Reactions of singlet oxygen in humic waters

SUMMARY. The oxidation of 2, 5-diniethylfuran (DMF) to cis-1, 2- diacetylethylene (DAE) is a specific test for singlet oxygen (¹O₂). A method has been developed for the measurement of DAB by direct injection gas chromatography. By the use of this method, the photochemical generation of ¹O2 has been demonstrated in samples of two Canadian humic waters.
Two other photochemical reactions probably mediated by ¹O₂generation, the oxidation of histidine and the inactivation of a-chymotrypsin, have been demonstrated in these waters.
The possible ecological and environmental implications of these findings are discussed.