Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA.
MS™, LLC, Newark, DE, 19711, USA.
Rapid Commun Mass Spectrom. 2021 Jan;35 Suppl 1:e8829. doi: 10.1002/rcm.8829. Epub 2020 Nov 20.
The developments of new ionization technologies based on processes previously unknown to mass spectrometry (MS) have gained significant momentum. Herein we address the importance of understanding these unique ionization processes, demonstrate the new capabilities currently unmet by other methods, and outline their considerable analytical potential.
The inlet and vacuum ionization methods of solvent-assisted ionization (SAI), matrix-assisted ionization (MAI), and laserspray ionization can be used with commercial and dedicated ion sources producing ions from atmospheric or vacuum conditions for analyses of a variety of materials including drugs, lipids, and proteins introduced from well plates, pipet tips and plate surfaces with and without a laser using solid or solvent matrices. Mass spectrometers from various vendors are employed.
Results are presented highlighting strengths relative to ionization methods of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization. We demonstrate the utility of multi-ionization platforms encompassing MAI, SAI, and ESI and enabling detection of what otherwise is missed, especially when directly analyzing mixtures. Unmatched robustness is achieved with dedicated vacuum MAI sources with mechanical introduction of the sample to the sub-atmospheric pressure (vacuum MAI). Simplicity and use of a wide array of matrices are attained using a conduit (inlet ionization), preferably heated, with sample introduction from atmospheric pressure. Tissue, whole blood, urine (including mouse, chicken, and human origin), bacteria strains and chemical on-probe reactions are analyzed directly and, especially in the case of vacuum ionization, without concern of carryover or instrument contamination.
Examples are provided highlighting the exceptional analytical capabilities associated with the novel ionization processes in MS that reduce operational complexity while increasing speed and robustness, achieving mass spectra with low background for improved sensitivity, suggesting the potential of this simple ionization technology to drive MS into areas currently underserved, such as clinical and medical applications.
基于质谱（MS）先前未知的过程开发新的电离技术已经取得了重大进展。在此，我们探讨了理解这些独特电离过程的重要性，展示了其他方法目前无法满足的新功能，并概述了它们相当大的分析潜力。
溶剂辅助电离（SAI）和基质辅助电离（MAI）的进样和真空电离方法以及激光喷雾电离，可以与商业和专用离子源一起使用，从大气或真空条件下产生离子，用于分析各种材料，包括从微孔板、移液器吸头和板表面引入的药物、脂质和蛋白质，有或没有激光，使用固体或溶剂基质。使用来自不同供应商的质谱仪。
结果突出了相对于电喷雾电离（ESI）和基质辅助激光解吸/电离的电离方法的优势。我们展示了多电离平台的实用性，该平台涵盖 MAI、SAI 和 ESI，并能够检测到否则会错过的东西，特别是在直接分析混合物时。专用的真空 MAI 源通过机械将样品引入亚大气压（真空 MAI）下，实现了无与伦比的稳健性。通过使用导管（进样电离），最好是加热，从大气压引入样品，实现了简单性和广泛基质的使用。直接分析组织、全血、尿液（包括鼠、鸡和人源）、细菌菌株和化学探针反应，特别是在真空电离的情况下，无需担心样品残留或仪器污染。
提供了一些示例，突出了与 MS 中新颖的电离过程相关的出色分析能力，这些过程降低了操作复杂性，同时提高了速度和稳健性，实现了具有低背景的质谱，提高了灵敏度，表明这种简单的电离技术有可能将 MS 推向目前服务不足的领域，如临床和医学应用。
