Registration Dossier

Physical & Chemical properties

Partition coefficient

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
partition coefficient
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Justification for type of information:
QSAR prediction
Principles of method if other than guideline:
Method: (calculated) Calculation using EpiWin version 4.10.
GLP compliance:
no
Type of method:
other: QSAR
Partition coefficient type:
octanol-water
Key result
Type:
log Pow
Partition coefficient:
6.68
Temp.:
20 °C
Remarks on result:
other: calculated with Kow win v.1.67
Conclusions:
As the testing of the log Pow was technically not feasable, the value was calculated with the accepted calculation programme KOWWIN 1.67. Log Pow = 6.68
Executive summary:

As the testing of the log Pow was technically not feasable, the value was calculated with the accepted calculation programme KOWWIN 1.67. Log Pow = 6.68

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2009-10-30 to 2009-10-31
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
OECD 117, GLP
Qualifier:
according to
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Version / remarks:
(2004)
Deviations:
yes
Remarks:
minor; Sodium nitrate was used instead of an organic substance for the determination of the dead time (reason: small inorganic molecule has less interaction on a reversed phase chromatographic column than organic substances. Standards injected separately.
Qualifier:
according to
Guideline:
EU Method A.8 (Partition Coefficient)
Version / remarks:
Council Regulation (EC) No. 440/2008
Deviations:
yes
Remarks:
minor; Sodium nitrate was used instead of an organic substance for the determination of the dead time (reason: small inorganic molecule has less interaction on a reversed phase chromatographic column than organic substances. Standards injected separately.
Principles of method if other than guideline:
The partition coefficient (P) is defined as the ratio of the equilibrium concentrations (c) of a dissolved substance in a two-phase system consisting of
two largely immiscible solvents. In the case n-octanol and water:
Pow = C n-octanol / C water
The partition coefficient therefore is the quotient of two concentrations and is usually given in the form of its logarithm to base 10 (log P).
For preliminary information the following calculated value was available (estimation software EPIWIN): log Pow = 5.62 (calculation was made with the measured boiling point: 263°C and the measured melting point (glas transition temperature): -116°C)
As the HPLC method is applicable when the log Pow value falls within the range 0 to 6, that method was chosen for the determination of the partition
coefficient. HPLC is performed on analytical columns packed with a commercially available solid phase containing long hydrocarbon chains chemically bound onto silica. Chemicals injected onto such a column move along it at different rates because of the different degrees of partitioning between
the mobile phase and the hydrocarbon stationary phase. Mixtures of chemicals are eluted in order of their hydrophobicity, with water-soluble
chemicals eluted first and oil-soluble chemicals last, in proportion to their hydrocarbon-water partition coefficient. This enables the relationship
between the retention time on such a (reverse phase) column and the n-octanol / water partition coefficient to be established. The partition
coefficient is deduced from the capacity factor k', given by the expression
t(r) - t(0)
k'= -------------
t(0)
in which, t(r) = retention time of the test substance, and t(o) = average time a solvent molecule needs to pass through the column (dead time).

The test substance was dissolved in n-octanol and water at varying concentrations and analzyed by HPLC. The elution times were used to calculate
the capacity factor k', from which the partition coefficient was deduced.
GLP compliance:
yes
Type of method:
HPLC method
Partition coefficient type:
octanol-water
Specific details on test material used for the study:
- Name of test material (as cited in study report): Isodecyl methacrylate
- Substance type: organic
- Physical state: liquid
Analytical method:
high-performance liquid chromatography
Key result
Type:
log Pow
Partition coefficient:
>= 6.45 - <= 7.44
Temp.:
22 °C
pH:
ca. 7
Remarks on result:
other: According to OECD 117 and EU test method A.8. 8 Isomers of the test item Isodecyl methacrylate were detected during the determination of the partition coefficient. The log Pow was reported to be 6.45, 6.66, 6.88, 6.97, 7.08, 7.35 and 7.44.
Details on results:
Eight components (chain length isomers) were detected. Since the highest log Pow of the reference items is 6.50 (4.4'-DDT) the results for the
isomers were extrapolated.

Temperature [°C]

Mean

22.3

Min

22.2

Max

22.7

 

Dead Time

Serial no.

To [min]

1

0.447

2

0.447

3

0.448

Mean

0.447

 

Calibration Data of the Reference Items

Reference item

tR

 [min]

tRMean

[min]

k

Log k

Log Pow

2-Butanone

0.595

0.594

0.595

0.329

-0.483

0.30

Acetanilide

0.760

0.760

0.760

0.699

-0.156

1.00

Anisole

1.144

1.145

1.145

1.558

0.193

2.10

Benzophenone

1.351

1.353

1.352

2.022

0.306

3.20

Naphthalene

1.688

1.688

1.688

2.773

0.443

3.60

Biphenyl

2.000

2.000

2.000

3.471

0.540

4.00

DDT

4.901

4.905

4.903

9.961

0.998

6.50

tR           :Retention time

k         : Capacity factor reference item

Pow    : Partition Coefficient (n-octanol / water) acc. guideline

Isodecyl methacrylate

 

tR

[min]

k

Log k

Log Pow

delta

log Pow

Peak Area

[%]

Isomer 1

5.891

5.907

12.169

12.205

1.085

1.087

6.44

6.45

0.01

1.61

1.44

Mean

 

6.45

 

1.52

Isomer 2

6.569

6.574

13.685

13.696

1.136

1.137

6.66

6.66

0.00

0.75

0.80

Mean

 

6.66

 

0.78

Isomer 3

7.338

7.341

15.404

15.411

1.188

1.188

6.88

6.88

0.00

7.63

7.54

Mean

 

6.88

 

7.59

Isomer 4

7.676

7.678

16.159

16.164

1.208

1.209

6.96

6.97

0.01

23.6

23.2

Mean

 

6.97

 

23.4

Isomer 5

8.168

8.167

17.259

17.257

1.237

1.237

7.08

7.08

0.01

42.0

41.4

Mean

 

7.08

 

41.7

Isomer 6

8.440

8.449

17.867

17.887

1.252

1.253

7.15

7.15

0.00

11.2

11.1

Mean

 

7.15

 

11.2

Isomer 7

9.324

9.348

19.844

19.897

1.298

1.299

7.34

7.35

0.01

11.7

12.1

Mean

 

7.35

 

11.9

Isomer 8

9.806

9.834

20.921

20.984

1.321

1.322

7.44

7.44

0.00

1.43

2.27

Mean

 

7.44

 

1.85

tR           :Retention time

k         : Capacity factor reference item

Pow    : Partition Coefficient (n-octanol / water) acc. guideline

Conclusions:
The partition coefficient n-octanol / water (Pow) of Isodecyl methacrylate was determined according to OECD guideline 117 and EU test method A.8 with the HPLC method. Eight isomers of the test item Isodecyl methacrylate were detected during the determination of the partition coefficient (n-octanol/water) log Pow. The partition coefficient n-octanol / water (Pow) was reported to be 6.45, 6.66, 6.88, 6.97, 7.08, 7.35 and 7.44. The results of isomer 2 to isomer 8 were extrapolated. The main component (isomer 5) has an estimated log Pow of 7.08.
Executive summary:

The partition coefficient n-octanol / water (Pow) of Isodecyl methacrylate was determined according to OECD guideline 117 and EU test method A.8 with the HPLC method. Eight isomers of the test item Isodecyl methacrylate were detected during the determination of the partition coefficient (n-octanol/water) log Pow. The partition coefficient n-octanol / water (Pow) was reported to be 6.45, 6.66, 6.88, 6.97, 7.08, 7.35 and 7.44.The results of isomer 2 to isomer 8 were extrapolated. The main component (isomer 5) has an estimated log Pow of 7.08.

The retention times of these eight isomers of the test item Isodecyl methacrylate were between 5.9 and 9.8 minutes. These retention times correspond to partition coefficients (n-octanol/water) between log Pow = 6.45 and 7.44.

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Description of key information

Log Pow 6.68, calculated with KOWWIN v1.68

Key value for chemical safety assessment

Log Kow (Log Pow):
6.68
at the temperature of:
20 °C

Additional information

Read across from structural analogue substance Isodecyl methacrylate CAS: 29964 -84 -9:

The experimental log Pow was determined with 6.45 to 7.44, where the main constituent Isodecyl methacrylate has a log Pow of 7.44. The calculated log Pow of Dodecyl methacrylate (KOWWIN 1.68) is 6.68. Compared with the measured value Isodecyl methacrylate the calculated log Pow of Dodecyl methacrylate is in the same order of magnitude and therefore the calculation method is valid for this group of substances.

Consequently, the calculated value of 6.68 for n-Dodecyl methacrylate is considered as valid.