Room Temperature Ionic Liquids As Useful Overlayers for Estimating\ud Food Quality from Their Odor Analysis by Quartz Crystal\ud Microbalance Measurements

摘要

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