Optimization of sample preparation for plasma desorption mass spectrometry of peptides and proteins using a nitrocellulose matrix

Molecular ion yields and spectrum quality in plasma desorption mass spectrometry of peptides and proteins have been studied as a function of the method of sample of preparation. Parameters like matrix preparation, pH of the sample solution, method of applying the sample on the matrix and sample quantity have been studied. The best matrix was found to be nitrocellulose prepared by electrospraying. Various techniques for applying the sample result in different sensitivity. The highest sensitivity is obtained using the spin‐drying technique, which results in high‐quality spectra with 1–2 pmol of trypsin (mol. wt 23,463). The results obtained using different sample preparation techniques are discussed and directions for an optimal procedure are given.