Separation of polybrominated diphenyl ethers in fish for compound-specific stable carbon isotope analysis

Application of compound-specific stable carbon isotope analysis for the biotransformation and trophic dynamics of PBDEs in a feeding study with fish

“…The robustness of the method applied in the present study for PBDE CSIA has been verified in a previous study (Zeng et al, 2012b). GCeCeIRMS ion chromatograms (m/z ¼ 44) of the three fish extracts are shown in Fig.…”

Tracing the biotransformation of polychlorinated biphenyls (PCBs) in common carp (Cryprinus carpio): Enantiomeric fraction and compound-specific stable carbon isotope analyses

“…Therefore, extensive purification steps are required to attain high-purity extracts before CSIA. The method for purification of PCBs in fish for compound-specific isotope analysis was based on our previous studies (Zeng et al, 2012(Zeng et al, , 2013a, with minor modifications. Briefly, the remainder of the fish carcass samples used for stable carbon isotope analysis was Soxhelt-extracted with 350 mL Hex/Acetone (1:1 v/v) for 72 h. The extract was concentrated to approximately 1 mL by rotary evaporator and the solvent exchanged with hexane (10 mL).…”

“…Degradation, especially biodegradation, is frequently accompanied by a substantial kinetic isotope effectd the heavier isotopes (here 13 C) react more slowly than the light isotopes in most chemical and biological reactions, and thus results in the enrichment of heavier isotopes in the remaining compounds and their depletion in the degradation products (Luo et al, 2013;Schmidt et al, 2004). The fractionation of stable isotopes (e.g., carbon, hydrogen, and nitrogen) generated by abiotic and biotic transformation of a compound is often significantly larger than that induced by phase-transfer processes, providing a unique approach for the identification and quantification of the transformation, and sometimes even for elucidating its mechanism (Schmidt et al, 2004;Zeng et al, 2012). The main benefit of using CSIA is the ability to track the fate of contaminants in complex matrices without the need to identify and quantify intermediates and metabolic products.…”

Compound‐specific carbon isotope analysis for mechanistic characterization of debromination of decabrominated diphenyl ether

“…Determining the carbon isotope composition for a target organic pollutant requires sophisticated separation and purification procedures since background organic carbon and organic compounds with similar structures overshadow the carbon isotope signature of the target organic pollutant. The traditional CSIA method uses gas chromatography–combustion isotope ratio mass spectrometry (GC/C‐IRMS) and has been successfully applied in characterizing bioaccumulation processes and abiotic and biotic degradation of a wide range of persistent organic pollutants in the environment . Such a GC/C‐IRMS method was also used by Mai and colleagues for the measurement of the carbon isotope compositions of tri‐ to hexa‐BDEs in sediments and biological samples .…”

“…The traditional CSIA method uses gas chromatography–combustion isotope ratio mass spectrometry (GC/C‐IRMS) and has been successfully applied in characterizing bioaccumulation processes and abiotic and biotic degradation of a wide range of persistent organic pollutants in the environment . Such a GC/C‐IRMS method was also used by Mai and colleagues for the measurement of the carbon isotope compositions of tri‐ to hexa‐BDEs in sediments and biological samples . However, GC/C‐IRMS is not suitable for highly brominated PBDEs, especially for BDE‐209, because BDE‐209 is not thermally stable and tends to be incompletely combusted due to the inhibitory effect of Br − .…”