TRACE ELEMENTS IN MEDICINE (MOSCOW)
2016, 17(1): 30-37
ORIGINAL PAPERS

DETERMINATION OF TRACE ELEMENTS IN VITAMIN-MINERAL COMPLEXES AND MEDICINAL HERBS USING DIAZOTIZED POLYURETHANE-FOAM SORBENTS

A.A. Chaplenko, O.V. Monogarova, K.V. Oskolok, S.A. Chaplenko

Lomonosov Moscow State University, Faculty of Chemistry, Leninskiye Gory, 1/3, Moscow 119991, Russia

DOI: 10.19112/2413-6174-2016-17-1-30-37  

ABSTRACT. In this paper we propose a method of X-ray fluorescence (XRF) determination of some essential trace elements in medicinal plant raw material and vitamin-mineral complexes at the level of 100–101 µg/ml with preliminary sorption concentrating. To increase sensitivity and selectivity of the determination it is proposed to use a simple and effective approach based on the extraction of metal ions from aqueous solutions on chemically modified polyurethane-foam sorbents followed by direct XRF analysis of the resulting concentrate. We optimized the conditions of sorption preconcentrating of Co(II), Ni(II) and Zn(II) ions in chelate forms with the sorbents covalently-modified by organic reagents. The formulated principles of selecting the conditions for analytical signal make it possible to increase the sensitivity and linearity of the calibration range by an order of magnitude as compared to existing hybrid sorption-XRF techniques. The proposed approach is applied for the analysis of several kinds of medicinal plant materials (coltsfoot leaves, nettle leaves, yarrow herb) and vitamin-mineral complexes («Alfavit», «Vitrum», «Multi-tabs»).

KEYWORDS: trace elements, medicinal plant raw material, vitamin-mineral complexes, foamed polyurethane sorbents, X-ray fluorescence analysis.