Improving the analyte ion signal in matrix‐assisted laser desorption/ionization imaging mass spectrometry via electrospray deposition by enhancing incorporation of the analyte in the matrix

Abstract

The use of an incorporation spray to apply solvent by ESD to a matrix layer already deposited by ESD provides an increase in signal by both promoting incorporation of the analyte within and homogenizing the distribution of the incorporated analyte throughout the matrix layer. Copyright © 2017 John Wiley & Sons, Ltd.

Characterizing and alleviating ion suppression effects in atmospheric pressure matrix‐assisted laser desorption/ionization

“…Previously, the development of a matrix with high salt‐tolerance was reported to alleviate the ISE in protein and peptide analysis . Several studies compared the effects of matrix application techniques on several aspects of MALDI‐MSI performance, including analyte diffusion, reproducibility, and sensitivity that are directly related to the ISE of a MALDI source . MALDI sensitivity was also reported to be improved through the rational design of matrices and the addition of glycerol which generates multiply charged protein/peptide ions .…”

“…25,26 Several studies compared the effects of matrix application techniques on several aspects of MALDI-MSI performance, including analyte diffusion, reproducibility, and sensitivity that are directly related to the ISE of a MALDI source. [27][28][29] MALDI sensitivity was also reported to be improved through the rational design of matrices and the addition of glycerol which generates multiply charged protein/peptide ions. [30][31][32] Multiply charged ions can also be produced with matrix and vacuum alone without the use of a laser, 33 with a reflective geometry, 34 or with a laser in a transmission geometry.…”

Mass Spectrometry Imaging: A Review of Emerging Advancements and Future Insights

“…This dry application method usually requires an additional “incorporation spray” after the matrix has been applied. 39 Some electrospray devices have allowed for control of the crystal size, which can directly relate to the spatial resolution achievable. 40 Other methods have also benefited from the inclusion of an electric field, decreasing crystal size and thereby increasing spatial resolution.…”

“…One example is electrospray deposition, for which units tend to be home-built. This dry application method usually requires an additional “incorporation spray” after the matrix has been applied . Some electrospray devices have allowed for control of the crystal size, which can directly relate to the spatial resolution achievable .…”

Comparison of freeze vacuum drying and conventional drying methods in matrix‐assisted laser desorption/ionization mass spectrometry analyses of peptides

“…To improve the quantitative nature of MALDI‐MS, various sample preparation methods have been introduced, such as electrospray deposition of the sample and matrix, use of an ionic liquid matrix, or adding an additive such as methanol . Recently, freeze vacuum drying (FVD) was introduced for this purpose by our group .…”