Determination of 41 polybrominated diphenyl ethers in soil using a pressurised solvent extraction and GC-NCI-MS method

A rapid and reliable analytical method based on pressurised solvent extraction (PSE) and GC-NCI-MS was developed for the determination of 41 different PBDEs in soil. All PBDEs, including mono- to hepta-BDEs (sum of 39 congeners), one nona-BDE and deca-BDE, were efficiently extracted from soil samples using the extraction technology of PSE. The extract was then cleaned up on a florisil column. Satisfactory separation of 41 PBDE congeners was obtained on a 15-m DB-5MS capillary column, saving the use of another 30-m column specific for the separation of mono- to hepta-BDEs. PBDEs were identified and quantified by GC-MS in negative chemical ionisation (NCI) mode, and further confirmed in semi electron impact (SEI) mode when the ion source was also NCI. The method detection limits ranged from 0.01 to 0.03?ng?g^?1?dw for mono- to hepta-BDEs, 1.43?ng?g^?1?dw for the nona-BDE and 0.20?ng?g^?1?dw for deca-BDE. The applicability of the method was tested in soil samples collected from an e-waste recycling site at Guiyu. Twenty-one PBDEs (mono- to deca-) were detected, and eighteen congeners were quantified. The concentration range of PBDEs was 0.78–436?ng?g^?1?dw. BDE-47, BDE-99, BDE-153, BDE-183, BDE-206 and BDE-209 were the dominant congeners, and BDE-209 accounted for 62% of the total PBDEs. The congener profiles of PBDEs in soil samples were similar to those in three commercial PBDE products (Penta-, Octa- and Deca-BDE), and Deca-BDE product was the most important contributor.