National Centre of Excellence in Mass Spectrometry Imaging, NiCE-MSI, National Physical Laboratory, Teddington TW11 0LW, U.K.
Plasmion GmbH, 86167 Augsburg, Germany.
Anal Chem. 2020 Dec 1;92(23):15285-15290. doi: 10.1021/acs.analchem.0c03524. Epub 2020 Nov 11.
Atmospheric pressure ionization methods confer a number of advantages over more traditional vacuum based techniques, in particular ease of hyphenation to a range of mass spectrometers. For atmospheric pressure matrix assisted desorption/ionization (AP-MALDI), several ion sources, operating in a range of geometries have been reported. Most of these platforms have, to date, generally demonstrated relatively low ion yields and/or poor ion transmission compared to vacuum sources. To improve the detection of certain ions, we have developed a second-generation transmission mode (TM) AP-MALDI imaging platform with in-line plasma postionization using the commercially available SICRIT device, replacing the previously used low temperature plasma probe from our developmental AP-TM-MALDI stage. Both plasma devices produce a significant ionization enhancement for a range of compounds, but the overall higher enhancement obtained by the SICRIT device in addition to the ease of installation and the minimal need for optimization presents this commercially available tool as an attractive method for simple postionization in AP-MALDI MSI.
大气压电离方法相较于更传统的真空技术具有许多优势，特别是易于与多种质谱仪联用。对于大气压基质辅助解吸/电离（AP-MALDI），已经报道了几种在不同几何结构下工作的离子源。与真空源相比，迄今为止，这些平台中的大多数通常显示出相对较低的离子产率和/或较差的离子传输。为了提高某些离子的检测灵敏度，我们开发了第二代传输模式（TM）大气压 MALDI 成像平台，该平台使用市售的 SICRIT 设备进行在线等离子体后电离，取代了我们之前开发的 AP-TM-MALDI 平台中使用的低温等离子体探针。这两种等离子体设备都能显著增强多种化合物的电离，但 SICRIT 设备获得的整体增强效果更高，并且易于安装，优化需求最小，因此，该商用工具成为大气压 MALDI MSI 中简单后电离的一种有吸引力的方法。
