Polychlorinated Alkanes in feed from the German market

Polychlorinated Alkanes (PCAs) were analysed in 47 feed samples, 13 and 34 respectively of animal and plant origin, collected from the southern German market in 2023. The overall median concentration of ∑PCAs- was determined as 10ngg^-1 ww, with plant-based feeds being considerably lower than feed of animal origin, with respective median values of 8.8 and 44ngg^-1 ww. Highest levels of PCAs with respect to fresh weight were found in plant-based fats and oils, including the highest sample at more than 9000ngg^-1 ww, followed by feed of animal origin, particularly fish meal. Seeds, press cakes, meals and soy based products were usually lower. The ratio of ∑PCAs- to ∑PCAs- was below 1 for almost all samples, potentially resulting from the European enforcement of the Stockholm Convention. Homologue response pattern revealed a small difference in the abundances of chain lengths - between feed of animal origin and plant-based feeds.