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目的水中土臭素(GSM)、2-甲基异莰醇(2-MIB)、2-异丙基-3甲氧基吡嗪(IPMP)、2-异丁基-3-甲氧基吡嗪(IBMP)、2,4,6-三氯苯甲醚(TCA)、二甲基三硫醚(DMTS)和β-紫罗兰酮(β-lonone)的吹扫捕集-气相色谱-质谱联用检测方法。方法对7种典型嗅味物质的色谱分离条件、样品吹扫条件等进行优化。在40 ml水样中加入2 g氯化钠,吹扫捕集装置于20℃高纯氦气吹扫11 min,250℃下脱附2 min,吹扫流量为40 ml/min。以保留时间和质谱全扫描(Scan)方式进行定性分析,扫描质量为m/z 35~350;以质谱选择离子监测(SIM)模式进行定量分析。结果7种嗅味物质浓度为2.5 ng/L~500 ng/L时,线性关系良好;除了TCA的最低检出限为2.50 ng/L之外,其他6种嗅味物质的检出限均为1.25 ng/L。在20 ng/L、100 ng/L 2种加标浓度水平下,回收率分别为77%~120%、91%~109%,相对标准偏差分别为3.9%~10.5%、2.0%~6.8%。结论该方法快速、准确,可用于水中7种异味有机物的检测。
In the water of interest, geosmin (GSM), 2-methylisoxalane (2-MIB), 2-isopropyl-3methoxypyrazine (IPMP), 2- isobutyl-3-methoxypyrazine (IBMP), 2,4,6-trichloroanisole (TCA), dimethyl trisulfide (DMTS) and β-lonone by gas chromatography-mass spectrometry Detection method. Methods The chromatographic separation conditions of 7 typical odorous substances and the conditions of sample purging were optimized. Add 2 g of sodium chloride to a 40 ml water sample. The purge and trap device was purged with high purity helium at 20 ° C for 11 min and desorbed at 250 ° C for 2 min with a purge flow of 40 ml / min. Qualitative analysis was performed with retention time and mass spectral scan (Scan), with a mass of m / z 35-350; quantitative analysis was performed by mass spectrometry selected ion monitoring (SIM) mode. Results The results showed that the linear relationship was good when the concentrations of seven odorant compounds were between 2.5 ng / L and 500 ng / L. The detection limits of the six other odorant compounds except TCA were 2.50 ng / L 1.25 ng / L. Under 20 ng / L and 100 ng / L spiked levels, the recoveries ranged from 77% to 120% and from 91% to 109% with relative standard deviations of 3.9% -10.5% and 2.0% -6.8% . Conclusion The method is rapid and accurate and can be used for the detection of seven kinds of odor organic compounds in water.