Preparation and evaluation of mesoporous cellular foams coating of solid-phase microextraction fibers by determination of tetrabromobisphenol A, tetrabromobisphenol S and related compounds

Two kinds of mesoporous cellular foams (MCFs), including mesoporous silica materials (MCF-1) and phenyl modified mesoporous materials (Ph-MCF-1), were synthesized and for the first time used as fiber-coating materials for solid-phase microextraction (SPME). By using stainless steel wire as the supporting core, four types of fibers were prepared by sol-gel method and immobilized by epoxy-resin method. To evaluate the performance of the home-made fibers for SPME, seven brominated flame retardants (BFRs), including tetrabromobisphenol A (TBBPA), tetrabromobisphenol S (TBBPS) and related compounds were selected as analytes. The main parameters that affect the extraction and desorption efficiencies, such as extraction temperature, extraction time, desorption time, stirring rate and ionic strength of samples were investigated and optimized. The optimized SPME coupled with high performance liquid chromatography (HPLC) was successfully applied to the determination of the seven BFRs in water samples. The linearity range was from 5.0 to 1000 mu g L-1 for each compound except TBBPS (from 1.0 to 1000 mu g L-1), with the correlation coefficients (r(2)) ranging from 0.9993 to 0.9999. The limits of detection of the method were 0.4-0.9 mu g L-1. The relative standard deviations varied from 1.2 to 5.1% (n=5). The repeatability of fiber-to-fiber and batch-to-batch was 2.5-6.5% and 3.2-6.7%. The recoveries of the BFRs from aqueous samples were in the range between 86.5 and 103.6%. Compared with three commercial fibers (100 mu m PDMS, 85 mu m PA and 65 mu m PDMS/DVB), the MCFs-coated fiber showed about 3.5-fold higher extraction efficiency. (C) 2012 Elsevier B.V. All rights reserved.