SPECIATION OF METALS ASSOCIATED WITH NATURAL-WATER COMPONENTS BY ONLINE MEMBRANE FRACTIONATION COMBINED WITH INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION AND MASS SPECTROMETRIES

Specially designed multistage membrane filtration devices for the size fractionation of suspended particles and solutes were tested and used for speciation studies of metals associated with natural water compon ents. The separated fractions were adapted to analysis by plasma sourc e atomic emission and mass spectrometry. The distribution patterns for Al, Fe, Zn, Mn, Ni, Co, as well as Na, K, Mg, Ca in samples of river waters in Saxony were studied. Alkali and alkaline earth metals are di stributed evenly between the fractions whereas easily hydrolysed trace elements mainly remain in the fraction containing the largest amounts of particulate matter. The distribution of the analytes between the d ifferent fractions is influenced by both the storage time of the solut ion before fractionation and the addition of acids to stabilise the aq ueous samples during storage.