Open access publications in the SLU publication database

Abstract

Chlorinated fatty acids (CIFAs) have been found to account for a considerable portion of the
extractable organically bo und chlorine in aquatic animals. Methods particularly suitable for the
determination of CIFAs have relatively newly been developed, which may explain why these
compounds did not come to attention as a potentially hazardous environmental pollutant until during
the recent decade. The presence of CIFAs in human tissues has not yet been reported, and it is not
known if human cells can incorporate and metabolise these compounds.

Recently a new halogen specific detector (XSD) has been introduced. It is described to be a
sensitive, selective, and robust detector in the determination of halogenated pesticides. It has been
declared to be more stable and easier to maintain than other halogen selective detectors. The XSD
operates in an oxidative pyrolysis mode and the sample compounds are converted into their
oxidation products. When halogen-containing compounds enter the hot detector, the detector current
will increase. CIF As have not earlier been studied by an XSD.

The aim of this work was to study i) the XSD, connected to a gas chromatograph, in the
determination of CIFA methyl esters (CIFAMEs), and ii) the incorporation and metabolism of
CIFAs in human cell lines, as determined by XSD detection.

It was shown that the XSD provides a detection limit (0.2 ng of dichlorostearic acid methyl
ester) and a selectivity ((response CIFAMEs)/(response unchlorinated fally acid methyl esters)) >>
10⁴ similar to that of the electrolytic conductivity detector (ELCD), commonly used in
determination of CIFAMEs. Furthermore, the XSD was found to be very easy and stable to maintain
in the analysis of CIFAMEs.

In the determination of CIFAs obtained from human cell lines, it was established that human
cells can incorporate dichlorostearic acid and degrade it to dichloropalmitic acid and
dichloromyristic acid, probably through α3-oxidation. CIFAs were found both in the neutrallipid and
in the phospholipid fraction of the cultured cells. Dichloromyristic acid was the shortest CIFAs
detected and was found to be released to the culture medium to a higher extent than the other
CIFAs.

The XSD was found to be a good alternative to the ELCD in the determination of CIFAs and the
XSD is suitable for use in continued studies of the turnover of CIFAs in human cells.