Polar Organic Chemical Integrative Sampler (POCIS) devices are used to determine time-weighted average concentrations (TWACs) of organic chemicals in water. Ability of POCIS to give accurate TWACs in the field requires laboratory-derived compound-specific sampling rates to remain robust under changing environmental conditions (e.g., temperature, flow, pH, etc.) throughout the deployment period. However, recent reports indicate sampling rates diverge over variable environmental conditions, which requires environmental effects on sampling rates to be thoroughly investigated and quantified for reliable use. This work explored the ability of POCIS to maintain a linear uptake of 12 pesticides over a range of concentrations (e.g., 20-100 µg L<sup>-1</sup>) for constant and pulsed (fluctuating concentration) exposures. If concentration had little to no effect on POCIS as hypothesized, sampling rates would remain constant and analyte accumulation would be linear over the concentration range tested. POCIS exposure concentration was renewed daily under constant temperature and flow conditions. Flow velocities were calculated using an adapted alabaster dissolution method. Experiments were performed by suspending 10 POCIS in the test system for 21 days. The analyte uptake was quantified every other day using UPLC-MS/MS in multiple reaction monitoring mode; data were used to calculate sampling rates. TWACs for constant and pulsed exposures ranged from 20 to 100 µg L<sup>-1</sup>. Sampling rates differed between constant and pulsed exposures and showed shortened integrative capabilities at higher concentrations. Results provide insight into the effects of environmental concentrations on TWACs obtained from POCIS deployment.

Concentration exposure effects on the integrative capability of polar organic chemical integrative samplers

255th National Meeting (2018)

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