Use of electron ionization and atmospheric pressure chemical ionization in gas chromatography coupled to time-of-flight mass spectrometry for screening and identification of organic pollutants in waters

• Published in: Journal of Chromatography A 2014-04, Vol.1339, p.145-153
• Main Authors: Portolés, Tania, Mol, Johannes G.J., Sancho, Juan V., Hernández, Félix
• Format: Article
• Language: English
• Subjects: Analysis methods; Analytical chemistry; Applied sciences; Atmospheric pressure; Atmospheric pressure chemical ionization; Barometric pressure; Chemistry; Chromatographic methods and physical methods associated with chromatography; Contaminants; Emerging pollutants; Exact sciences and technology; Gas chromatographic methods; Gas chromatography; Hybrid quadrupole time-of-flight mass spectrometry; Ionization; Mass spectrometry; Natural water pollution; Pesticides; Pollution; Polycyclic aromatic hydrocarbons; Screening; Water samples; Water treatment and pollution
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2014.03.001

•The new APCI designed for GC promotes soft ionization.•Wide scope screening is favoured by the expected presence of the M+·/MH+.•Fragmentation occurred under MSE acquisition mode allows identity confirmation. A new approach has been developed for multiclass screening of organic contaminants in water based on the use of gas chromatography coupled to hybrid quadrupole high-resolution time-of-flight mass spectrometry with atmospheric pressure chemical ionization (GC–(APCI)QTOF MS). The soft ionization promoted by the APCI source allows effective and wide-scope screening based on the investigation of the molecular ion and/or protonated molecule. This is in contrast to electron ionization (EI) where ionization typically results in extensive fragmentation, and diagnostic ions and/or spectra need to be known a priori to facilitate detection of the analytes in the raw data. Around 170 organic contaminants from different chemical families were initially investigated by both approaches, i.e. GC-(EI)TOF and GC-(APCI)QTOF, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and a notable number of pesticides and relevant metabolites. The new GC–(APCI)QTOF MS approach easily allowed widening the number of compounds investigated (85 additional compounds), with more pesticides, personal care products (UV filters, musks), polychloronaphthalenes (PCNs), antimicrobials, insect repellents, etc., most of them considered as emerging contaminants. Both GC-(EI)TOF and GC-(APCI)QTOF methodologies have been applied, evaluating their potential for a wide-scope screening in the environmental field.