A contemporary gas chromatography-electron capture detection (GC-ECD) method for regulatory analysis of polybrominated diphenyl ethers (PBDEs) in unfiltered secondary-treated wastewater.

Polybrominated diphenyl ethers (PBDEs), a class of flame retardants used extensively in consumer products, have become ecological and public health hazards. Monitoring exposure to them has therefore become a priority as well. At the request of a regulating body, a cost-effective GC-ECD method that exploits advances in gas chromatography was developed in this study to monitor particularly PBDE-28, 47, 99, 100, 153, 154, 183 and 209 in treated municipal wastewater. The proposed method utilizes a programmable injector, an injection volume splitter, and two short open capillary columns (DB-5XLB and DB-5MS) in additoin to a pair of Ni-based halogen-specific electron capture detectors to analyze the PBDEs. All eight PBDEs and PCB-209 surrogate are baseline resolved within a 0.02 min retention time window. The analytes were also recovered quantitatively from single injections of fortified wastewater extracts (range: 76.2-101 % with relative percent deviation range: 2.4-11.7 %). The method detection limits were 1.0-3.4 ng/L for smaller PBDEs and 40 ng/L for PBDE-209. For quantitation, 16 six-point concentration calibration curves, eight for each column, were generated. The relative standard deviations range associated with the curves was 1.6-12 % (r > 0.998) for smaller PBDEs and 26-45 % (r: 0.984-0.994) for PBDE-209. Additionally, DB-5MS retention times (t range: 6.85-18.40 min) were found to relate strongly with DB-XLB retention times (t: 7.03-23.32 min) by the polynomial t =-0.02[t] + 1.33[t]-1.94 (r² =0.9997). The relationship suggests that the 182 congeners larger than PBDE-27, but not included here, could be detected and quantified by the proposed method.