... times of 3.0 ms per step of 1 m/ z unit. Fragment ionsformed by collision a ctivation of selected precursor ionswith nitrogen in the R F-only quadrupole collision ce ll, wereanalyzed by scanning ... and analyzed by aMALDI-TOF mass s pectrometer (MALDITM;Micromass,Manchester, UK). Mass spectra were acquired for the massrange of 600–2000 Da under a pulsed nitrogen laser of wavelength ... Zou5and Shih-Hsiung Wu11Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan;2Department of Chemistry and3Department of Life Scienceand Institute of Plant Biology, National Taiwan...