Institute of Organic Chemistry, Leopold-Franzens University Innsbruck, 6020 Innsbruck, Austria.
Anal Chem. 2020 Nov 3;92(21):14314-14318. doi: 10.1021/acs.analchem.0c02615. Epub 2020 Oct 16.
Desorption electrospray ionization (DESI), easy ambient sonic-spray ionization (EASI) and low-temperature plasma (LTP) ionization are powerful ambient ionization techniques for mass spectrometry. However, every single method has its limitation in terms of polarity and molecular weight of analyte molecules. After the miniaturization of every possible component of the different ion sources, we finally were able to embed two emitters and an ion transfer tubing into a small, hand-held device. The pen-like interface is connected to the mass spectrometer and a separate control unit via a bundle of flexible tubing and cables. The novel device allows the user to ionize an extended range of chemicals by simple switching between DESI, voltage-free EASI, or LTP ionization as well as to freely move the interface over a surface of interest. A mini camera, which is mounted on the tip of the pen, magnifies the desorption area and enables a simple positioning of the pen. The interface was successfully tested using different types of chemicals, pharmaceuticals, and real life samples. Moreover, the combination of optical data from the camera module and chemical data obtained by mass analysis facilitates a novel type of imaging mass spectrometry, which we name "interactive mass spectrometry imaging (IMSI)".
解吸电喷雾电离（DESI）、常压环境声波喷雾电离（EASI）和低温等离子体（LTP）电离都是用于质谱分析的强大的环境电离技术。然而，每种方法在分析物分子的极性和分子量方面都有其局限性。在对不同离子源的各个可能组件进行小型化之后，我们最终能够将两个发射器和一个离子传输管嵌入到一个小型手持式设备中。笔状接口通过一束柔性管和电缆连接到质谱仪和单独的控制单元。该新型设备允许用户通过简单地在 DESI、无电压 EASI 或 LTP 电离之间切换，以及自由地在感兴趣的表面上移动接口，从而对更广泛范围的化学物质进行电离。安装在笔尖端的微型摄像机放大了解吸区域，并能够简单地定位笔。该接口已成功地使用不同类型的化学物质、药物和实际样品进行了测试。此外，来自摄像机模块的光学数据与通过质谱分析获得的化学数据的组合促进了一种新型的成像质谱技术，我们将其命名为“交互式质谱成像（IMSI）”。
