顶空固相微萃取/气质联用测定水中10种致嗅物质  

Online Headspace Solid-phase Microextraction/Gas Chromatography-Mass Spectrometry for Determination of Ten Odorous Compounds in Water

作　　者：彭睿 马越 张文艺 PENG Rui;MA Yue;ZHANG Wen-yi(Shenzhen Shenshui Longhua Water Co.Ltd.,Shenzhen 518110,China)

机构地区：[1]深圳市深水龙华水务有限公司,广东深圳518110

出　　处：《中国给水排水》2023年第18期147-154,共8页China Water & Wastewater

摘　　要：采用顶空固相微萃取/气相色谱质谱法测定水体中二乙基二硫醚、二甲基三硫醚、2,4-辛二烯醛、正壬醇、2-异丙基-3-甲氧基吡嗪、β-环柠檬醛、吲哚、2,4,6-三氯苯甲醚、2-甲基异莰醇、土臭素等10种微生物源致嗅物质。用单因素实验优化了气相色谱升温程序、固相微萃取纤维头涂层、氯化钠加入量、萃取温度、萃取时间、解吸时间。结果表明,使用85μm CAR/PDMS萃取纤维头、每10 mL水样中加入3.5 g氯化钠、于80℃萃取温度下萃取60 min、于250℃进样口中解吸5min时,对10种嗅味物质的测定效果良好。同时,在《生活饮用水标准检验方法第8部分:有机物指标》(GB/T 5750.8—2023)推荐的2-甲基异莰醇检测方法基础上,将2-甲基异莰醇与内标物2-异丁基-3-甲氧基吡嗪保留时间附近处的升温速率调整至0℃/min,可有效避免两物质难以分离,从而导致低浓度下2-异丁基-3-甲氧基吡嗪在95 m/z处的碎片会影响2-甲基异莰醇定量的问题。在此条件下,10种嗅味物质在5.0~80.0 ng/L范围内线性良好,方法检出限为0.05~3.26 ng/L,加标回收率为74.3%~128.1%,相对标准偏差为1.9%~14.4%。此方法预处理简便、检测快速、灵敏度高,适用于水体中10种微生物源致嗅物质的检测。A headspace solid-phase microextraction/gas chromatography-mass spectrometry method was used to determine 10 microbial-derived odorous compounds in water,including diethyl disulfide,dimethyl trisulfide,2,4-octadiene aldehyde,n-nonanol,2-isopropyl-3-methoxypyrazine,β-cyclocitral,indole,2,4,6-trichloroanisole,2-methylisoborneol and geosmin.The gas chromatography ramp-up procedure,solid phase microextraction fiber head coating,dosage of sodium chloride,extraction temperature,extraction time and desorption time were optimized by single factor experiments.The 10microbial-derived odorous compounds were well detected under the following conditions:85μm CAR/PDMS extraction fiber head,adding 3.5 g of sodium chloride to every 10 mL of water sample,extracting at 80℃for 60 min and desorption at 250℃for 5 min in the injection port.Based on the 2-methylisoborneol detection method recommended in Standard Examination Methods for Drinking Water—Part 8:Organic Indices,the temperature rise rate near the retention time of 2-methylisoborneol and 2-isobutyl-3-methoxypyrazine was adjusted to 0℃/min,which effectively avoided the 2-isobutyl-3-methoxy pyrazine fragments at 95 m/z at low concentration affecting the quantification of 2-methylisobornol caused by the difficult separation between 2-methylisoborneol and 2-isobutyl-3-methoxypyrazine.Under these conditions,the linearity of the 10 microbial-derived odorous compounds was good in the range of 5.0-80.0 ng/L,the detection limits were 0.05-3.26 ng/L,the spiked recoveries were between 74.3%and 128.1%,and the relative standard deviations were 1.9%-14.4%.This analytical method is simple,rapid and sensitive,and is suitable for the detection of 10 kinds of microbial-derived odorous compounds in water.

关 键 词：致嗅物质 固相微萃取 气相色谱-质谱法 

分 类 号：TU991[建筑科学—市政工程]