3P-27 PDF
大気圧下での高電界による分子イオンとプロトン付加分子の競合生成
Ambient ionization is a useful method for in-situ analysis. Here we performed positive-ion atmospheric pressure corona discharge ionization (APCDI) experiments with benzene derivatives, and observed molecular and protonated analytes, M+. and [M+H]+, according to the structure and property of analytes. It was suggested that M+. ions were generated via an electron tunneling due to high electric field (E≈108V/m), while [M+H]+ ions were formed by proton transfer from water clusters H+(H2O)n standing in ambient ion evolution areas. The results indicated that analyte ions M+. and [M+H]+ were competitively generated dependent upon proton affinity and ionization energy of analytes.