NEGATIVE-ION ELECTROSPRAY MASS-SPECTRA OF PEPTIDES DERIVATIZED WITH 4-AMINONAPHTHALENESULPHONIC ACID

The detection limits of a series of small peptides derivatized with 4- aminonaphthalenesulphonic acid have been determined using a magnetic s ector mass spectrometer operated in the negative-ion mode. The instrum ent (AutoSpec-QFPD) is equipped with an electrospray ion source and bo th array and point detectors. Detection limits when using the array de tector were on the sub-femtomole level at a mass resolution of 2000 (f ull width half maximum height). Cone-voltage and linked-scan collision -induced dissociation spectra were recorded using both the array and p oint detectors. When using the array detector, amino acid sequence inf ormation could be obtained from as little as 50 fmol of sample consume d,