An Ultra-High-Resolution Mass Spectrometer with an Intermediate-Pressure Matrix-Assisted Laser Desorption/Ionization Source

The demand for high-resolution, high-throughput and spatially resolved mass analysis has been a key focus in developing mass spectrometers. We have developed a novel high-performance mass spectrometer by integrating matrix-assisted laser desorption/ionization (MALDI) source with a new planar electrostatic ion trap mass analyzer for ultrahigh-resolution MALDI source mass analysis. Performance characterization experiments show that with a transient time of 800 ms, the resolution for 392 Th can exceed 530 K by utilizing high-order harmonics, and the spectrometer can distinguish the isotopic peaks in the Met-Arg-Phe-Ala acetate salt (MRFA) M+2 peak family. Preliminary results also show an overall mass range from 133 to 9500 Th by stitching together multiple single scans with at least 6-fold mass range, and a low detection limit of 32 fg. Initial tests on analysis of edible oils demonstrate its capability to distinguish plant and animal oils based on triacylglycerols.