Influence of metallic, ceramic, and plastic MALDI surface materials on the ionization efficiency and quality of mass spectrometric data

摘要

Imperfections of the Matrix Assisted Laser Desorption Ionization (MALDI) process of proteins and peptides impose considerable limitations on the utility of mass spectrometry (MS) in basic life sciences and ultimately on the application in biomarker discovery and medical diagnostics. Improved understanding of and control over the MALDI ionization process therefore holds the potential to largely expand the performance of mass spectrometry.Presented here is a MALDI Time-of-Flight (TOF) MS study using 21 different metals, ceramics, and plastics as MALDI surfaces and a tryptic digest of BSA and an artificial protein mix as samples. The surface materials cover a wide range of physical and chemical properties. Remarkably, there was no clear correlation found between the observed ion yield and any of the considered individual material properties. Furthermore, the investigation also confirms the notoriously low ionization efficiency of MALDI, typically 10"5 to 10"6, and illustrates the need for fundamentally novel solutions to solve this problem.