Аннотация:Natural water samples and humic substance solutions were probed for their phototransient behavior. Laser flash kinetic spectroscopy was used to study two transients common to most samples. One transient with a maximum around 720 nm was quenched by decreasing pH and nitrous oxide. It was present in all waters with DOC and had a spectrum which resembled that of a solvated electron. The signal was linear with laser power. The quantum yield for this transient was measured. Samples with higher ground state absorbance yielded a transient with a maximum at 475 nm that was quenched by oxygen. This transient seemed to be a photophysical hybrid with triplet and radical cation character. Additional work done to characterize these transients and predict their environmental fates is discussed.
