^(14)C-环氧虫啶光学异构体在不同土壤中的矿化、结合残留及其在腐殖质中的分布  

Diastereoselective Mineralization and Bound Residue Formation of ^(14)C-cycloxaprid and Its Distribution in Humus in Aerobic and Flooded Paddy Soils

作　　者：张晗雪[1] 陈敏[1] 王伟[1] 李忠[2] 叶庆富[1] 

机构地区：[1]浙江大学原子核农业科学研究所/农业部核农学重点实验室,浙江杭州310029 [2]华东理工大学药学院,上海200237

出　　处：《核农学报》2016年第1期145-153,共9页Journal of Nuclear Agricultural Sciences

基　　金：农业部公益性行业科研专项(201103007);国家自然科学基金青年项目(21207113);浙江大学基本科研业务费专项资金(2014FZA6016)

摘　　要：环氧虫啶是我国自主创制的手性新烟碱类杀虫剂,从对映体层面研究其环境行为和归趋对科学使用手性农药及其风险评估有着重要意义。本文采用^(14)C标记技术,研究了环氧虫啶2个对映异构体(1S2R-环氧虫啶,1R2S-环氧虫啶)和外消旋混合物(RM)在酸性红砂土S1、中性黄松土S2及碱性滨海盐土S3好氧和淹水培养中的矿化、结合残留形成及其在腐殖质中的分布规律。结果表明:土壤施药后培养100 d,环氧虫啶的异构体在3种土壤2种培养方式中的矿化、结合残留形成及在腐殖质中的分布均无明显差异;环氧虫啶在好氧和淹水培养的3种土壤中矿化量均有显著差异,在好氧的S1中矿化量最低(占引入量的0.21%~0.23%),S3中矿化量最高(占引入量的16.45%~17.06%),淹水的3种土壤中矿化均小于1%;环氧虫啶在好氧和淹水的S2和S3中结合残留量有显著差异,在S1中结合残留量差异不显著且残留量最小(56.84%~64.38%),好氧的S2中结合残留量最大(占引入量的79.55%~82.99%),淹水的S3中结合残留量最大(占引入量的73.85%~84.11%);环氧虫啶2种光学异构体和外消旋混合物在3种土壤2种培养方式下,结合残留在土壤腐殖质中的分布均呈现富啡酸>胡敏素>胡敏酸的规律。因此,手性杀虫剂环氧虫啶在土壤中的行为归趋不存在对映体选择性。Cycloxaprid, a novel neonicotinoid insecticide developed independently in China, has two optical stereoisomers,1S2R-cycloxaprid and 1R2S-cycloxaprid. The environmental behavior and fate of chiral pesticides in antipode level had great significance to the scientific use and risk assessment of cycloxaprid. The stereoisomer-specific mineralization and bound residue（ BR） of cycloxaprid in aerobic soils and flooded paddy soils were studied using^（14）Cisotope tracing,respectively in this study. The results were as follows： No significant difference was observed between the two optical isomers for the mineralization,BR and its distribution in humus at 100 days after the application.Significant difference in the mineralization of the stereoisomers was observed between aerobic and anoxic condition in soils（ p 0. 05）. Under aerobic condition,and the mineralization of cycloxaprid in S1 was the lowest（ 0. 21% to0. 23% of the applied amount）,and the highest in S3（ 16. 45% to 17. 06% of the applied）. Under anoxic condition,the mineralization of cycloxaprid was less than 1% in all tested soils. Significant difference in the BR of cycloxaprid was observed between aerobic and anoxic conditions in S2 and S3（ p 0. 05）,while no significant difference was found in S1. The BR in S1 was the lowest under both aerobic and anoxic conditions（ 56. 84% to 64. 38% of the applied amount）,while the highest in aerobic S2（ 79. 55% to 82. 99% of the applied amount） and in anoxic S3（ 73. 85% to84. 11% the applied amount）,respectively. Bound residue of^（14）C-cycloxaprid distributed in humus showed a tendency of fulvic acid humin humic acid in three soils under both aerobic condition and anoxic condition. The results indicated that no significant selectivity difference has been found in the environmental behavior and fate of chiral insecticide,cycloxaprid in soil.

关 键 词：14C-环氧虫啶 手性 矿化 结合残留 腐殖质 新烟碱杀虫剂 

分 类 号：S481.8[农业科学—农药学] S153[农业科学—植物保护]