SFE-GC-MS (Supercritical Fluid Extraction - Gas Chromatography - Mass Spectrometry)
To provide a chemical description at the molecular level of secondary organic aerosols, LISA has developed a method of analysis by supercritical fluid extraction coupled on-line to gas chromatography and mass spectrometry (SFE/GC/MS). This technique allows an improvement of sensitivity, reduced loss and contamination. On the other hand, the other benefits are time gain and low use of solvents, since the whole sample is transferred from the extraction cell to chromatographic column.
This technique is used in routine to study the chemical composition of organic aerosols generated from experiments in atmospheric simulation chambers in particular the CESAM chamber.
This technique was for example used to analyze secondary organic aerosol formed by sabinene, indene and styrene-methyl ozonolysis. With an in-situ derivation step, the analysis of these particles allowed the identification and quantification of dozens of species moderately to very polar, many of which are poly-functionals (di-carboxylic acids, hydroxy-carboxylic acid, Keto-carboxylic acids...).
Photos and diagram of the experimental device for analysis of the organic fraction of aerosols by SFE-GC-MS - I: pump, II cooling system: pump, III: extraction chamber, IV - GC - MS