DETERMINATION OF SMALL QUANTITIES OF HEAVY-METALS IN WATER-SOLUBLE SALTS AND NATURAL-WATER BY X-RAY-FLUORESCENCE

Techniques for X-ray fluorescence (XRF) determination of heavy metals in natural waters and pure salts combined with preconcentration, are p roposed. In these techniques, concentrates are small quantities of aqu eous phase. Preconcentration of the said impurities was carried out ei ther by extraction of their carbamate complexes with subsequent re-ext raction of these elements in an aqueous phase or by directed crystalli sation of aqueous eutectic salt solutions. For making specimens from t he liquid concentrates their viscosity was essentially increased by th e introduction of dry gelatine into the concentrates. Techniques for t he determination of heavy metal impurities on the level of maximum per missible concentration (natural waters) and up to 1 x 10(-5)-2 x 10(-5 ) mass% (pure salts) by extraction-XRF and crystallisation-XRF were de veloped. (C) 1998 Elsevier Science B.V. All rights reserved.