Interdisciplinary Graduate School, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi, 400-8511, Japan.
Department of Chemistry, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK.
Rapid Commun Mass Spectrom. 2020 Jan 15;34(1):e8535. doi: 10.1002/rcm.8535.
The objective of this work is to study the interaction of methanol droplets with the heated surface for the improved detection of low-volatility and thermally labile compounds by the flash evaporation that occurs below the Leidenfrost temperature.
5 μL solutions of low-volatility compounds in methanol were introduced into the heated tube. Desorbed analytes were ionized in the sealed atmospheric pressure chemical ionization (APCI) source by direct current (DC) corona discharge using air as the reagent gas.
The rapid desorption of low-volatility compounds accompanied by the flash evaporation of methanol solvent was observed in the temperature range of 60-100°C. Linear relationships between the signal intensities and the solute concentrations in the range of 0.01-5 ppm for morphine, cocaine, methamphetamine, and amphetamine were obtained at 95°C.
The observed rapid desorption of low-volatility compounds below the Leidenfrost temperature would provide useful information in many fields, e.g., the interaction of liquid droplets with heated matter, liquid sample introduction into the injection port of a gas chromatograph, coupling of the flash evaporation with pulse valve operated miniaturized mass spectrometer, etc.
本工作的目的是研究甲醇液滴与受热表面的相互作用，通过低于莱顿弗罗斯特温度发生的闪蒸来提高对低挥发性和热不稳定化合物的检测能力。
将低挥发性化合物在甲醇中的 5μL 溶液引入加热管中。解吸的分析物在密封的大气压化学电离（APCI）源中通过直流（DC）电晕放电用空气作为试剂气体进行离子化。
在 60-100°C 的温度范围内观察到低挥发性化合物的快速解吸以及甲醇溶剂的闪蒸蒸发。在 95°C 时，吗啡、可卡因、甲基苯丙胺和苯丙胺的浓度在 0.01-5ppm 范围内获得了信号强度与溶质浓度之间的线性关系。
在莱顿弗罗斯特温度以下观察到的低挥发性化合物的快速解吸将为许多领域提供有用的信息，例如液滴与受热物质的相互作用、将液体样品引入气相色谱仪的进样口、闪蒸蒸发与脉冲阀操作的微型质谱仪的耦合等。
