Automated and simultaneous determination of priority substances and polychlorinated biphenyls in wastewater using headspace solid phase microextraction and high resolution mass spectrometry

Highlights: • A fully automated method for the determination of organic pollutants was developed. • The combination of on-line HS-SPME with highly sensitive HRMS has been proposed. • The method involved the simultaneous monitoring of pesticides, PCBs, PAHs and BDEs. • The developed method resulted robust, reliable and highly sensitive and selective. • Pesticides, PAHs and PCBs were detected in wastewater samples. - Abstract: The re-use of wastewater has been in growing demand but a possible negative feature is the possibility of organic pollutants being present after its treatment. In order to control the presence of contaminants in wastewater, a completely automated methodology capable of determining a total of 55 organic pollutants including pesticides, polycyclic aromatic hydrocarbons (PAHs), brominated diphenyl ethers (BDEs) and polychlorinated biphenyls (PCBs) at ultra-trace levels has been developed. The proposed method is based on an on-line combination of headspace solid phase microextraction (HS-SPME) and gas chromatography coupled to double-focusing magnetic sector high resolution mass spectrometry (GC-HRMS). HS-SPME as well as GC-HRMS conditions were optimized so as to achieve maximum extraction efficiency and sensitivity which was reinforced by using multiple ion detection (MID) as acquisition mode. Special attention was directed to fiber conditioning and stability by calorimetric and scanning electron microscopy (SEM) analysis. Method validation showed good linearity (R² > 0.99), recoveries between 86 and 113%, relative standard deviation (RSD) values −1. Finally, the proposed method was successfully applied to wastewater samples revealing the presence of PAHs and PCBs_S and certain pesticides, mainly anthracene, chlorpyrifos, p,p'-DDD and p,p'-DDT and the metabolite p,p'-DDE.