title: Atrazine contamination at the watershed scale and environmental factors affecting sampling rates of the polar organic chemical integrative sampler (POCIS).
abstract: Polar organic chemical integrative samplers (POCIS) were used to estimate atrazine contamination at 24 stream/river sites located across a watershed with land use ranging from 6.7 to 97.4% annual crops and surface water nitrate concentrations ranging from 3 to 5404 μg/L. A gradient of atrazine contamination spanning two orders of magnitude was observed over two POCIS deployments of 28 d and was positively correlated with measures of agricultural intensity. The metabolite desisopropyl atrazine was used as a performance reference compound in field calibration studies. Sampling rates were similar between field sites but differed seasonally. Temperature had a significant effect on sampling rates while other environmental variables, including water velocity, appeared to have no effect on sampling rates. A performance reference compound approach showed potential in evaluating spatial and temporal differences in field sampling rates and as a tool for further understanding processes governing uptake of polar compounds by POCIS.
authors.affiliation: Ottawa-Carleton Institute of Biology, 30 Marie Curie, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada. Electronic address: rdalt018@uottawa.ca.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Dalton
authors.affiliation: Ottawa-Carleton Institute of Biology, 30 Marie Curie, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
authors.forename: Frances R
authors.initials: FR
authors.lastname: Pick
authors.affiliation: Ottawa-Carleton Institute of Biology, 30 Marie Curie, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada; Science and Technology Branch, Environment Canada, 1125 Colonel By Drive, Raven Road, Carleton University, Ottawa, Ontario K1A 0H3, Canada.
authors.forename: Céline
authors.initials: C
authors.lastname: Boutin
authors.affiliation: Ottawa-Carleton Institute of Biology, 30 Marie Curie, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada.
authors.forename: Ammar
authors.initials: A
authors.lastname: Saleem
mesh_terms: D001280:Atrazine / Q000032:analysis*; D002138:Calibration; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D006540:Herbicides / Q000633:toxicity; D009930:Organic Chemicals / Q000737:chemistry; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006540:Herbicides; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D001280:Atrazine
keywords: Atrazine; Herbicide; Passive sampling rate; Performance reference compound; Polar organic chemical integrative sampler (POCIS)