Methodological variation in headspace analysis of liquid samples using electronic nose

In past years, numerous electronic nose (e-nose) developments have been published describing analyses of solid-, liquid- or gaseous media in microbiological-, environmental-, agricultural- or medical applications. However, little has been reported about complex methodological pitfalls that might be associated with commercially available e-nose technology. In this paper, some of these pitfalls such as temperature, the use of filters and mass flow using different sampling methods (static- and dynamic sampling) are described for two generations of conducting polymer e-noses (ST114/214, CPs, both Scensive Tech. Ltd.). A comparison with metal oxide semiconducting field effect transistor/metal oxide semiconductor (MOSFET/MOS) e-noses regarding stability across replicates and over time was made. Changes in temperature were found to give larger sensor responses, whereas the application of filters led to quantitative and qualitative changes in sensor responses due to a change in mass flow which was also affected by the sampling method. Static sampling provided more stable flows across replicates. Variation was investigated for CPs and MOSFET/MOS e-noses that gave different responses over time and across replicates. These methodological factors cause a lack of stability and reproducibility, demonstrating the pitfalls of e-nose technology and therefore limit their utility for discriminating between samples.

[1]  R M Stuetz,et al.  Use of a chemical sensor array for detecting pollutants in domestic wastewater. , 2002, Water research.

[2]  Claudio Domenici,et al.  Fluid dynamic simulation of a measurement chamber for electronic noses , 2002 .

[3]  S Nimmermark,et al.  Use of electronic noses for detection of odour from animal production facilities: a review. , 2001, Water science and technology : a journal of the International Association on Water Pollution Research.

[4]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[5]  Conrad Bessant,et al.  Monitoring haemodialysis using electronic nose and chemometrics. , 2004, Biosensors & bioelectronics.

[6]  Simona Benedetti,et al.  Comparison of an Electronic Nose with the Sensory Evaluation of Food Products by “Triangle Test” , 2004 .

[7]  A. Nake,et al.  Outdoor in situ monitoring of volatile emissions from wastewater treatment plants with two portable technologies of electronic noses , 2005 .

[8]  Sergey A. Piletsky,et al.  Ammonia sensors based on sensitive polyaniline films , 1996 .

[9]  R. W. Marshall,et al.  Detection and simultaneous identification of microorganisms from headspace samples using an electronic nose. , 1997 .

[10]  Patrick Mielle.  ‘Electronic noses’: Towards the objective instrumental characterization of food aroma , 1996 .

[11]  N. Magan,et al.  Electronic noses and disease diagnostics , 2004, Nature Reviews Microbiology.

[12]  J. Gardner,et al.  An electronic nose system to diagnose illness , 2000 .

[13]  M. K. Andrews,et al.  High sensitivity conducting polymer sensors , 1996 .

[14]  M. Koudelka-Hep,et al.  Electronic noses – A mini-review , 1999 .

[15]  Ida A. Casalinuovo,et al.  Application of Electronic Noses for Disease Diagnosis and Food Spoilage Detection , 2006, Sensors (Basel, Switzerland).

[16]  David Smith,et al.  Selected ion flow tube mass spectrometry (SIFT-MS) for on-line trace gas analysis. , 2005, Mass spectrometry reviews.

[17]  Duk-Dong Lee,et al.  Sensing behaviors of polypyrrole sensor under humidity condition , 2005 .

[18]  Ovidio Salvetti,et al.  A neural approach for improving the measurement capability of an electronic nose , 2003 .

[19]  José Pedro Santos,et al.  Comparative study of sampling systems combined with gas sensors for wine discrimination , 2007 .

[20]  E. Martinelli,et al.  Lung cancer identification by the analysis of breath by means of an array of non-selective gas sensors. , 2003, Biosensors & bioelectronics.

[21]  Ingemar Lundström,et al.  Classification of complex gas mixtures from automotive leather using an electronic nose , 2000 .

[22]  Giovanni Pioggia,et al.  A radially symmetric measurement chamber for electronic noses , 2005 .

[23]  Naresh Magan,et al.  Milk-sense: a volatile sensing system recognises spoilage bacteria and yeasts in milk , 2001 .

[24]  K. R. Kashwan,et al.  Robust electronic-nose system with temperature and humidity drift compensation for tea and spice flavour discrimination , 2005, 2005 Asian Conference on Sensors and the International Conference on New Techniques in Pharmaceutical and Biomedical Research.

[25]  Eugenio Martinelli,et al.  Counteraction of environmental disturbances of electronic nose data by independent component analysis , 2002 .

[26]  W J Harper,et al.  The strengths and weaknesses of the electronic nose. , 2001, Advances in experimental medicine and biology.

[27]  Krishna C. Persaud,et al.  Use of an Electronic Nose to Measure Odour Concentration Following Application of Cattle Slurry to Grassland , 1997 .

[28]  A. D. Wilson,et al.  Development of conductive polymer analysis for the rapid detection and identification of phytopathogenic microbes. , 2004, Phytopathology.

[29]  O. N. Timofeeva,et al.  Conducting polymer interaction with gaseous substances I. Water , 1991 .

[30]  Thierry Talou,et al.  MOS–MOSFET gas sensors array measurements versus sensory and chemical characterisation of VOC’s emissions from car seat foams , 2003 .

[31]  J. Roggen,et al.  The influence of relative humidity on the response of tin oxide gas sensors to carbon monoxide , 1991 .

[32]  J. Bosset,et al.  Classification of unifloral honeys with an MS-based electronic nose using different sampling modes: SHS, SPME and INDEX , 2004 .

[33]  Diana Hodgins,et al.  The development of an electronic ‘nose’ for industrial and environmental applications , 1995 .

[34]  Naresh Magan,et al.  Use of an electronic nose system for diagnoses of urinary tract infections. , 2002, Biosensors & bioelectronics.

[35]  D. J. Marlin,et al.  Use of an Electronic Nose To Diagnose Mycobacterium bovis Infection in Badgers and Cattle , 2005, Journal of Clinical Microbiology.

[36]  J. Bosset,et al.  The electronic nose applied to dairy products: a review , 2003 .

[37]  V. I. Krinichnyi,et al.  The study of conducting polymer interaction with gaseous substances IV. The water content influence on polyaniline crystal structure and conductivity , 1992 .