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Rationale Brominated organic compounds (BOCs) are common persistent toxic pollutants. Compound-specific stable bromine isotope ratio analysis is one of the potential approaches for investigating BOC transformations in the environment. In the present study, we demonstrate that precise bromine isotope analysis of BOCs can be successfully performed by gas chromatography/quadrupole mass spectrometry (GC/qMS) systems that are widely available in analytical laboratories. Methods Optimization and validation of the GC/qMS method were performed by analysis of bromoform, 3-bromophenol and 4-bromotoluene. In addition, comparison of the results obtained by GC/qMS and GC/multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) for 1,2-dibromoethane and 3-bromophenol samples with different bromine isotope composition was carried out to evaluate the analytical performance of the developed method. Results Precisions in the range 0.2-0.3‰ were attained for sample amounts in the range of tens to thousands pmol. Good correlation between the results obtained by GC/qMS and GC/MC-ICPMS for laboratory standard materials (1,2-dibromoethane and 3-bromophenol) (regression coefficient R2 > 0.98) was achieved. Conclusions The GC/qMS method for bromine isotope analysis shows a good performance and can be applied routinely for studying transformations of BOCs. Due to the observed dependence of the measured isotope ratios on the amount of the analyte and the calculation scheme applied, normalization of the results versus appropriate standards is required for source attribution applications. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We developed an analytical method for precise and accurate analysis of δ34S, δ81Br, and δ37Cl in individual anionic species by coupled ion chromatography (IC) and multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). The method is based on the online separation and purification of ions by IC prior to their isotope analysis by MC-ICPMS. The developed technique significantly simplifies δ34S, δ81Br, and δ37Cl analysis in environmental samples. In cases when several anionic species of the same element are present in the sample, they might be analyzed in a single analytical run. Major isobaric interferences for the analyzed elements were reduced by using "dry" plasma conditions and applying sufficient mass resolution power. The sample-standard bracketing technique was used for instrumental drift correction. In the case of analysis, precisions up to 0.15‰ (1sd ) have been achieved for analytes containing down to 5 nmol of S; for δ81Br, the attained precision was 0.1 ‰ (1sd ) for analytes containing down to 0.6 nmol of Br. Precisions of 0.2%c have been obtained for δ37Cl with analytes containing 0.7 μmol of Cl. Robustness of the developed analytical method, as well as high precisions and accuracies, has been demonstrated for the laboratory standard solutions and for environmental samples. [ABSTRACT FROM AUTHOR]

In the present study, carbon and bromine isotope effects during UV-photodegradation of bromophenois in aqueous and ethanolic solutions were determined. An anomalous relatively high inverse bromine isotope fractionation (εreactive position UP to +S.l%c) along with normal carbon isotope effect (εreactive position of -12,6% c to -23.4%o) observed in our study may be attributed to coexistence of both mass-dependent and mass-independent isotope fractionation of C-Br bond cleavage. Isotope effects of a similar scale were observed for all the studied reactions in ethanol, and for 4-bromophenol in aqueous solution. This may point out related radical mechanism for these processes. The lack of any carbon and bromine isotope effects during photodegradation of 2-bromophenol in aqueous solution possibly indicates that C-Br bond cleavage is not a rate-limiting step in the reaction. The bromine isotope fractionation, without any detectable carbon isotope effect, that was observed for 3- bromophenol photolysis in aqueous solution probably originates from mass-independent fractionation. [ABSTRACT FROM AUTHOR]

Abstract: The study proposes a new method for the high-precision determination of bromine isotope ratio in inorganic samples. In the suggested method, inorganic bromide is wet-oxidized into molecular bromine and transferred into the MC-ICPMS by continuous flow of helium. Analysis of natural inorganic bromide samples from various sources revealed identical δ81Br values within the range of the method uncertainty. [Copyright &y& Elsevier]

Abstract: This work presents a new methodology for the precise determination of bromine isotope ratio in individual organic compounds based on the simultaneous introduction of brominated organic compounds and strontium as an external spike into MC-ICPMS. Using the proposed methodology, an external precision (2σ) up to 0.1‰ has been attained. The new approach for the bromine isotope ratio analysis could be applied for the investigating the fate of the organobromine compounds in the environment. [Copyright &y& Elsevier]

The potential of compound-specific stable isotope analysis (CSIA) to characterize biotransformation of brominated organic compounds (BOCs) was assessed and compared to chlorinated analogues. Sulfurospirillum multivorans and Desulfitobacterium hafniense PCE-S catalyzed the dehalogenation of tribromoethene (TBE) to either vinyl bromide (VB) or ethene, respectively. Significantly lower isotope fractionation was observed for TBE dehalogenation by S. multivorans (ε C = −1.3 ± 0.2‰) compared to D. hafniense (ε C = −7.7 ± 1.5‰). However, higher fractionation was observed for dibromoethene (DBE) dehalogenation by S. multivorans (ε C = −16.8 ± 1.8‰ and −21.2 ± 1.6‰ for trans - and cis -1,2- (DBE) respectively), compared to D. hafniense PCE-S (ε C = −9.5 ± 1.2‰ and −14.5 ± 0.7‰ for trans -1,2-DBE and cis- 1,2-DBE, respectively). Significant, but similar, bromine fractionation was observed for for S. multivorans (ε Br = −0.53 ± 0.15‰, −1.03 ± 0.26‰, and −1.18 ± 0.13‰ for trans -1,2-DBE, cis- 1,2-DBE and TBE, respectively) and D. hafniense PCE-S (ε Br = −0.97 ± 0.28‰, −1.16 ± 0.36‰, and −1.34 ± 0.32‰ for cis -1,2-DBE, TBE and trans- 1,2 - DBE, respectively). Variable C Br dual-element slopes were estimated at Λ (ε C /ε Br ) = 1.03 ± 0.2, 17.9 ± 5.8, and 29.9 ± 11.0 for S. multivorans debrominating TBE, cis- 1,2-DBE and trans- 1,2-DBE, respectively, and at 7.14 ± 1.6, 8.27 ± 3.7, and 8.92 ± 2.4 for D. hafniense PCE-S debrominating trans- 1,2-DBE, TBE and cis- 1,2-DBE, respectively. A high variability in isotope fractionation, which was substrate property related, was observed for S. multivorans but not D. hafniense , similar as observed for chlorinated ethenes, and may be due to rate-limiting steps preceding the bond-cleavage or differences in the reaction mechanism. Overall, significant isotope fractionation was observed and, therefore, CSIA can be applied to monitor the fate of brominated ethenes in the environment. Isotope effects differences, however, are not systematically comparable to chlorinated ethenes. [ABSTRACT FROM AUTHOR]

The present study investigated dual carbon-bromine isotope fractionation of the common groundwater contaminant ethylene dibromide (EDB) during chemical and biological transformations, including aerobic and anaerobic biodegradation, alkaline hydrolysis, Fenton-like degradation, debromination by Zn(0) and reduced corrinoids. Significantly different correlation of carbon and bromine isotope fractionation (ΛC/Br) was observed not only for the processes following different transformation pathways, but also for abiotic and biotic processes with, the presumed, same formal chemical degradation mechanism. The studied processes resulted in a wide range of ΛC/Br values: ΛC/Br = 30.1 was observed for hydrolysis of EDB in alkaline solution; ΛC/Br between 4.2 and 5.3 were determined for dibromoelimination pathway with reduced corrinoids and Zn(0) particles; EDB biodegradation by Ancylobacter aquaticus and Sulfurospirillum multivorans resulted in ΛC/Br = 10.7 and 2.4, respectively; Fenton-like degradation resulted in carbon isotope fractionation only, leading to ΛC/Br 8. Calculated carbon apparent kinetic isotope effects (13C-AKIE) fell with 1.005 to 1.035 within expected ranges according to the theoretical KIE, however, biotic transformations resulted in weaker carbon isotope effects than respective abiotic transformations. Relatively large bromine isotope effects with 81Br-AKIE of 1.0012-1.002 and 1.0021-1.004 were observed for nucleophilic substitution and dibromoelimination, respectively, and reveal so far underestimated strong bromine isotope effects. [ABSTRACT FROM AUTHOR]