Direct analysis of highly oxidised organic aerosol constituents by on-line ion trap mass spectrometry in the negative-ion mode

• Published in: Rapid communications in mass spectrometry 2002-01, Vol.16 (6), p.496-504
• Main Authors: Warscheid, Bettina, Hoffmann, Thorsten
• Format: Article
• Language: English
• Subjects: Aerosols - analysis; Cyclohexenes; Ions; Mass Spectrometry - methods; Monoterpenes; Organic Chemicals - analysis; Oxidation-Reduction; Ozone - chemistry; Terpenes - chemistry
• ISSN: 0951-4198; 1097-0231
• DOI: 10.1002/rcm.602

On‐line ion trap mass spectrometry (ITMS) enables the characterisation of constituents of biogenic secondary organic aerosols in complex organic reaction mixtures. This real‐time analysis is achieved by directly introducing the airborne particles into the ion source of the mass spectrometer. Negative‐ion chemical ionisation at atmospheric pressure (APCI(−)) was used as the ionisation method of choice. The aerosols were generated from the gas‐phase ozonolysis of two C10H16‐terpenes (α‐pinene and limonene), and investigated by performing on‐line APCI(−)−ITMSn. Highly oxidised compounds were tentatively identified as important particle‐phase products. Based on recent investigations of low‐energy collision‐induced dissociation pathways of a wide range of deprotonated multifunctional carboxylic acid species derived from monoterpene precursors (Warscheid B, Hoffmann T. Rapid Commun. Mass Spectrom. 2001; 15: 2259), the formation of structurally different C10H16O5 and C10H16O6 species, such as acidic esters from α‐pinene and aldo‐hydroxycarboxylic acids from limonene, is proposed. Copyright © 2002 John Wiley & Sons, Ltd.