| 摘要: |
| 本文建立了便携式固相微萃取-气质联用（SPME-GCMS），结合离子隔离技术现场测定水中四种异味物质（土臭素、2-甲基异莰醇、二甲基二硫醚、二甲基三硫醚）的方法，比较了全扫描（SCAN）、选择离子扫描（SIM）和离子隔离技术（SIS）分析同一浓度四种异味物质的信噪比结果，结果表明SIS模式的信噪比高，是SIM模式的1.6-3.6倍，方法灵敏度好。在建立的实验条件下，四种异味物质检出限在0.6-1.5 ng/L之间，线性系数均大于0.999，相对标准偏差范围3.7%-8.1%，地表水实际样品的加标回收率范围82.4-97.8%。利用本方法于6-9月份在江苏省CC河现场监测地表水样品中土臭素、2-甲基异莰醇，不同点位间土臭素、2-甲基异莰醇浓度存在差异，各点位土臭素、2-甲基异莰醇浓度随时间变化趋势一致，实际监测应用效果良好。分析土臭素、2-甲基异莰醇与水质指标水温、氨氮、总磷、总氮、浊度间pearson相关系数，土臭素、2-甲基异莰醇与以上水质指标比较，无显著相关性。本方法结合了新型离子隔离技术高灵敏度、高选择性和便携固相微萃取-气质联用仪操作简单、快捷的优点，能实现对水体中四种异味物质的现场快速监测。 |
| 关键词: 离子隔离技术 异味物质 固相微萃取 便携式气相色谱-质谱联用 现场监测 |
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| 基金项目:江苏省环境监测科研基金项目 |
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| Portable solid phase microextraction- Gaschromatographymass spectrometry combined with ion isolation technology field measurement Study on four odor substances in the water |
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| Abstract: |
| This paper established an on-site monitoring method for four odor substances (geosmin, 2-methylisoborneol, dimethyl disulfide, dimethyl sulfid) in water by using portable solid phase microextraction-Gas chromatography mass spectrometry (SPME-GCMS) combined with select ion storage (SIS) technology. Compared with the full scan (SCAN) or selected ion monitor (SIM) technology, SIS showed great sensitivity with highest signal-to-noise ratios, surpassing those in the SIM mode by 1.6-3.6 times. Under the established experimental conditions, the detection limit of the four odor substances was between 0.6 and 1.5 ng/L, with linear coefficient greater than 0.999 and relative standard deviation ranging from 3.7% to 8.1%. The recoveries from real surface water samples fell within the range of 82.4% to 97.8%. Monitoring geosmin and 2-methylisoborneol in surface water sampled in CC River in Jiangsu Province between June and September using this method unveiled concentration variations at different sampling locations. Consistent temporal trends in geosmin and 2-methylisoborneol concentrations were observed at each site, providing evidence of satisfactory monitoring efficacy. Pearson correlation coefficient analysis showed that there was no significant correlation between odor substance (geosmin, 2-methylisoborneol) concentrations and water quality parameters (water temperature, ammonia nitrogen, total phosphorus, total nitrogen, and turbidity). By amalgamating the heightened sensitivity and selectivity of SIS technology with the operational expediency of portable SPME-GCMS apparatus, this method facilitates swift on-site monitoring of four odor compounds in water. |
| Key words: select ion storage odor substances solid phase microextraction portable gas chromatography-mass spectrometry field monitoring |
