Reaction products of propane-1,2-diamine with 2-[(2-methylphenoxy)methyl]oxirane

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 2016-01-21 to 2018-08-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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 - HPLC Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7570 (Partition Coefficient, n-octanol / H2O, Estimation by Liquid Chromatography)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

mass spectrometry

Key result

Type:

Pow

Partition coefficient:

>= 337 - <= 4 585

Temp.:

20 °C

pH:

8.5

Key result

Type:

log Pow

Partition coefficient:

>= 2.53 - <= 3.66

Temp.:

20 °C

pH:

8.5

Details on results:

The partition coefficient of the test item was determined using HPLC. The constituents of the test item were identified by HPLC-MS analysis.
The calculated log Pow value for 1-((2-Amino-2-methylethyl)amino)-3-(2-methylphenoxy)propan-2-ol and 1-((2-Amino-1-methylethyl) amino)-3-(2-methylphenoxy)propan-2-ol (first eluting peak of the test item at retention time 5.07 min) was 2.53. These two constituents differ only in the position of one methyl group and the isomers cannot be separated with the current chromatographic method and co-eluate in one peak. It is concluded that the determined log Pow is valid for both isomers.
The calculated log Pow value for 3,3’-(Propane-1,2-diylbis(azanediyl))bis(1-(2-methylphenoxy)propan-2-ol) (second eluting peak of the test item at retention time 7.33 min) was 3.38.
The calculated log Pow value for 1,3-Bis(2-methylphenoxy)propan-2-ol (last eluting peak of the test item at retention time 8.48 min) was 3.66.

The equation of the calibration curve fitted to the calibration points was as follows:

log k = 0.323 * log Pow - 0.800 (Rsq = 0.92)

Table 1.: Measured and calculated data for each component of the test item

Test iem	Retention time (min)		log k		log Pow		Pow		Repeatability log unit
			Calculated
1-((2-Amino-2-methyl ethyl)amino)-3-(2-methyl phenoxy)propan-2-ol and 1-((2-Amino-1-methyl ethyl)amino)-3-(2-methyl phenoxy)propan-2-ol	5.06		0.017		2.53		337		0.01
	5.06		0.017		2.53		337
	5.08		0.021		2.54		345
	5.07		0.019		2.53		341
	5.07		0.019		2.53		341
	5.07		0.019		2.53		341
Mean	5.07		0.019		2.53		340
CV%	0.15		-		-		-
Test item	Retention time (min)		log k		log Pow		Pow		Repeatability log unit
			Calculated
3,3’-(Propane-1,2-diylbis (azanediyl))bis(1-(2-methyl phenoxy)propan-2-ol)	7.31		0.289		3.37		2344		0.01
	7.32		0.290		3.37		2359
	7.34		0.292		3.38		2389
	7.34		0.292		3.38		2389
	7.33		0.291		3.38		2374
	7.34		0.292		3.38		2389
Mean	7.33		0.291		3.38		2374
CV%	0.17		-		-		-
Test item		Retention time (min)		log k		log Pow		Pow		Repeatability log unit
				Calculated
1,3-Bis(2-methylphenoxy) propan-2-ol		8.48		0.384		3.66		4585		0.00
		8.48		0.384		3.66		4585
		8.47		0.383		3.66		4562
		8.47		0.383		3.66		4562
		8.48		0.384		3.66		4585
		8.48		0.384		3.66		4585
Mean		8.48		0.383		3.66		4578
CV%		0.06		-		-		-

Table 2.: Constituents of the test item

Component	m/z
1,3-Bis(2-methyl phenoxy)propan-2-ol	272.3389
3,3'-(Propane-1,2-diylbis(azanediyl))bis (1-(2-methylphenoxy) propan-2-ol)	402.52706
1-((2-Amino-1-methylethyl)amino)-3-(2-methylphenoxy) propan-2-ol	238.32598
1-((2-Amino-2-methylethyl)amino)-3-(2-methylphenoxy) propan-2-ol	238.32598

Conclusions:

The log Pow of the constituents of the test item was determined to be 2.53, 3.38 and 3.66, respectively.

Executive summary:

A study was conducted in accordance with OECD TG 117 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLC method. The constituents of the test item were determined by HPLC-MS analysis. A solution of the test substance was prepared in acetonitrile at ca. 2 mg/mL concentration level and was diluted with the mobile phase to 1000 µg/ml solution. After equilibration of the HPLC system, the three calibration series and three test item series were measured alternately. Retention times tR were measured and averaged and the decimal logarithms of the capacity factors k were calculated. The linear regression parameters of the relationship log Pow = f(log k) were also calculated from the data obtained with the calibration mixture and, therewith, log Pow of the test substance was determined from its measured capacity factor. The value found for the partition coefficients n-octanol/water for the main constituents was 2.53. The minor constituents had log Pow of 3.38 and 3.66, respectively.

Description of key information

The log Pow of the constituents of the test item was determined to be 2.53, 3.38 and 3.66, respectively. As key value the log Pow of the main constituents was chosen (= 2.53).

Key value for chemical safety assessment

Log Kow (Log Pow):

2.53

at the temperature of:

20 °C

Additional information

A study was conducted in accordance with OECD TG 117 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLC method. The constituents of the test item were determined by HPLC-MS analysis. A solution of the test substance was prepared in acetonitrile at ca. 2 mg/mL concentration level and was diluted with the mobile phase to 1000 µg/ml solution. After equilibration of the HPLC system, the three calibration series and three test item series were measured alternately. Retention times tR were measured and averaged and the decimal logarithms of the capacity factors k were calculated. The linear regression parameters of the relationship log Pow = f(log k) were also calculated from the data obtained with the calibration mixture and, therewith, log Pow of the test substance was determined from its measured capacity factor. The value found for the partition coefficients n-octanol/water for the main constituents was 2.53. The minor constituents had log Pow of 3.38 and 3.66, respectively.