Mkhize Dennis S, Quinn Laura P, Nyoni Hlengilizwe, Mamba Bhekie B, Msagati Titus A M
National Metrology Institute of South Africa, Private Bag X34, Lynnwood Ridge, 0040, Pretoria, South Africa; Department of Applied Chemistry, Faculty of Science, University of Johannesburg, Doornfontein Campus, P.O. Box 17011, Johannesburg, 2028, South Africa.
National Metrology Institute of South Africa, Private Bag X34, Lynnwood Ridge, 0040, Pretoria, South Africa.
Water Sci Technol. 2019 Mar;79(5):808-819. doi: 10.2166/wst.2019.044.
A passive sampling device, based on molecularly imprinted membranes (MIM), was fabricated and optimised for sampling polychlorinated biphenyls (PCBs) in aquatic ecosystems. The newly-developed passive sampler was subjected to in-situ calibration studies to determine PCB sampling rates under various conditions of water turbulence and temperature. This was carried out by exposing the passive samplers to water spiked with PCBs in a continuous-flow exposure setup. The samplers were preloaded with known concentrations of performance reference compounds (PRCs) prior to exposure. Sampling rates of seven indicator PCBs' congeners (PCBs 28, 52, 101, 118, 138, 153 and 180) ranged between 15.3 and 95.6 L/d for the different environmental conditions investigated. To determine the field suitability, the samplers were preloaded with PRCs and deployed for 10 days at the Roodeplaat and Hartbeespoort Dams, in South Africa. Water samples were taken at the end of the deployment period to compare the spot-and-grab samples to the developed samplers. PCBs 28, 101 and 138 were detected in the samplers deployed at Hartbeespoort Dam. The samplers deployed at the Roodeplaat Dam had quantifiable amounts of PCBs 28, 52, 101, 138 and 180 (0.047-0.828 ng mL d). The sampler enhanced the detectability of PCB 52 and PCB 180, which were not detected in water samples. The field suitability trials indicated that the developed sampler could successfully be used for PCB monitoring. The sampler enhanced the detection of PCBs that would otherwise be too low to detect in samples collected through the traditional spot-and-grab sampling technique.
一种基于分子印迹膜（MIM）的被动采样装置被制造出来并进行了优化，用于在水生生态系统中采样多氯联苯（PCBs）。新开发的被动采样器进行了现场校准研究，以确定在不同水动力和温度条件下的多氯联苯采样率。这是通过在连续流动暴露装置中将被动采样器暴露于添加了多氯联苯的水中来实现的。在暴露之前，采样器预先加载了已知浓度的性能参考化合物（PRCs）。在所研究的不同环境条件下，七种指示性多氯联苯同系物（多氯联苯28、52、101、118、138、153和180）的采样率在15.3至95.6升/天之间。为了确定现场适用性，采样器预先加载了性能参考化合物，并在南非的鲁德普拉特和哈特比斯波特大坝部署了10天。在部署期结束时采集水样，将即时采集的水样与开发的采样器进行比较。在哈特比斯波特大坝部署的采样器中检测到了多氯联苯28、101和138。在鲁德普拉特大坝部署的采样器中检测到了可量化的多氯联苯28、52、101、138和180（0.047 - 0.828纳克/毫升·天）。该采样器提高了多氯联苯52和多氯联苯180的可检测性，而在水样中未检测到这两种物质。现场适用性试验表明，开发的采样器可成功用于多氯联苯监测。该采样器提高了多氯联苯的检测能力，否则通过传统的即时采集采样技术采集到的样品中多氯联苯含量过低而无法检测。
