Hexabromocyclododecane in White-Sided Dolphins (Lagenorhynchus acutus) Stranded on the Northeastern United States Coast

 

Aaron M. Peck*, Karen J.S. Tuerk, and John R. Kucklick

Analytical Chemistry Division

Chemical Science and Technology Laboratory

Hollings Marine Laboratory

331 Fort Johnson Road, Charleston, SC 29412

Phone: 843.762.8949 Fax: 843.762.8742

Email: aaron.peck@nist.gov or aaron.peck@noaa.gov

 

 

Hexabromocyclododecane (HBCD) is a brominated flame retardant used primarily in expanded polystyrene foams and other styrene resins. The technical HBCD mixture consists of three diastereomers: a-HBCD (~6%), b-HBCD (~8%), and g-HBCD (~80%). Each diastereomer has a pair of stereoisomers. The objective of this work was to measure the concentrations of the three HBCD isomers in banked Atlantic White-Sided Dolphins (Lagenorhynchus acutus) and determine the enantiomeric distribution in these animals. Blubber (n = 47) and liver (n = 6) samples were obtained from the National Biomonitoring Specimen Bank (NBSB) maintained by NIST. All samples were collected from animals stranded in good condition on the Massachusetts coast between 1993 and 2000. Separate aliquots from the blubber samples were previously analyzed for PBDEs and other persistent organic pollutants. Each tissue sample was extracted with dichloromethane using pressurized fluid extraction. Following extraction, lipids and other matrix interferences were removed by size exclusion chromatography and solid phase extraction using 5% deactivated alumina. Prior to GPC, a sub-sample of each liver extract was used for gravimetric lipid content determination. Samples were analyzed using liquid chromatography-triple quadrupole mass spectrometry (LC/MS/MS). Separation of the diastereomers was performed with a C18 column. A cyclodextrin column was used to separate the enantiomers. The [M-1]- Br- (640.6 78.9 and 640.6 80.9) transition was monitored for detection and quantification. a-HBCD was found in all blubber and liver samples. b-HBCD and g-HBCD were not detected in any samples. The a-HBCD concentration in blubber ranged from 14.4 ng/g to 283 ng/g with a median concentration of 80.8 ng/g. The a-HBCD concentration in liver ranged from 2.92 ng/g lipid to 68.3 ng/g lipid with a median concentration of 18.1 ng/g lipid. The enantiomeric fractions (EF) in blubber ranged from 0.42 to 0.74 with a median of 0.61. The EF in liver ranged from 0.42 to 0.62 with a median of 0.55.