Baudin Nastasia, Garrod Mark, Bramke Irene, Mckillican Carol, Schäfer Hendrik, Hand Laurence, Cione Ana, Bending Gary D, Marshall Samantha
University of Warwick, Coventry, CV4 7AL, UK.
Syngenta Ltd, Jealott's Hill International Research Centre, Warfield, Bracknell, RG42 6EY, UK.
Environ Monit Assess. 2025 Jan 30;197(2):207. doi: 10.1007/s10661-025-13635-0.
Brazilian soils have distinctive characteristics to European and North American soils which are typically used to investigate pesticide fate. This study aimed to compare soil-water partition coefficient (K), reversibility of adsorption and degradation half-life (DT) of 5 pesticides covering a wide range of physico-chemical properties in contrasting Brazilian soils (Argissolo, Gleissolo, Latossolo and Neossolo) and a temperate (UK) alfisol soil, and to study their relationship with soil OM, clay and expandable clay content, CEC and pH. In addition, we used a novel laboratory test to evaluate sorption reversibility, the 3-Phase Assay (3PA). This stationary extraction system uses an organic solvent that sequesters compounds present in the soil aqueous solution and forces the diffusion of reversibly sorbed compounds. K (mL/g) values ranged from 4.85 to 79.26 for ametryn, 0.80 to 37.58 for clodinafop, 1.49 to 6.57 for fomesafen, 9.93 to 488.90 for thiabendazole and 2.52 to 6.77 for trifloxysulfuron. Desorption of the test compound (% applied radioactivity) ranged from 37.29 to 101.91 for ametryn, 32.05 to 100.67 for clodinafop, 34.73 to 73.33 for fomesafen and 4.15 to 66.87 for thiabendazole. Sorption reversibility was not assessed for trifloxysulfuron due to hydrolytic instability. DT (days) ranged from 29 to 90 for ametryn, 1 to 466 for clodinafop, 49 to 601 for fomesafen, 4 to 342 for thiabendazole and 22 to 38 for trifloxysulfuron. The data generated gives an overview of pesticide fate in Brazilian soils used for regulatory testing and is helpful for exposure risk assessment. The results showed that pesticide behaviour in Brazilian soils was not systematically different from those in European and North American soils. The 3PA was shown to be a reliable and simple method for assessing pesticide desorption in soil and could be adapted to assess pesticide bioavailability. The use of the 3PA allowed a more thorough explanation of the observed differences in degradation behaviour between the compounds.
巴西土壤具有与欧洲和北美土壤不同的独特特征，而欧洲和北美土壤通常用于研究农药的归宿。本研究旨在比较5种具有广泛物理化学性质的农药在不同的巴西土壤（铁铝土、潜育土、砖红壤和新成土）以及一种温带（英国）淋溶土中的土壤-水分配系数（K）、吸附可逆性和降解半衰期（DT），并研究它们与土壤有机质、粘土和可膨胀粘土含量、阳离子交换量和pH值的关系。此外，我们使用了一种新颖的实验室测试方法——三相分析法（3PA）来评估吸附可逆性。这种静态萃取系统使用一种有机溶剂来隔离土壤水溶液中存在的化合物，并促使可逆吸附化合物的扩散。莠灭净的K（mL/g）值范围为4.85至79.26，氯吡氟禾灵为0.80至37.58，乙羧氟草醚为1.49至6.57，噻菌灵为9.93至488.90，三氟啶磺隆为2.52至6.77。受试化合物的解吸率（施用放射性的百分比），莠灭净为37.29至101.91，氯吡氟禾灵为32.05至100.67，乙羧氟草醚为34.73至73.33，噻菌灵为4.15至66.87。由于水解不稳定性，未对三氟啶磺隆进行吸附可逆性评估。莠灭净的DT（天）范围为29至90，氯吡氟禾灵为1至466，乙羧氟草醚为49至601，噻菌灵为4至342，三氟啶磺隆为22至38。所生成的数据概述了用于监管测试的巴西土壤中农药的归宿，有助于进行暴露风险评估。结果表明，巴西土壤中农药的行为与欧洲和北美土壤中的行为没有系统性差异。三相分析法被证明是一种评估土壤中农药解吸的可靠且简单的方法，并且可以适用于评估农药的生物有效性。三相分析法的使用能够更全面地解释所观察到的化合物之间降解行为的差异。
