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Author
Losada Baranera, Mar
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Abstract
Polychlorinated biphenyls (PCBs) are a family of organochlorine aromatic compounds classified as persistent organic pollutants (POPs) due to their persistence, bioaccumulation and toxicity.
The presence of these compounds in the environment has decreased since their production as technical mixtures (such as aroclors) was banned years ago. However, these compounds can also be unintentionally generated in the production of other products, such as pigments. These are known as UP-PCBs. In organic pigments, specifically in some azo pigments, in diketopyrrolopyrrole, in phthalocyanines and in violet dioxazines, the presence of UP-PCBs has been detected. Depending on the reaction conditions, the solvent used and the reagents, the formation of congeners is more favored, presenting higher contribution ranges. The analysis of PCBs in pigments is carried out by means of a solvent extraction of PCBs and a purification treatment that, in many cases, is based on the use of sulfuric acid. The instrumental determination is carried out by gas chromatography coupled to mass spectrometry with columns of different polarity. The profiles of PCB congeners found in pigments are clearly different from those found in Aroclors. Specifically, some PCBs (1, 3, 11, 12, 13 and 109) are specific to pigments and do not appear in Aroclors' technical mixtures. Some other PCBs (48, 52, 56, 67, 146, 206, 207, 208 and especially 209) are in much higher proportions to pigments than aroclors.
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