Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.chroma.2009.12.076
Title (Primary) Relevance of 1,2,5,6,9,10-hexabromocyclododecane diastereomer structure on partitioning properties, column-retention and clean-up procedures
Author Mariussen, E.; Haukås, M.; Arp, H.P.H.; Goss, K.-U.; Borgen, A.; Sandanger, T.M.
Source Titel Journal of Chromatography A
Year 2010
Department AUC
Volume 1217
Issue 9
Page From 1441
Page To 1446
Language englisch
Keywords Brominated flame retardants; Hexabromocyclododecane; Partitioning properties; Retention characteristics
Abstract To optimize clean-up procedures for the analysis of a-, ß-, and ?-hexabromocyclododecanes (HBCD) in environmental and biological extracts, their retention behavior on silica gel and florisil was investigated using diverse mobile-phase solvents and accounting for matrix effects. The ß-diastereomer, relative to the a- and ?-diastereomers, is substantially retained on both florisil and silica gel regardless of the solvent used. The ß-diastereomer is therefore prone to undergo selective loss during clean-up. This sequence is counterintuitive to sequences based on reverse-phase chromatography with a C18-column, in which the a- (and not the ß-) isomer is eluted first when using a polar solvent. There has been some discrepancy regarding the structures of these diastereomers in the literature, with structures based on X-ray crystallography only becoming recently available. Based on these X-ray crystal structures, physical-chemical properties (the octanol-water partitioning constant, the Henry's law constant, subcooled liquid vapour pressures and subcooled liquid water solubilities) of the HBCD diastereomers were estimated using the quantum-chemistry based software COSMOtherm, and were found to differ from previously calculated values using different structures (e.g. log Kaw for a-, ß-, and ?-HBCD are here estimated to be -8.3, -9.3 and -8.2 respectively). Hypothesis relating differences in structure to physical-chemical properties and retention sequences are presented. The extra retention of the ß-diastereomer on silica gel and florisil is likely because it can form both greater specific (i.e. polar) and non-specific (i.e. non-polar) interactions with surfaces than the other diastereomers. Non-specific interactions can also account for the counter-intuitive elution orders with C18-reverse-phase chromatography. These results indicate that care should be taken when isolating HBCDs and other molecular diastereomers from environmental and biological samples, and that reported concentrations of ß-HBCD in the literature may be negatively biased.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=10278
Mariussen, E., Haukås, M., Arp, H.P.H., Goss, K.-U., Borgen, A., Sandanger, T.M. (2010):
Relevance of 1,2,5,6,9,10-hexabromocyclododecane diastereomer structure on partitioning properties, column-retention and clean-up procedures
J. Chromatogr. A 1217 (9), 1441 - 1446 10.1016/j.chroma.2009.12.076