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.

摘要

首次研究了具有吡唑起源的杀菌剂异吡唑啉在来自不同气候带的异质土壤基质中的生态命运。决定命运的研究包括在通过吸附和解吸的转化以及通过水解、光解和生物降解的降解方面检查 Isopyrazam 的行为。通过标准批次平衡模式进行的吸附表达了其对土壤物理和化学特性的依赖性。通过物理吸附和弱放热反应表达的土壤和 Isopyrazam 分子之间形成了整体较弱的吸附相互作用，由吉布斯自由能的负值 (-14 至 -20 kJ/mol) 显示。最高吸附达到K _d(ads) = 23 µg/mL 的土壤具有显着的有机质含量 (0.73%)，随后通过线性和 Freundlich 模型分析形成 C 型等温线。旨在确定土壤基质中异吡唑啉酮的归宿的分析程序包括紫外-可见分光光度法和气相色谱-质谱法。在水解、光解和生物降解实验中获得的最短半衰期分别为 16.7、4.3 和 19.7 天。结果显示异吡唑啉具有正常的结合力，因此对所选土壤的持久性较低，同时对转化途径高度敏感。当前的工作可以扩展到进一步优化这些降解途径，以设置实用的手段来使用这些程序进行环境清理，使用自然途径。