ANALYTICAL APPROACHES TO THE QUANTITATIVE DETERMINATION OF THE CHEMICAL ELEMENTS CONTENT IN COALS AND COAL ROCKS USING IСP-MS AND INAA METHODS

Abstract

The relevance of the study is caused by significant interest of scientists working in the field of coal geology and specialists of chemical and analytical laboratories practicing quantitative elemental analysis of environmental objects, to the problem of high-precision determination of low concentrations of chemical elements in coals and coal materials for the subsequent use of the obtained data in solving scientific and various technological tasks. The main aim is to consider and generalize the most frequently used methodological approaches to the determination of chemical elements in a wide range of their contents in coals (coal materials), as well as to assess the precision and accuracy of the ICP-MS method results obtained after open acid decomposition of samples and their fusion with lithium metaborate, comparing data with the INAA results method and statistical data processing. Objects: coals, carbonaceous siltstones and coalified timber from the Spetsugli germanium deposit, located on the southwestern edge of the Khanka massif in the eastern part of the Pavlovskoe coal-bearing depression, Primorsky Krai. Methods: inductively coupled plasma mass spectrometry (ICP-MS), applied after transferring the studied samples to a dissolved form, and a non-destructive quantitative method of instrumental neutron activation analysis (INAA). Methods of mathematical statistics were used to process the obtained results. Results. The results of ICP-MS analysis of three certified reference materials (CRM) of fly ash from KATEK GSO 9237-2008 (ZUK-2), brown coal ash from the Azeiskoe coal deposit GSO 7177-95 (ZUA-1) and bituminous CLB-1 coal of the US Geological Survey were obtained, presented in the form of data on their trace element composition in comparison with the certified and recommended values. The results of the determination of some elements given in the paper supplement the data on these CRMs presented in the certificate. Comparison of ICP-MS analysis results for samples of coals and carbonaceous rocks after different methods of chemical sample preparation: technique of open acid digestion and fusion with lithium metaborate, was carried out. The behavior of individual elements during these processes has been studied. Matching the obtained data by ICP-MS and INAA methods is performed. All results were processed metrologically and their permissible discrepancy was shown.

Keywords

• inductively coupled plasma mass spectrometryinductively coupled plasma mass spectrometry
• instrumental neutron activation analysis
• certified reference materials
• chemical sample preparation
• coal
• carbonaceous rocks
• spetsugli
• pavlovsk coal-bearing depression