title: Differences in the chromatographic and mass spectral properties of 3,3',5,5'-tetrachlorodiphenoquinone and 2,3,7,8-tetrachlorodibenzo-p-dioxin.
abstract: Tetrachlorodiphenoquinones have the same exact mass and elemental composition as the toxic environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin. However, analysis of 3,3'-5,5'-tetrachlorodiphenoquinone showed a pronounced tendency toward chemical reduction in the mass spectrometer to the quinol compound, producing a molecular ion two mass units higher than 2,3,7,8-tetrachlorodibenzo-p-dioxin. Distinct differences were also apparent between the mass spectral fragmentation patterns of 3,3',5,5'-tetrachlorodiphenoquinone and 2,3,7,8-tetrachloridibenzo-p-dioxin. The 3,3',5,5'-tetrachlorodiphenoquinone spectrum shows a successive loss of carbon monoxide, with the most prominent fragment corresponding to loss of two molecules of carbon monoxide plus chlorine. In the mass fragmentation of 2,3,7,8-tetrachlorodibenzo-p-dioxin carbon monoxide loss is suppressed, but loss of one molecule of carbon monoxide plus chlorine is a major fragment ion. During an alumina column clean-up procedure 3,3',5,5'-tetrachlorodiphenoquinone did not coelute with the fraction containing 2,3,7,8-tetrachlorodibenzo-p-dioxin. This evidence indicates that tetrachlorodiphenoquinones are unlikely to interfere with mass spectrometric determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin in environmental samples.
mesh_terms: D016227:Benzoquinones; D002855:Chromatography, Thin Layer / Q000379:methods; D004147:Dioxins; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D007536:Isomerism; D013058:Mass Spectrometry / Q000379:methods; D000072317:Polychlorinated Dibenzodioxins; D011809:Quinones; D013053:Spectrophotometry; D013329:Structure-Activity Relationship
chemical_list: D016227:Benzoquinones; D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins; D011809:Quinones; C048435:3,3'5,5'-tetrachlorodiphenoquinone