Identification of non-target compounds using gas chromatography with simultaneous atomic emission and mass spectrometric detection (GC-AED/MS): analysis of municipal wastewater

Abstract

Parallel atomic emission (AED) and mass spectrometric detection (MSD) was used for the gas chromatographic (GC) analysis of non-target compounds in influent and effluent water of a sewage treatment plant. Because of their potential environmental impact, non-target analysis was mainly focused on chlorinated compounds. With solid-phase extraction (SPE, styrene–divinylbenzene copolymer adsorbent) for analyte enrichment from 25 ml of aqueous sample, detection limits were 0.2–0.5 µg l^–1 for these compounds. After screening for chlorinated compounds with AED, the essentially identical retention times observed with both detectors allowed their precise allocation in the MS total ion chromatogram. In this way, seven non-target chlorinated compounds could be identified. Furthermore, some 20 of the most abundant compounds present in the influent were also identified, and the GC profiles of the influents and effluents were compared. The removal of GC-amenable compounds in the treatment plant was 85–90%. However, several compounds, such as the flame retardants Fyrol PCF and Fyrol CEF, were not efficiently removed, and were detected in the effluent at concentrations of up to 1 µg l^–1.