日本質量分析学会 第66回質量分析総合討論会

Program

Oral Sessions

Day 1, May 15(Tue.) 17:20-17:40 Room C (Seiun 2)

Generation and propagation of MALDI ion packet probed by UV laser photo dissociation

(Niigata Univ. Pharm. Appl. Sci.)
oTatsuro Shirota, Kennosuke Hoshina

We investigated spatio-temporal distribution of CHCAH+ ions by irradiating a flat-shaped UV laser beam (1 mm thickness) to the propagating ion packet. CHCAH+ ions in the irradiated volume decrease by photodissociation into small fragment ions, resulting in a partially missing signal profile of CHCAH+ in the MALDI-MS spectra. Since the extent of the decrease is proportional to number of ions in the irradiated volume, spatio-temporal ion distributions were extracted from measured partially missing profiles as a function of the laser delay(Δt) and the distance between the MALDI plate to the post laser beam (d). From the analyses, we found that the ion packet of (CHCA)H+ extend to d=1 mm within t=50-100 ns after MALDI laser irradiation and the ion ejection from the sample surface lasts for 200 ns under a static extraction electric field at 3.54×105 V/m. Similar results were obtained for (CHCA)2H+.