A sample plate for a MALDI process is provided which comprises an electrically
conductive substrate having a hydrophobic coating whose thickness and hydrophobic
character can be modified by changing the coating substrate and/or the concentration
of the substrate. Different coating substances that have provided optimal performance
of the sample plate for reproducible deposition and analysis by MALDI-MS and MALDI-MS/MS
processes of analyte mixtures include synthetic waxes such as paraffin compositions,
lipids, organic acids, silicon-containing compounds, silica polymers and natural
waxes. Metal polishes that have been used to clean and regenerate plate surfaces
have also provided a sample plate that has optimal performance for reproducible
deposition and analysis by MALDI-MS and MALDI-MS/MS processes of analyte mixtures.
