Solvent effect in polymer analysis by MALDI-TOF mass spectrometry

Solvent effect is one of the important factors in sample preparation which may affect matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectra of synthetic polymers. MALDI imaging, a useful imaging tool for discovering biomarkers in tissues, is applied here for better comprehension of solvent effect in polymer analysis by MALDI-TOF mass spectrometry. Nylon-6 was chosen as a model polymer for the study of solvent effect. Its MALDI mass spectra in different solvents were performed. MALDI imaging analysis was performed for studying the incorporation of analytes into matrix crystals in different solvent combinations. Specifically, the colocalization of matrix and analyte was obtained through Pearson’s correlation (PC) coefficient analysis of their MALDI images. The results demonstrated that satisfactory spectra were obtained in higher PC value conditions. PC decreased along with an increase in the ratio of poor solvent, which suggested that we should minimize the poor solvent ratio to obtain better MALDI spectra.