Metodutveckling för analys av PBDE och HBCD i sediment

Sammanfattning: Brominated flame retardants (BFRs) has for many years been used in products to reduce their flammability, mainly in electronic products, textiles and construction materials. In 2003, Sweden imported 300 tons of brominated flame retardants. Leakage of these compounds has polluted natural environments. Fishes has shown increased contents of these substances, especially fat fish, since brominated flame retardants tends to accumulate in fatty tissues. They are also regarded as persistent and that gives them the ability to travel long distances. What also is really scary is that increased levels of brominated flame retardants have been detected in human breast milk. The knowledge of the brominated flame retardants is limited and not so much research has been done in this field. There are many reasons though, to keep the research going. Partly their structural resemblance to well-known toxics as PCB, but also their ability to accumulate in biological systems and enrich in food chains. In which way they affect humans we really don’t know yet. Experiments on mice have been done and behavioural disturbances were observed as well as a decrease in learning capacity. The BRFs chosen for this study are hexabromocyclododecan (HBCD) and a polybrominated diphenyl ether (PBDE) called pentabromodiphenylether (BDE 99). About 25 % of the flame retardants produced in the world every year, consists of the brominated ones. If we look at the PBDEs it’s mainly tetrabromodiphenylether (BDE 47), pentabromodiphenylether (BDE 99), octabromodiphenylether (BDE 205) and decabromodiphenylether (BDE 209) that are common flame retardants. As from July 1st 2006, PBDE was forbidden in electric and electronic products (15). January 1st 2007, a Swedish prohibition concerning the use of BDE-209 was established. BDE- 209 is not allowed on the Swedish market if the content of substance exceed 0,1 percent of weight (23). BDE-99 is classified as environmentally dangerous and a healthrisk. It´s not only toxic for waterliving organisms but also for humans if exposed during a long time (19). We shall develop a well functioning, reproducible and economic method to analyse HBCD and PBDE in sediment. It includes extraction, cleanup and sample analyses with a ECD (electron capture detector) equipped capillary gas chromatograph. Several analyses of adequate diluted standards has been analysed in a GC-ECD to find suitable temperature gradients. Then we produced spiked sediment samples with known amounts of standards. To homogenize the spiked samples we used a mixer. As a first step in the extraction we used acetone as a solvent. Then we used cyclohexane and NaCl (2%) to separate the nonpolar and polar substances from each other. Cleanup with concentrated sulphuric acid was done and for some samples we also used Florisil. To concentrate the extract it was evaporated with N2(g).The extract was then analysed in a GC-ECD and then the results was compared with the standards. The result of this project showed that our method of extraction is useful. We managed to extract 50 % HBCD, 30 % BDE-99 and 60 % BDE-99 (dried sediment).