2-(cyclohexylamino)ethanesulphonic acid

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-05-10 to 2016-05-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

27 July 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Deviations:

no

Principles of method if other than guideline:

The preliminary partition coefficient (log Pow) was estimated using a preliminary screening test. The main test was not performed because the preliminary log Pow is not in the applicable range of the method.

GLP compliance:

yes

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

ca. -2.2

Temp.:

20 °C

Remarks on result:

other: pH value was not determined as it was a preliminary screening test

Details on results:

The estimated Particion Coefficient was calculated as the ratio of the concentrations of the test substance in water and n-octanol (without pH correction).

The difference between the assumed maximal concentration and the measured concentration of the substance in water corresponds to the concentration of the substance in n-octanol:

Measurement	Assumed maximal concentration [mg/mL]	Measured concentration in water phase [mg/mL]	Indirectly determined concentration n-octanol phase [mg/mL]
1	1.920	1.904	0.017
2	1.388	1.382	0.007

The Partition Coefficient was calculated using the formula: P_OW= c (n-octanol) / c (water).

Measurement	POW	log POW
1	0.00867	-2.06
2	0.00471	-2.33

The mean value of the log P_OW was determined as -2.20.

Conclusions:

The partition coefficient of the test item was calculated from the solubilities of the test item in 1-octanol and water to be Pow = 0.00669 and the log Pow = -2.2.

Executive summary:

A study was conducted in accordance with OECD TG 107 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance. As the test substance is a zwitterionic compound and dissociated at any pH value the test, the partition coefficient could not be determined of the non-dissociated compound, as would be required by the guidelines. Therefore, the partition coefficient was calculated from the solubilities of the test item in 1-octanol and water. The water and 1-octanol samples were analysed using HPLC. The partition coefficient of the test item was calculated to be Pow = 0.00669 and the log Pow = -2.2.

Description of key information

The partition coefficient of the test item was calculated from the solubilities of the test item in 1-octanol and water to be Pow = 0.00669 and the log Pow = -2.2 (reference 4.7 -1).

Key value for chemical safety assessment

Log Kow (Log Pow):

-2.2

at the temperature of:

20 °C

Additional information

A study was conducted in accordance with OECD TG 107 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance. As the test substance is a zwitterionic compound and dissociated at any pH value the test, the partition coefficient could not be determined of the non-dissociated compound, as would be required by the guidelines. Therefore, the partition coefficient was calculated from the solubilities of the test item in 1-octanol and water. The water and 1-octanol samples were analysed using HPLC. The partition coefficient of the test item was calculated to be Pow = 0.00669 and the log Pow = -2.2.