吹扫捕集-气相色谱-三重四级杆质谱法测定地表水中的苯系物

Simultaneous determination of BTEX in surface water by P&T-GC-MS/MS

采用吹扫捕集(P&T)与气相色谱-三重四级杆质谱联用技术,建立汉江地表水中6种苯系物的分析方法。采用顶空自动进样器的吹扫捕集模式对采集水样进行预处理,调节NaCl浓度为0.26 g/mL,恒温炉温度80℃,样品瓶恒温时间25 min。采用Rtx-5MS色谱柱(30.0 m×0.25 mm,0.25μm),升温程序为:初始温度50℃,保持1 min,以25℃/min升高至125℃,然后以10℃/min升高至300℃,保持1 min。选择电子轰击离子源(EI),在多反应检测模式(MRM)下进行质谱检测。6种苯系物的检出限(3S/N)为0.01~0.03μg/L,定量下限(10S/N)为0.03~0.10μg/L,线性范围为0.03~25μg/L,相关系数大于0.9994。所建方法应用于汉江水中6种苯系物的分析检测,加标回收率为82.8%~102.3%,相对标准偏差(n=3)为0.12%~8.18%,结果满足环境水质分析要求。

Six BTEXs in surface water was analyzed by purge and trap(P&T)with gas chromatography-triple quadrupole mass spectrometry(GC-MS/MS).The P&T mode of headspace automatic sampler was used for sample pretreatment of surface water samples.The NaCl concentration of water sample was adjusted to 0.26 g/mL.The adjusted surface water was heated under 80℃for 25 min.A Rtx-5MS column(30.0 m×0.25 mm,0.25μm)was used for the separation of 6 BTEX by gas chromatography(GC).The initial temperature of column was 50℃,keeping for 1 min,then increased to 125℃at 25℃/min,and then increased to 300℃at 10℃/min,keeping for 1 min.Electron impact(EI)ion source and multiple reactions monitoring(MRM)mode were selected for triple quadrupole mass spectrometry(MS/MS).Under the optimized conditions, the limits of detection (3S/N) were in the range of 0.01-0.03 μg/L and the lower limits ofdetermination (10S/N) were in the range of 0.03-0.10 μg/L. The linear range of target 6 BTEX ranged from0.03 to 25 μg/L with correlation coefficient all above 0.999 4. The proposed method was applied for thedetermination of 6 BTEX in Hanjiang river water of Xiangyang. The sample recoveries were in the range of82.8%-102.3% with relative standard deviation (n=3) of 0.12%-8.18%. The obtained results met therequirements of environmental water analysis.