Design and construction of a simple Knudsen Effusion Mass Spectrometer (KEMS) system for vapour pressure measurements of low volatility organics
Design and construction of a simple Knudsen Effusion Mass Spectrometer (KEMS) system for vapour pressure measurements of low volatility organics
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DOI：
10.5194/amt-2-355-2009
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发表时间：
2009-01-01
影响因子：
3.8
通讯作者：
Topping, D. O.
中科院分区：
文献类型：
--
作者：
Booth, A. M.;Markus, T.;Topping, D. O.
介绍了克努森流出质谱仪 (KEMS) 的设计和初步结果。该设计改编自高温合金研究，旨在用它来测量低挥发性有机物的蒸气压。该系统使用带有流出孔的温度控制单元。这会产生分子束，由四极质谱仪采样，并使用校准至已知蒸气压的电子轰击电离。我们测定了前 5 种饱和直链二元酸的 P-(298K) 和 Delta H-sub：草酸分别为 2.15 +/- 1.19x10(-2) Pa 和 75 +/- 19 KJ mol(-1)，丙二酸分别为 5.73 +/- 1.14x10(-4) Pa 和 91 +/- 4 KJ mol(-1)，琥珀酸 1.13 +/- 0.47x10(-4) Pa 和 93 +/- 6 KJ mol(-1)，戊二酸 4.21 +/- 1.66x10(-4) Pa 和 123 +/- 22 KJ mol(-1)，6.09 +/- 3.85x10(-6) Pa 和 125 +/- 40 KJ mol(-1) 为己二酸。
A design of and initial results from a Knudsen Effusion Mass Spectrometer (KEMS) are presented. The design was adapted from high temperature alloy studies with a view to using it to measure vapour pressures for low volatility organics. The system uses a temperature controlled cell with an effusive orifice. This produces a molecular beam which is sampled by a quadropole mass spectrometer with electron impact ionization calibrated to a known vapour pressure. We have determined P-(298K) and Delta H-sub of the first 5 saturated straight chain dicarboxylic acids: 2.15 +/- 1.19x10(-2) Pa and 75 +/- 19 KJ mol(-1) respectively for oxalic acid, 5.73 +/- 1.14x10(-4) Pa and 91 +/- 4 KJ mol(-1) for Malonic acid, 1.13 +/- 0.47x10(-4) Pa and 93 +/- 6 KJ mol(-1) for Succinic acid, 4.21 +/- 1.66x10(-4) Pa and 123 +/- 22 KJ mol(-1) for Glutaric acid and 6.09 +/- 3.85x10(-6) Pa and 125 +/- 40 KJ mol(-1) for Adipic acid.