A Mechanism for Ionization of Nonvolatile Compounds in Mass Spectrometry: Considerations from MALDI and Inlet Ionization

• DOI: 10.1007/s13361-012-0414-y
• Publication Date: 2012-07-11T18:43:43Z
• Authors: Sarah Trimpin; Beixi Wang; Ellen D. Inutan; Jing Li; Christopher B. Lietz; Andrew Harron; Vincent S. Pagnotti; Diana Sardelis; Charles N. McEwen
• Keywords: Ambient ionization; Atmospheric-pressure laser ionization; MALDI imaging

Mechanistic arguments relative to matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) address observations that predominately singly charged ions are detected. However, recently a matrix assisted ablation method, laserspray ionization (LSI), was introduced can use the same sample preparation and as MALDI, but produce highly from proteins. In generated neutral molecules by photon energy provided matrix, while in LSI produced inside heated inlet tube linking atmospheric pressure first vacuum region of spectrometer. Some matrices also with MALDI ion sources operated at intermediate or high vacuum. The operational similarity large difference charge states observed these methods, provides information fundamental importance proposed mechanisms for MALDI. Here, we present data suggesting prompt delayed reported both fast processes producing LSI. supplied clusters/droplets well their size time available desolvation determining factors observed. Further, droplets/clusters may be common link nonvolatile compounds variety MS including