Hexanamide, N-(2-hydroxyethyl)-3,5,5-trimethyl-

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012/07/16 - 2013/03/22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Principles of method if other than guideline:

Shake flask method was found to not be feasible; therefore, according to the guideline, solubilities in each solvent were measured and a ratio was reported.

GLP compliance:

no

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

4.4

Temp.:

25 °C

pH:

5.7

Remarks on result:

other: estimated based on solubility ratios

Details on results:

An emulsion of substance with n-octanol and water was formed, with a peak on the solvent front, visible on LC-MS. The peak did not appear in water and solvent blanks. It was determined that this could be due to hydrolysis products. It was learned that the substance is surface active. Therefore, an alternative method to estimate the log Kow was sought, as per the guideline method.
The solubility of test substance in water is 40 mg/l (by turbidity measurement). The octanol solubility was determined using a visual assessment. As the test substance is miscible at 90% (900000 mg/l), this value along with the water solubility value of 40 mg/l, was used to estimate the partition coefficient. Log P = log 900000/40 = 4.4.

Conclusions:

Under the study conditions, the partition coefficient of the test substance was determined to be 4.4 at 25 °C.

Executive summary:

A study was conducted to determine the partition coefficient of the test substance, using an estimation method according to EU Method A.8. The estimation method is based on the ratio of the individual solubilities in octanol and water. The solubility of test substance in water is 40 mg/L at 23°C, which was determined by turbidity measurement. The octanol solubility was determined using a visual assessment. As the test substance is miscible at 90% (900000 mg/L), this value along with the water solubility value of 40 mg/L, was used to estimate the partition coefficient. Log Kow = log 900000/40 = 4.4. Under the study conditions, the log partition coefficient (Log Kow) of the test substance was determined to be 4.4 at 25°C (Wicks, 2013).

Description of key information

The partition coefficient of the test substance was determined by using an estimation method (solubility ratio) according to the EU Method A.8 (Wicks, 2013).

Key value for chemical safety assessment

Log Kow (Log Pow):

4.4

at the temperature of:

25 °C

Additional information

estimated based on solubility ratios