Analysis of Three Hexabromocyclododecane (HBCD) Isomers by C30 Liquid Chromatography and Tandem Mass Spectrometry
Nathan G. Dodder, Lane C. Sander, Heather M. Stapleton and Michael J. Welch
Analytical Chemistry Division, Chemical Science and Technology Laboratory
National Institute of Standards and Technology, Gaithersburg, MD 20899-8392
Hexabromocyclododecane (HBCD) is a brominated flame retardant. Due to its production level and ability to escape from treated products, it has been detected in the environment. Data on the environmental occurrence of HBCD is lacking, but it is likely that HBCD will fall into the same category as other persistent environmental pollutants, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), which have the ability to be atmospherically transported long distances and bioaccumulate.
The commercial HBCD mixture consists of three isomers, termed α-HBCD, β-HBCD and γ-HBCD. There is currently a discrepancy in the literature regarding the exact stereochemical structure of the three isomers.
Figure 1. HBCD Structure
The commercial mixture is approximately 6% α-HBCD, 8% β-HBCD and 76% γ-HBCD. However, reports in the literature have shown that α-HBCD is the dominant isomer found in biota. This could be the result of a selective degradation process, a selective uptake process, or both. In either case, an isomer specific detection method is necessary to understand the fate of these compounds. Gas chromatography is unable to separate the three isomers; therefore, a liquid chromatography tandem mass spectrometry method was developed.
Liquid chromatography using a C30 column was able to separate the three HBCD isomers. Negative mode ESI and tandem mass spectrometry were used to detect the HBCD. Linear calibration curves were generated for the three isomers. Also, an investigation was made into the retention mechanism of the C30 column. Data on the temporal trend of HBCD in sea lions will be presented.
Name: Nathan G. Dodder
Mentor’s name: Michael J. Welch
Analytical Chemistry Division
Chemical Science and Technology Laboratory
Building 227, Room B154
Mail Stop 8392
Not a Sigma Xi member.