ABSTRACT: An array of quartz crystals coated with different
room-temperature ionic liquids (RTILs) is proposed for the
analysis of flavors by quartz crystal microbalance (QCM)
measurements. Seven RTILs were adopted as sensing layers, all
containing imidazolium or phosphonium cations, differing from
one another in the length and branching of alkyl groups and
neutralized by different anions. The array was at first applied to
the analysis of 31 volatile organic compounds (VOCs), such as
alcohols, phenols, aldehydes, esters, ketones, acids, amines,
hydrocarbons and terpenes, chosen as representative components
of a wide variety of food flavors. Multivariate data analysis by the
principal component analysis (PCA) approach of the set of the
corresponding responses led to separated clusters for these
different chemical categories. To further prove the good
performance of the RTIL-coated quartz crystal array as an
“electronic nose”, it was applied to the analysis of headspaces
from cinnamon samples belonging to different botanical varieties
(Cinnamon zeylanicum and Cinnamon cassia). PCA applied to responses recorded on different stocks of samples of both varieties
showed that they could be fully discriminated.
