Iron oxide-based nanoparticles (NP) were covalently modified with sinapic acid (SA) through a condensation reaction to assist the ionization of both large and small molecules. The morphology of SA-modified NPs (SA-NP) was characterized by transmission electron microscopy (TEM), and the modification of the NP surface with SA was confirmed using ultraviolet (UV) and infrared (IR) spectroscopy. The number of SA molecules was estimated to be 6 per NP. SA-NP-assisted laser desorption/ionization was carried out on small molecules, such as pesticides and plant hormones, and large molecules, such as peptides and proteins. A peptide fragment from degraded proteins was detected more efficiently compared with conventional methods.

The use of mass spectrometry imaging (MSI) revealed the localization of-solanine and-chaconine as natural toxins for Potato (Solanum tuberosum L.). The content of Potato glycoalkaloids,-solanine and-chaconine, were quantitatively determined by high performance liquid chromatography (HPLC). Matrix assisted laser desorption/ionization-based tandem mass spectrometry (MS) could determine-solanine and-chaconine from raw potato extraction and section. After budbreak,-solanine and-chaconine were produced and localized at periderm and germ compared with that before budbreak. At germ region, these glycoalkaloids did not exist whole germ region but eccentrically localize at germ surface and central region. The amount of-chaconine was twofold higher than-solanine at periderm. At germ region, there was no difference between these toxins.