The influence of matrix concentration and solvent composition on the results of MALDI‐MSI, with the aid of wet‐interface matrix deposition

Abstract

Imaging mass spectrometry is a powerful technique for the molecular analysis of tissue sections. As in many analytical methods, sample preparation is one of the main and most important steps to obtain results of good quality. Usually, the matrix concentration and solvent composition in different studies are taken for granted without any further consideration. In our studies, we aimed to find how matrix concentration and a type of solvent influence the signal. Moreover, what is the relationship between these parameters, and how do they influence the spectra, and obtained ion maps. In our experiments, we used SunCollect®, which is a commercially available wet-interface system for matrix deposition. We decided to choose two matrix concentrations (DHB: 15 and 25 mg/ml; 9AA: 7 and 5 mg/ml) and two different water solutions of solvents in two different percentages for the matrices (DHB: 50% and 70% of MeOH and acetonitrile (ACN); 9AA 70% and 50% of EtOH and MeOH). In the end, the influence of these parameters on obtained spectra and ion maps was assessed.