水样过0.45 μm滤膜,分取10 mL滤液和已经于450℃处理2 h的氯化钠2.5 g混合,在顶空仪中于65℃平衡5 min,再用二乙烯苯基/Carboxen/聚二甲基硅氧烷(DVB/CAR/PDMS)固相微萃取纤维头在500 r·min^-1转速下于65℃萃取30 min,于250℃热解吸3 min,所得气体进入气相色谱-质谱仪,在HP-5MS毛细管色谱柱上用升温程序分离,用附电子轰击离子(EI)源的质谱仪检测。结果显示,土臭素、2-甲基异莰醇的质量浓度在2.0~200.0 ng·L^-1内,β-紫罗兰酮的质量浓度在1.0~100.0 ng·L^-1内分别与其对应的峰面积呈线性关系,检出限(3.36s)分别为1.38,1.12,0.78 ng·L^-1;对纯水及太湖水源水进行3个浓度水平的加标回收试验,水源水中3种嗅味物质的检出量分别为1.78,3.07,3.81 ng·L^-1,回收率为92.3%~111%,测定值的相对标准偏差(n=6)为0.98%~13%,适用于水源水中嗅味物质的测定。

The water sample was passed through a 0.45 μm filter membrane, and an aliquot (10 mL) of the filtrate was mixed with 2.5 g of sodium chloride that had been treated at 450℃ for 2 h. Targets in the sample were extracted by Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS) solid microextraction fiber head at 65℃ for 30 min with rotating speed of 500 r·min^-1, and thermally desorbed at 250℃ for 3 min. The obtained gas was introduced into the gas chromatography-mass spectrometer. Separation was performed on HP-5MS chromatographic capillary column with temperature program, and detection for geosmin, 2-methylisoborneol and β-ionone was performed with mass spectrometer equipped with an electron impact ion (EI) source. It was shown that linear relationships between values of the mass concentration and the corresponding peak area were kept in the range of 2.0-200 ng·L^-1 (for geosmin and 2-methylisoborneol) and 1.0-100 ng·L^-1 (for β-ionone), with detection limits (3.36s) of 1.38, 1.12, 0.78 ng·L^-1, respectively. Test for the spiked recovery was carried out on pure water and source water of Taihu lake at the 3 concentration levels, the detected amounts of the 3 odorants in the source water were 1.78, 3.07, 3.81 ng·L^-1, and the recovery was found in the range of 92.3%-111%, with RSDs (n=6) of the determined values in the range of 0.98%-13%, indicating that the proposed method was suitable for the determination of odorants in source water.