碳纳米管顶空固相微萃取测定水中的多溴联苯醚

建立了顶空固相微萃取联结气相色谱-电子捕获检测器（HS-SPME-GC-ECD）测定水中多溴联苯醚的方法。制作了多壁碳纳米管涂层固相微萃取探头。优化了萃取时间，萃取温度，搅拌速度，顶空体积，溶液的pH，离子强度及有机溶剂等影响萃取效率的各种因素。比较了室温和100 ℃顶空萃取和直接萃取的效率。结果表明，室温下直接萃取比顶空萃取的效率高2-4倍，而在100 ℃时顶空萃取比直接萃取的效率高1-8倍。除BDE-154外，无论直接萃取还是顶空萃取，100 ℃时的萃取效率均高于室温。方法的线性范围50-1600 ng/L，相关系数为0.995-0.998，5种多溴联苯醚的最低检出限（S/N=3）为1.14-16.25 ng/L，相对标准偏差（RSD%，n=5）小于10%。本方法用于真实水样的测定，回收率为74.2%-98.7%。

Determination of Polybrominated Diphenyl Ethers in Water Samples by Headspace Solid‐Phase Microextraction

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 °C were compared. At room temperature (ca. 25 °C) the response obtained with SPME was 2–10 times higher than with HS‐SPME. However, at 100 °C HS‐SPME gave responses 1–8 times higher than SPME. The responses obtained with SPME and HS‐SPME at 100 °C 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 samples with recovery of 74.2% –98.7%.