Enhancement of Ionization Efficiency Using Zeolite for Imaging Mass Spectrometry of a Drug with Matrix-Assisted Laser Desorption/Ionization

Abstract

Imaging mass spectrometry using matrix-assisted laser desorption/ionization has increasingly got attention as a new analysis method of pharmacokinetics to accelerate the drug discovery processes. However, the detection sensitivity has been too low for practical analysis. By mixing zeolite (NaY5.6) with a conventional organic matrix, α-cyano-4-hydroxycinnamic acid (CHCA), the ion signal intensity of a drug, buspirone, at a concentration of 100 ng/mL was enhanced to about 1.6 times compared with that measured using CHCA only. The zeolite matrix enabled the detection of buspirone at a concentration of 0.1 ng/mL. The ion signal intensity of buspirone obtained from a brain section of a mouse administered buspirone was also enhanced to about two times by using the zeolite matrix compared with that measured using CHCA.