Department of Sanitary Engineering, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, The Netherlands.
Anal Chim Acta. 2011 Aug 26;700(1-2):114-25. doi: 10.1016/j.aca.2010.12.040. Epub 2011 Jan 14.
The influence of natural organic matter on the screening of pharmaceuticals in water was determined by using high resolution liquid chromatography (HRLC) combined with full scan mass spectrometry (MS) techniques like time of flight (ToF) or Orbitrap MS. Water samples containing different amount of natural organic matter (NOM) and residues of a set of 11 pharmaceuticals were analyzed by using Exactive Orbitrap™ LC-MS. The samples were screened for residues of pharmaceuticals belonging to different classes like benzimidazoles, macrolides, penicillins, quinolones, sulfonamides, tetracyclines, tranquillizers, non-steroidal anti-inflammatory drugs (NSAIDs), anti-epileptics and lipid regulators. The method characteristics were established over a concentration range of 0.1-500 μg L(-1). The 11 pharmaceuticals were added to two effluent and two influent water samples. The NOM concentration within the samples ranged from 2 to 8 mg L(-1) of dissolved organic carbon. The HRLC-Exactive Orbitrap™ LC-MS system was set at a resolution of 50,000 (FWHM) and this selection was found sufficient for the detection of the list of pharmaceuticals. With this resolution setting, accurate mass measurements with errors below 2 ppm were found, despite of the NOM concentration of the different types of water samples. The linearities were acceptable with correlation coefficients greater than 0.95 for 30 of the 51 measured linearities. The limit of detection varies between 0.1 μg L(-1)and 100 μg L(-1). It was demonstrated that sensitivity could be affected by matrix constituents in both directions of signal reduction or enhancement. Finally it was concluded that with direct shoot method used (no sample pretreatment) all compounds, were detected but LODs depend on matrix-analyte-concentration combination. No direct relation was observed between NOM concentration and method characteristics. For accurate quantification the use of internal standards and/or sample clean-up is necessary. The direct shoot method is only applicable for qualitative screening purposes. The use of full scan MS makes it possible to search for unknown contaminants. With the use of adequate software and a database containing more than 50,000 entries a tool is available to search for unknowns.
采用高分辨液相色谱（HRLC）结合飞行时间（ToF）或轨道阱 MS 等全扫描质谱（MS）技术，研究了天然有机物（NOM）对水中药物筛选的影响。采用 Exactive OrbitrapTM LC-MS 对含有不同量 NOM 和一组 11 种药物残留的水样进行分析。该方法对属于不同类别的药物（如苯并咪唑类、大环内酯类、青霉素类、喹诺酮类、磺胺类、四环素类、镇静剂、非甾体抗炎药（NSAIDs）、抗癫痫药和脂质调节剂）的残留进行了筛选。该方法在 0.1-500μg/L 的浓度范围内建立了方法特征。11 种药物分别添加到两个出水和两个进水水样中。水样中 NOM 浓度范围为 2-8mg/L 的溶解有机碳。HRLC-Exactive OrbitrapTM LC-MS 系统的分辨率设定为 50,000（半峰全宽），该分辨率足以检测到所列药物。在这种分辨率设置下，即使在不同类型水样的 NOM 浓度下，也可以发现误差低于 2 ppm 的准确质量测量。30 个测量线性中，有 30 个的相关系数大于 0.95，线性关系良好。检测限在 0.1μg/L 到 100μg/L 之间变化。结果表明，基质成分既可以降低信号，也可以增强信号，从而影响灵敏度。最后得出结论，采用直接进样法（无需样品预处理）可以检测到所有化合物，但检测限取决于基质-分析物-浓度的组合。未观察到 NOM 浓度与方法特征之间存在直接关系。为了进行准确的定量，需要使用内标和/或样品净化。直接进样法仅适用于定性筛选目的。全扫描 MS 的使用使得搜索未知污染物成为可能。使用适当的软件和包含 50,000 多个条目的数据库，可以搜索未知物。
