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 (¹O₂) generation by fulvic acids (FAs) from different sources was estimated by time-resolved luminescence technique. All FAs turn up the highest quantum yields of ¹O₂ for neutral and alkali solutions [ϕ⁵³²(¹O₂)] = (0.3•2.5)í10^•2] and 3•5-fold decrease in ϕ⁵³²(¹O₂) for acidic solutions. Potential of FA ChangSheng (the best ¹O₂ generating agent among investigated FAs) in relation to photodegradation of non-UVA-absorbing herbicide Amitrole (3-amino-1,2,4-triazole) was demonstrated.