IR-MALDI ion mobility spectrometry: physical source characterization and application as HPLC detector

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• 作者：José Villatoro ; Martin Zühlke ; Daniel Riebe…
• 关键词：Ion mobility spectrometry ; IR ; MALDI ; Shadowgraphy ; Laser ; Imaging ; HPLC
• 刊名：International Journal for Ion Mobility Spectrometry
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：19
• 期：4
• 页码：197-207
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Analytical Chemistry; Physical Chemistry; Molecular Medicine; Proteomics; Ecotoxicology; Safety in Chemistry, Dangerous Goods;
• 出版者：Springer Berlin Heidelberg
• ISSN：1865-4584
• 卷排序：19

文摘

Infrared matrix-assisted laser dispersion and ionization (IR-MALDI) in combination with ion mobility (IM) spectrometry enables the direct analysis of biomolecules in aqueous solution. The release of ions directly from an aqueous solution is based on a phase explosion, induced by the absorption of an IR laser pulse, which disperses the liquid as vapor, nano- and micro-droplets. The ionization process is characterized initially by a broad spatial distribution of the ions, which is a result of complex fluid dynamics and desolvation kinetics. These processes have a profound effect on the shape and width of the peaks in the IM spectra. In this work, the transport of ions by the phase explosion-induced shockwave could be studied independently from the transport by the electric field. The shockwave-induced mean velocities of the ions at different time scales were determined through IM spectrometry and shadowgraphy. The results show a deceleration of the ions from 118 m∙s−1 at a distance of 400 μm from the liquid surface to 7.1 m∙s−1 at a distance of 10 mm, which is caused by a pile-up effect. Furthermore, the desolvation kinetics were investigated and a first-order desolvation constant of 325 ± 50 s−1 was obtained. In the second part, the IR-MALDI-IM spectrometer is used as an HPLC detector for the two-dimensional separation of a pesticide mixture.