Micro-solid phase extraction followed by thermal extraction coupled with gas chromatography-mass selective detector for the determination of polybrominated diphenyl ethers in water.

A method of analyzing environmental contaminants in water based on micro-solid phase extraction (μ-SPE) followed by thermal extraction (TE) and a cold-trapping step, coupled with gas chromatography-mass selective detection (GC-MSD) was developed and validated. μ-SPE-TE- GC-MSD was employed in the determination of five polybrominated diphenyl ethers. The μ-SPE sorbent was chitosan-graphene oxide (CS-GO) composite, which was prepared by mixing CS and GO by means of ultrasonication. The CS in the composite was cross-linked with glutaraldehyde. After μ-SPE, the analytes in the extract were extracted thermally in a thermal desorption unit tube combined with a cooled injection system, coupled to GC-MSD. The extraction conditions were optimized for the detection of the target compounds in water. This method provided linearity ranges of between 0.1 and 20μgL(-1) (depending on the analytes), with coefficients of determination, r(2), ≥0.9982. The calculated relative recoveries were between 71.52 and 96.15% whereas precision (based on % relative standard deviations) was between 3.54 and 11.36%. The method showed limit of detection and limit of quantification ranges of between 0.007 and 0.016μgL(-1), and between 0.023 and 0.054μgL(-1), for the two groups of analytes, respectively. The method was applied to the determination of the target analytes in water.