PRECONCENTRATION OF TRACE-ELEMENTS IN WATER FOR SPECIATION STUDIES

Trace element speciation has recently become one of the most important problems in water analysis. Proper combination of preconcentration techniques with instrumental determination methods is essential to speciation analysis, because sensitivity and selectivity of direct determination methods are generally lacking. The present paper describes such preconcentration techniques as filtration, centrifugation, flotation and sorption, which have been developed in the author's laboratory for the speciation of heavy metals in river and pond waters by electron microscopy, X‐ray microanalysis and chemical analysis. The application of freeze concentration to the speciation of silica in high‐purity waters is also discussed. Copyright © 1990 The Chemical Society Located in Taipei & Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim, Germany