A chemometric approach toward the detection and quantification of coffee adulteration by solid-phase microextraction using polymeric ionic liquid sorbent coatings

Author(s)

Toledo, Bruna R. ^{[1, 2, 3]} ; Hantao, Leandro W. ^{[1, 2, 3]} ; Ho, Tien D. ^[1] ; Augusto, Fabio ^{[2, 3]} ; Anderson, Jared L. ^{[1, 4]}

Affiliation

^[1] Univ Toledo, Dept Chem, Toledo, OH 43606 - USA

^[2] Univ Estadual Campinas, Inst Chem, BR-13084970 Campinas, SP - Brazil

^[3] Univ Estadual Campinas, Natl Inst Bioanalyt Sci & Technol, BR-13084970 Campinas, SP - Brazil

^[4] Univ Toledo, Sch Green Chem & Engn, Toledo, OH 43606 - USA

• Document type: Journal article
• Source: Journal of Chromatography A; v. 1346, p. 1-7, JUN 13 2014.
• Web of Science Citations: 19

Abstract

Solid-phase microextraction (SPME) using cross-linked polymeric ionic liquid (PIL)-based sorbent coatings was used to extract volatile aroma-related compounds from coffee samples. Several PIL-based coatings were screened alongside a commercial poly(acrylate) (PA) SPME coating. The best performing PIL-based SPME fiber, poly(1-vinyl-3-hexadecylimidazolium bis{[}(trifluoromethyl)sulfonylimide]) with 50% (w/w) 1,12-di(3-vinylbenzylimidazolium)dodecane dibis{[}(trifluoromethyl)sulfonyl]imide incorporated cross-linker, was used to isolate the volatile fraction of Arabica coffee. To illustrate the importance of trace analyte isolation, a method for the detection and quantification of coffee adulteration is described. Chromatographic profiles obtained by gas chromatography/mass spectrometry (GC/MS) were used to create the chemometric model. Partial least squares (PLS) regression was employed to correlate the aroma-related chemical fingerprint to the degree of adulteration. The proposed method successfully detected fraud down to 1% (w/w) of adulterant and accurately determined the degree of coffee adulteration (i.e, root mean square error of calibration and prediction of 0.54% and 0.83% (w/w), respectively). Finally, important aroma-related compounds including furans, methoxyphenols, pyrazines, and ketones were identified. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 12/22375-3 - Ionic liquid sorbent phases: synthesis, characterization and applications in GCxGC
• Grantee: Leandro Wang Hantao
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate