Pulsed Large Volume Injection Gas Chromatography Coupled with Electron-Capture Negative Ionization Quadrupole Mass Spectrometry for Simultaneous Determination of Typical Halogenated Persistent Organic Pollutants

A pulsed large-volume injection gas chromatography coupled with electron-capture negative ionization quadrupole mass spectrometry (pLVI-GC/ECNI-qMS) was developed for the simultaneous determination of typical halogenated persistent organic pollutants (H-POPs). By monitoring the characteristic ions of large mass-to-charge ratio (m/z) for each of the H-POPs rather than the chlorine and/or bromine ions, this method avoided the possible interferences arising from the H-POPs themselves and from complex matrices encountered frequently in current GC/qMS methods; and allowed, on the other hand, the use of 13C-labeled and perdeuterated analogues as internal standards for reliable quantification. pLVI up to 120 μL improved the instrumental detection limits down to pg–fg mL−1, comparable to or lower than those obtained by the recognized GC/high-resolution MS methods reported so far. The H-POPs including 12 polybrominated diphenyl ethers, 1 polybrominated biphenyl, 10 polychlorinated biphenyls (PCBs), 4 hexachlorocyclohexane isomers, and hexachlorobenzene were involved in this study. The method developed demonstrated good linearity (r2 = 0.9904–0.9999) within 0.5 to 50,000 pg mL−1 for PCBs and 0.05 to 5000 pg mL−1 for other H-POPs, and was satisfactory in terms of both repeatability (0.07%–2.2%) and reproducibility (2.1%–8.4%). It was validated by analyzing a NIST standard reference material SRM-1946 of Lake Superior fish tissue with low 0.01 to 63 pg g−1 method detection limits, and successfully applied to the determination of the H-POPs in five reference materials of different matrices.