Multi-residue analytical method for the determination of endocrine disruptors and related compounds in river and waste water using dual column liquid chromatography switching system coupled to mass spectrometry

The present study describes a novel, fully automated method, based on column switching using EQuan (TM) columns for an integrated sample preconcentration and liquid chromatography coupled to tandem mass spectrometry (LC-LC-MS/MS). The method allows the unequivocal identification and quantification of the most relevant environmental endocrine disruptors compounds (EDCs) and compounds suspected to be EDCs, such as natural and synthetic estrogens and their conjugates, antimicrobials, parabens, bisphenol A, alkylphenolic compounds, benzotriazoles, and organophosphorus flame retardants, in surface river water and wastewater samples. Applying this technique, water samples were directly injected into the chromatographic system and the target compounds were concentrated into the loading column. Thereafter, the analytes were transferred into the analytical column for subsequent detection by MS-MS (QqQ). A comparative study employing three types of columns, with different chemical modifications, was performed in order to determine the optimal column that allowed maximum retention and subsequent elution of the analytes. Using this new optimized methodology a fast and easy online methodology for the analysis of EDCs in surface river water and wastewater with low limits of quantification (LOQ) was obtained. LOQs ranged from 0.008 to 1.54 ng/L for surface river water and from 0.178/0.364 to 12.5/25.0 ng/L (except for alkylphenol monoethoxylates) for effluent/influent waste water. Moreover, employing approximately 1 h, a complete analysis was performed which was significant improvement in comparison to other methods reported previously. This method was used to track the presence and fate of target compounds in the Ebro River which is the most important river in Spain whose intensive agricultural and industrial activities concentrate mainly close to the main cities in the basin, deteriorating soil and water quality. (C) 2013 Elsevier B.V. All rights reserved.