Disclosing phototransformation mechanisms of decabromodiphenyl ether (BDE-209) in different media by simulated sunlight: Implication by compound-specific stable isotope analysis.
Environ Sci Pollut Res Int
; 31(10): 14980-14989, 2024 Feb.
Article
in En
| MEDLINE
| ID: mdl-38286932
ABSTRACT
As one of the typical brominated flame retardants, decabromodiphenyl ether (BDE-209) has been widely detected in environment. However, scarce information was available on BDE-209 phototransformation mechanisms in various media. In this study, compound-specific stable isotope analysis was first applied to investigate BDE-209 phototransformation in n-hexane, MeOHH2O (vv, 82), and simulated seawater by simulated sunlight. BDE-209 transformation followed pseudo-first-order kinetic, with degradation rate in the following of n-hexane (2.66 × 10-3 min-1) > simulated seawater (1.83 × 10-3 min-1) > MeOHH2O (1.41 × 10-3 min-1). Pronounced carbon isotope fractionation was first observed for BDE-209 phototransformation, with carbon isotope enrichment factors (εC) of -1.01 ± 0.14, -1.77 ± 0.26, -2.94 ± 0.38 in n-hexane, MeOHH2O and simulated seawater, respectively. Combination analysis of products and stable carbon isotope, debromination with cleavage of C-Br bonds as rate-limiting step was the main mechanism for BDE-209 phototransformation in n-hexane, debromination and hydroxylation with cleavage of C-Br bonds as rate-limiting steps in MeOHH2O, and debromination, hydroxylation and chlorination in simulated seawater. This present study confirmed that stable carbon isotope analysis was a robust method to discovery the underlying phototransformation mechanisms of BDE-209 in various solutions.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Halogenated Diphenyl Ethers
/
Flame Retardants
/
Hexanes
Language:
En
Journal:
Environ Sci Pollut Res Int
/
Environ. sci. pollut. res. int. (Internet)
/
Environmental science and pollution research international (Internet)
Year:
2024
Document type:
Article