Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 2017-12-11 to 2018-04-05
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 123 (Partition Coefficient (1-Octanol / Water), Slow-Stirring Method)
Version / remarks:
2006
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
slow-stirring method
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficient
Key result
Type:
log Pow
Partition coefficient:
7.38
Temp.:
25 °C
pH:
ca. 8.4
Remarks on result:
other: +/- 0.02
Details on results:
Thermostated glass flasks containing the aqueous phase and n-octanol were slowly stirred, after dosing the test item dissolved in octanol, until equilibrium distribution of the test item between the two phases was achieved. The temperature was kept constant at 25 °C ± 1 °C. The concentration of the test item in the phases was measured by HPLC with MS/MS detection. The partition coefficient (n-octanol/water) log Pow was calculated. The equilibrium distribution was defined to be achieved, when four sampling intervals separated by at least 5 hours yielded similar log Pow values, expressed by a plateau with zero slope. The testing was performed in triplicate.
The following value for the log Pow was obtained: 7.38 ± 0.02 at a mean pH value of 8.4

Any other information on results incl. tables

Slow-Stirring Test - Results Obtained for log PowVersus Stirring Time

Stirring Time

[hours]

Sample Name

Measured Concentration in n-Octanol
[µg/L]

Measured Concentration in Water
[µg/L]

Log Pow

Mean

409

1

24152779

751

4.51

4.49

2

23897066

772

4.49

3

24460544

824

4.47

427

1

23778180

812

4.47

4.46

2

23532394

824

4.46

3

23999211

857

4.45

433

1

25106342

840

4.48

4.47

2

25332196

867

4.47

3

25227445

880

4.46

451

1

23818338

845

4.45

4.45

2

23527758

805

4.47

3

23643908

872

4.43

The tabulated values of the samples represent rounded results obtained by calculation using the exact data.

 

 Results obtained for log PowAverage Value

Experimental
Unit

i

Stirring Time

[hours]

Log Pow

Log Pow ,i

Statistical Weight of Uniti
Wi

Log Pow ,Av
±
σLog Pow ,Av

Unit 1

409

4.51

4.47

1.07 E-06

4.47
±0.01

427

4.47

433

4.48

451

4.45

Unit 2

409

4.49

4.47

4.18 E-07

427

4.46

433

4.47

451

4.47

Unit 3

409

4.47

4.45

5.24 E-07

427

4.45

433

4.46

451

4.43

The tabulated values of the samples represent rounded results obtained by calculation using the exact data.

 

 Calculation of Mass Balance for the First Experimental Unit

 

n-Octanol

Water

Stirring Time [hours]

Measured Concentration [µg/L]

Sample Volume
[ml]

Amount Test Item
[µg]

Measured Concentration [µg/L]

Sample Volume ** [ml]

Amount Test Item [µg]

113.5

24200763

0.1

2420

196

12.5

2.45

119.5

25600658

0.1

2560

251

12.9

3.22

138.5

25146934

0.1

2515

284

13.0

3.70

144.5

25600080

0.1

2560

321

9.66

3.10

162.5

24265064

0.1

2427

402

11.7

4.70

168

25101467

0.1

2510

410

11.1

4.53

283

28693855

0.1

2869

649

12.6

3.79

289

27233100

0.1

2723

676

9.53

3.74

307

28511180

0.1

2851

703

8.11

4.41

313

27367971

0.1

2737

758

10.9

3.17

409

24152779

0.1

2415

751

9.37

4.62

427

23778180

0.1

2378

812

11.0

5.63

433

25106342

0.1

2511

840

10.3

4.82

451

23818338

0.1

2382

845

10.7

6.55

457a

24054715

0.1

2405

897

11.5

7.81

 

 

+ 48.5*

+ 1166654*

 

+ 625*

+ 561*

 

Measured total amount

1204917

Measured total amount

655

The tabulated values of the samples represent rounded results obtained by calculation using the exact data.

* amounts remaining in test vessel after last sampling

** including dead volume in the sampling pipe

a: the log Powdetermined for this stirring time was not used for the calculation of the average log Pow. The equilibrium was achieved for the 4 previous measurements and still stable till 457 hours stirring (slope not significantly different from 0).

  

Mass Balance for Determination of Log Pow

Test

Measured Total Amount in n-Octanol
[µg]

Measured Total Amount in Water
[µg]

Measured Total amount both phases

[µg]

Added total amount

[µg]

Recovery


[%]

1

1204917

655

1205572

1282050

94

2

1261170

630

1261801

1282050

98

3

1261395

677

1262072

1282050

98

The tabulated values of the samples represent rounded results obtained by calculation using the exact data.

 

Applicant's summary and conclusion

Conclusions:
During this study, the partition coefficient (n-octanol/water) log Pow of the test item TRIISONONYLAMINE was determined using the slow-stirring method.
The following value for the log Pow was obtained: 7.38 ± 0.02 at a mean pH value of 8.4 at 25°C.
Executive summary:

During this study the partition coefficient (n-octanol/water) log Pow of the test item TRIISONONYLAMINE was determined using the slow-stirring method (OECD 123) and following GLP. The slow-stirring method was used, because the shake flask method (OECD guideline no. 107, applicable for logPow values between -2 and 4) cannot be applied. The log Pow value was estimated to be 11.6 (KOWIN v1.67). The slow-stirring method is applicable for highly hydrophobic compounds. Due to the process of slowly stirring, the formation of n-octanol microdroplets in water is avoided, eliminating the risk of an apparently enhanced concentration of the test item in water and thus an underestimation of the log Pow value.

Thermostated glass flasks containing the aqueous phase and n-octanol were slowly stirred, after dosing the test item dissolved in n-octanol, until equilibrium distribution of the test item between the two phases was achieved. The temperature was kept constant (± 1 °C) at 25 °C. The concentration of the test item in the phases was measured by HPLC-MS/MS. From the measured concentrations, the partition coefficient (n-octanol/water) was calculated. The equilibrium distribution was achieved, when four sampling intervals yielded similar log Pow values (plateau with zero slope).

The following value for the log Pow was obtained: 7.38 ± 0.02 at a mean pH value of 8.4.