| The ability to monitor aquatic environments for polar organic contaminants (i.e., pesticides, pharmaceuticals, etc.) has recently became a topic of considerable interest. Many of these chemicals, although typically not bioconcentratable, have been linked to acute toxicity and chronic sublethal effects such as endocrine disruption. A prototype sampling device was developed and has been demonstrated to sample model polar organic contaminants such as 17alpha-ethynylestradiol, diazinon, and atrazine over extended periods.;The Polar Organic Chemical Integrative Sampler (POCIS) consists of a mixture of polymeric solid-phase extraction resins within a hydrophilic membrane enclosure. Of the several polymeric resins evaluated as sequestration agents, the admixture of Isolute ENV+ polystyrene divinylbenzene and S-X3 dispersed Ambersorb 1500 exhibited a strong affinity for waterborne polar organic analytes with near quantitative recoveries using an organic solvent elution. The selection of a membrane barrier involved the inspection of polymeric membranes of various chemical and physical properties. Polyethersulfone was chosen due to its durability, resistance to biofouling, and its applicability for sampling waterborne polar organic chemicals.;Sampling rates of the model compounds for a single POCIS (membrane surface area ∼20 cm2) exposed for 28 days were determined to range from 0.050 to 0.070 L/d under quiescent conditions and 0.186 to 0.302 L/d for a more turbulent system. The POCIS acts as an infinite sink for polar organic chemicals thereby sampling integratively (i.e., linear uptake) for exposure times ≥28 days. Theory suggests ambient environmental water concentrations may be estimated from the concentration of the analyte in the sampler and experimentally measured sampling rates.;A proof-of-concept field deployment was used to demonstrate the ability of the POCIS to perform under actual environmental conditions. Following a 28 day deployment in a wetland complex consisting of treated effluent from a municipal wastewater treatment facility and water from the Missouri River, qualitative recovery of a variety of compounds was achieved. Mass spectral data exhibited highly complex patterns indicating the presence of large numbers of compounds. Tentatively identified compounds include among many others: atrazine, hydroxyatrazine, ibuprofen, ethynylestradiol, sulfamerazine, and sulfadiazine. |
