顶空固相微萃取-气质联用测定水中嗅味化合物

[目的]建立顶空固相微萃取-气质联用测定水中痕量嗅味化合物的方法。[方法]水样中加入氯化钠,顶空固相微萃取出水中2-甲基异冰片、土臭素两种嗅味化合物,气质联用测定其含量。[结果]建立的2-甲基异冰片、土臭素标准曲线的回归方程分别为y=5 923.0x-199.5、y=21 346x+5 851.8,相对标准偏差分别为8.9%、8.7%,相关系数均大于0.99;加标回收率在90%~110%,表明方法准确、可靠。2012年7月初、8月初测定杭州饮用水原水中2-甲基异冰片浓度较高,达60 ng/L以上,土臭素浓度都较低。[结论]固相微萃取具有简单、快速、萃取效率高、灵敏度高等特点。该方法线性良好,最大偏差10%,符合水中痕量2-甲基异冰片、土臭素的测定要求。

Determination of Odor Compounds in Water by GC/MS with Headspace Solid Phase Micro-extraction

[ Objective ] The aim was to establish the determination method of trace odor compounds in water by GC/MS with headspace solid phase micro-extraction. [ Method ] The sodium chloride was added into water sample, the 2-methyl isoborneol and Geosmin were extracted by headspace solid phase micro-extraction, and then determined their content by GC/MS. [ Result ] The standard curve of 2-methyl isoborneol and Geosmin were y = 5923.0x - 199.5 and y = 21 346x ＋ 5 851.8 resp. , their relative standard deviation was 8.9% and 8.7% resp. , their correlation coefficient were both more than 0.99; their recovery rate of 2-methyl isoborneol and Geosmin were from 90% to 110% , which showed that this method was accurate and reliable. The 2-methyl isoborneol concentration of raw water of Hangzhou drinking water was both high by over 60 ng/L in early July and early August in 2012, and the Geosmin concentration was both low. [ Conclusion] The solid phase mi- cro-extraction method has the characteristics of simple, fast, high extraction efficiency, high sensitivity, good linearity. The maximum devia- tion of established method is 10%, is consistent with the request of trace 2- methyl isoborneol andGeosmin determination.