Discrimination of Chemical Compounds and Functional Groups by Pattern Recognition Using an Integrated Sensor

Abstract

An integrated sensor with three elements (zinc oxide, tin oxide and tungsten oxide) was fabricated by thick film techniques in order to develop a smell sensor. Using this sensor and pattern recognition method, the possibility of identifying 15 chemical compounds which belong to the alcohol, ester, ketone, benzene and hydrocarbon group was examined. The following results were obtained: All 15 compounds have different patterns, so they can be individually identified; compounds which have the same functional groups have similar patterns; and, when gas sensitivity of three elements is displayed in a three‐dimensional space, the compounds with the same functional group form a specific closed space. This indicates that the sensor can identify functional groups of chemical compounds.

Using Electronic Odor Sensors To Discriminate among Oak Barrel Toasting Levels

“…Different types of sensors may be used to detect volatile substances in the gas phase. Metal oxide sensors (MOS) (tin oxide, SnO 2 ; zinc oxide, ZnO; and tungsten oxide, WO 3 ), which may or may not be doped with precious metals (especially palladium, Pd, and platinum, Pt), have been used for many years in gas detection and have provided the basis of many new research developments (Seiyama, 1978;Windismann, 1979;Oyabu, 1984;Moseley and Williams, 1987;Oishi et al, 1988;Gardner, 1989;Mosely and Williams, 1991). Their ability to detect aromas and discriminate among them has been tested in many fields, particularly in the agrifood industry (Moy, 1992;Gardner et al, 1992a,b;Moy, 1993;Moy and Chatonnet, 1993).…”

Aroma discrimination by pattern recognition analysis of responses from semiconductor gas sensor array

“…Recently several attempts of constructing aroma-sensing systems, i.e., the so-called "artificial nose" (Persaud and Pelosi, 1985), have been made by utilizing various gas sensors. Metal oxide semiconductor sensors (Persaud and Dodd, 1982; Oishi et al, 1988; Abe et al, 1989;Weimer et al, 1990), surface-acoustic wave (SAW) sensors (Rose-Pehrsson et al., 1988) and quartz-resonator sensors (Ema et al, 1989) seem potential methods. Although every sensor has its own advantages and disadvantages, there are not such sensors that can show perfect selectivity to specific compounds or a group of compounds.…”