comparative study of two methods for olfactory measurement

Comparative Study of Two Comparative Study of Two Methods for Olfactory Methods for Olfactory

MeasurementMeasurement

○ Saeko 　 Amano , 　 Hiroyuki Ueno Tokyo Metropolitan Research Institute for Environmental Protection

Triangle Odor Bag MethodTriangle Odor Bag Method　　　　　　　　 and Dynamic Olfactometryand Dynamic Olfactometry

Outline of this presentation Outline of this presentation

1.1. Dilution accuracy between the European methoDilution accuracy between the European method and the Japanese method using GC and HPLd and the Japanese method using GC and HPLCC

2.2. Difference of odour threshold between the EuroDifference of odour threshold between the European method and the Japanese method pean method and the Japanese method

3.3. Difference among 3 method Difference among 3 method ththee European method, the Japanese method and European method, the Japanese method and European-like Japanese methodEuropean-like Japanese method


1. Dilution accuracy between the Europ1. Dilution accuracy between the European method and the Japanese methean method and the Japanese method using GC and HPLCod using GC and HPLC

2. Difference of odour threshold between the Euro2. Difference of odour threshold between the European method and the Japanese method pean method and the Japanese method

3. Difference among 3 method 3. Difference among 3 method tthehe European method, the Japanese method anEuropean method, the Japanese method and European-like Japanese methodd European-like Japanese method

Differences between the Japanese Differences between the Japanese method and the European methodmethod and the European method

The Japanese method

The European method

Dilution Bag &

Syringe

Flow controller,

Needle valve, etc.

Presentation DescendingAscending 　　 random

Step factor 　 3 　 2

Sniffing condition

Air in the bag

Air emanated from port

Panel Selection　

5 standard solutions

n-Butanol

1. Dilution accuracy between the European method and the 1. Dilution accuracy between the European method and the Japanese methodJapanese method

Sample Dilution factorThe European The European

methodmethodThe Japanese The Japanese

methodmethod

NoNoDilutionDilution

factorfactorDilutionDilution

factorfactor

44 3333 303055 6565

10010066 136136

77 266266 30030088 560560

1000100099 10321032

Sample, Dilution factor

Hydrogen Sulfide

Hexanal

Propion aldehyde


Analytical method Make the original

gas

Dilute with odor-free air according to European method or Japanese method

Adsorb gas to cartridge

（ SUPELCO　DNPH)

Elute with acetnitrile

HPLC－UV

Trap gas to cold concentration tube

Heat tube and inject to GC

GC-FPD　

Aldehyde Hydrogen Sulfide


50

75

100

125

150

10 100 1000 10000

Result of dilution test -1Result of dilution test -1 ( Hydrogen Sulfide) ( Hydrogen Sulfide)

Hydrogen Sulfide is hardly adsorbed

during the test .

Recovery

(%

)

Dilution Factor

◆ 　 Dynamic　　　　　 Olfactometer（ The European method)

■ 　 Triangle Odor　　　　　　 Bag Method（ The Japanese method)


0

50

100

150

200

10 100 1000 10000

Result of dilution test -2Result of dilution test -2 ( Hexanal) ( Hexanal)

The Japanese method have nice recovery when dilution factor is more than 300. The European method nearly get good recovery of each dilution factor.

Recovery

(%

)

Dilution Factor




0

50

100

150

10 100 1000 10000

Result of dilution test -3Result of dilution test -3 ( Propion aldehyde) ( Propion aldehyde)

The result is as same as that of hexanal .

Recovery

(%

)

Dilution Factor




Conclusion of dilution accuracy Conclusion of dilution accuracy testtest

The difference of dilution accuracy between the European method and the Japanese method was shown by using Hydrogen Sulfide, hexanal and propionaldehyde as samples.Concerning hydrogen sulfide, both method could get almost 100% recovery.About aldehyde containing hexanal and propionaldehyde, recovery varied a little widely at the European method ,however, the European method nearly got good recovery . On the other hand, the Japanese method didn’t get good result when their dilution value was lower. But when dilution factor was more than 300, the Japanese method had good recovery as to the European method.



1. Dilution accuracy between the European metho1. Dilution accuracy between the European method and the Japanese method using GC and HPLd and the Japanese method using GC and HPLCC

2. Difference of odour threshold betwee2. Difference of odour threshold between the European method and the Japan the European method and the Japanese methodnese method

3. Difference among 3 method 3. Difference among 3 method tthehe European method, the Japanese method anEuropean method, the Japanese method and European-like Japanese methodd European-like Japanese method

odoranodorantt

n-butanoln-butanol

HexanalHexanal

Hydrogen SulfideHydrogen Sulfide

TrimethylamineTrimethylamine

Isobutyric acidIsobutyric acid

Ethyl AcetateEthyl Acetate

Standard odourants of the European method

2.Difference of odour threshold between two method for olfactory measurement2.Difference of odour threshold between two method for olfactory measurement

Standard odourants of the Japanese methos

Odour quality

smell of stinking socks, smell of natto

Smell of rotten fish

Smell of rotten egg

Smell of cutting grass

Smell of thinner

Olfactory Olfactory measurementmeasurement

Measurements by both method for each odourant were performed in a same day using same panel members

Number of Measurement : 3~


Result of odour threshold measuremenResult of odour threshold measurementt

2.Difference of odour threshold between European method and Japanese method2.Difference of odour threshold between European method and Japanese method

Except for isobutyric acid, threshold of the European method are higher than that of the Japanese method

log Threshold (ppｔ )

DynamicOlfactmetry

Triangle odorbag method

n-butanol 4.8 4.1Hexanal 3.4 2.4

Ethyl Acetate 3.1 2.6Hydrogen Sulfide 3.1 2.5Trimethyl amine 3.1 2.7Isobutyric acid 3.6 4.0

Result of odour threshold measuremenResult of odour threshold measurementt

2.Difference of odour threshold between European method and Japanese method2.Difference of odour threshold between European method and Japanese method

Concentrations of threshold measured by the European method are about 3-9 times higher than that measured by the Japanese method except for butyric acid.Dynamic

Olfactmetry(A)


(B)

Proportion(A/B)

n-butanol 75 14 5.3Hexanal 2.9 0.3 9.0

Ethyl Acetate 1389 384 3.6Hydrogen Sulfide 1.5 0.3 4.5Trimethyl amine 1.7 0.5 3.2Isobutyric acid 4 11 0.4

Threshold (ppｂ )

Standard deviation of odour thresholdStandard deviation of odour threshold

Standard division of each sample is also same between two method.


DynamicOlfactmetry


n-butanol 0.1 0.3Hexanal 0.2 0.1

Ethyl Acetate 0.2 0.2Hydrogen Sulfide 0.4 0.2Trimethyl amine 0.2 0.1Isobutyric acid 0.2 0.1

Standard deviation

Summary of odour threshold’s differencSummary of odour threshold’s differencee

Olfactory measurement was done using 6 odour Olfactory measurement was done using 6 odour substances.substances.Except for isobutyric acid, concentrations of threshold measured by the European method are about 3-9 times higher than that measured by the Japanese method.Standard division are also same between two methods.


Outline of this presentation Outline of this presentation 1.1. Dilution accuracy between the European method aDilution accuracy between the European method a

nd the Japanese method using GC and HPLCnd the Japanese method using GC and HPLC

2.2. Difference of odour threshold between the EuropeDifference of odour threshold between the European method and the Japanese method an method and the Japanese method

3. Difference among 3 method 3. Difference among 3 method thethe European method, the Japanese methoEuropean method, the Japanese method and European-like Japanese methodd and European-like Japanese method

Differences between Japanese Differences between Japanese method and European methodmethod and European method

The Japanese method

The European method

Dilution Bag & Syringe

Flow controller, Needle valve, etc.

Presentation Descending Ascending 　random

Step factor 3 2Forced choice 3 2Sniffing condition

Air in the bag


Panel Selection　

5 standard solutions

n-Butanol

3. Difference among three methods 3. Difference among three methods

Condition of experimentCondition of experimentThe

European method

The Japanese method

European-like Japanse method

Dilution


Bag & Syringe

Bag & Syringe

Presentation

Ascending 　　 random

DescendingAscending 　　 random

Step factor 2 3 2Forced choice 2 3 2

Sniffing condition


Air in the bag

Air in the bag


The European method

The Japanese method

European-like Japanse method

Dilution


Bag & Syringe

Bag & Syringe

Presentation

Ascending 　　 random

DescendingAscending 　　 random

Step factor 2 3 2Forced choice 2 3 2

Sniffing condition


Air in the bag

Air in the bag

Condition of experimentCondition of experiment3. Difference among three methods 3. Difference among three methods

Samples and PanelsSamples and PanelsSamplesSamples

n-butanol n-butanol Source sample of offset printing Source sample of offset printing

(mixture of odour)(mixture of odour) 　　

Panel membersPanel members12 person12 personss

(divide 2 groups and 6 members each)(divide 2 groups and 6 members each)

MeasurementsMeasurementsEach measurement was done one time in a day anEach measurement was done one time in a day and repeated four daysd repeated four days

　　　　　　


20

30

40

50

1 2 3

Differences among 3 methodsDifferences among 3 methods((offset printing smelloffset printing smell))

The Europea

n method

The Japanese method

European-like Japanese method

10 x

log

Odo

ur c

once

ntr

atio

nEuropean-like Japanese method had same log odour conc. as the European method and lower than the Japanese method.

Low

←

Sen

sit

ivit

y →　

Hig

h


Differences among 3 methodsDifferences among 3 methods(n-butanol)(n-butanol)

0

1

2

31 2 3

log

Th

resh

old

(p

pb

)Sensitivity of European-like Japanese method is lower than the Japanese method.

The Europea

n method

The Japanese method

European-like Japanese methodL

ow

←

Sen

sit

ivit

y →　

Hig

h


Results of odour threshold in this year’s Results of odour threshold in this year’s ( n-butanol)( n-butanol)

0

1

2

3

1 2 3 4

log

Th

resh

old

(p

pb

)

◆The European method ■ The Japanese method

First time Second time

Sensitivity by Japanese method are higher than that by European method. This result show same trend as that of offset printing

Low

←

Sen

sit

ivit

y →　

Hig

h


Summary of difference among 3 Summary of difference among 3 methodmethod

European-like Japanese European-like Japanese method( ascending presentation method( ascending presentation and two forced choice mode)and two forced choice mode) was was compared with the European compared with the European method and the Japanese method.method and the Japanese method.

Sensitivity of European-like Sensitivity of European-like Japanese method is lower than the Japanese method is lower than the Japanese methodJapanese method


Conclusion(1/2)Conclusion(1/2)

Dilution accuracy of hydrogen sulfide and alDilution accuracy of hydrogen sulfide and aldehyde is good on both method when dilutiodehyde is good on both method when dilution factor is more than 300. n factor is more than 300. Concentrations of threshold measured by the European method are 3-9 times higher than that measured by the Japanese methodEuropean-like Japanese method European-like Japanese method had same threshold as the European method.

Conclusion(2/2)Conclusion(2/2)These results shows that deference between Japanese and European methods is mainly caused by the definition of the threshold, not by dilution method or materials.

Main reason may be as follows: Answer of panelist is recognized as “true” when “correct and certain” is observed in the European method while the Japanese method recognize the answer as “true” whenever it is correct.

Future PlanFuture Plan

Study of difference in race.Study of difference in race. ( We take a test in Poland on and after tomorrow with your h( We take a test in Poland on and after tomorrow with your h

elp, and compared with the result in Japanese)elp, and compared with the result in Japanese)

research dilution accuracy of Isobutyric acidresearch dilution accuracy of Isobutyric acid

Thank you for your attention

ENDEND

ConclusionConclusionDilution accuracy of hydrogen sulfide is good on bDilution accuracy of hydrogen sulfide is good on both method. Concerning hexanal, the European meoth method. Concerning hexanal, the European method is almost well and the Japanese method as sthod is almost well and the Japanese method as same as that one which is limited ame as that one which is limited dilution factor to more than 300.Except for isobutyric acid, concentration s of threshold measured by the European method are about 3-9 times higher than that measured by the Japanese methodEuropean-like Japanese method European-like Japanese method had same log odour concentration as the European method in the case of using off-set printing, but difference that of using n-butanol.

12

345

67

n-butanol hexanal Isobutyric acid Ethyl acetate

Result of odour thresold-2 (winter)Result of odour thresold-2 (winter)H

igh

←

　S

en

siti

vit

y o

f p

an

el　

　→

　lo

wLog

Th

resh

old

(p

pｔ

)

n-Butanol 　 hexanal

◆Dynamic Olfactometer ■ Triangle Odor Bag Method

IsobutyricAcid

EthylAcetate

2.Difference of odour thresold between European method and Japanese method2.Difference of odour thresold between European method and Japanese method

Except for isobutyric acid, thresold of Europian method are higher than that of Japanese method

2

3

4

5

n-butanol hexanal Hydrogen

sulfide

Trimethylamine

Result of odour thresold-1 (summer)Result of odour thresold-1 (summer)H

igh

←

　S

en

siti

vit

y o

f p

an

el　

　→

　lo

wLog

Th

resh

old

(p

pｔ

)

n-Butanol 　 hexanal

Hydrogen sulfide

Trimethylamine

2.Difference of odour thresold between European method and Japanese method2.Difference of odour thresold between European method and Japanese method

Thresold of Europian method are higher than that of Japanese method. But standard deviation are different.

◆Dynamic Olfactometer ■ Triangle Odor Bag Method

Main PointsMain Points

におい袋を用いた、オルと同一の希釈倍におい袋を用いた、オルと同一の希釈倍数、サンプルの出し方の方法を数、サンプルの出し方の方法を MethodAMethodAとし、オル、におい袋法と比較した。とし、オル、におい袋法と比較した。オフセット印刷臭については、 Method Aと折るファクトメーターは同一の臭気濃度をしめした。ブタノールについてはブタノールについては MethodAMethodA のみ高いのみ高い閾値を示し、オルファクトとにおいは差閾値を示し、オルファクトとにおいは差がなかった。がなかった。

3. Study of difference among three 3. Study of difference among three method method

22 点比較と点比較と 33 点比較点比較臭袋法４臭袋法４

２倍系列上昇法２倍系列上昇法臭袋法５臭袋法５

２倍系列上昇法２倍系列上昇法

３点比較３点比較２点比較２点比較n-n-ブタノールブタノール個人閾値の全平均個人閾値の全平均　　　　　　　　 (ppb(ppbの対数の対数））

2.02.0 2.02.0

標準偏差（個人間標準偏差（個人間）） 0.340.34 0.290.29

標準偏差（個人内標準偏差（個人内）） 0.270.27 0.250.25

オフセット印刷臭オフセット印刷臭個人閾値の全平均個人閾値の全平均　（希釈倍数の対数）　（希釈倍数の対数） 3.33.3 3.33.3標準偏差（個人間標準偏差（個人間）） 0.320.32 0.260.26

標準偏差（個人内標準偏差（個人内）） 0.220.22 0.290.29

Differences among 3 Differences among 3 methodsmethods

European European methodmethod

Japanese Japanese methometho

ddMethodAMethodA

n-butanoln-butanolLog Threshold Log Threshold

(ppb)(ppb)1.61.6 1.61.6 2.02.0

Off-set printingOff-set printing

Log Odour Conc.Log Odour Conc. 3.23.2 3.83.8 3.33.3

Concering off-set printing, Method A had same log odour conc. as European method and be different from Japanese method. But as n-butanol, Log threshold of method A is high among 3 methods.

3. Study of difference among three 3. Study of difference among three method method

High ← 　 Sensitivity of panel 　　→　 LowLow ← 　 log threshold (ppb) 　　→　 HighHigh ← 　 log odor coc. 　　→　 Low

Caution!

差異の要因の定量的検討差異の要因の定量的検討上昇法と下降法（閾値の定義（回答方上昇法と下降法（閾値の定義（回答方法）の違い）法）の違い）２倍系列と３倍系列２倍系列と３倍系列３点比較と２点比較３点比較と２点比較

実験方法実験方法上昇法・下降法等の測定条件を変えて同一臭気上昇法・下降法等の測定条件を変えて同一臭気を同一パネルにより両手法によって測定を同一パネルにより両手法によって測定オルファクトメーターはハードウェア・ソフトオルファクトメーターはハードウェア・ソフトウェアの制約から条件の変更が難しいため、臭ウェアの制約から条件の変更が難しいため、臭袋法の条件を変更袋法の条件を変更各条件で各条件で 11日１回ずつ合計４日間測定日１回ずつ合計４日間測定

comparative study of two methods for olfactory measurement

Documents

japanese method difference

hexanalthe japanese

japanese method didnt

european method1

japanese methodoutline

japanese methoddifferences

dilution factor1

presentation dilution