School of Criminal Sciences, University of Lausanne, Batochime, 1015 Lausanne, Switzerland.
School of Criminal Sciences, University of Lausanne, Batochime, 1015 Lausanne, Switzerland.
Sci Total Environ. 2014 Nov 15;499:319-26. doi: 10.1016/j.scitotenv.2014.08.047. Epub 2014 Sep 6.
One aim of this study is to determine the impact of water velocity on the uptake of indicator polychlorinated biphenyls (iPCBs) by silicone rubber (SR) and low-density polyethylene (LDPE) passive samplers. A second aim is to assess the efficiency of performance reference compounds (PRCs) to correct for the impact of water velocity. SR and LDPE samplers were spiked with 11 or 12 PRCs and exposed for 6 weeks to four different velocities (in the range of 1.6 to 37.7 cm s(-1)) in river-like flow conditions using a channel system supplied with river water. A relationship between velocity and the uptake was found for each iPCB and enables to determine expected changes in the uptake due to velocity variations. For both samplers, velocity increases from 2 to 10 cm s(-1), 30 cm s(-1) (interpolated data) and 100 cm s(-1) (extrapolated data) lead to increases of the uptake which do not exceed a factor of 2, 3 and 4.5, respectively. Results also showed that the influence of velocity decreased with increasing the octanol-water coefficient partition (log K(ow)) of iPCBs when SR is used whereas the opposite effect was observed for LDPE. Time-weighted average (TWA) concentrations of iPCBs in water were calculated from iPCB uptake and PRC release. These calculations were performed using either a single PRC or all the PRCs. The efficiency of PRCs to correct the impact of velocity was assessed by comparing the TWA concentrations obtained at the four tested velocities. For SR, a good agreement was found among the four TWA concentrations with both methods (average RSD<10%). Also for LDPE, PRCs offered a good correction of the impact of water velocity (average RSD of about 10 to 20%). These results contribute to the process of acceptance of passive sampling in routine regulatory monitoring programs.
本研究的目的之一是确定水流速度对硅橡胶（SR）和低密度聚乙烯（LDPE）被动采样器对指示性多氯联苯（iPCB）的吸收的影响。第二个目的是评估性能参考化合物（PRC）对校正水流速度影响的效率。将 11 或 12 种 PRC 加入到 SR 和 LDPE 采样器中，在河流条件下使用带有河水的通道系统，在 4 种不同的流速（1.6 至 37.7cm/s）下暴露 6 周。对于每个 iPCB，都发现了流速与吸收之间的关系，这使得能够确定由于流速变化而导致的吸收的预期变化。对于两种采样器，流速从 2 增加到 10cm/s、30cm/s（插值数据）和 100cm/s（外推数据），吸收的增加都不超过 2、3 和 4.5 倍。结果还表明，当使用 SR 时，iPCB 的辛醇-水分配系数（log K（ow））增加时，流速的影响减小，而对于 LDPE，则观察到相反的效果。通过计算 iPCB 的吸收和 PRC 的释放，从 iPCB 的吸收中计算水中 iPCB 的时间加权平均（TWA）浓度。这些计算使用单个 PRC 或所有 PRC 进行。通过比较在四个测试流速下获得的 TWA 浓度，评估了 PRC 校正流速影响的效率。对于 SR，两种方法（平均 RSD<10%）都发现四个 TWA 浓度之间具有良好的一致性。对于 LDPE，PRC 也提供了对水流速度影响的良好校正（平均 RSD 约为 10%至 20%）。这些结果有助于被动采样在常规监管监测计划中的接受过程。
