Octan-1-ol

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-04-30

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

Test procedure in accordance with national standard methods (OECD) without GLP.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

The test substance is a mixture of Alcohols, C8-10. But the result is for octan-1-ol because chromatography (column elution) method was used during the study.

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

3.5

Temp.:

23 °C

pH:

5.7

Calibration

For calibration 20 -30 mg of the reference samples are weighed into a 100 ml columetric flask and filled up to 100 ml with the mobile phase. The calibration mixture (L090443) is analysed twice and the average retention times are given in the table. The individual values are reported in the attached chromatographic reports.

correlation log k und Pow

slope: 2.01

axis intercept: 2.28

correlations coefficient: 0.998

Measurement (repeat determination)

200 -300 mg of the test sample are weighed into a 100 ml volumetric flask and filled up to 100 ml with methanol.

retention time (minutes) for C8: 6.69 / 6.72

peak area C8: 87294 / 87238

capacity factor k C8: 4.03 / 4.05

log k C8: 0.61 / 0.61

log POW C8: 3.5 / 3.5

retention time (minutes) for C10: 21.57 / 21.66

peak area C10: 110201 / 115120

capacity factor k C10: 15.22 / 15.28

log k C10: 1.18 / 1.18

log POW C10: 4.7 / 4.7

Conclusions:

Fatty alcohol 810, a mixture of octan-1 -ol and decan-1 -ol was determined according OECD Guideline 117. The partition coefficients were determined for octan-1-ol: 3.5 and for decan-1-ol: 4.7 at 25 °C with a pH of 5.7.

Executive summary:

Fatty alcohol 810, a mixture of octan-1 -ol and decan-1 -ol was determined according OECD Guideline 117. The partition coefficients were determined for octan-1-ol: 3.5 and for decan-1-ol: 4.7 at 25 °C with a pH of 5.7.

Description of key information

The octanol-water partition coefficient of octan-1-ol is 3.5 (by HPLC method)

Key value for chemical safety assessment

Log Kow (Log Pow):

3.5

at the temperature of:

23 °C

Additional information

A log n-octanol/water partition coefficient of octan-1-ol has been determined using a sample of a commercial UVCB alcohol (Alcohols, C8-10). A log K_ow value of 3.5 at 23°C and pH 5.5 was determined for the octan-1-ol constituent using HPLC (column elution) method in accordance with OECD 117 Test Guideline. The result is considered to be reliable.

It is supported by a second HPLC value of 2.7 using a different commercial product, and values of 3.0 - 3.15, taken from a reliable and definitive reference source for partitioning data (Hansch and Leo, 1995).

The value of 3.15 taken from literature for pure octan-1-ol is used in exposure modelling.

Discussion of trends in the Category of C6-24 linear and essentially-linear aliphatic alcohols:

As chain length increases, the free energy required for a molecule to dissolve becomes less favourable for larger molecules. The octanol-water partition coefficient increases with molecular weight because each additional -CH₂- group makes the octanol phase more preferred over water in terms of relative solvation energy.