Dodecyl methacrylate

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

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

Reference 2

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

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

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

t_{R           :}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

t_{R           :}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.