Determination of oxygenated compounds in secondary organic aerosol from isoprene and toluene smog chamber experiments

Autores UPV
Año
Revista INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY

Abstract

The determination of multifunctional oxygenated compounds in secondary organic aerosols (SOA) usually requires a derivatisation protocol prior to gas chromatography-mass spectrometry analysis (GC-MS). Our proposed protocol, a combination of O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA) plus diluted N-methyl-N-trimethyl-silyltrifluoroacetamide (MSTFA) without catalyst, has improved the determination of carbonyls, polyhydroxyl-compounds, hydroxyl- carbonyls, hydroxyl-carboxylic acids and di-carboxylic acids. The optimised derivatisation protocol has been successfully used for blanks, standard mixtures and photo-oxidation products from isoprene and toluene generated in a high-volume simulation chamber (European Photoreactor, EUPHORE). Some previously identified degradation products for isoprene including tetrols such as threitol, erythritol; 2-methyltetrols and 2-methylglyceric acid; and for toluene including nitrophenols, methyl-nitrophenols, benzaldehyde, p-cresol, benzoic acid, glyoxylic acid and methyl-glyoxylic acid, have been identified in our aerosol samples, thus confirming the successful applicability of the proposed derivatisation protocol. Moreover, the reduction of artefacts and enhanced signal-to-noise ratio, have allowed us to extend the number of multifunctional compounds determined. These findings have demonstrated the validity of this analytical strategy, which will contribute to a better understanding of the atmospheric degradation chemistry of biogenic and anthropogenic pollutants. © 2012 Taylor & Francis.