Samanipour Saer, Dimitriou-Christidis Petros, Nabi Deedar, Arey J Samuel
School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), ENAC IIE LMCE GR C2 544 Station 2, 1015 Lausanne, Switzerland.
Norwegian Institute for Water Research, Gaustadalléen 21, 0349 Oslo, Norway.
ACS Omega. 2017 Feb 22;2(2):641-652. doi: 10.1021/acsomega.6b00440. eCollection 2017 Feb 28.
We quantified the concentrations of two little-studied brominated pollutants, 1,3,5-tribromobenzene (TBB) and 4-bromobiphenyl (4BBP), in the deep water column and sediments of Lake Geneva. We found aqueous concentrations of 625 ± 68 pg L for TBB and 668 ± 86 pg L for 4BBP over a depth range of 70-191.5 m (near-bottom depth), based on duplicate measurements taken at five depths during three separate 1 month sampling periods at our sampling site near Vidy Bay. These levels of TBB and 4BBP were 1 or 2 orders of magnitude higher than the quantified aqueous concentrations of the components of the pentabrominated biphenyl ether technical mixture, which is a flame retardant product that had a high production volume in Europe before 2001. We observed statistically significant vertical concentration trends for both TBB and 2,2',4,4',6-pentabromobiphenyl ether in the deep water column, which indicates that transport and/or degradation processes affect these compounds. These measurements were enabled by application of a comprehensive two-dimensional gas chromatograph coupled to an electron capture negative chemical ionization time-of-flight mass spectrometer (GC×GC-ENCI-TOFMS) and to a micro-electron capture detector (GC×GC-μECD). GC×GC-ENCI-TOFMS and GC×GC-μECD were found to be >10× more sensitive toward brominated pollutants than conventional GC×GC-EI-TOFMS (with an electron impact (EI) ionization source), the latter of which had insufficient sensitivity to detect these emerging brominated pollutants in the analyzed samples. GC×GC also enabled the estimation of several environmentally relevant partitioning properties of TBB and 4BBP, further confirming previous evidence that these pollutants are bioaccumulative and have long-range transport potential.
我们对日内瓦湖深水区水柱和沉积物中两种研究较少的溴化污染物——1,3,5-三溴苯（TBB）和4-溴联苯（4BBP）的浓度进行了量化。基于在维迪湾附近采样点进行的三个独立的1个月采样期内，在五个深度处进行的重复测量，我们发现在70 - 191.5米（近底部深度）的深度范围内，TBB的水体浓度为625 ± 68皮克/升，4BBP的水体浓度为668 ± 86皮克/升。这些TBB和4BBP的浓度水平比五溴联苯醚技术混合物各成分的量化水体浓度高1或2个数量级，五溴联苯醚技术混合物是一种阻燃产品，2001年前在欧洲产量很高。我们观察到深水区水柱中TBB和2,2',4,4',6-五溴联苯醚的垂直浓度趋势具有统计学意义，这表明运输和/或降解过程会影响这些化合物。这些测量通过使用与电子捕获负离子化学电离飞行时间质谱仪（GC×GC - ENCI - TOFMS）和微电子捕获检测器（GC×GC - μECD）联用的综合二维气相色谱仪得以实现。结果发现，与传统的GC×GC - EI - TOFMS（带有电子轰击（EI）电离源）相比，GC×GC - ENCI - TOFMS和GC×GC - μECD对溴化污染物的灵敏度高10倍以上，而后者灵敏度不足，无法检测分析样品中这些新出现的溴化污染物。GC×GC还能够估算TBB和4BBP的几种与环境相关的分配特性，进一步证实了之前的证据，即这些污染物具有生物累积性和远距离传输潜力。
