Особенности анализа вод, почв и донных отложений в масс-спектрометрии с индуктивно-связанной плазмой

Abstract

The paper discusses the possibilities and limitations of the method of mass spectrometry with inductively coupled plasma on the example of elemental analysis of natural and drinking waters, soils and grounds. It is shown that the combination of this method with the simpler atomic emission method makes it possible to expand the range of determined elements, simplify the mass-spectral analysis and increase its reliability. It is shown that the use of the ICP-MS method in the analysis of various objects makes it possible to determine the majority of elements with extremely low detection limits. The reason for the manifestation of matrix effects is the positive space charge formed between the interface and the extractor, the composition of which is determined by the composition of singly charged argon ions. The increase in the concentration of ions in this region is the appearance of a matrix element, which facilitates the scattering of ions from this region. It was found that the heavier the ions of the matrix element, the more the space charge density increases and the scattering occurs. A serious limitation of the method is associated with interferences due to the presence of a certain amount of two and three-charged ions in the plasma. These ions, which have approximately the same mass as the isotopes of the element being determined, are formed as a result of various plasma-chemical reactions and interfere with the determination.