Corona discharge ion mobility spectrometry of aliphatic and aromatic hydrocarbons

Positive ion mobility spectra of n-alkanes (n-C-5 to n-C-19), branched chai n alkanes (C-5 to C-9) and aromatic compounds (benzene and alkylated benzen es) were acquired with an ion mobility spectrometer equipped with a corona discharge ionization source. Reduced mobilities and mass-to-mobility correl ation curves were determined for these compounds. Depending on their concen tration, the n-alkanes form one or two product ion peaks. The mobilities of product ion peaks regularly decrease with increasing chain length. The sam e behavior was observed for branched chain alkanes. However, characteristic fragment ions are additionally formed in comparison with n-alkanes. The in vestigated aromatic hydrocarbons show simple spectra consisting of up to th ree;characteristic product ion peaks. The obtained mass-to-mobility correla tion curve differs from that determined using photoionization. (C) 2000 Els evier Science B.V. All rights reserved.