双流路顶空热脱附-气相色谱质谱联用测定水中土臭素和二甲基异莰醇

Determination of geosmin and 2-methylisopropanol in water using dual flow headspace thermal desorption gas chromatography-mass spectrometry

建立双流路顶空热脱附-气相色谱质谱联用测定水中土臭素和2-甲基异莰醇的方法。采用双流路顶空提取针将顶空气体进行连续吹扫至冷阱吸附,快速升温解吸,载气反向将待测组分送入气相色谱质谱联用仪分析。对恒温时间、温度等实验条件进行了优化,内标法定量,土臭素和2-甲基异莰醇在2.0~100ng·L^(-1)线性回归相关系数≥0.999,方法最低检出浓度为0.74ng·L^(-1)和1.50ng·L^(-1),5ng·L^(-1)、20ng·L^(-1)和100ng·L^(-1)三个浓度加标回收率在90.3~105%,精密度在1.76~6.91%。方法简便、灵敏、重现性好,可用于环境水和生活饮用水中土臭素和2-甲基异莰醇检测。

A dual flow headspace thermal desorption gas chromatography-mass spectrometry method was established for the determi-nation of geosmin and 2-methylisopropanol in water.The headspace gas was continuously blown and swept by the dual-flow head-space extraction needle until it was absorbed in the cold trap,and then rapidly heated and desorbed.The analyte was carried by reverse carrier gas and analyzed by gas chromatography-mass spectrometry.The experimental conditions such as constant time and temperature were optimized,and quantified using internal standard.The linear regression correlation coefficient between geosmin and 2-methylisocamphenol was≥0.999 at 2.0~100 ng·L^(-1).The lowest detection concentrations of the method were 0.74ng·L^(-1)and 1.50ng·L^(-1).The recovery rates of the three concentrations of 5 ng·L^(-1),20 ng·L^(-1),and 100 ng·L^(-1)were 90.3~105%,and the precision was 1.76~6.91%.The method was simple,sensitive,and well-reproducible as well as could be used for the detection of geosmin and 2-methylisoborneol in environmental water and drinking water.