Short- and medium-chain chlorinated paraffins in human blood serum of Czech population

Highlights: • Validated method for the determination of SCCPs and MCCPs in human blood serum • First results for SCCP and MCCP levels in human blood serum in Europe • Lower (up to 70 times) CP medians in Czech samples (compared to China) Short- and medium-chain chlorinated paraffins (SCCPs; MCCPs) are widespread environmental pollutants with bioaccumulation potential and adverse effects on human health. The analysis of blood serum is an important strategy to assess the human exposure to various contaminants, including SCCPs and MCCPs. Lately, the information about the exposure of Chinese population has been reported; nevertheless, data on human exposure to SCCPs and MCCPs outside East Asia are still very limited. In this pilot study, SCCPs and MCCPs were determined in 27 serum samples obtained from Czech adults. The samples were extracted by a three-step extraction (repeated with a clean solvent) by a mixture of n-hexane:diethyl ether (9:1, v/v) with subsequent clean-up on Florisil® solid phase extraction column. Gas chromatography coupled with high resolution mass spectrometry operated in negative chemical ionisation was employed for the instrumental analysis. The method recoveries ranged from 71 to 89% with repeatabilities of <20% (expressed as relative standard deviation). In the samples, SCCP concentrations were in the range of <150–2600 ng/g lipid weight, lw (median 370 ng/g lw) and the MCCP concentrations were in the range of <200–2110 ng/g lw (median 360 ng/g lw), respectively. To the best of our knowledge, our reported results are the first data about chlorinated paraffins in human blood serum in Europe, showing exposure to these compounds with yet to be studied effects on human health.