A chemometric approach toward the detection and quantification of coffee adulteration by solid-phase microextraction using polymeric ionic liquid sorbent coatings.
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.
Department of Chemistry, The University of Toledo, Toledo, OH 43606, USA; Institute of Chemistry and National Institute of Bioanalytical Science and Technology, University of Campinas, Campinas, SP 13084-970, Brazil.
Bruna R
BR
Toledo
Department of Chemistry, The University of Toledo, Toledo, OH 43606, USA; Institute of Chemistry and National Institute of Bioanalytical Science and Technology, University of Campinas, Campinas, SP 13084-970, Brazil.
Leandro W
LW
Hantao
Department of Chemistry, The University of Toledo, Toledo, OH 43606, USA.
Tien D
TD
Ho
Institute of Chemistry and National Institute of Bioanalytical Science and Technology, University of Campinas, Campinas, SP 13084-970, Brazil.
Fabio
F
Augusto
Department of Chemistry, The University of Toledo, Toledo, OH 43606, USA; School of Green Chemistry and Engineering, The University of Toledo, Toledo, OH 43606, USA. Electronic address: Jared.Anderson@UToledo.edu.
Jared L
JL
Anderson
D040503:Coffea / Q000737:chemistry*; D063427:Food Quality; D005524:Food Technology / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D052578:Ionic Liquids / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D012044:Regression Analysis; D052617:Solid Phase Microextraction
D052578:Ionic Liquids; D011108:Polymers
Adulteration; Arabica coffee; Gas chromatography/mass spectrometry; Partial least squares regression; Polymeric ionic liquid; Solid-phase microextraction