Determination of HFRs and OPFRs in PM_2.5 by ultrasonic-assisted extraction combined with multi-segment column purification and GC-MS/MS

Toxic chemicals such as flame retardants are associated with atmospheric fine particles (PM_2.5), which are an important pollutant in the world. In this study, a sensitive method using gas chromatography-tandem triple quadrupole mass spectrometry combined with ultrasonic-assisted extraction and multi-phase column purification was developed for simultaneously determination of 29 flame retardants including halogenated flame retardants (HFRs) and organophosphate flame retardants (OPFRs) in PM_2.5 samples. Extraction time, as well as the type and volume of elution solvent were optimized. The recoveries of all target flame retardants from PM_2.5 samples were in the range of 70%‒130%, with good repeatability and reproducibility (0.39%‒17.4%). The instrumental detection limits (IDLs) and method quantitation limits (MQLs) of HFRs were in the range of 0.004‒5.44 pg and 0.002‒2.52 pg m⁻³, while those of OPFRs were 0.003‒0.23 pg and 0.07‒5.41 pg m⁻³, respectively. The developed method has been successfully applied for analysis of target flame retardants in atmospheric PM_2.5 collected from the cities of Guangzhou and Taiyuan, China. HFRs were found at concentrations of 45.7‒1230 pg m⁻³ and 51.2‒82.3 pg m⁻³ in Guangzhou and Taiyuan. The concentrations of HFRs were lower than those of OPFRs, which were detected at concentrations of 6004‒49,800 pg m⁻³ and 16,741‒34,346 pg m⁻³ in Guangzhou and Taiyuan. Accordingly, the analytical method is robust and useful for further elucidating the contamination profiles of flame retardants in PM_2.5.