Passive Sampling of Organic Compounds (PaSOC), Kimswerd, The Netherlands.
Syngenta Crop Protection, Greensboro, North Carolina, USA.
Environ Toxicol Chem. 2020 Jul;39(7):1334-1342. doi: 10.1002/etc.4731. Epub 2020 Jun 4.
Field-based atrazine sampling rates (R ) obtained by the polar organic chemical integrative sampler (POCIS) method were measured in 9 headwater streams over 3 yr covering 5 to 6 exposure periods of 2 to 3 wk/site/yr. Rates were best in line with the model R = 148 mL/d, with a standard deviation of 0.17 log units (factor 1.5). The POCIS canisters reduced mass transfer coefficients of the water boundary layer by a factor of 2 as measured by alabaster dissolution rates. A mechanistic model that accounts for flow and temperature effects yielded a fair estimate of the effective exchange surface area (12.5 ± 0.8 cm ). This model could only be tested for higher flow velocities because of uncertainties associated with the measurement of flow velocities <1 cm/s. Pictures of sorbent distributions in POCIS devices showed that the effective exchange surface area varied with time during the exposures. Error analysis indicated that sorbent distributions and chemical analysis were minor error sources. Our main conclusion is that an atrazine sampling rate of 148 mL/d yielded consistent results for all 3 yr across 9 headwater streams. Environ Toxicol Chem 2020;39:1334-1342. © 2020 SETAC.
基于现场的莠去津采样率（R）是通过极性有机化学综合采样器（POCIS）方法在 3 年内的 9 个源头溪流中测量的，涵盖了 5 至 6 个 2 至 3 周/站点/年的暴露期。速率与模型 R = 148 mL/d 最为吻合，标准偏差为 0.17 个对数单位（1.5 倍）。POCIS 小瓶通过石膏溶解速率测量将水边界层的质量转移系数降低了 2 倍。一个考虑到流动和温度效应的机械模型得出了有效交换表面积的合理估计值（12.5 ± 0.8 cm ）。由于与<1 cm/s 流速测量相关的不确定性，只能对较高流速进行该模型测试。POCIS 装置中吸附剂分布的图片表明，在暴露期间有效交换表面积随时间变化。误差分析表明，吸附剂分布和化学分析是较小的误差源。我们的主要结论是，在 9 个源头溪流的 3 年内，莠去津的采样率为 148 mL/d 可产生一致的结果。环境毒理化学 2020；39:1334-1342。©2020 SETAC。
