Photolysis of thiabendazole in aqueous solution and in the presence of fulvic and humic acids

Irradiation of thiabendazole in aqueous solution at λ ≥ 290 nm resulted in 91.6% substrate transformation in 4 h. The degradation approximately followed first order kinetics; rate constant, 1.73 × 10−4 s−1 and half-life, 1.01 h. Irradiation under UV-light (λ ≥ 290 nm) in the presence of fulvic and humic acids (isolated from soil, Scheyern, Germany) resulted in 90.8% and 88.4% degradation of the chemical respectively. Several products were isolated and their structure determined by GC-MS. Humic and fulvic acid seem to have little effect on photolysis of thiobendazole in water.