Novel approach to enhance sensitivity in surface ‐assisted laser desorption/ionization mass spectrometry imaging using deposited organic‐inorganic hybrid matrices

AbstractSample pretreatment is key to obtaining good data in matrix ‐assisted laser desorption/ionization mass spectrometry imaging (MALDI‐MSI). Although sublimation is one of the best methods for obtaining homogenously fine organic matrix crystals, its sensitivity can be low due to the lack of a solvent extraction effect. We investigated the effect of incorpora ting a thin film of metal formed by zirconium (Zr) sputtering into the sublimation process for MALDI matrix deposition for improving the detection sensitivity in mouse liver tissue sections treated with olanzapine. The matrix‐enhanced surface‐assisted laser desorption/ionization (ME‐SALDI) met hod, where a matrix was formed by sputtering Zr to form a thin nanoparticle layer before depositing MALDI organic matrix comprisingα‐cyano‐4‐hydroxycinnamic acid (CHCA) by sublimation, resulted in a significant improvement in sensitivity, with the ion intensity of olanzapine being about 1800 times that observed using the MALDI method, comprising CHCA sublimation alone. When Zr sputtering was performed after CHCA deposition , however, no such enhancement in sensitivity was observed. The enhanced sensitivity due to Zr sputtering was also observed when the CHCA solution was applied by spraying, being about twice as high as that observed by CHCA spraying alone. In addition, the detection sensitivity of these various pretr eatment methods was similar for endogenous glutathione. Given that sample preparation using the...
Source: Journal of Mass Spectrometry - Category: Chemistry Authors: Tags: RESEARCH ARTICLE Source Type: research