Automatic Searching and Evaluation of Priority and Emerging Contaminants in Wastewater and River Water by Stir Bar Sorptive Extraction followed by Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry

摘要

A new analytical method based on stir bar sorptive extraction (SBSE), followed by comprehensive two-dimensional gasnchromatography (GCxGC-TOF-MS), has been developed for the automatic searching and evaluation of nonpolar or semipolarncontaminants in wastewater and river water. The target compounds selected were 13 personal care products (PCPs), 15 polycyclicnaromatic hydrocarbons (PAHs) and 27 pesticides. Excellent results have been obtained in terms of separation efficiency and also innterms of compound identification. Exceptionalmethod detection limits were achieved applying the optimizedmethod, at or below 1nng/L formost of the compounds in real samples. The reliable confirmation of analyte identity was possible at this low concentrationnlevel, even for typically troublesome compounds such as the PAHs. The other validation parameters were good. In addition tonobtaining analytical information such as identification and quantification of target analytes, it is also possible to screen for nontargetncompounds or unknowns. New contaminants have been identified in the wastewater effluents and river water samples, such asncholesterol and its degradation products, pharmaceuticals, industrial products, other pesticides, and PCPs. The multidimensionalninformation generated by the instrument can also be used by the researchers for contrasting samples and identifying, much moreneasily, the major differences between samples. We have used this feature to propose studies of comparison between thenfingerprinting of different water samples, such as the contamination variation along a river affected by the discharge of urbannwastewaters and also the contamination variation over a period of time in the effluent. Results show that the most frequentlyndetected contaminants (and the contaminants detected at higher concentrations) were the PCPs. The musk fragrances galaxolidenand tonalid were the most concentrated compounds in the samples. The pesticides and PAHs were present at much lowernconcentration than PCPs.