Several aquatic heterogeneous humic-solute fractions with known molecular-s
ize ranges were fractionated further by coupled size-exclusion chromatograp
hy (SEC) and polyacrylamide gel electrophoresis (PAGE). The results of SEC-
PAGE, obtained for several humic-solute fractions, corresponded reasonably
well to the known molecular-size distributions of the dissolved organic mat
ter (DOM). Despite the limited resolving power PAGE appears to offer an alt
ernative coarse method, beside SEC, for fractionation of the heterogeneous
humic matter (HM).