ELECTROSPRAY COLLISION-INDUCED DISSOCIATION OF DERIVATIZED PEPTIDES -STUDIES ON A HYBRID MAGNETIC-SECTOR ORTHOGONAL TIME-OF-FLIGHT MASS-SPECTROMETER/

A series of peptides C-terminally derivatised with 4-aminonaphthalenes ulphonic acid has been analysed on a hybrid magnetic sector-orthogonal time-of-flight mass spectrometer by negative-ion electrospray with co llision-induced dissociation. The fragmentation reactions of 400 eV (l aboratory frame of reference) [M-H](-) projectile ions in collisions w ith helium, argon, xenon and methane target gases have been investigat ed. With all the collision gases, C-terminal fragment ions predominate ; side-chain cleavages were observed with xenon as the collision gas, but not with helium. The collision gas can be rapidly changed from hel ium to xenon, thereby giving spectra containing complementary sequence information from picomole amounts of sample. (C) 1997 Elsevier Scienc e B.V.