气相色谱-质谱联用法测定生活饮用水中的土臭素和2-甲基异莰醇

Determination of geosmin and 2-methylisoborneol in drinking water by gas chromatography-mass spectrometry

目的建立饮用水及水源水中土臭素和2-甲基异莰醇的液液萃取气相色谱-质谱联用测定方法。方法土臭素和2-甲基异莰醇经过正己烷液液萃取、浓缩、进样,经气相色谱-质谱联用法分析测定,选择离子模式定量。结果该方法分离效果好,土臭素和2-甲基异莰醇的浓度为2.5 ng/L^100.0 ng/L时,线性关系良好,线性方程分别为y=1 335.72x+390.6(r=0.999 2)和y=1 130.80x+287.8(r=0.999 3),检出限分别为1.0 ng/L和2.0 ng/L。标准样品添加量为10.0 ng、20.0 ng、50.0 ng时,方法的加标回收率为83%~94%,相对标准偏差(RSD)为3.0%~4.9%。对待测组分在水中的稳定性进行了研究,样品于4℃保存7 d后仍可获得较准确的结果。结论该方法简便,灵敏度高,可用于饮用水及水源水中土臭素和2-甲基异莰醇的测定。

To establish a method for the determination of geosmin and 2 - methylisoborneol in drirnking water and source water by gas chromatography - mass spectrometry（ GC - MS） after liquid - liquid extraction. Methods Geosmin and 2 - methylisoborneol in sample were conducted for n - hexane liquid - liquid extraction, concentration, sample, and analyzed by GC - MS. And ion monitoring mode was used for quantitative analysis. Results This method was with good isolation effect,and good linearity was obtained when the concentration of geosmin and 2 -methylisoborneol were among 2.5 ng/L-100.0 ng/L,the regressiong equations were 3 = 1 335.72x ＋ 390.6 （ r =0. 999 2） and y = 1 130. 80x ＋ 287.8 （ r = 0. 999 3 ）, with the detection limits respectively 1. 0 ng/L and 2.0 ng/L. Furthermore, the recovery rates of geosmin and 2 - methylisobomeol were among 83% - 94% while the contents of added standard were 10. 0 ng, 20.0 ng, 50.0 ng, and the relative standard deviations were among 3.0% - 4.9%. The stability of analysis compositions in water was tested, and accurate results could be obtained with the samples under 4 ℃ for 7 d. Conclusion This method is simple and sensitive, and suitable for the detection of geosmin and 2 - methylisoborneol in drinking water and source water.