Analytical Sciences

Abstract − Analytical Sciences, 24(9), 1141 (2008).

Solid Phase Microextraction Fibers Coated with Sol-gel Aminopropylsilica/polydimethylsiloxane: Development and Its Application to Screening of Beer Headspace
André F. P. BIAJOLI and Fabio AUGUSTO
Institute of Chemistry, State University of Campinas (Unicamp), CP 6154, Campinas-SP 13084-971, Brazil
The preparation and applicability of solid phase microextraction (SPME) fibers coated with a sol-gel organically modified silica based on 3-aminopropyltrimethoxysilane and polydimethylsiloxane (APTMS/PDMS) are described here. Micrographs of the coated fibers revealed a rugous surface; the thickness of the coating was estimated to be less than 30 µm. The APTMS/PDMS fibers were tested with synthetic samples and compared to commercial fibers for headspace SPME analysis of beer. Extraction and desorption using the APTMS/PDMS fibers were faster, which is typical for sol-gel SPME fibers. For polar and semi-polar compounds on beer headspace, the extraction efficiencies of the APTMS/PDMS fiber were superior to those of conventional fibers. The APTMS/PDMS fiber was found to be capable of extracting a broad range of analytes, including highly polar acidic species such as organic acids.