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Methods for synthesis of nonabromodiphenyl ethers and a chloro-nonabromodiphenyl ether
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljökemi.
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljökemi.
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljökemi.
Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljökemi.
Vise andre og tillknytning
2006 (engelsk)Inngår i: Chemosphere, Vol. 63, nr 4, s. 562-569Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Polybrominated diphenyl ethers (PBDEs) have been used extensively as brominated flame retardants (BFRs) in textiles, upholstery and electronics. They are ubiquitous contaminants in wildlife and humans. A low concentration of nonabrominated diphenyl ethers (nonaBDEs) is present in commercial DecaBDE and they are also abiotic and biotic debromination products of decabromodiphenyl ether (BDE-209). The objective of the present work was to develop methods for synthesis of the three nonaBDEs, 2,2',3,3',4,4',5,5',6-nonabromodiphenyl ether (BDE-206), 2,2',3,3',4,4',5,6,6'-nonabromodiphenyl ether (BDE-207) and 2,2',3,3',4,5,5',6,6'-nonabromodiphenyl ether (BDE-208), with the intention of making them available as authentic standards for analytical, toxicological and stability studies, as well as studies regarding physical-chemical properties. Two methods were developed, one based on perbromination of phenoxyanilines and the other via reductive debromination of BDE-209 by sodium borohydride followed by chromatographic separation of the three nonaBDE isomers formed. An additional nonabrominated compound, 4'-chloro-2,2',3,3',4,5,5',6,6'-nonabromodiphenyl ether (Cl-BDE-208), was also synthesized in the present work. Cl-BDE-208, prepared by the perbromination of 4-chlorodiphenyl ether, may be used as an internal standard in analysis of highly brominated diphenyl ethers. BDE-206, BDE-207, BDE-208 and Cl-BDE-208 were characterized by 1H NMR, 13C NMR, electron ionization mass spectra and by their melting points. The structures of all three nonaBDEs have been characterized previously by X-ray crystallography.

sted, utgiver, år, opplag, sider
2006. Vol. 63, nr 4, s. 562-569
Forskningsprogram
miljökemi
Identifikatorer
URN: urn:nbn:se:su:diva-24889PubMedID: 16297962OAI: oai:DiVA.org:su-24889DiVA, id: diva2:198480
Merknad
Part of urn:nbn:se:su:diva-7519Tilgjengelig fra: 2008-04-23 Laget: 2008-04-23 Sist oppdatert: 2010-01-25bibliografisk kontrollert
Inngår i avhandling
1. Synthesis of highly brominated diphenyl ethers and aspects on photolysis and indoor spreading
Åpne denne publikasjonen i ny fane eller vindu >>Synthesis of highly brominated diphenyl ethers and aspects on photolysis and indoor spreading
2008 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Adding chemicals to materials to decrease flammability can be dated back to as early as 450 BC when the Egyptians used alum to reduce flammability of wood. Almost 2500 years later brominated flame retardants (BFRs) are used to prevent ignition of textiles, electronics and polymers. BFRs in major use today are polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA), including derivatives. There have been three industrial PBDE mixtures produced. Extensive scientific reporting has shown increasing concentrations of PBDEs in wildlife and in humans. This in combination with reports on their physico-chemical characteristics and chemical reactivity have led to that two of the PBDE products have been classified as being persistent, bioaccumulative and toxic, which has led to legislative measures, in e.g. EU, Norway and the USA.

The availability of pure reference standards is a prerequisite for much toxicologically related research. Hence the main objective of this thesis was to develop additional methods for synthesis of highly brominated diphenyl ethers. Further, to quantify and identify photolysis products of decabromodiphenyl ether (decaBDE) and to perform a case study regarding PBDE exposure in aircrafts.

Synthesis of highly brominated BDE congeners by perbromination of mono- or diaminodiphenyl ethers followed by diazotization of the amino group(s) and introduction of hydrogen(s) in the molecules is a convenient route for synthesis of some octaBDEs and all nonaBDEs. Selective bromination of diaminodiphenyl ether, followed by diazotization of the amino groups and substitution with bromines yielded a hexaBDE or a heptaBDE which were then further brominated to octaBDE congeners.

Even though several studies have been performed on photolysis of decaBDE a new study with a more quantitative approach was performed as part of this thesis. Debrominated PBDE products were identified and quantified and a marker PBDE for UV degradation of DecaBDE was identified i.e., 2,2’,3,3’,5,5’,6,6-octabromodiphenyl ether (BDE-202). Polybrominated dibenzofuranes, methoxlated brominated dibenzofuranes, pentabromophenol and hydroxylated bromobenzenes were also detected. The PBDEs accounted for approximately 90% of the total amount of substances in each sample and the PBDFs for about 10%. Also, a case study on potential exposure to PBDEs in humans travelling long distances by aircraft was done. It was shown that PBDE concentrations in dust onboard aircrafts may be high and increased PBDE serum levels were indicated in a majority of the travellers.

The present thesis has contributed to make higher brominated diphenyl ethers available as reference standards, allowing better quantitative assessments possible regarding both abiotic studies and exposure assessments. New toxicological testing can also be pursued.

sted, utgiver, år, opplag, sider
Stockholm: Institutionen för miljökemi, 2008. s. 81
HSV kategori
Forskningsprogram
miljökemi
Identifikatorer
urn:nbn:se:su:diva-7519 (URN)978-91-7155-579-3 (ISBN)
Disputas
2008-05-23, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 12 A, Stockholm, 13:00
Opponent
Veileder
Tilgjengelig fra: 2008-04-23 Laget: 2008-04-23bibliografisk kontrollert

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