Confirmation of polybrominated biphenyl residues in feeds and dairy products, using an ultraviolet irradiation-gas-liquid chromatographic technique.

An ultraviolet (UV) irradiation-gas-liquid chromatographic (GLC) detection procedure was used to confirm the presence of polybrominated biphenyl (PBB) residues in sample extracts after GLC quantitation. Chromatograms of PBB standard and sample extract solutions showed similar photodecomposition peak patterns dependent on time and intensity of UV irradiation. Confirmation of PBBs in sample extracts by this procedure was possible for any amount detectable by the GLC system employed. Prolonged UV irradiation resulted in complete disappearance of all PBB peaks from the chromatogram, permitting their distinction from background peaks due to extraneous sample material unaffected by UV irradiation.