Tracing neonicotinoid insecticides and their transformation products from paddy field to receiving waters using polar organic chemical integrative samplers

Neonicotinoid insecticides are ubiquitous in surface water worldwide, yet the transportation and transformation of these compounds in aquatic environment remain unclear. In the present study, polar organic chemical integrative sampler with mixed-mode adsorbents (POCIS-MMA) was developed for simultaneously tracing environmental fate of seven neonicotinoids and 10 transformation products (TPs) from a paddy field to receiving waters in Poyang Lake basin, Jiangxi, China. All neonicotinoids (5.20 ? 0.75-866 ? 143 ng/L) and seven TPs (116 ? 4-334 ? 78 ng/L) were detected, demonstrating widespread occurrence of these insecticides in aquatic environment. Dinotefuran (up to 802 ? 139 ng/L) and its TP, 1-methyl-3- (tetrahydro-3-furylmethyl) guanidium dihydrogen (DN) (103 ? 4-320 ? 76 ng/L) were the dominant neonicotinoids and TPs with mean concentrations of 200 ? 296 and 208 ? 58 ng/L, respectively. Spatial attenuation of neonicotinoids stretched downstream along the rivers, while TP concentrations firstly increased (D1-S6) and then kept constant (S7-S16) from upstream to downstream. Though paddy field was the main source of neonicotinoids, additional input sources downstream were identified by analyzing the composition of neonicotinoids and their TPs. Our study highlighted the applicability of POCIS-MMA passive sampling to investigate the transportation and transformation of neonicotinoids in agricultural waterways.

Automated summary

A new passive sampling technique was developed to track the distribution and transformation of neonicotinoid insecticides in aquatic environments, revealing their widespread presence with paddy fields as the main source but additional input sources downstream.