大体积浓缩-固相微萃取-气相色谱-质谱联用测定水样中6种典型嗅味物质

Determination of Six Typical Taste and Odor Compounds Using Large Volume Concentration,Solid Phase Micro-extraction and Gas Chromatography-Mass Spectrometry

2-甲基异崁醇(2-MIB)、土臭素(GSM)、2,4,6-三氯苯甲醚(TCA)、β-环柠檬醛(β-Cyclocitral)、β-紫罗兰酮(β-Ionone)和二甲基三硫醚(DMTS)为不同特征水体的典型嗅味物质。本研究建立了大体积浓缩-固相微萃取-气相色谱-质谱联用同时测定这6种痕量物质的方法。自制大体积玻璃萃取瓶,萃取体积为100 mL。优化的萃取条件:萃取时间30 min,NaCl离子浓度0.3 g/mL,萃取温度65℃,解吸时间2 min,溶液pH值4～9范围内,不影响萃取效果。各物质的检出限均低于1 ng/L,具有较高的灵敏度;加标回收率为86.0%～114.2%,具有较好的精密度;浓度在1～200 ng/L范围内线性关系良好。本方法应用于江河湖泊、水库、自来水出厂水和管网末端水等水体中嗅味物质的定量检测,结果表明:在富营养化的水体中DMTS,2-MIB和β-Cyclocitral的浓度较高;TCA在管网末端水中含量较高。

The taste and odor （T＆O） compounds including 2-methylisoborneol （2-MIB）, geosmin （ GSM）, 2,4,6-trichloroanisole （2,4,6-TCA）, fl-Cyclocitral, fl-Ionone and Dimethyl trisulfide （DMTS） ubiquitously exist in water environments. To simultaneously detect these compounds, large volume concentration and SPME-GC/MS method using a 100-mL customized extraction bottle was developed. The extraction conditions were optimized as follows ： extraction time of 30 min, NaC1 concentration of 0.3 g/mL, extraction temperature of 65 ~C, and desorption time of 2 min. The extraction was not significantly influenced by pH values （4-9）. This method exhibited high sensitivity with the detection limits below 1 ng/L, good precision with recoveries ratio ranged between 86.0% and 114.2% , and good linear response for the concentrations from 1.0 to 200 ng/L. It was successfully applied to analyze various environment water samples from rivers, lakes, reser- voirs as well as the effluent of water works and distribution systems. The results indicated that the concentra- tions of DMTS, 2-MIB and fl-Cyclocitral were relatively high in eutrophication water, while TCA was primary detected in distribution system with higher concentration.