Electronic noses can be used for this purpose. If properly trained, electronic Oligomycin A mw noses can detect the presence of odours in ambient air, estimate odour concentration and attribute the perceived odour to a specific odour source [20]. Inhibitors,Modulators,Libraries During the last decade research activity aiming at the development of specific electronic noses for the continuous monitoring of Gemcitabine hydrochloride environmental odours has been carried Inhibitors,Modulators,Libraries out at the Politecnico di Milano, in collaboration with Sacmi s.c. and Progress S.r.l.Since the first instrument developed mainly for laboratory use (EOS 835) [21], during the last years an innovative electronic nose was realized (EOS 507) [22], designed with the aim of guaranteeing better performance in the field under variable meteorological conditions and with diluted odours [23].

This paper discusses the laboratory and field tests conducted in order to evaluate the performance of this new instrument. The performance evaluation in the Inhibitors,Modulators,Libraries laboratory was concerned specifically the verification of the ability to discriminate and correctly classify different specific odorous compounds (pure substances selected as Inhibitors,Modulators,Libraries representative Inhibitors,Modulators,Libraries of typical environmental odour emissions) and to estimate their odour concentration.The electronic nose performance was further verified by a field monitoring trial conducted in a rural area in the north of Italy where Inhibitors,Modulators,Libraries three odour emitting plants are present, with the aim of identifying the major source of annoyance.

During the monitoring four electronic noses EOS 507 were used together with an ��old�� EOS 835 electronic nose, in order to compare the instrument performances and thus verify the effectiveness of the innovations and improvements Inhibitors,Modulators,Libraries introduced in the new EOS 507.

2.?State of the ArtOne of the first studies published concerning the use of an electronic nose to monitor the presence of different odours Inhibitors,Modulators,Libraries in ambient air was performed by Misselbrook et al.[24]. In their work the authors compared the reliability of two different devices, Odourmapper (developed by UMIST) and Aromascan GSK-3 (Aromascan plc, Crewe, UK) in odour quantification. Sensor responses of both instruments to different samples with variable odour concentration had the same trend, but variances of the experimental data responses were not satisfying (62 and 59%, respectively).

A better correlation between odour concentration and sensors responses was found by Stuetz et Brefeldin_A al.

[6]. The first works on odour quantification performed by electronic noses showed that the algorithms kinase inhibitor Cisplatin used for odour concentration estimation and the investigated odour concentration range are crucial factors that can affect the analysis. Micone and Guy [25] obtained good reliability by using an electronic nose for analyzing Vismodegib hedgehog odour samples with an odour concentration between 50 and 150 ouE/m3. However, the instrument accuracy turned out to worsen when the odour concentration increased.Another important factor to be considered is the influence of environmental conditions on sensor responses.