Electronic Sensor Technology 1 A New Type of Electronic Nose for Analyzing Malodor Introduction - Electronic Nose and Sensor Arrays Fast

Electronic Sensor Technology WWW.ESTCAL.COM1

A New Type of Electronic Nose for Analyzing Malodor

• Introduction - Electronic Nose and Sensor Arrays

• Fast Chromatography as a Sensor Arrays

•Quantifiable Results - US EPA Validation

• VaporPrintsTM Images and Pattern Recognition

• Breath and Common Mouthwash odors

•Other Useful VaporPrintTM Applications

• Summary and Conclusions

Edward J. Staples, Ph.D.

Electronic Sensor Technology1077 Business Center CircleNewbury Park, California

Ph: 805-480-1994 FAX: 805-480-1984WebSite: www.estcal.comemail: [email protected]


A New Type of Electronic Nose for Analyzing Malador

A new type of Electronic Nose which simulates the human olfactory response with a 500 element array of nearly orthogonal sensors in 10 seconds is described in this paper. This electronic nose is the first to be validated by the US EPA with both volatiles as well as semi-volatile organic compounds. Application of this new technology to identify and quantify breath odors can identify specific analytes and their concentrations in breath. This new eNose contains a large number of orthogonal sensors, very detailed VaporPrintTM images which are used to identify complex odors and fragrances. With orthogonal 500 sensors, the olfactory response can be mapped into a visual image and this allows accurate pattern recognition by humans as well as computers.

Unlike conventional sensor arrays this eNose speciates and quantifies the individual analytes present in breath. This paper will present results obtained from bacteria and other malodors associated with human diseases. In addition, VaporPrintTM images associated with common mouthwashes will be presented.


Electronic Noses(Sensor Arrays)

•Technical Approach– Sensor Arrays to mimic

the human olfactory response

– Visual Image– Pattern Recognition

•Specificity– Orthogonality– Sensor Separation– Meaningful Sensor

Sequence or Order

•Ability to Calibrate– Sensitivity– Accuracy– Precision– Speed


Fast Gas Chromatography

•GC/SAW Electronic Nose with programmable sampling preconcentrator

• 10 Second Analysis Speed

• Volatile Compounds - ppb MDL

• Semi-Volatile Compounds - ppt MDL


Cal 1 in Air

Cal 1 Air0oC SAW30 secondSample

Cal 2 Air0oC SAW30 secondSample

chloroform

benze

ne

toluene

ethylben

zene

1,1,2,2 trich

loroethan

e

1,2 DCE

Carbon te

trach

loride

TCE PCE Xylene


Calibration Filesfor Air

* 30 Second Sample 0oC Detector


Water Calibration

Cal 1Water0o SAW30 sec Sample

Cal 2Water0o SAW30 sec Sample

chloroform

benze

ne

toluene

ethylben

zene

1,1,2,2 trich

loroethan

e

1,2 DCE

Carbon te

trach

loride

TCE

PCEXylen

e


Calibration Filesfor Water

* 30 Second Sample 0oC Detector


Minimum Detection Levels for Common VOC

30 second Sample of Vapor0oC SAW Detector

MINIMUM DETECTION LEVEL

Analyte AIR (ppb) WATER (ppb)

Chloroform45 0.65

Cis 1,2 Dichloroethene47 1.7

Benzene42 0.96

Carbon Tetrachloride130 16.49

Trichloroethylene6.3 0.40

Toluene11 0.15

Tetrachloroethylene5.7 0.57

Ethylbenzene2.7 0.07

O - Xylene2.5 0.11

1,1,2,2 Tetrachloroethane3.6 0.56


Chromatogram viewed as a serial polling of a sensor array

•Step 1 - Preconcentrate

•Step 2 - Desorb & Inject

•Step 3 - Observe elution of analytes from GC column


Display Formatsand Vapor Signatures

FrequencyPattern

Ethlybenzene

Benzene

Tolueneo-Xylene

124 Trimethylbenzene

DerivativePattern


VaporPrintTM Pattern Recognition

•Evaluation performed using Humans and Artificial Intelligence/Neural Net Software

•Result - Human perception is practically optimal at recognizing VaporPrintTM images.

Example


Useful Attributes of an Electronic Nose

• Dental and Oral Characteristics – visual, sound, tactile– X-ray images– olfactory evaluation

(quantitative)

• Electronic Nose– improves olfactory capabilities– transfers olfactory stimulus to

visual pattern recognition

Oldsmobile Alero

Oldsmobile Aurora

Example: Learning to recognize

the olfactory image ‘that new car smell’


•Volatile Organics

•Bacteria Odor Signatures

•Breath Odor

•Detection/Diagnostics

•Gastrointestinal

•Salivary Treatment

•Animal studies

•Other– Medical Diagnosis– Early

identification of Infectious disease

– Biological agents– Body Odors

Near Real Time (10 Seconds)Chromatography

with an Electronic Nose


Now the Speed of a Sensor Array and the Performance of a Fast Gas

Chromatograph

SAW SensorVapor

Signature

ProcessedVapor

Signature

US EPA ValidatedChromatography

Software DefinableSensor Arrays


VaporPrintTM Images of Mouthwash Odors

Tom’s Spearmint Tom’s Peppermint Scope Peppermint

Long’s Mint Scope mint Long’s Blue Mint

Listerine Mint


Comparison of Mints

Long’s Mint

Listerine Cool Mint

Long’s Blue Mint

Quantitative Comparisons (Analyte by Analyte)

Vol-1 Mint-M3 Mint-M2 Mint-M1 Mint-h1 Mint-h2 Amount

(ppm) Amount

(ppm) Amount

(ppm) Amount

(ppm) Amount

(ppm) Amount

(ppm)

19 76.9 184 144 scope mint1 16.6 976 85.4 140 Listerine Cool Mint

13 119 115 Longs Blue Mint 10.4 38.2 152 419 Longs Mint


Long’s and ScopeMint

Scope Peppermint

Scope Mint

Tom’s Peppermint

Tom’s Spearmint

Listerine Cool Mint

Long’s Blue Mint


Tom’s Peppermint and Scope Mint


Scope Mint and Peppermint


Salmonella typhimurium

Strep pneumonia

Shigella flexneri Salmonella

enteritidis

Hemophilus influenza Enterococcus

faecalis E. Coli O157E. Coli

Staph aureus

Pseudomonas aeruginosa

Klebsiella pneumonia

Candida albicans

Cultures Prepared by: Department of Pathology and Laboratory Medicine, State Public Health Laboratory of Nevada

VaporPrintTM of Infectious Bacteria Cultures


DioxinsOnions Garlic

CoffeeMushroomsAuto Exhaust

Peanut Butter Cup

PCBAroclor 1260

US Currency

DieselGasoline Kitt-Kat


Summary

• Flash Chromatography using Surface Acoustic Wave GC Detectors– Small, Solid State, low cost– no polymer coatings to degrade >> high

stability

• 10 Second analysis time provides a fast and portable malodor analyzer

• Functional Electronic Nose– Serial Polling simulates 500 orthogonal

Sensors in 10 Seconds– Minimal overlapping responses (co-

elution)– EPA Methods Insure Accuracy &

Precision

• Sensitivity– ppb for VOCs– ppt for Semi-VOC

• Save Money and Time with real time Quantitative Results in-situ

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Commercial Availability

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Electronic Sensor Technology 1 A New Type of Electronic Nose for Analyzing Malodor Introduction - Electronic Nose and Sensor Arrays Fast