Short- and medium-chain chlorinated paraffins in biota from the European Arctic — differences in homologue group patterns

Congener and homologue group patterns of chlorinated paraffins (CPs) in biota can be influenced by different processes, but these are not well studied yet. Short- (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were quantified in liver from Arctic char and seabirds (little auk and kittiwake) collected at Bear Island (European Arctic) as well as in cod from Iceland and Norway. CP concentrations were between 5 and 88 ng/g wet weight (ww) for SCCPs and between 5 and 55 ng/g ww for MCCPs with one exception of 370 ng/g measured in a liver sample from little auk. The SCCP homologue group patterns were compared with those of technical mixtures and of SCCPs present in cod liver from the Baltic Sea. The latter showed a more common SCCP homologue distribution (sum of C11 and C12N60%) in contrast to cod liver from the Northwest of Europe, which had a high abundance of C10 and C12 congeners. Seabirds from Bear Island contained an equally distributed SCCP homologue group pattern. In Arctic char, the SCCP distribution was closer to technical products, but with a high proportion (average of 18.9%) of C10 congeners. A comparison of C10/C12 ratios confirmed the higher abundance of C10 congeners in samples from higher latitudes. For the first time, MCCPs could be detected in Arctic samples. The average proportion of C14 congeners was 65.8%. The C14/C15 abundance ratio was similar to technical mixtures. High-chlorinated CPs (ClN7) were also detectable. The average chlorine content of the SCCPs was 61.9% (59.0–63.3%), and that of the MCCPs 55.8% (54.5–57.4%).