Desorption, factors that influence solvent

Additional advantages are offered by extending the applicability of the MALDI methods to insoluble polymers [65] and saturated polyolefins [66]. One of the key factors that influence the success and the quality of MALDI mass spec-trometric analysis is the sample preparation. Thus, prerequisites for traditional sample preparation method require soluble analytes and matrices and the compatibility of the solvents for both matrix and analyte systems, subsequent solvent removal, and the homogeneity of the crystallized analyte/matrix mixture on the surface of the MALDI sample holder [67-71]. These factors can introduce severe mass discrimination effects. The advantages of solvent-free preparation in comparison to conventional solvent-based MALDI-MS were recently reported [65, 72]. The MALDI mass spectra obtained by the solvent-free sample preparation method were compared by Trimpin et al. [72] with mass spectra obtained by conventional solvent-based MALDI-MS and by laser desorption (LD)-MS under identical experimental conditions, stressing the capability of solvent-free MALDI-MS to characterize insoluble samples. 

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