scholarly journals Multi-elemental analysis of high-purity molybdenum by electrothermal vaporization inductively coupled plasma mass spectrometry

2020 ◽  
Author(s):  
N.S. Medvedev ◽  
A.V. Volzhenin ◽  
A.I. Saprykin

High purity molybdenum and its compounds are used for the synthesis of ionizing radiation detectors for search for dark matter and double beta decay. Properties of these detectors largely depend on their trace composition. The new mass-spectrometry with inductively coupled plasma (ICP-MS) and electrothermal vaporization (ETV) method was developed for the analysis of high-purity molybdenum. The samples were introduced into the ICP using the ETV device. The vaporization curves of matrix element (molybdenum) and trace elements were studied in detail. The dependence of analytical signal and limits of detection (LODs) of analytes versus ETV-ICP-MS instrumental parameters (ICP power, transport flow, ion optics settings) was established. The proposed method of ETV-ICP-MS analysis allowed us to control the content of 28 trace elements in high-purity molybdenum with a purity of 6N (99.9999% wt.) and provided LODs from 0.3 to 200 ng g-1. Using of ETV for ICP-MS analysis of molybdenum led to decreasing of the LODs of trace elements from 3 to 200 times comparing with ICP-MS analysis with standard sample introduction system. The validation of proposed ETV-ICP-MS method was performed by spike experiment and by comparing the results of ETV-ICP-MS, ICP-MS, and atomic absorption spectrometry with electrothermal vaporization (GFAAS) analysis.

2019 ◽  
Vol 85 (4) ◽  
pp. 110-113
Author(s):  
Olexandr Ponomarenko ◽  
Anatolyi Samchuk ◽  
Kateryna Vovk ◽  
Igor Shvaika ◽  
Ganna Grodzinskaya

The analytical technologies of sample preparation of rocks and mushrooms using the microwave field for the determination of germanium by the method of mass spectrometry with inductively coupled plasma (ICP-MS analysis) have been developed. Germanium is a rare element. Germanium is homology of silicon and carbon. To date, the definition of low content of germanium in geological objects is a rather complex analytical task, which requires its concentration - extraction, co-precipitation, ion exchange. At present, the harmonious combination of the method of natural objects decomposition in the microwave field and germanium determination using ICP-MS analysis is particularly promising. Sample preparation of silicate rocks for ICP-MS determination of germanium was carried out by decomposition in a mixture of hydrofluoric, phosphate and nitric acids (5: 5: 2) in a microwave oven program at 240°C for 30 min. Sample preparation of mushrooms for ICP-MS germanium determination was carried out according to the following scheme. Initially, the dried sample was sealed in the presence of CaO, after dissolving it in a mixture of HNO3+HF+H3PO4 (6:6:1). Ge solution was extracted by Nazarenko V.A. extraction method. The developed analytical schemes have made it possible to significantly reduce the duration and labor intensity of sample preparation. The obtained solutions were analyzed using an inductively coupled plasma mass spectrometer. The developed method for determining germanium by ICP-MS analysis has been successfully tested on standard rock samples. The obtained results are in accordance with the accepted attribute, the relative standard deviation Sr ranges from 0.7-0.9. The data on the content and distribution of germanium in the Boletales fungi are obtained. They indicate wild mushrooms contain high levels of germanium, especially Boletus and Mushroom biospores. These studies are necessary because the essential properties of germanium and its compounds attract special attention of scientists today. Complementary Ge compounds which have hypotensive, bactericidal, antiviral and antitumor effects have already been synthesized.


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