Peterson DS. Matrix-free methods for laser desorption/ionization mass spectrometry.
MASS SPECTROMETRY REVIEWS 2007;
26:19-34. [PMID:
16967450 DOI:
10.1002/mas.20104]
[Citation(s) in RCA: 198] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Matrix assisted laser desorption/ionization (MALDI) is a soft ionization mass spectrometric method that has become a preeminent technique in the analysis of a wide variety of compounds including polymers and proteins. The main drawback of MALDI is that it is difficult to analyze low molecular weight compounds (<1,000 m/z) because the matrix that allows MALDI to work interferes in this mass range. In recent years there has been considerable interest in developing laser desorption/ionization (LDI) techniques for the analysis of small molecules. This review examines the approaches to matrix-free LDI mass spectrometry including desorption/ionization on silicon (DIOS), sol-gels, and carbon-based microstructures. For the purposes of this review matrix-free methods are defined as those that do not require matrix to be mixed with the analyte and therefore does not require co-crystallization. The review will also examine mechanisms of ionization and applications of matrix-free LDI-MS.
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