THE INTERACTIONS OF MN-54 WITH AMINOPOLYCARBOXYLIC ACIDS IN AQUATIC SYSTEMS

The interactions of Mn-54 radionuclide with ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) were studied in freshwate r system (Butoniga impoundment), and in diluted seawater system (the R asa Bay) by high voltage paper electrophoresis. Depending on the EDTA or NTA concentrations it was possible to detect the distribution of ca tionic, anionic and immobile Mn-54 species, and to calculate their ele ctrophoretic mobilities. The apparent concentration stability constant s of Mn-54-EDTA or Mn-54-NTA complexes were calculated from the respec tive titration curves. Logarithmic values of the apparent concentratio n stability constants for Mn-54-EDTA complex corrected for the influen ce of pH, K-c(alpha H), are in the range 6.20-7.38 in two different wa ter types, while corrected for the effect of pH and Ca2+, K-c(alpha L) , in 5% seawater amount from 11.29 to 11.89. Logarithmic values of the apparent concentration stability constants for Mn-54-NTA complex corr ected for the influence of pH, K-c(alpha H), are in the range 6.42-5.2 1 in two different water types, while corrected for the effect of pH a nd Ca2+, K-c(alpha L), in 5% seawater amount from 6.92 to 6.47. Copyri ght (C) Elsevier Science Ltd