Устранение матричных неспектральных помех при элементном анализе биологических жидкостей на квадрупольном масс-спектрометре с индуктивно связанной плазмой

Abstract

The comparison of two most frequently used sample preparation techniques of biological fluids before mass-spectrometric determination of Mn, Co, Cu, Zn, As, Se, Cd and Pb – simple (direct) dilution and acid mineralization – was carried out using quadrupole mass-spectrometer. The significant underestimation of the results in comparison with diluted samples for the elements with relatively high ionization potentials was found while analyzing digested biofluids. The key role of acid effect was proven to be the reason of such discrepancy. Moreover, the contributions of saline and organic matrix non-spectral interferences in both diluted and mineralized samples – to the underestimation of the obtained results were evaluated. It was shown that the selection of the appropriate internal standard based on matching of the standard’s and analyte’s ionization potentials not the masses can eliminate the described interferences without matrix-matched calibration. Furthermore, the working mass-spectrometer conditions that allow to use any single internal standard (irrespective of it’s mass and/or ionization potential) were found. Based on the experimental data the approach of element determination in biological fluids with the use of quadrupole ICP-MS was suggested. It provides the possibility of simultaneous determination of various elements without changing the work mass-spectrometer conditions. The satisfactory agreement between the found and certified concentration values for all the elements analyzed in the diluted and mineralized samples of whole blood and urine reference materials proved the applicability of the approach. Keywords: biological fluids, elemental analysis, inductively coupled mass-spectrometry, matrix non-spectral interferences, internal standards (Russian) DOI: http://dx.doi.org/10.15826/analitika.2014.18.2.003 K.B. Osipov 1 , I. F. Seregina 1 , M. A. Bol`shov 1,2 1 Lomonosov Moscow State University, Moscow, Russian Federation 2 Institute for Spectroscopy RAS , Troitsk, Moscow, Russian Federation