Analysis of Legacy and Current-use Brominated Flame Retardants in Settled Dust: Validation and Application of a Sample Preparation Method using Ultrasonic Processor and Single Cleanup Columns

Abstract

Analytical method development and monitoring of brominated flame retardants (BFRs), including legacy and current-use substances, in the environment is a crucial task to understand their contamination status and potential adverse impacts. However, there is no standardized procedure for BFR analysis in settled dust and atmospheric particulate matter, and analytical results of some BFRs in the Standard Reference Material (SRM) 2585 showed significant variations between studies. In this work, we developed efficient methods for determining 41 polybrominated diphenyl ethers (PBDEs) and six other BFRs, including hexabromocyclododecane (HBCDD), pentabromoethylbenzene (PBEB), hexabromobenzene (HBB), 2,2',4,4',5,5'-hexabromobiphenyl (BB-153), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), and decabromodiphenyl ethane (DBDPE), in settled dust and air particulate samples. The samples were extracted using an ultrasonic processor and the extracts were cleaned up using single columns containing Florisil and acidic silica gel. The methods were validated using the SRM 2585, the SRM 1648a, and matrix-spike samples, showing adequate recovery, precision, and detection limits. We found a variation in BDE-209 concentrations in the SRM 2585 sample derived using different solvent types, suggesting the need for suitable techniques and solvents to enhance extraction efficiency and method accuracy. Concentrations of BFRs were first reported for the SRM 1648a. The validated methods were applied to analyze BFRs in settled dust samples collected from different microenvironments in northern Vietnam (e.g., roads, houses, and offices in urban areas, and houses and workshops in e-waste processing areas), showing the dominance of BDE-209 (median 320; 16–61,000 ng/g), DBDPE (130; 5.5–21,000 ng/g), and HBCDD (36; < 0.10–750 ng/g).