Characterization of MassTech AP MALDI Source with Agilent 6545 QTOF and 6560 IM-QTOF for MS Imaging

Atmospheric pressure (AP) MALDI is broadly used in the high-throughput mass analysis of lipids, peptides, and small molecule as well as MS imaging (MSI) studies. AP-MALDI is an affordable and quickly mounted addition onto MS instruments operating with electrospray ionization sources. Its clear advantage is easy sample handling at the atmospheric conditions along with the use of semi-volatile matrices that can be important in MSI experiments taking hours of instrument operation. The AP MALDI source developed by MassTech Inc was hyphenated to Agilent 6545, a high-resolution mass spectrometer. Samples were prepared from peptide standards mixed with alpha-CHCA, a MALDI matrix. Limits of detection for peptides were attained at single fmol or sub-fmol levels. Importantly, the isotopic peak intensities followed closely to their theoretical values. This spectral feature is typically not observed in ion trap or FT-ICR instruments. AP MALDI MS imaging was demonstrated using tissue-simulating peptide spots. MS imaging experiment typically included an imaging area setup using new Target Next software, data collection using Agilent MS Hunter acquisition software, and data format conversion for using an industry standard imaging visualization software package. MS images with a 30-micron spatial resolution and high S/N ratios for analyte peaks have been demonstrated.

For Research Use Only. Not for use in diagnostic procedures.