New method for resolving the enantiomeric composition of 2-methyltetrols in atmospheric organic aerosols

• Published in: Journal of Chromatography A Vol. 1218; no. 51; pp. 9288 - 9294
• Main Authors: González, Nélida J.D., Borg-Karlson, Anna-Karin, Redeby, Johan Pettersson, Nozière, Barbara, Krejci, Radovan, Pei, Yuxin, Dommen, Josef, Prévôt, André S.H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 23.12.2011; Elsevier
• Subjects: 2-Methylerythritol; 2-Methylthreitol; aerosols; Aerosols - analysis; Air Pollutants - analysis; Analytical chemistry; Atmosphere - chemistry; boreal forests; Butadienes - analysis; Butadienes - chemistry; capillary gas chromatography; Chemistry; Chiral GC-MS; Chromatographic methods and physical methods associated with chromatography; enantiomers; Erythritol - analogs & derivatives; Erythritol - analysis; Erythritol - chemistry; Exact sciences and technology; Gas chromatographic methods; Gas Chromatography-Mass Spectrometry - methods; Hemiterpenes - analysis; Hemiterpenes - chemistry; Isoprene; Limit of Detection; mass spectrometry; oxidation; Oxidation-Reduction; Pentanes - analysis; Pentanes - chemistry; Reproducibility of Results; Secondary Organic Aerosols; Stereoisomerism; Sweden; tracer techniques; Trees; Sweden; Secondary Organic Aerosols; Chiral GC–MS; 2-Methylthreitol; Isoprene; 2-Methylerythritol; Separation; Derivatization; Solvent extraction; Ultrasound assisted extraction; Sample preparation; Enantiomer; Acetylation; Ultrasound; Coupled method; Chiral GC-MS; Chiral stationary phase; Air; Acetic anhydride; Operating conditions; Gas chromatography; Suspended particle; Alditol; Cyclodextrin; Optical resolution; Aerosols; Mass spectrometry
• ISSN: 0021-9673; 1873-3778; 1873-3778
• DOI: 10.1016/j.chroma.2011.10.069

► Chiral GC–MS method determines the enantiomeric composition of 2-methyltetrols. ► Enantiomer composition was used as a tool to study the origin of 2-methyltetrols. ► The validated method proved not to influence the enantiomer composition. ► Non-racemic mixtures of 2-methyltetrols were found in ambient aerosol samples. ► The method elucidated a primary origin contribution to atmospheric 2-methyltetrols. In order to facilitate the determination of the primary and secondary origin of atmospheric organic aerosols, a novel method involving chiral capillary gas chromatography coupled with mass spectrometry has been developed and validated. The method was focused on the analysis of 2-methylerythritol and 2-methylthreitol, considered to be tracers of secondary organic aerosols from the oxidation of atmospheric isoprene. The method was validated by performing various tests using authentic standards, including pure enantiomeric standards. The result showed that the analytical method itself does not affect the enantiomeric composition of the samples analyzed. The method was applied on atmospheric aerosols from a boreal forest collected in Aspvreten, Sweden and on laboratory samples obtained from liquid phase oxidation of isoprene and smog chamber experiments. Aerosol samples contained one enantiomer of 2-methylerythritol in significantly larger quantities than the others. In contrast, the liquid-phase oxidation of isoprene and its gas-phase oxidation in the smog chamber produced all enantiomers in equal quantities. The results obtained where the enantiomer fraction, EF, is larger than 0.50 suggest that 2-methyltetrols in atmospheric aerosols may also have biological origin. Information about the differences between enantiomer fractions obtained using this method brings new insights in the area of atmospheric aerosols.