2007Novel combined stir bar sorptive extraction coupled.pdf

As ( P e a a o L d ? K 1 r fl u a b ( g [ t h f f 0 dJournal of Chromatography A, 1160 (2007) 71–80 Novel combined stir bar sorptive extraction coupled with ultrasonic assisted extraction for the determination of brominated flame retardants in environmental samples using high performance liquid chromatography Chunhe Yu, Bin Hu ? Department of Chemistry, Wuhan University, Wuhan 430072, China Received 26 February 2007; received in revised form 8 May 2007; accepted 11 May 2007 Available online 18 May 2007 bstract A combined stir bar coated with poly (dimethysiloxane)--cyclodextrin (PDMS--CD) on single side has been prepared for the first time by ol–gel method and was coupled with ultrasonic assisted extraction (UAE) for the determination of some brominated flame-retardant compounds BFRs) in soil and dust samples by high performance liquid chromatography (HPLC). Four different kinds of coatings including PDMS--CD, DMS, carbowax (CW)-PDMS-poly (vinyl alcohol) (PVA) and PDMS-PVA were evaluated for stir bar sorptive extraction of BFRs by orthogonal xperiment design. The experimental results reveal that the PDMS--CD combined stir bar exhibited the best extraction efficiency for the target nalytes. The reproducibility for the preparation of PDMS--CD combined stir bar ranged from 1.3% to 15.7% in one batch, and 7.2% to 15.1% mong batches. Extraction time, desorption solvent, concentration of methanol and NaCl in the matrix, pH, temperature and stirring speed were ptimized. The combined stir bar can avoid direct friction of the coating with the bottom of the vessel, and could be used for more than 100 times. inearity (0.993), repeatability (10.5%), reproducibility (16.5%), recovery (56–118%) and detection limits (2.9–4.2 g L?1) were proper to etermine the seven BFRs. The developed method was applied to the determination of BFRs in soil and dust with satisfactory results. ive ex t e u h c a R t n s a2007 Elsevier B.V. All rights reserved. eywords: Brominated flame retarda