Alcohols, C8-10, ethoxylated, sulfates, ammonium salts

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 Jan - 5 Feb 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 123 (Partition Coefficient (1-Octanol / Water), Slow-Stirring Method)

GLP compliance:

no

Type of method:

slow-stirring method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

1.067

Temp.:

25 °C

pH:

9

Remarks on result:

other: RSD = 0.47 %

Study results:

The concentration of the test item in the water and 1-octanol phase was determined after 90, 92, 94 and 96 hours, ensuring that an equilibrium concentration was established in both phases. At each test time, three different test solutions were analyzed. The concentrations of the test item in the different test solutions are listed below:

Test solution	Weighed sample, mg	Volume 1-octanol, mL
1	804.0	40 (32.8 g)
2	804.8	40 (32.8 g)
3	804.6	40 (32.8 g)

Measured concentrations of the test item in the 1-octanol and buffer solution phases of the three different test solutions at 4 different times are summarized in the following 2 tables.

Time, h	Test solution 1, test item in mg/g 1-octanol	Test solution 2, test item in mg/g 1-octanol	Test solution 3, test item in mg/g 1-octanol
90	8.538	8.968	8.429
92	9.003	9.137	8.634
94	8.678	8.775	8.759
96	9.203	8.977	9.075
Mean	8.855	8.964	8.724

Time, h	Test solution 1, test item in mg/g buffer solution	Test solution 2, test item in mg/g buffer solution	Test solution 3, test item in mg/g buffer solution
90	0.7533	0.7601	0.7534
92	0.7571	0.7618	0.7633
94	0.7512	0.7584	0.7559
96	0.7650	0.7665	0.7584
Mean	0.7566	0.7617	0.7578

Equilibrium for all test solutions was established. The mass balance could be calculated on the basis of the measured concentrations of the test item (found value) and the corrected real sample weights of test item in 40 mL 1-octanol and 700 mL buffer solution after 96 hours.

	Test solution 1	Test solution 2	Test solution 3
Weighed sample, mg	747.6	1113	1119
Found value, mg in 40 mL 1-octanol	296.8	289.7	292.7
Found value, mg in 700 mL buffer solution	533.9	536.5	531.3
Recovery, %	111.1	110.2	109.8

The calculated value considers the real sample weight and the three time points of measurement before the 96 hours measurement. The real sample weight has to be corrected for the amounts of test item that has been removed from the octanol and aqueous phases for measurement.

Subsequently, the ratios of concentrations and their logarithms were calculated.

Time, h	Test solution 1		Test solution 2		Test solution 3
	co/cw	log (co/cw)	co/cw	log (co/cw)	co/cw	log (co/cw)
90	11.33	1.054	11.80	1.072	11.19	1.049
92	11.89	1.075	11.99	1.079	11.31	1.053
94	11.55	1.063	11.57	1.063	11.59	1.064
96	12.03	1.080	11.71	1.069	11.97	1.078

The resulting mean values for the different test solutions are listed below.

Test solution	Mean value co/cw	Standard deviation	Mean value log (co/cw)	Standard deviation
1	11.70	0.317	1.068	0.012
2	11.77	0.178	1.071	0.007
3	11.51	0.345	1.061	0.013
mean	11.66		1.067
RSD	1.14%		0.47%

Description of key information

log Pow  = 1.067 at 25 °C, pH = 9

Key value for chemical safety assessment

Log Kow (Log Pow):

1.067

at the temperature of:

25 °C

Additional information

The partition coefficient of the substance was determined using slow stirring method according to OECD 123.