Development of a Reference Sample for Rapid Analysis of an Elemental Composition of Medicinal Plant Raw Materials

Abstract

Objective: Development and validation of a technique for preparation of a reference sample for elemental microanalysis using the XRF technique in terms of repeatability, reproducibility, and optimization of the technique for rapid determination of the elemental composition of medicinal plants based on X-ray fluorescence analysis. Methods: Samples: fresh shoots of Kalanchoe daigremontiana, ready reference sample "Birch Leaf" LB-1 (A. P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia), and IAEA reference sample SRM 2976 (IAEA, MEL, Monaco). The dispersed fraction was analyzed using a Master Sizer 2000 instrument (Malvern Panalytical, Worcestershire, UK). Elemental analysis using an energy dispersive X-ray fluorescence spectrometer EDX-7000 Shimadzu (Shimadzu Corporation, Kyoto, Japan), GZ-AAS using an Agilent instrument, model 240Z AA instrument (Agilent Technologies, Inc., Santa Clara, USA) with electrothermal atomization and Zeeman background correction, and ICP-MS using an Agilent 7500 CE instrument (Agilent Technologies, Inc., Santa Clara, USA). Results: By the LALLS method, they were separated by the maximum distribution, which was 63 microns, and a minor fraction of 39 microns. This indicates sufficient homogeneity in the sample. Further, homogeneity was proved by the XRF method by measuring six independent samples obtained by the quartering method. Also, the elemental composition of the reference samples was determined: completely dried, homogenized before sifting, and homogenized after sifting. Further, the obtained reference sample of K. daigremontiana was compared with reference samples: IAEA SRM 2976 and "birch leaf methods: ICP-MS, GZ-AAS, XRF. Conclusion: The reference sample will allow for rapid analysis of medicinal plant raw materials. Standardization of medicinal plants by the content of microelements will allow observing species differences as well as adjusting the concentrations of microelements for therapeutic purposes using medicinal plants.