Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, 8092 Zürich, Switzerland.
Swiss Centre for Applied Ecotoxicology Eawag-EPFL, 8600 Dübendorf, Switzerland.
Water Res. 2015 Mar 15;71:306-17. doi: 10.1016/j.watres.2014.12.043. Epub 2014 Dec 31.
In a large field study, the in-situ calibration of the Chemcatcher(®) passive sampler - styrenedivinylbenzene (SDB) covered by a polyether sulfone (PES) membrane - was evaluated for 322 polar organic micropollutants. Five rivers with different agricultural and urban influences were monitored from March to July 2012 with two methods i) two-week time-proportional composite water samples and ii) two-week passive sampler deployment. All substances - from different substance classes with logKow -3 to 5, and neutral, anionic, cationic, and zwitterionic species - were analyzed by liquid-chromatography high-resolution tandem mass spectrometry. This study showed that SDB passive samplers are well-suited for the qualitative screening of polar micropollutants because the number of detected substances was similar (204 for SDB samples vs. 207 for composite water samples), limits of quantification were comparable (median: 1.3 ng/L vs. 1.6 ng/L), and the handling in the field and laboratory is fast and easy. The determination of in-situ calibrated sampling rates (field Rs) was possible for 88 compounds where the R(2) from the regression (water concentration vs. sampled mass on SDB disk) was >0.75. Substances with moderately fluctuating river concentrations such as pharmaceuticals showed much better correlations than substances with highly fluctuating concentrations such as pesticides (R(2) > 0.75 for 93% and 60% of the investigated substances, respectively). Flow velocity (0.05-0.8 m/s) and temperature (5-20 °C) did not have an evident effect on the field Rs. It was observed that ionic species had significantly lower field Rs than neutral species. Due to the complexity of the different transport processes, a correlation between determined field Rs and logDow could only predict Rs with large uncertainties. We conclude that only substances with relatively constant river concentrations can be quantified accurately in the field by passive sampling if substance-specific Rs are determined. For that purpose, the proposed in-situ calibration is a very robust method and the substance specific Rs can be used in future monitoring studies in rivers with similar environmental conditions (i.e., flow velocity, temperature, pH).
在一项大型野外研究中，评估了原位校准 Chemcatcher（®）被动采样器 - 苯乙烯二乙烯基苯（SDB）覆盖的聚醚砜（PES）膜 - 用于 322 种极性有机微量污染物。从 2012 年 3 月到 7 月，监测了 5 条受农业和城市影响不同的河流，采用两种方法：i）两周时间比例复合水样和 ii）两周被动采样器部署。所有物质 - 从不同物质类别，logKow 为-3 到 5，以及中性、阴离子、阳离子和两性离子 - 均通过液相色谱高分辨串联质谱法进行分析。这项研究表明，SDB 被动采样器非常适合极性微量污染物的定性筛选，因为检测到的物质数量相似（SDB 样品为 204 种，复合水样为 207 种），定量限相当（中位数：1.3ng/L 对 1.6ng/L），野外和实验室的处理快速简便。对于 88 种化合物，可以确定原位校准的采样速率（现场 Rs），其中回归（水样浓度与 SDB 盘上采样量）的 R2>0.75。与浓度波动较大的物质（如农药）相比，浓度波动较大的物质（如药品）的相关性要好得多（分别有 93%和 60%的研究物质的 R2>0.75）。流速（0.05-0.8m/s）和温度（5-20°C）对现场 Rs 没有明显影响。观察到离子物质的现场 Rs 明显低于中性物质。由于不同传输过程的复杂性，确定的现场 Rs 与 logDow 之间的相关性只能预测具有较大不确定性的 Rs。我们得出结论，如果通过被动采样准确量化河流中的物质浓度，则只能对具有相对恒定河流浓度的物质进行准确量化。为此，提出的原位校准是一种非常稳健的方法，可以在具有相似环境条件（即流速、温度、pH 值）的河流中，将特定物质的 Rs 用于未来的监测研究。
