Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans
(PCDFs) and polychlorinated biphenyls (PCBs) are major representatives of persistent
organic pollutants. While PCDD/Fs are unwanted by-products, mainly from waste
incineration and industrial processes, PCBs were manufactured and widely used as
transformer oils until bans enter in force at the late ’70s. These compounds are highly
toxic and can easily bioaccumulate and biomagnify throughout the food chain reaching
the top living organisms, including human beings. Food is the main route of human
exposure to PCDD/Fs and PCBs, with products from animal origin contributing largely
to the dietary intake. In this sense, several contamination episodes involving feed and
food products that occurred at the late ’90s led to the establishment of a European
regulatory framework that aims to both, set maximum levels for these compounds in
different food/feed categories and to lay down analytical methods for the determination
of these compounds. In this work, an overview of the different chemical methodologies
that have been applied during the last decades to the determination of PCDD/Fs and
PCBs, more in particular dioxin-like PCBs, in food and feed samples is presented.
Advances in extraction and purification steps are described, but special attention is
given to the evaluation of several mass spectrometric techniques in comparison to gas
chromatography coupled to high-resolution mass spectrometry (GC-HRMS), which has
traditionally been the unique confirmatory technique until recently.
Keywords: Clean-up, Dioxin-like PCBs, EU regulations, Extraction, Feed, Food,
GC-HRMS, GC-MS/MS, Ion trap, Mass spectrometry, PCBs, PCDDs, PCDFs,
Triple quadrupole.
