HIGH-SENSITIVITY COLLISIONALLY-ACTIVATED DECOMPOSITION TANDEM MASS-SPECTROMETRY ON A NOVEL QUADRUPOLE ORTHOGONAL-ACCELERATION TIME-OF-FLIGHT MASS-SPECTROMETER/

Consideration of the special problems encountered in ultra-high sensit ivity biopolymer sequencing studies has led to the development of a no vel quadrupole/orthogonal-acceleration time-of-flight tandem mass spec trometer described for the first time here, The performance characteri stics of this new geometry are demonstrated, including fully resolved daughter-ion spectra with mass accuracies of 0.1 dalton, which allow r emoval of interpretation ambiguities and easy differentiation of charg e states even in weak collisionally-activated decomposition tandem mas s spectra, The instrument has been applied to a variety of biopolymer research problems, including the structure determination of major hist ocompatibility complex peptide antigens using liquid chromatography/el ectrospray mass spectrometry and nanoflow-electrospray tandem mass spe ctrometry, and sequencing capability in the low-femtomole and attomole ranges is demonstrated.