Aquatic Ecosystems Protection Research Division, Environment Canada, Montreal, QC, Canada H2Y 2E7.
Chemosphere. 2011 Aug;84(8):1085-94. doi: 10.1016/j.chemosphere.2011.04.056. Epub 2011 May 12.
A new approach for the identification of suspect trace organic contaminants in drinking and surface waters is presented. Samples were initially analyzed using a target determination method for two contamination tracers, carbamazepine (CBZ) and atrazine (ATZ). This method used offline solid-phase extraction and online solid-phase extraction techniques coupled to liquid chromatography-triple quadrupole mass spectrometry to accelerate the sample preparation process and improve method performance. CBZ and ATZ were found respectively in 31% and 56% of the samples, and concentrations were usually <20 ng L(-1). These samples were re-analyzed with a similar method on a quadrupole time-of-flight mass spectrometer to identify suspect contaminants by means of exact mass measurements and isotope patterns. A database of 264 common organic contaminants was built and used in conjunction with a Molecular Feature algorithm to identify the presence of these substances in drinking and surface water collected from different sources at various locations across Canada. Several organic contaminants were identified in the samples, but only the presence of caffeine, desethylatrazine, simazine and venlafaxine could be verified by comparison to pure standards. The presence of desethylatrazine was also confirmed by MS/MS experiments. These results suggest that target analysis for tracers of organic contamination may be a helpful tool to prioritize samples which should be further screened for suspect contaminants. This study also shows that the combination of separation techniques (offline and online SPE, LC) contribute to advance the applicability of high-resolution mass spectrometry for the identification of trace organic contaminants by accelerating the preparation step, reducing complexity and increasing analyte concentrations for optimal detection.
提出了一种用于识别饮用水和地表水中可疑痕量有机污染物的新方法。最初使用针对两种污染示踪剂卡马西平 (CBZ) 和莠去津 (ATZ) 的目标测定方法对样品进行分析。该方法使用离线固相萃取和在线固相萃取技术与液相色谱-三重四极杆质谱联用，以加速样品制备过程并提高方法性能。在 31%的样品中分别发现了 CBZ 和 ATZ，浓度通常<20ngL(-1)。使用类似的方法在四极杆飞行时间质谱仪上重新分析这些样品，通过精确质量测量和同位素模式来识别可疑污染物。建立了一个包含 264 种常见有机污染物的数据库，并结合分子特征算法，用于识别从加拿大各地不同来源采集的饮用水和地表水中这些物质的存在。在样品中鉴定出几种有机污染物，但仅通过与纯标准品比较可以验证咖啡因、去乙基莠去津、西玛津和文拉法辛的存在。通过 MS/MS 实验也证实了去乙基莠去津的存在。这些结果表明，针对有机污染示踪剂的目标分析可能是一种有用的工具，可以优先对应该进一步筛选可疑污染物的样品。本研究还表明，分离技术（离线和在线 SPE、LC）的组合有助于通过加速制备步骤、降低复杂性和增加分析物浓度来提高痕量有机污染物的高分辨率质谱分析的适用性，从而实现最佳检测。
