Determination of 117 endocrine disruptors (EDCs) in water using SBSE TD-GC-MS/MS under the European Water Framework Directive

Abstract

The aim of this work is the highly sensitive determination of 117 contaminants in surface waters at very low concentrations. Gas chromatography-amenable priority compounds from the European Water Framework Directive (EWFD, 45 priority substances) and substances from the Turkish Regulation on the Management of Surface Water Quality (TRMSWQ, 250 substances) were analyzed. Almost a third to one half of the compounds in the TRMSWQ list were successfully detected in a single gas chromatography-tandem mass spectrometry (GC-MS/MS) injection. Analyzing these pollutants in water samples is difficult with conventional extraction methods. An efficient, easy and fast method for both extraction and analysis is thus important. Here, the stir bar sorptive extraction (SBSE) approach employing Twister(R) was used for analyte enrichment from 100 mL water samples. The Twister apparatus was used for thermal desorption. Compounds were separated via gas chromatography (GC) and detected by tandem mass spectrometry (MS/MS) utilizing an Agilent 7000D MS instrument. The analysis method was comprehensively validated, and complied with the requirements of the EWFD and Turkish regulation for surface water quality for inland surface water. The method includes various endocrine disruptor compounds listed in the EWFD, such as polychlorinated biphenyls, polycyclic aromatics hydrocarbons, polybrominated diphenyl ethers, phenols, phthalates and pesticides. The method is also applicable for the analysis of similar contaminants that are not on this list. The analyzed pollutants have varying polarities based on octanol-water coefficients and are extracted by SBSE. This method may be preferred for the analysis of pollutants with an octanol-water partition coefficient (log Ko/w) higher than 2. The SBSE method, which is easy, lab-friendly and quick, taking a total of only 2 h for parameter analysis, was optimized to reduce time and chemical usage. The entire extraction and analysis was completed in virtually 3 h. The limits of quantification (LOQs) ranged from 0.12 to 50 ng/L and complied with the requirements for analytical methods to be used in the analysis of the compounds included in the directives. Several quality parameters including linearity, trueness and precision were studied, with good results, and uncertainty was also estimated. Precision (in terms of relative standard deviation [RSD]) was lower than 40%, recoveries ranged from 60 to 120%, and determination coefficients were higher than 0.990 for all analytes.