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES) in the analysis of high-purity reagents were studied on an example high-purity waters, acid solutions, and trace impurity concentrates. The analytical and background signals in the injection of solutions into inductively coupled plasma (ICP) by pneumatic nebulization and electrothermal vaporization were compared and the of limits of detection in the analysis of high-purity reagents with impurity preconcentration by evaporation were estimated and compared.