ODORS AND FLAVORS IDENTIFIED WITH HYBRID MODULAR SENSOR SYSTEMS

Hybrid sensor systems contain different types of chemical sensors wher eby each type (transducer principle) contains an array of individual s ensors. This leads to a large flexibility in the choice of transducers and sensor materials with the general aim of optimising the analytica l performance of the total system. This concept makes it possible to o ptimise the quantitative analysis of mixtures of known gases as it wil l be demonstrated for mixtures of volatile organic compounds (VOCs). A lternatively this makes it possible to optimise the system for charact erising odours and flavours. This will be demonstrated for different p lastic as well as textile materials used in car industries and for dif ferent products of food industries, i.e. coffees, tobaccos, whiskeys, and olive oils. In our modular sensor systems we used arrays of differ ent semiconductor gas sensors (based on metal oxides), of polymer coat ed quartz microbalance (QMB) sensors, of calorimetric sensors and of e lectrochemical sensors. with an option to add metal oxide semiconducto r field effect transistor (MOSFET) sensors, These arrays are arranged as separate components in a modular sensor system 'MOSES'. For the qua litative discrimination of different odour samples a headspace-autosam pler was added and transient sensor signals were monitored, The use of different transducer principles is shown to be essential for an unequ ivocal identification of odours and flavours. (C) 1997 Elsevier Scienc e S.A.