Toward Quantitative Infrared Matrix Assisted Laser Desorption Electrospray Ionization (IR-MALDESI) Mass Spectrometry Imaging of Biological Tissue

摘要

The use of exogenous ice for IR-MALDESI was validated. The ice layer improved the frequency of detection and average intensity of three ARV drugs from an incubated tissue. Several cationization agents in the ESI solvent were investigated and their effect on ion abundance was compared. The sodiated form of the drugs provided higher average intensity and removed an isobaric interference. Finally, the use of an evenly coated compound for normalization was shown to improve pixel to pixel variation nearly three-fold. These findings are important steps toward developing a quantitative MSI method.