DETECTION OF FEMTOMOLE AND SUB-FEMTOMOLE LEVELS OF PEPTIDES BY TANDEM MAGNETIC-SECTOR REFLECTRON TIME-OF-FLIGHT MASS-SPECTROMETRY AND MATRIX-ASSISTED LASER DESORPTION IONIZATION

This article describes results of low-level (sub-femtomole) detection of peptides by matrix-assisted laser desorption ionization. The matrix-assisted laser desorption ionization method can be used for low-level detection of the parent ion, either [M + H]+ or [M + Na]+, and collision-induced dissociation of the parent ion can be performed at the picomole level. The instrument used for these studies is a novel high-performance magnetic sector (electric(E)/magnetic(B) sector) /reflectron time-of-flight (TOF) tandem mass spectrometer (EB/TOF).