Recognition of fish storage time by a metalloporphyrins-coated QMB sensor array

'Electronic nose' applications have been increasing in number in recent years. The reliability of these applications is mainly based on the selectivity properties of the sensors composing the array and on the stability of their characteristics. In this paper an electronic nose based on metalloporphyrins-coated quartz microbalance sensors is described. Due to the nature of the chosen metals, the sensors are particularly suitable to classify environments in which compounds containing donor atoms, such as mines, alcohols and sulphides, play a key role. The aroma of fish during storage is one of these environments. The array has been applied both for classification and for identification of the degree of freshness of stored cod fish. Data on the recognition of storage days and continuous short time monitoring are reported and discussed. Results of the electronic nose response are displayed by a method that is based on the parametrization of the input temporal evolution and allows an adequate representation of the evolving chemical environment