Do pesticides degrade in surface water receiving runoff from agricultural catchments? Combining passive samplers (POCIS) and compound-specific isotope analysis

Evaluating pesticide degradation in artificial wetlands with compound-specific isotope analysis: A case study with the fungicide dimethomorph

“…POCIS were deployed in triplicate in the stormwater wetland forebay area over three consecutive periods of 28 days, from June 30 th to September 22 nd . The POCIS were transported on ice to the laboratory and extracted within 15 h after collection or frozen at -20 °C before extraction (Gilevska et al, 2022a). Briefly, each POCIS was opened to transfer the sorbent to an SPE cartridge, which was then covered by HDPE frits.…”

“…The pesticides obtained from the sediment, soil, or plants were extracted using a solid-liquid extraction protocol (modified ultrasonic-assisted extraction) described previously (Gilevska et al, 2022b). The POCIS were handled and extracted separately using SPE (Gilevska et al, 2022a).…”

“…While POCIS measurements represent an integrative δ 13 C value over 30 days, punctual δ 13 C values were retrieved from the grab water samples from the wetland (Gilevska et al, 2022a).…”

“…Combined with concentration analysis, pesticide CSIA can provide multiple lines of evidence for pesticide transformation in wetlands and allow for the quantification of the extent of degradation when corresponding isotope fractionation values (e) are known. Only a few studies have investigated pesticide degradation in surface water using CSIA (Alvarez-Zaldivar et al, 2018;Gilevska et al, 2022a;Masbou et al, 2022;Schreglmann et al, 2013;Suchana et al, 2022), and reference studies on pesticide CSIA in wetland systems are currently limited (Chen et al, 2022) .…”

Dispersive liquid–liquid microextraction as a novel enrichment approach for compound-specific carbon isotope analysis of chlorinated phenols

“…5 Consequently, an enrichment step prior to the analysis of environmental samples is even more crucial than for concentration analysis. [6][7][8] In order to achieve a sufficient enrichment of contaminants from environmental samples different approaches were established in the last two decades, including purge & trap (P&T) and solid-phase microextraction (SPME) 6 for (semi-)volatile compounds, or solid phase extraction (SPE) 9 and passive-sampling 10 for non-volatile compounds, such as pesticides. These techniques are preferred over conventional liquid-liquid extraction (LLE) that has various drawbacks such as high solvent consumption and limited automation.…”