Identification of Baltic Sea salmon based on PCB and dioxin profiles

Salmon and herring from the Baltic Sea are prohibited for sale for human consumption in the European Union or only allowed to be marketed under certain conditions. Fish from certain specific geographical origins also command higher prices in the market than fish from elsewhere. It is, therefore, important to be able to enforce correct labeling of geographical origin through authentication. One authentication strategy is to examine trace markers specific for a geographical origin. The chemical contaminants polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-. p-dioxins and dibenzofurans (PCDD/Fs) were released inhomogeneously into the environment for many years and may therefore be suitable as markers. This study comprises PCBs and PCDD/Fs analyses of 79 samples of salmon originating from Canada, Chile, China, Norway, USA, Vietnam, and the Baltic Sea near Denmark, all sampled from 2002 through 2015. Principal component analyses (PCA) were built from the combined PCB and PCDD/F profile as well as separately from the individual PCB and PCDD/F profiles. Use of the PCB profile for the PCA provided stronger power to distinguish between salmon of different geographical origin than using the PCDD/F profile or the combined profiles.