Electronic nose


Electronic nose

An electronic nose is a device intended to detect odors or flavors.

Over the last decade, “electronic sensing” or “e-sensing” technologies have undergone important developments from a technical and commercial point of view. The expression “electronic sensing” refers to the capability of reproducing human senses using sensor arrays and pattern recognition systems.Since 1992, research has been conducted to develop technologies, commonly referred to as electronic noses, that could detect and recognize odors and flavors. The stages of the recognition process are similar to human olfaction and are performant for identification, comparison, quantification and other applications. However, hedonic evaluation is a specificity of the human nose given that it is related to subjective opinions. These devices have undergone much development and are now used to fulfill industrial needs.

Other techniques to analyze odors

In industry, aroma assessment is usually performed by human sensory analysis, Chemosensors or by gas chromatography (GC, GC/MS). The latter technique gives information about volatile organic compounds but the correlation between analytical results and actual odor perception is not direct due to potential interactions between several odorous components.

Electronic Nose working principle

The electronic nose was developed in order to mimic human olfaction that functions as a non-separative mechanism: i.e. an odor / flavor is perceived as a global fingerprint.

Electronic Noses include three major parts: a sample delivery system, a detection system, a computing system.

The sample delivery system enables the generation of the headspace (volatile compounds) of a sample, which is the fraction analyzed. The system then injects this headspace into the detection system of the electronic nose. The sample delivery system is essential to guarantee constant operating conditions.

The detection system, which consists of a sensor set, is the “reactive” part of the instrument. When in contact with volatile compounds, the sensors react, which means they experience a change of electrical properties. Each sensor is sensititive to all volatile molecules but each in their specific way. Most electronic noses use sensor-arrays that react to volatile compounds on contact: the adsorption of volatile compounds on the sensor surface causes a physical change of the sensor. A specific response is recorded by the electronic interface transforming the signal into a digital value. Recorded data are then computed based on statistical models. [http://www.alpha-mos.com/en/products/prohome.php Alpha M.O.S, a full range of solutions for odor or taste and VOC assessments from R&D to QC ] ]

The more commonly used sensors include metal oxide semiconductors (MOS), conducting polymers (CP), quartz crystal microbalance, surface acoustic wave (SAW), and field effect transistors (MOSFET).

In recent years, other types of electronic noses have been developed that utilize mass spectrometry or ultra fast gas chromatography as a detection system.

The computing system works to combine the responses of all of the sensors, which represents the input for the data treatment. This part of the instrument performs global fingerprint analysis and provides results and representations that can be easily interpreted. Moreover, the electronic nose results can be correlated to those obtained from other techniques (sensory panel, GC, GC/MS).

How to perform an analysis

As a first step, an electronic nose need to be trained with qualified samples so as to build a database of reference. Then the instrument can recognize new samples by comparing volatile compounds fingerprint to those contained in its database. Thus they can perform qualitative or quantitative analysis.

Range of applications

Electronic nose instruments are used by Research & Development laboratories, Quality Control laboratories and process & production departments for various purposes:

in R&D laboratories for:
* Formulation or reformulation of products
* Benchmarking with competitive products
* Shelf life and stability studies
* Selection of raw materials
* Packaging interaction effects
* Simplification of consumer preference testin Quality Control laboratories for at line quality control such as:
* Conformity of raw materials, intermediate and final products
* Batch to batch consistency
* Detection of contamination, spoilage, adulteration
* Origin or vendor selection
* Monitoring of storage conditions.In process and production departments for:
* Managing raw material variability
* Comparison with a reference product
* Measurement and comparison of the effects of manufacturing process on products
* Following-up cleaning in place process efficiency
* Scale-up monitoring
* Cleaning in place monitoring.

Various application notes describe analysis in areas such as Flavor & Fragrance, Food & Beverage, Packaging, Pharmaceutical, Cosmetic & Perfumes, Chemical companies. More recently they can also address public concerns in terms of olfactive nuisance monitoring with networks of on-field devices. [ [http://www.alpha-mos.com/notes/an_en.php Alpha M.O.S, Applications Notes ] ]

References


* [http://science.nasa.gov/headlines/y2004/06oct_enose.htm NASA researchers are developing an exquisitely sensitive artificial nose for space exploration]


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • electronic nose — see ↑e nose • • • Main Entry: ↑electronic …   Useful english dictionary

  • electronic nose —  { }Electronic Nose{ }   «Электронный нос»   Мультисенсорная система для газового анализа, имитирующая работу органа обоняния млекопитающего. «Электронный нос» включает массивы (набор) неселективных сенсоров (чаще всего используются… …   Толковый англо-русский словарь по нанотехнологии. - М.

  • electronic nose — n. A device containing electronic sensors that can detect chemicals associated with particular smells. Example Citation: She predicted that the electronic nose would come in handy in diagnosing disease. Doctors often use their sense of smell… …   New words

  • electronic nose — a device that analyses vapours close to a product as a measure of quality, rather as a nose can detect different odours. The device has to be trained, e.g. for detection of freshness in a particular species of fish. Not yet in use commercially.… …   Dictionary of ichthyology

  • nose on a chip — n. A computer chip with sensors that can detect chemicals associated with certain smells. Example Citation: Electronic aroma analyzers have also been used to test the quality of seafood, cheese, meat, coffee, beer, and wine, as well as a nose on… …   New words

  • nose cone — i. A conical shaped dome usually attached to the front fuselage to house radar or other electronic equipment. ii. The front cone of a propeller. iii. The intake for jet engines for streamlining and directing the airflow as well as to regulate the …   Aviation dictionary

  • NASA e-nose — NASA s Electric Nose Could something that is normally used to find leaks of ammonia in shuttles eventually be used to sniff out cancer? The creators of the electronic nose, or e nose, at the University of Rome think it will. This machine has… …   Wikipedia

  • e-nose — /ē nōz/ noun An electronic device which detects the presence of specified compounds, used in the food, defence and health industries (in full electronic nose). e nose noun see separate entry. • • • Main Entry: ↑E …   Useful english dictionary

  • artficial nose — a device that analyses vapours close to a product as a measure of quality, rather as a nose can detect different odours. The device has to be trained, e.g. for detection of freshness in a particular species of fish. Not yet in use commercially.… …   Dictionary of ichthyology

  • Dope Nose — Single by Weezer from the album Maladroit Released 2002 Format …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.