Electrospray/collision-induced dissociation of derivatised peptides: studies on a hybrid magnetic sector–orthogonal time-of-flight mass spectrometer

Abstract A series of peptides C-terminally derivatised with 4-aminonaphthalenesulphonic acid has been analysed on a hybrid magnetic sector–orthogonal time-of-flight mass spectrometer by negative-ion electrospray with collision-induced dissociation. The fragmentation reactions of 400 eV (laboratory frame of reference) [M–H] − projectile ions in collisions with helium, argon, xenon and methane target gases have been investigated. 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 helium to xenon, thereby giving spectra containing complementary sequence information from picomole amounts of sample.