Public Health Laboratory, Minnesota Department of Health, Saint Paul, Minnesota, United States.
Chemosphere. 2021 Mar;266:128961. doi: 10.1016/j.chemosphere.2020.128961. Epub 2020 Nov 12.
Eight samples were obtained to characterize the chemical loads in water recycled for reuse applications. The sources included stormwater, rooftop runoff, wastewater, mixed water, and drinking water as a comparison. The water was reused for irrigation, cleaning, toilet flushing, and cooling purposes. Large-volume injection (650 μL) high-performance liquid chromatography and quadrupole time-of-flight mass spectrometry were employed to separate and detect features by suspect and non-target screening. The instrumental method had the advantage that no sample extractions were required prior to analysis. Two chromatographic methods were developed to separate positive- and negative-ionizing compounds and retention time models were developed for both. Retention time models provide an additional measure of confidence for probable and tentative identifications. The two models had predictive R-which indicates how well the models predicts new observations-of 0.87. After data-reduction, the number of features detected in the samples ranged from 304 to 1513. Feature metrics such as the average response-per-feature provided a simple method to characterize similarities and differences between samples. Additionally, a statistical comparison was performed by principal component analysis. Of the 97 suspect-screening compounds, 20 were positively identified. Benzotriazole/benzothiazole-derivatives and per- and poly-fluoroalkyl substances were the most frequently detectedcompounds during suspect screening. Other compounds detected included pharmaceuticals, drug metabolites, and sucralose. Features were prioritized for non-target analysis based on in-house library matches, magnitude of response, and frequency of occurrence. Fifty-five unique compounds were positively identified via non-target analysis. The identified compounds included 17 pharmaceuticals, 17 pesticides, 13 industrial compounds, four personal-use compounds, and four biological compounds.
共采集了 8 个样本，以表征用于再利用的循环水的化学负荷。这些样本的来源包括雨水、屋顶径流、污水、混合水和饮用水。这些水被用于灌溉、清洁、冲洗厕所和冷却等用途。采用大体积进样（650μL）高效液相色谱和四极杆飞行时间质谱进行分离和检测，通过嫌疑筛查和非靶向筛查来识别特征。该仪器方法的优点是在分析之前不需要进行样品提取。开发了两种色谱方法来分离正离子化和负离子化化合物，并为两者建立了保留时间模型。保留时间模型为可能的和暂定的鉴定提供了额外的置信度度量。这两个模型的预测 R 值（表示模型对新观测值的预测程度）为 0.87。经过数据缩减，从样品中检测到的特征数量范围为 304 到 1513。特征指标，如每个特征的平均响应，可以简单地描述样品之间的相似性和差异。此外，还通过主成分分析进行了统计比较。在 97 种可疑筛查化合物中，有 20 种被阳性鉴定。苯并三唑/苯并噻唑衍生物和全氟及多氟烷基物质是可疑筛查中最常检测到的化合物。其他检测到的化合物包括药物、药物代谢物和三氯蔗糖。根据内部库匹配、响应幅度和出现频率，对非靶向分析的特征进行了优先级排序。通过非靶向分析，共鉴定出 55 种独特的化合物。鉴定出的化合物包括 17 种药物、17 种农药、13 种工业化合物、4 种个人使用化合物和 4 种生物化合物。
