Rapid Determination of Polybrominated Diphenyl Ethers in Dust by GC-MS Combimed with Ultrasonic Assisted Dispersion Liquid-Liquid Microextraction

The sample (0.100 0 g) was added into 10 mL of n-hexane-acetone (1+1) mixture for ultrasonic extraction at 30℃ for 20 min. After the supernatant was transferred, the sample was ultrasonically extracted twice with 10 mL of n-hexane-acetone (1+1) mixture. The combined supernatants were concentrated to nearly dry by nitrogen flowing, and 5 ml of water was added. After mixing well, a mixture of 0.75 mL of acetone and 30 μL of carbon tetrachloride were rapidly injected with a syringe, and the mixture was shaken for a few seconds and centrifuged at 4 500 r·min^-1 for 5 min. The sedimentary phase was removed and separated on a DB-5HT quartz capillary column (15 m×0.25 mm, 0.1 μm). Electron impact ion source and selective ion monitoring mode were used for mass spectrometric analysis. Linear relationships were found between the peak area and the mass ratio of the 7 PBDEs in definite ranges. The detection limits (3S/N) were between 0.90 and 10.0 mg·kg^-1. Values of recovery obtained by standard addition method were in ther range of 61.3%-122%, and the relative standard deviations (n=6) of the measured values were between 2.3% and 12%.