Xiong Jingjing, Li Huizhen, Ma Xue, Tan Baoxiang, Gong Yongting, Xie Danping, Wang Li, Yi Hao, You Jing
State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China; Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
Sci Total Environ. 2023 Dec 15;904:166824. doi: 10.1016/j.scitotenv.2023.166824. Epub 2023 Sep 4.
Irrational use of fipronil for rice pest control often occurred, resulting in high concentrations of fipronil and its transformation products (TPs) (collectively termed fiproles) in aquatic sediment, calling for a better understanding of the migration and transformation of fipronil in surface water as well as efficient methods for source identification. Herein, the fate and transport of fiproles from a paddy field to receiving rivers were assessed in Poyang Lake basin, Jiangxi, China using polar organic chemical integrative samplers with mixed-mode adsorbents (POCIS-MMA). Average concentrations of fiproles in water were 6.16 ± 6.32 ng/L, with median, minimum, and maximum values being 2.99 ± 0.67, 0.40 ± 0.08, and 18.6 ± 3.1 ng/L, respectively. In all samples, over half of fiproles (55.9 %-90.8 %) presented in the form of TPs and fipronil desulfinyl was the dominant TP. Two approaches were applied for source identification, including the change of molar concentration ratios of fipronil to its TPs and the relative attenuation values of fiproles normalized to a reference compound (acetamiprid) that was stable in aquatic environment. While the paddy field upstream was the main source of waterborne fiproles, additional input sources in the downstream region were identified. The present study indicated that the combination of attenuation of molar concentration ratios of micro-pollutants to their respective TPs and relative attenuation values of micro-pollutants' concentrations normalized to a reference compound measured by POCIS is an effective means to study the migration and transformation of micro-pollutants in field.
氟虫腈在水稻害虫防治中的不合理使用屡见不鲜，导致水生沉积物中氟虫腈及其转化产物（TPs）（统称为氟虫腈类）浓度过高，因此需要更好地了解氟虫腈在地表水中的迁移和转化情况以及有效的溯源方法。在此，在中国江西鄱阳湖流域，使用配备混合模式吸附剂的极性有机化合物综合采样器（POCIS-MMA）评估了氟虫腈类从稻田到受纳河流的归趋和迁移情况。水中氟虫腈类的平均浓度为6.16±6.32 ng/L，中位数、最小值和最大值分别为2.99±0.67、0.40±0.08和18.6±3.1 ng/L。在所有样品中，超过一半的氟虫腈类（55.9%-90.8%）以TPs的形式存在，且氟虫腈亚砜是主要的TP。采用了两种溯源方法，包括氟虫腈与其TPs摩尔浓度比的变化以及将氟虫腈类相对于在水生环境中稳定的参考化合物（啶虫脒）的相对衰减值进行归一化。虽然上游稻田是水中氟虫腈类的主要来源，但也确定了下游地区的其他输入源。本研究表明，将微污染物与其各自TPs的摩尔浓度比的衰减以及通过POCIS测量的微污染物浓度相对于参考化合物的相对衰减值相结合，是研究微污染物在田间迁移和转化的有效手段。
