2P-05 PDF
Application of mass defect-based filtering in combination with GC×GC–ToFMS for screening contaminants in environmental and biological samples
Non-target analytical techniques such as two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–ToFMS) enable the detection of a wide range of environmental contaminants. However, with complex environmental matrices, it is often difficult to quickly identify potential compounds of toxicological significance. An interesting approach for identifying the masses of similarly-structured compounds is to exploit their specific positions on the Kendrick mass defect plots1).
We implemented the mass defect-based filtering of halogenated compounds and polyaromatic hydrocarbon (PAH)-related compounds as R scripts and applied them to identify these contaminants on GC×GC–ToFMS chromatograms of environmental and biological sample extracts. The halogen filter could detected not only our routine targets such as PCBs, dioxins, organochlorine pesticides but also allowed tentative identification of several classes of non-routinely monitored compounds, including mixed brominated/chlorinated dioxins in e-waste burning soils, polychlorinated terphenyls and highly chlorinated derivatives of the pesticides DDT and chlordanes in raptors, and halogenated bipyrroles and hexahydroxanthene in piscivorous birds. The PAH filter also enabled quick identification of a large number of PAHs and their methylated derivatives in soils/sediments. Despite some limitations with very complex matrices, the mass defect-based filters are useful complementary tools of GC×GC–ToFMS for rapid identification of several classes of environmental contaminants.