Determination of small quantities of heavy metals in water-soluble salts and natural water by X-ray fluorescence

Abstract

Techniques for X-ray fluorescence (XRF) determination of heavy metals in natural waters and pure salts combined with preconcentration, are proposed. In these techniques, concentrates are small quantities of aqueous phase. Preconcentration of the said impurities was carried out either by extraction of their carbamate complexes with subsequent re-extraction of these elements in an aqueous phase or by directed crystallisation of aqueous eutectic salt solutions. For making specimens from the liquid concentrates their viscosity was essentially increased by the introduction of dry gelatine into the concentrates. Techniques for the determination of heavy metal impurities on the level of maximum permissible concentration (natural waters) and up to 1×10 −5–2×10 −5 mass% (pure salts) by extraction-XRF and crystallisation-XRF were developed.