摘要
采用顶空固相微萃取-气相色谱/质谱联用测定了水中常见的3种异味化合物,即2-甲基异茨醇、土腥素和β-柠檬醛.研究并讨论了纤维头的类型、盐的种类和浓度、温度、萃取时间、搅拌和解吸时间等因素对异味化合物萃取量的影响.结果表明:在水样中加入30%(W/V)的NaCl溶液,采用65 μm PDMS/DVB纤维头,在搅拌的条件下,于60℃顶空萃取40 min为异味化合物固相微萃取的最佳条件.在优化的条件下,使异味化合物吸附于纤维涂层后, 将其在250℃高温下解吸,再用GC-MS分析.土腥素、β-柠檬醛、2-甲基异茨醇的检出限依次为1.0、1.3和1.7 ng/L;其相对标准偏差分别为4.9%、8.4%和6.2%.3种异味化合物在5～1000 ng/L的范围内线性关系良好,相关系数均大于0.997.因此,用该方法分析水中痕量(ng/L级)的异味化合物,结果满意.
Three major odorous compounds are 2-methylisoborneol （2-MIB）, geosmin and β-cyclocitral,which in water were determined by coupling headspace solid-phase microextraction （HS-SPME） with gas chromatography-mass spectrometry （GC-MS）. The operating conditions of HS-SPME, such as fibre type, salt concentration, water temperature, stirring, absorption time and desorption time were studied and discussed.The highest absorption of the odorous compounds were obtained under the following operating conditions as the addition of 30% （m/V）NaCl, stirring at 60℃ for 40 min, using 65μm polydimethyl siloxane/divinylbenzene coated fibre. After the odorous compounds had been absorbed in the fibre under the optimal conditions of HS-SPME, they were desorbed at 250℃ and determined by GC-MS. The limits of detection for geosmin,β-cyclocitral and 2-MIB in water were 1.0, 1.3, 1.7 ng./L, and the relative standard deviations for them were 4.9% , 8.4% , 6.2% , respectively. There were good linear correlation （ the calibration coefficients were all above 0. 997） for the three odorous compounds in the range of 5 - 1000 ng/L. Therefore, trace levels of the odorous compounds at ng/L in water could be quantified by the simple method with satisfactory result.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2005年第8期1058-1062,共5页
Chinese Journal of Analytical Chemistry
基金
国家重点基础研究发展规划项目(No.2002CB412306)
中国科学院知识创新工程重要方向性项目(No.KSCX2-1-10)
中国科学院水生生物所创新领域前沿项目(No.220316)资助。
关键词
顶空固相微萃取
气相色谱
质谱
水分析
异味化合物
Solid-phase microextraction, gas chromatography-mass spectrometry, odorous compound, 2-meth ylisobomeol, geosmin, β-cyclocitral
