title: Deconvolution of Soft Ionization Mass Spectra of Chlorinated Paraffins To Resolve Congener Groups.
abstract: We describe and illustrate a three-step data-processing approach that enables individual congener groups of chlorinated paraffins (CPs) to be resolved in mass spectra obtained from either of two soft ionization methods: electron capture negative ionization mass spectrometry (ECNI-MS) or atmospheric pressure chemical ionization mass spectrometry (APCI-MS). In the first step, general fragmentation pathways of CPs are deduced from analysis of mass spectra of individual CP congeners. In the second step, all possible fragment ions in the general fragmentation pathways of CPs with 10 to 20 carbon atoms are enumerated and compared to mass spectra of CP mixture standards, and a deconvolution algorithm is applied to identify fragment ions that are actually observed. In the third step, isotope permutations of the observed fragment ions are calculated and used to identify isobaric overlaps, so that mass intensities of individual CP congener groups can be deconvolved from the unresolved isobaric ion signal intensities in mass spectra. For a specific instrument, the three steps only need to be done once to enable deconvolution of CPs in unknown samples. This approach enables congener group-level resolution of CP mixtures in environmental samples, and it opens up the possibility for quantification of congener groups.
authors.affiliation: Department of Environmental Science and Analytical Chemistry, Stockholm University , Svante Arrhenius väg 8, SE-10691 Stockholm, Sweden.
authors.forename: Bo
authors.initials: B
authors.lastname: Yuan
authors.affiliation: Department of Environmental Science and Analytical Chemistry, Stockholm University , Svante Arrhenius väg 8, SE-10691 Stockholm, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Alsberg
authors.affiliation: Institute for Chemical and Bioengineering, Swiss Federal Institute of Technology, ETH Zürich , Vladimir-Prelog-Weg 1, CH-8093 Zürich, Switzerland.|Institute for Sustainability Sciences , Agroscope, Reckenholzstrasse 191, CH-8046 Zürich, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Bogdal
authors.affiliation: Department of Environmental Science and Analytical Chemistry, Stockholm University , Svante Arrhenius väg 8, SE-10691 Stockholm, Sweden.
authors.forename: Matthew
authors.initials: M
authors.lastname: MacLeod
authors.affiliation: Department Analytical Chemistry, Helmholtz Centre for Environmental Research-UFZ , Permoserstraße 15, DE-04318 Leipzig, Germany.
authors.forename: Urs
authors.initials: U
authors.lastname: Berger
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Shuangqing Road 18, CN-100085 Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Shuangqing Road 18, CN-100085 Beijing, China.
authors.forename: Yawei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Environmental Science and Analytical Chemistry, Stockholm University , Svante Arrhenius väg 8, SE-10691 Stockholm, Sweden.
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: de Wit