How is sample a prepared for MALDI TOF analysis?
• the type of matrix material, and • the presence of impurities. The sample to be analyzed is dissolved in an appropriate volatile solvent, usually with a trace of TFA (trifluoroacetic acid) if positive ionization is being used, at a concentration of ca. 10 pmol/uL and an aliquot (1-2 uL) of this is removed and mixed with an equal volume of a solution containing a large excess of a matrix.
