Matrix-Assisted Infrared-Laser Desorption-Ionization Mass Spectrometry of Organic Molecules on NaNO3

Abstract

We demonstrate sensitive mass identification of model organic compounds directly from sodium nitrate by infrared matrix-assisted laser desorption and ionization mass spectrometry. Sensitivity limits of order 10−6 are achieved for resonant desorption, with a linear calibration verified for crown ether molecules over almost three decades in concentration. We also have observed that crown ether molecules can abstract atomic sodium from the sample when irradiated at the resonant frequency of the NO3 stretching vibrations around 7.1 μm. A model for this process is proposed which suggests great promise for this technique on untreated tank waste.