Fluoreszenzspektroskopische Untersuchungen an Huminsäuren

Fluorescence Spectroscopic Studies on Humic Acids The procedures of the fluorescence spectra of three humic acids have been investigated and compared. Differences were found in three points:

• 1 To get the maximum of fluorescence emission, different concentrations of the three humic acids were necessary.
• 2 The humic substances differed in pH-dependence of the fluorescence.
• 3 With nearly equal wavelength of fluorescence emission, distinct deviations of the exciting wavelength were pointed out.

The results show a connection between the conditions of the fluorescence and the contents of phenolic hydroxyl groups of the selected humic acids. The measurement of fluorescence is a relatively simple method for the characterization of humic acids.