A novel electronic nose based on miniaturized SAW sensor arrays coupled with SPME enhanced headspace-analysis and its use for rapid determination of volatile organic compounds in food quality monitoring

Instrumental methods and sensory analysis are described as usable tools for the determination of the storage period, the quality and the origin of food. Apart from the time-consuming aspect of these methods, they are sensitive to misinterpretation. The use of polymer coated surface acoustic wave (SAW) sensor arrays combined with solid-phase microextraction (SPME) is a very promising technique for highly sensitive and selective organic gas detection. Beside new developments in the fabrication of SAW sensors, the evaluation of SPME parameters enables now the highly reproducible detection of volatiles in the ppm and ppb range. In this work we present the coupling of a SAW based micronose, with the SPME technique in conjunction with headspace auto sampling. To prove the practical usage of this analytical concept in the field of food quality control different tests were successful conducted. Differentiation between apple varieties, ripe and unripe pineapple, and finally the detection of an off-flavor in sugar. The main advantages of this setup include its rapidity (short preparation times, short extraction times, short measuring times), simplicity and last but not least the low-costs. Since this device is easy to handle a broad range of applications is possible, e.g. on-line measurement of chemical and biochemical processes, supplement for human sensory experiments and detection of microorganisms contamination.