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Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 26 SEP 2007 to 23 JAN 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

other: High performance liquid chromatograph (HPLC) with UV-VIS detector, reversed phase column and an aqueous mobile phase

Key result

Type:

log Pow

Partition coefficient:

0.89

Temp.:

25 °C

Remarks on result:

other: pH not reported

Details on results:

Six common standards, which have known log Pow values were used as reference standards. For the determination of the dead time a thiourea solution was used. From the regression curve (log k' vs. log Pow) the n-octanol / water partition coefficient (log Pow) of DIMETHYL 2-METHYL GLUTARATE was calculated and found to be log Pow = 0.89

Table 1: Retention Times in Minutes of the Reference Items and the Test Item

 

	Number of analysis	Mean retention time (min)	k’	Log k’	Log Pow
Thiourea (= dead time)	2	1.93	-	-	-
Reference items:
4-Acetylpyridine Benzene Toluene Bromobenzene 1,4-Dichlorobenzene 1, 2, 4-Trichlorobenzene	6 6 6 6 6 6	2.82 5.81 8.67 9.53 12.87 23.45	0.46 2.01 3.49 3.94 5.67 11.16	-0.34 0.30 0.54 0.60 0.75 1.05	0.5 2.1 2.7 3.0 3.4 4.2
Slope = 0.372 Linear Regression:                                                     y-axis intercept = -0.5                                  Coefficient of regression (r) = 0.999

 

 

Table 2: Result of DIMETHYL 2-METHYL GLUTARATE analyses

 

Number of analysis	Retention time (min)	k’	Log k’	Log Pow	Mean log Pow
Test item peak
1 2 3	3.24 3.23 3.23	0.68 0.68 0.68	-0.16934 -0.17000 -0.17000	0.89 0.89 0.89	0.89

 

The tabulated values represent rounded results, which were obtained by calculation using the

exact raw data.

Conclusions:

Using the HPLC method, the n-octanol / water partition coefficient of DIMETHYL 2-METHYL GLUTARATE was determined to be log Pow = 0.89
Therefore, DIMETHYL 2-METHYL GLUTARATE is considered to have a low potential for bioaccumulation.

Executive summary:

The determination of the partition coefficient (n-octanol/water) of DIMETHYL 2-METHYL GLUTARATE was performed according to the EEC Directive 92/69, A.8 “Partition coefficient” (1992) and the OECD guideline No. 117, “Partition coefficient (n-octanol/water), High Performance Liquid Chromatography (HPLC) method” (2004).

During the preliminary test, the log Pow of DIMETHYL 2-METHYL GLUTARATE was estimated to be 1.3. Thus having the free choice between both methods, the HPLC-method was chosen to conduct the main test. Six common standards, which have known log Pow values in the range of 0.5 to 4.2, were used as reference standards during the main test.

The DIMETHYL 2-METHYL GLUTARATE solution was injected three times and the combined reference solution was injected six times. The thiourea solution was injected twice.

The log Pow was calculated using a regression curve (log k' vs. log Pow) and was found to be 0.89. Therefore, DIMETHYL 2-METHYL GLUTARATE is considered to have a low potential for bioaccumulation.

Description of key information

The log Pow was calculated using a regression curve (log k' vs. log Pow) and was found to be 0.89. Therefore, DIMETHYL 2-METHYL GLUTARATE is considered to have a low potential for bioaccumulation. 

Key value for chemical safety assessment

Log Kow (Log Pow):

0.89

at the temperature of:

25 °C

Additional information

One experimental study, scored as Klimisch 1, is available (Weissenfeld M., 2008) and selected as a key study.