Determination of Polybrominated Diphenyl Ethers in Water Samples by Headspace Solid-Phase Microextraction Technique with Carbon Nanotube Coated Fibers

摘要

A headspace solid-phase microextraction (HS-SPME) method was developed for gas chromatography with electron-capture detection (GC-ECD) of polybrominated diphenyl ethers (PBDEs) in water samples. Silicon fibers coated with multiwalled carbon nanotube (MWCNT) with a 35 μm thickness were prepared for the SPME. Various parameters affecting the efficiency for the SPME of PBDEs, such as extraction time, temperature, agitation, volume of headspace, pH of sample, addition of salt and acetone were studied and optimized. The extraction efficiencies by HS-SPME and SPME at 25 and 100℃ were compared. At room temperature (ca. 25 ℃) the response obtained with SPME was 2-10 times higher than with HS-SPME. However, at 100℃ HS-SPME gave responses 1-8 times higher than SPME. The responses obtained with SPME and HS-SPME at 100℃ were higher than those at room temperature by a factor of 0.7-1.4 for SPME and by a factor of 2-40 for HS-SPME. The linear range of the developed method was 50-1600 ng/L with the linear correlation coefficients (r) ranging from 0.995 to 0.998. The limits of detection (S/N=3) for the five PBDEs were in the range of 1.1-16.0 ng/L and the precision (RSD, n=5) for peak area was 5.0%-9.1%. The developed method was successfully applied to the analysis of real water sam-ples with recovery of 74.2%-98.7%.