Direct Molecular Analysis of Garlic Using Internal Extractive Electrospray Ionization Mass Spectrometry / 分析化学

ABSTRACT

Theapplicationofinternalextractiveelectrosprayionizationmassspectrometry(iEESI-MS)was extended to direct molecular analysis of garlic tissues. By obviating time-consuming sample preparations, fragile active garlic substances such as organosulfur compounds ( e. g. , alliin, allicin ) were successfully detected and identified via collision-induced dissociation ( CID) , together with amino acids ( e. g. , arginine) and saccharides ( glucose, polysaccharides) . Mass spectral fingerprints of different kinds of garlic cloves, as well as various post-treatment ones, were further processed via principal component analysis ( PCA) to better visualize the differences. Our experimental results indicated that iEESI-MS allowed rapid recognition of metabolic changes in the garlic tissue subject to various external stimuli. The merits included simplicity of analysis, high speed ( less than 2 min per sample ) , good specificity, and minimal disturbance to the bioactivity of analytes.