Pyrethroids are hydrophobic and bind strongly to soil/sediment and dissolved organic carbon. Thus, it is a challenging task to measure freely dissolved (C-free) and total pyrethroids (C-total) in sediment pore water for calculating the organic carbon sorption coefficients (Koc) which is critical for ecotoxicological (ecotox) risk assessments for benthic organisms. Solid phase microextraction (SPME) and isotopic-D6-labeled standards were used to measure C-free and C-total in pore water simultaneously. C-free and C-total were measured and Kocs were generated for nine pyrethroids (bifenthrin, cyfluthrin, lambda-cyhalothrin, cypermethrin, deltamethrin, esfenvalerate, fenpropathrin, permethrin, and tefluthrin) in three sediments (a fresh water sediment, a marine sediment, and OECD sediment) used for ecotox testing. As a comparison, C-total was also measured using a liquid-liquid extraction (LLE) from pore water and sediment. Koc coefficients generated using LLE and SPME methods were compared between experiments using traditional Koc study and simulated ecotox testing conditions; these differed markedly in sediment:water ratios. Because the Koc coefficients generated using simulated ecotox test conditions using SPME reflect freely dissolved pyrethroid concentrations, these values are the most relevant ones to use in benthic organism focused ecotox risk assessments.

Estimating organic carbon sorption coefficients (<i>K<sub>oc</sub></i>) of nine pyrethroids based on feely dissolved chemical concentrations measured with solid phase microextraction (SPME)

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Estimating organic carbon sorption coefficients (Koc) of nine pyrethroids based on feely dissolved chemical concentrations measured with solid phase microextraction (SPME)

Estimating organic carbon sorption coefficients (K_oc) of nine pyrethroids based on feely dissolved chemical concentrations measured with solid phase microextraction (SPME)