顶空固相微萃取-气质法测定水中嗅味物质

Determination of Odorous Compounds in Water by Headspace Solid-phase Microextraction Coupled with Gas Chromatography/Mass Spectrometry

建立了一种测定水中土臭素、2-甲基异莰醇、吲哚和3-甲基吲哚的方法——顶空固相萃取（HS—SPME）和气相色影质谱（GC／MS）法，该方法可以检测到ng／L级的致嗅物质。详细研究了萃取纤维头的选择、萃取时间和温度、样品含盐量对HS—SPME的影响。在优化条件下，本法测定2一甲基异莰醇和土臭素的线性范围为5—200ng／L，相关系数分别为0．9997、0．9998；测定吲哚和3-甲基吲哚的线性范围为200～5000ng／L，相关系数〉0．995；方法检出限分别为2．34、2．04、98．1、93．1ng／L；低浓度下RSD〈20％，高浓度下RSD〈10％；水样加标回收率为89．7％～109．5％。以IBMP为内标物，将本法成功应用于饮用水源、饮用水、河涌水中土臭素、2-甲基异莰醇、吲哚和3-甲基吲哚的测定，结果令人满意。

A method to determine geosmin, 2-methylisoborneol （2-MIB）, indole and skatole in water was built, namely headspace solid-phase microextraction （HS-SPME） coupled with gas chromatog- raphy/mass spectrometry （GC/MS）. The method could detect odorous compounds of the order of ng/L. The influence of fiber head, extraction time and temperature, salt content of sample on HS-SPME was in- vestigated. Under the optimized conditions, the linear ranges of the method for 2-MIB and geosmin were 5 to 200 rig/L, and the correlation coefficients were O. 999 7 and 0. 999 8, respectively. The linear ran- ges of the method for indole and skatole were 200 to 5 000 ng/L, and the correlation coefficients were both greater than 0. 995. The limits of detection （LOD） were 2.34 ng/L, 2.04 ng/L, 98.1 ng/L and 93.1 ng/L respectively. The relative standard deviation at low level was less than 20% and that at high level was less than 10%. The recovery rates of water samples were between 89.7% and 109.5%. Using IBMP as internal standard, the method was successfully applied to the determination of geosmin, 2-MIB, indole and skatole in source water, drinking water and watercourse water, with satisfactory results.