顶空固相微萃取-气相色谱-质谱联用法测定海洋沉积物中的苯系物

利用顶空固相微萃取（HS-SPME）与气相色谱-质谱（GC-MS）联用建立了测定海洋沉积物中的苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯以及苯乙烯等7种常见苯系物的检测分析方法。对无机盐的加入、平衡时间、萃取温度、萃取时间、解吸温度和时间等多个固相微萃取条件以及色谱条件进行了优化，内标法定量。结果表明：在0.500~20.0 ng/g范围内7种苯系物的线性关系良好，相关系数在0.995~0.999之间；方法检出限为0.0818~0.175 ng/g（干重）；日内和日间重现性较好，相对标准偏差分别为1.2%~3.6%（n=5）和0.4%~6.3%（n=3）；在每1.00 g海洋沉积物样品中2.0和15.0 ng加标水平下，平均加标回收率分别为61.7%~79.5%和77.1%~85.6%，相对标准偏差分别为5.4%~9.6%和3.9%~7.6%（n=5）。该方法快速、灵敏、简便，准确度高，重现性好，适合海洋沉积物样品中苯系物的痕量分析。

Determination of benzene series in marine sediment by headspace solid phase microextraction-gas chromatography-mass spectrometry

A method was developed for the determination of benzene series (BTEX) in marine sediment by headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The conditions for extraction and gas chromatography, such as the amount of salt added, equilibrium time, extraction temperature, extraction time, desorption time and injection temperature, were optimized. The analytes were quantitatively analyzed by the internal standard method. The results showed that the linear correlation coefficients of BTEX compounds were from 0.995 to 0.999 in the range of 0.500-20.0 ng/g. The detection limits of this method were from 0.0818 to 0.175 ng/g, with the RSDs of inter- and intra-day of 1.2%-3.6% (n=5) and 0.4%-6.3% (n=3). The average recoveries under two different spiked concentrations (2.0 and 15.0 ng) were 61.7%-79.5% and 77.1%-85.6% with RSDs of 5.4%-9.6% and 3.9%-7.6% (n=5), respectively. This method is quick, sensitive, simple, accurate and reproducible. It can be used to analyze the marine sediment samples with trace BTEX.