Free Amino Acid Quantitation in Corn Leaf Tissue using Desorption Electrospray Ionization (DESI)

摘要

The linearity, sensitivity, and precision of the DESI method for detection amino acid standards was established on both a triple quadrupole and TOF instruments. Detection of free amino acids was demonstrated in corn leaf tissues with high expression levels, however tissues with low expression levels had matrix interferences. Amino acids were detected with better than 5ppm mass accuracy in extracts by TOF but at low S/N. Matrix dilution reduced the suppression but at the loss of signal. Compared to OPA analysis, DESI is faster, and needs less sample handling. This speed comes at a compromise of some sensitivity and matrix effects for the amino acids studied.