title: Developing qualitative extraction profiles of coffee aromas utilizing polymeric ionic liquid sorbent coatings in headspace solid-phase microextraction gas chromatography-mass spectrometry.
abstract: Two solid-phase microextraction (SPME) sorbent coatings based on polymeric ionic liquids (PILs) have been utilized for the analysis of complex coffee aroma samples. The PIL-based SPME coatings examined, namely, poly(1-(4-vinylbenzyl)-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonyl]imide) [poly(VBHDIm(+) NTf(2)(-))], with ~14-μm thickness, and poly(1-vinyl-3-hexylimidazolium chloride) [poly(ViHIm(+)Cl(-))], with ~8-μm thickness, were employed for the headspace determination of up to 49 analytes from four different coffee beans: two French roast coffees of different brands, Sumatra coffee, and decaffeinated Sumatra coffee. The analysis was conducted using gas chromatography coupled to mass spectrometry. For comparative purposes, the commercial polyacrylate (PA, 85-μm film thickness) SPME coating was utilized under the same extraction conditions. The three SPME coatings tested behaved quite differently as a function of the families of compounds extracted. Thus, the poly(VBHDIm(+) NTf(2)(-) ) coating was extremely selective for aldehydes while also exhibiting good extraction efficiencies for acids. The poly-(ViHIm(+) Cl(-)) coating exhibited superior performance for aromatic alcohols, and the PA coating worked better for heterocyclic aromatics. Both PIL-based SPME sorbent coatings demonstrated exceptional selectivity and extraction efficiency when dealing with complex coffee aromas in spite of their small film thicknesses.
authors.affiliation: Department of Chemistry, The University of Toledo, Toledo, OH 43606, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: López-Darias
authors.forename: Jared L
authors.initials: JL
authors.lastname: Anderson
authors.forename: Verónica
authors.initials: V
authors.lastname: Pino
authors.forename: Ana M
authors.initials: AM
authors.lastname: Afonso
mesh_terms: D000143:Acids / Q000032:analysis / Q000302:isolation & purification; D000180:Acrylic Resins / Q000737:chemistry; D000438:Alcohols / Q000032:analysis / Q000302:isolation & purification; D000447:Aldehydes / Q000032:analysis / Q000302:isolation & purification; D003069:Coffee / Q000737:chemistry*; D005524:Food Technology / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007093:Imidazoles / Q000737:chemistry; D007094:Imides / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D012680:Sensitivity and Specificity; D052617:Solid Phase Microextraction / Q000379:methods*
chemical_list: D000143:Acids; D000180:Acrylic Resins; D000438:Alcohols; D000447:Aldehydes; D003069:Coffee; D007093:Imidazoles; D007094:Imides; D052578:Ionic Liquids; D011108:Polymers; C006903:carbopol 940