建立了静态顶空萃取、气相色谱-质谱联用(HS-GC/MS)同时测定海水中常见的痕量13种苯系物(BTEX)方法。对影响分析效果的主要条件:色谱柱类型、升温程序、顶空平衡温度、平衡时间以及气液体积比进行了详细的分析和优化。在优化条件下,该方法的线性相关系数大于0.999,线性范围为0.16~320μg/L,检出限(按信噪比为3计)为0.019~0.033μg/L;水样中3个加标水平(1.6、16和160μg/L)的回收率为81.25%~103.73%,相对标准偏差(RSD,n=6)为0.3%~4.4%。将该方法应用于上海黄浦区海水样品中苯系物的测定,结果令人满意。该方法分析时间为12 min,操作简单快捷,灵敏度高,环境友好,定性、定量准确、可靠。
A method for the simultaneous determination of 13 benzene series(BTEX) in seawater using gas chromatography-mass spectrometry with static headspace extraction(HS-GC/MS) was developed.To carefully characterize the performance of this method,several factors affecting parameters were studied in detail,such as the type of column,heating procedure,equilibrium temperature,equilibrium time and the volume ratio of gas phase to liquid phase.The optimized conditions were as follows: the polar column of DB-WAX;heating procedure,40 ℃ kept for 4 min,then raised to 120 ℃ at 10 ℃/min,to 180 ℃ at 25 ℃/min;equilibrium temperature,80 ℃;equilibrium time,10 min;and the volume ratio of gas phase to liquid phase,1∶1.Under the optimized conditions,the linear equations were obtained in the concentration range of 0.16-320 μg/L with correlation coefficients greater than 0.999.The limits of detection(S/N=3) were 0.019-0.033 μg/L.The recoveries at the three spiked levels of 1.6,16 and 160 μg/L ranged from 81.25% to 103.73% with the relative standard deviations(RSD,n=6) from 0.3% to 4.4%.The analytical results of the practical seawater samples from Shanghai Huangpu District were satisfactory.The determination of the 13 benzene series can be finished in 12 min.The method is simple,accurate,reliable,efficient and environmental-friendly.