Speciation of the volatile organic compounds (VOCs) in solventborne aerosol coatings by solid phase microextraction-gas chromatography

A method for the speciation of solventborne aerosol coatings is presented. Propellant from an aerosol coating is transferred to a gas collection bag and is then analyzed by GC-FID. The propellant-free liquid paint is then internally standardized with a mixture of C5 to C11 normal alkanes and analyzed on a 50-meter capillary column using solid phase microextraction (SPME) with GC-FID detection. This procedure makes it possible to assign linear retention indexes to virtually all of the individual volatile solvents in the coating with subsequent identification. After identification by SPME, the coating is dispersed in a high boiling solvent, internally standardized with a material not coeluting with the coating solvents, and is then analyzed by direct GC-FID. VOC regulations in California for aerosol coatings products require that the coatings have a reactivity (product weighted maximum incremental reactivity or PWMIR) which is below a designated value. Assignment of PWMIR values to aerosol coatings requires that the amount of each individual volatile component in a coating be known. Presented at the 79th Annual Meeting of the Federation of Societies for Coatings Technology, November 5–7, 2001, in Atlanta, GA. Department of Chemistry, Polymers and Coatings, San Luis Obispo, CA 93407.