固相微萃取-气相色谱法测定煤气中萘

摘要

The gas was collected with the special sampling bottle. Then, the content of naphthalene in gas was de-termined by gas chromatography( GC) after pretreatment with solid phase microextraction ( SPME) technology. The optimal extraction conditions of SPME were obtained by experiments: the 100 μm polydimethylsiloxane( PDMS) was used as extraction coating;the extraction time at rotate speed of 800 r/min was 5 min at room temperature;the desorption time of gas chromatography was 3 min. The baseline was smooth and steady in presence of acetone sol-vent peak. The determination of naphthalene was not affected by the acetone peak. The results showed that the con-tent of naphthalene exhibited good linearity in range of 5-200 mg/m3 with correlation coefficient of 0. 999 9. The detection limit of method was 0. 08 mg/m3 . The proposed method was applied to determination of naphthalene in gas. The relative standard deviation (RSD, n=7) was 2. 6%-4. 9%, and the recoveries were between 85% and 108%.%采用特制采样瓶收集煤气后,应用固相微萃取( SP ME )对样品进行前处理,采用气相色谱( GC )对煤气中的萘进行测定。通过试验确定了SP ME的最佳萃取条件为：采用100μm聚二甲基硅氧烷( PDMS)萃取涂层,于转速为800 r/min时室温下萃取5 min,气相色谱解吸时间为3 min。在丙酮溶剂峰存在的情况下,基线平稳,丙酮峰对萘的测定并无影响。实验结果表明,萘在5~200 mg/m3范围内有良好的线性关系,相关系数为0.9999。方法检出限为0.08 mg/m3。实验方法用于煤气中萘的测定,相对标准偏差(RSD,n=7)为2.6%~4.9%,加标回收率为85%~108%。