顶空固相微萃取-气质联用法测定水中2种环状缩醛、2-甲基异莰醇和土臭素  

Determination of Two Cyclic Acetals,2-Methylisoborneol and Geosmin in Water Samples by Headspace-Solid Phase Microextraction with Gas Chromatography/Mass Spectrometry

作　　者：周鑫盛 ZHOU Xinsheng(Shanghai SMI Raw Water Co.,Ltd.,Shanghai200125,China)

机构地区：[1]上海城投原水有限公司,上海200125

出　　处：《净水技术》2024年第S02期276-283,共8页Water Purification Technology

摘　　要：随着新国标背景下对饮用水的嗅味物质要求越来越高,文章采用顶空固相微萃取(HS-SPME Fiber)技术,建立了一种快速测定水中2-乙基-4-甲基-1,3-二氧戊环(2-EMD)、2-乙基-5,5-二甲基-1,3-二氧六环(2-EDD)、2-甲基异莰醇(2-MIB)、土臭素(GSM)的方法,重点针对离子浓度、孵化时间、振摇速率、萃取温度、萃取时间等影响因素进行了优化。优化后的条件为:DB-5 ms(30 m×0.25 mm×1.0μm)气相色谱柱,50/30μm DVB/CAR/PDMS纤维,氯化钠添加质量分数为20%,萃取温度为50℃,孵化时间为5 min,萃取时间为25 min,振摇速率为450 r/min,在250℃下解吸5 min后进入气相色谱质谱联用仪进行分析。该方法测得的4种化合物线性较好(r>0.995),相对标准偏差为0.6%~4.5%,加标回收率为92.7%~108.8%,方法检出限为0.7~1.6 ng/L。该方法可满足地表水样中嗅味物质的测定需要。With the increasing odor standard of drinking water against the background of new GB Standard published,an analytical method based on headspace solid-phase microextraction with gas chromatography/mass spectrometry(GC/MS)was established for the determination of 2-ethyl-4-methyl-1,3-dioxolane(2-EMD),2-ethyl-5,5-dimethyl-1,3-dioxane(2-EDD),2-methylisoborneol(2-MIB)and geosmin(GSM).The parameters affecting the extraction efficiency,including salt concentration,incubation time,agitator speed,extraction temperature and time,were mainly optimized.The optimal operation conditions were obtained as follows:DB-5 ms(30 mx0.25 mmx1.0μm)GC columns,50/30μm DVB/CAR/PDMS coated fiber,mass fraction of salting-out agent was 20%,incubating at 50℃for 5 min and extracting for 25 min at 450 r/min,then desorption at 250℃for 5 min in GC/MS for analysis.The linear correlation coefficients()of four compounds determined by this method were all superior to 0.995.Relative standard deviation of four compounds were from 0.6%to 4.5%and the recoveries were from 92.7%to 108.8%.Method detection limits were from 0.7 ng/L to 1.6 ng/L.This method can be used to determine the above-mentioned odorous compounds in raw water samples.

关 键 词：顶空固相微萃取 气相色谱质谱法 嗅味物质 2-乙基-4-甲基-1 3-二氧戊环 2-乙基-5 5-二甲基-1 3-二氧六环 2-甲基异莰醇 土臭素 

分 类 号：X832[环境科学与工程—环境工程]