Construction of a universal spectrometer for molecular ions equipped with an electrospray ion source

本研究的目的是建立一个简单的光谱仪的分子离子在气相中，这是配备了一个电喷雾离子源。 我们将一个商业电喷雾离子源内的荧光光谱仪，并试图测量色氨酸离子的荧光光谱的水/甲醇液滴从电喷雾发射。 随着电喷雾离子源与测量位置之间的距离从0增加到12 nm，色氨酸的荧光光谱的带位从347移动到366 nm。 我们的结论是，这种红移是由于优先蒸发的甲醇超过水的液滴之间的离子源放置在前面的离子源的接地板的旅行期间。 我们还尝试通过使用真空室内的加热管实现溶剂分子从离子中完全蒸发，并获得了去溶剂化离子的质谱。

The purpose of this study was to construct a simple spectrometer for molecular ions in the gas phase, which is equipped with an electrospray ion source. We have placed a commercial electrospray ion source inside a fluorescence spectrometer, and tried to measure fluorescence spectra of tryptophan ions in water/methanol droplets emitted from the electrospray. The band position of the fluorescence spectra of tryptophan shifts from 347 to 366 nm with increasing the distance between the electrospray ion source to the measurement position from 0 to 12 nm. We conclude that this red-shift is due to the preferential evaporation of methanol over water during the travel of the droplets between the ion source to a grounded plate placed in front of the ion source. We also tried to achieve complete vaporization of solvent molecules from the ions by using a heated tube inside a vacuum chamber, and we obtained mass spectra of desolvated ions.