Identification of hydroxyhalobiphenyls as their methyl ethers by gas chromatography mass spectrometry

Abstract

The mass spectra and gas chromatographic properties of 17 synthetic fluoro-, chloro- and bromomethoxy-biphenyls and 12 dichlorodimethoxybiphenyls have been examined. From this representative series it appears that the position of the methoxy group (ortho, meta and para to the biphenyl bond) in all monomethoxy compounds examined, and the positions of the two methoxy groups in most of the dimethoxy compounds, can be assigned unambiguously by their difference in fragmentation pattern. The value of this method was shown by metabolism experiments in which 4,4'-difluoro- and 4,4'-dibromobiphenyl were fed to rats and 4,4'-dichlorobiphenyl was administered to plants. All hydroxylated metabolites found were identified by gas chromatography mass spectrometry. Relationships between structure and gas chromatographic retention time of these compounds are discussed.

Potential chlorinated and brominated interferences on the polybrominated diphenyl ether determinations by gas chromatography–mass spectrometry

“…This fragment corresponded to CH 3 Br loss. The same fragmentation is well documented for ortho methoxy polychlorinated and polybrominated biphenyls [21,22]. The m/z 418 fragment could interfere with mass ion selected to monitor 13 C-penta-BDEs, used as internal standard in the isotopic dilution methodologies (Table 3).…”

Oxidation of chlorobenzene with Fenton's reagent

“…These peaks were tentatively identified as hydroxymonochlorobiphenyls or hydroxydichlorobiphenyls on the basis of the results of a computerized search of the " Retention time in minutes on column used for quantification. 6 Method of GC/MS identification: std, matched with mass spectra and retention times of standard; NBS, compared with NBS mass spectral database and spectra described by Tulp et al (14). 6 Method used for quantification.…”

Identification and Quantification of Polybrominated Diphenyl Ethers and Methoxy-Polybrominated Diphenyl Ethers in Baltic Biota

“…The m/z 418 ion is probably a result of a CH3Br loss. This type of fragmentation is well documented for ortho methoxy polychlorinated and polybrominated biphenyls (19,20). It can be attributed to a cyclization reaction in which the oxygen of an ortho methoxy group on one of the diphenyl ether rings attacks an ortho halogen (X) of the other ring, with a loss of CH 3X as the result.…”