Articles | Volume 8, issue 6
Atmos. Meas. Tech., 8, 2409–2416, 2015
Atmos. Meas. Tech., 8, 2409–2416, 2015

Research article 08 Jun 2015

Research article | 08 Jun 2015

Characterisation and optimisation of a sample preparation method for the detection and quantification of atmospherically relevant carbonyl compounds in aqueous medium

M. Rodigast, A. Mutzel, Y. Iinuma, S. Haferkorn, and H. Herrmann M. Rodigast et al.
  • Leibniz-Institute for Tropospheric Research (TROPOS), Atmospheric Chemistry Department (ACD), Permoserstr. 15, 04318 Leipzig, Germany

Abstract. Carbonyl compounds are ubiquitous in the atmosphere and either emitted primarily from anthropogenic and biogenic sources or they are produced secondarily from the oxidation of volatile organic compounds. Despite a number of studies about the quantification of carbonyl compounds a comprehensive description of optimised methods is scarce for the quantification of atmospherically relevant carbonyl compounds. The method optimisation was conducted for seven atmospherically relevant carbonyl compounds including acrolein, benzaldehyde, glyoxal, methyl glyoxal, methacrolein, methyl vinyl ketone and 2,3-butanedione. O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) was used as derivatisation reagent and the formed oximes were detected by gas chromatography/mass spectrometry (GC/MS). With the present method quantification can be carried out for each carbonyl compound originating from fog, cloud and rain or sampled from the gas- and particle phase in water. Detection limits between 0.01 and 0.17 μmol L−1 were found, depending on carbonyl compounds. Furthermore, best results were found for the derivatisation with a PFBHA concentration of 0.43 mg mL−1 for 24 h followed by a subsequent extraction with dichloromethane for 30 min at pH = 1. The optimised method was evaluated in the present study by the OH radical initiated oxidation of 3-methylbutanone in the aqueous phase. Methyl glyoxal and 2,3-butanedione were found to be oxidation products in the samples with a yield of 2% for methyl glyoxal and 14% for 2,3-butanedione after a reaction time of 5 h.

Short summary
An optimised method for derivatisation of carbonyl compounds with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) in aqueous samples is described. The comprehensive optimisation of the method leads to an improvement of the detection limit up to a factor of 10 highlighting the good sensitivity of the optimised method for atmospherically relevant carbonyl compounds. The optimised method was successfully applied to detect carbonyl compounds from the aqueous phase oxidation of 3-methylbutanone.