日本質量分析学会 第66回質量分析総合討論会

Program

Oral Sessions

Day 3, May 17(Thu.) 10:45-11:00 Room B (Seiun 1)

Development of an ambient ionization mass spectrometry using dark current discharge with argon

(1Yokohama City Univ., 2AMR)
oKanako Sekimoto1, Motoshi Sakakura2, Hiroshi Hike2, Takatomo Kawamukai2, Teruhisa Shiota2, Mitsuo Takayama1

Dark current discharge was examined with the Direct Analysis in Real Time (DART) ionization technique operated with argon gas. No ions were observed in the ambient background spectrum of argon DART only. If dark current discharge was generated in the analyte ionization area of the argon DART, background ions were readily observed. When various amino acids and anisole were introduced in the dark current discharge condition, (de)protonated molecules were dominantly formed for all the analytes. The resulting mass spectral pattern was quite similar to that observed in conventional DART using glow discharge and helium gas. This meant that ionization characteristics in dark current discharge with argon are comparable to those in helium DART. It suggested therefore that the dark current discharge forms excited argons which have ionization energy higher than metastable states and can occur Penning ionization with H2O to generate a reagent ion H3O+ for analyte protonation.