Possibilities of micro X-ray fluorescence spectrometry of solutions with preconcentration

Results of investigations in energy-dispersive X-ray fluorescence analysis aimed at the development of a high-sensitivity method of microanalysis of solutions are presented. A combined scheme of analysis of one drop of solution of the volume several microliters is proposed and tested. The scheme includes a new preconcentration method based on the drop evaporation in the presence of a micrograin of a hydrophilic adsorbent followed by the microanalysis of the solid phase on the portable device with a polycapillary lens with a focal spot of 10 μm designed at the Institute of Physical Optics. Analytically meaningful X-ray fluorescence spectra are obtained using DETATA (grain diameter about 100 μm) and SAC8 (50 μm) adsorbents and individual drops of model solutions containing Mn, Fe, Co, Ni, Cu, and Zn (0.2 mg/L and higher) and analytical characteristics of the proposed approach are demonstrated.