Abstract
Fungicide Isopyrazam having pyrazole genesis has been studied for its ecological fate inside heterogeneous pedospheric matrices from varied climatic zones for the first time. Fate-determinative studies included examination of Isopyrazam's behavior in terms of transformation via adsorption and desorption, and degradation via hydrolysis, photolysis, and biological degradation. Sorption conducted through standard batch equilibration mode expressed its dependence on soils' physical and chemical characteristics. Overall weaker adsorptive interactions were developed between soils and Isopyrazam molecules expressed through physio-sorption and weak exothermic response revealed by negative values for Gibbs free energy (−14 to −20 kJ/mol). The highest adsorption reaching up to K
d(ads)
= 23 µg/mL was obtained for soil having remarkable organic matter content (0.73%), subsequently forming C-type isotherm analyzed through linear and Freundlich model. Analytical procedures aimed at fate determination of Isopyrazam in soil matrices included ultraviolet-visible spectrophotometric and gas chromatography-mass spectrometry. Minimum half-lives obtained in hydrolysis, photolysis, and biodegradation experiments were 16.7, 4.3, and 19.7 days, respectively. Results showed normal binding, and thus, low persistence of Isopyrazam to the selected soils whilst being highly susceptible to transformative pathways. Current work can be extended to the further optimization of these degradative routes to device practical means for employment of these procedures for environmental clean-up using natural routes.