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Mass spectral identification and gas chromatographic determination of chlorinated bleaching adducts in flour-containing food items

Heikes, D.L.
Journal of agricultural and food chemistry 1992 v.40 no.3 pp. 489-491
foods, food contamination, chlorinated hydrocarbons, esters, herbicides, flour, United States
Bakery products and other flour-containing food items from the Food and Drug Administration's Total Diet Program were found to contain a series of unusual halogenated compounds when analyzed by a procedure designed for the gas chromatographic determination of chlorophenoxy alkyl acid herbicides as their methyl esters. These compounds were shown to occur in bleached flours and were not present in unbleached flours. Thus, they were assumed to be flour-bleaching adducts. Gas chromatography-mass spectrometry with chemical ionization (ethylene oxide) proved useful for the characterization of chlorinated derivatives of indigenous fatty acids: oleic, (Z)-9-octadecenoic acid, and linoleic, (Z,Z)-9,12-octadecadienoic, acid. Thus, 9,10-dichlorooctadecanoic acid, 9,10-dichloro-12-octadecenoic acid, 12,13-dichloro-9-octadecenoic acid, 9,10,12,13-tetrachlorooctadecanoic acid, 9-chloro-10-hydroxyoctadecanoic acid, 10-chloro-9-hydroxyoctadecanoic acid, isomers of chlorohydroxyoctadecenoic acid, and isomers of trichlorohydroxyoctadecanoic acid were identified and determined in several food items (breads, cakes, muffins, cookies, crackers, etc.). The most prominent residue was that of 9,10-dichloro-12-octadecenoic acid. Levels found in chocolate cake, yellow cake, and coffeecake commonly exceeded 20 ppm.