Efficiency of singlet oxygen generation by fulvic acids and its influence on UV photodegradation of herbicide Amitrole in aqueous solutions

pH-dependent efficiency of singlet oxygen ( 1 O 2 ) generation by fulvic acids (FAs) from different sources was estimated by time-resolved luminescence technique. All FAs turn up the highest quantum yields of 1 O 2 for neutral and alkali solutions [ ϕ 532 ( 1 O 2 )] = (0.3•2.5)í10 •2 ] and 3•5-fold decrease in ϕ 532 ( 1 O 2 ) for acidic solutions. Potential of FA ChangSheng (the best 1 O 2 generating agent among investigated FAs) in relation to photodegradation of non-UVA-absorbing herbicide Amitrole (3-amino-1,2,4-triazole) was demonstrated.