Reaction product of salicylaldehyde and formaldehyde and phenol

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 October 2018 to 07 November 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: A.24. “Partition Coefficient (n-octanol/water), High Performance Liquid Chromatography (HPLC) method.

Version / remarks:

Official Journal of the European Union L 54 of 01 March 2016.

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

> 6.5

Temp.:

25 °C

Remarks on result:

other: The main component of the test material is very strongly hydrophobic.

Details on results:

RESULTS OF THE PRELIMINARY TESTS
During the applied conditions, several peaks were detected from the test material in case of both aqueous and ACN samples. The sample in the organic solvent contained the same components as the saturated sample in water during the normal study period sufficient for chemicals of log Pow slightly above 6.5.
Because the two phases deviated from each other significantly visually, but the same components were detected, it is presumed, that only the water soluble (minor) components were detected from the organic solvent in the standard HPLC method. The main components appear not to have eluted from the column.
 
RESULT OF THE MAIN TEST
The three calibration series (reference solutions) and three test material series were measured using the standard conditions (Mobile Phase 1). The partition coefficient Pow was determined based on a calibration curve using six reference substances.
The capacity factors k were calculated from the dead time and retention times of the reference substances. The log k data of the reference substances were plotted against their log Pow values. The equation of the curve fitted to the calibration points is as follows:
 
log Pow = 2.518 × log k + 1.8675 (R² = 0.9358)
 
RESULT OF THE FURTER FEASIBILITY TEST
Considering the results of the Main test, only the minority water soluble fractions of the test material were detected, the main part of the test material (insoluble in water based on the visual assessment) was not determined during the Main test.
Therefore, additional conditions to the standard were applied in order to detect the presumed main component.
At three different specific wavelengths (200, 280 and 410 nm) the test material was applied using a gradient elution with 100% ACN content. The initial period was the same than in the main test; the same peaks were detected as previously. In further examinations, other peaks were detected at times about 10 times the duration for substances of log Pow of 6.5. The test material chromatograms were compared to the eluent using the three different wavelengths for detection.

Conclusions:

Under the conditions of the study it is considered that the main (or major) component is very strongly hydrophobic. Water soluble minor fractions were detected in the HPLC system, with log Pow value between 1 and 2.2. The HPLC estimation method is suitable within the range of 0 and 6.5. It is concluded that the main test material substance has a log Pow of >> 6.5.

Executive summary:

The partition coefficient of the test material was assessed in accordance with the standardised guidelines OECD 117 and EU Method A.24 under GLP conditions, using a high performance liquid chromatography method.

The highly coloured test material was not soluble in water and was not detectable in this HPLC method in the range up to log Pow 6.5. The test material was fully soluble in acetonitrile.

Water soluble minor fractions were detected in the HPLC system, several detectable components were found with log Pow values between 1 and 2.2.

Under the conditions of the study it is considered that the main (or major) component is very strongly hydrophobic. Water soluble minor fractions were detected in the HPLC system, with log Pow value between 1 and 2.2. The HPLC estimation method is suitable within the range of 0 and 6.5. It is concluded that the main test material substance has a log Pow of >> 6.5.

Description of key information

Under the conditions of the study it is considered that the main (or major) component is very strongly hydrophobic. Water soluble minor fractions were detected in the HPLC system, with log Pow value between 1 and 2.2. The HPLC estimation method is suitable within the range of 0 and 6.5. It is concluded that the main test material substance has a log Pow of >> 6.5.

Additional information

The partition coefficient of the test material was assessed in accordance with the standardised guidelines OECD 117 and EU Method A.24 under GLP conditions, using a high performance liquid chromatography method. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

The highly coloured test material was not soluble in water and was not detectable in this HPLC method in the range up to log Pow 6.5. The test material was fully soluble in acetonitrile.

Water soluble minor fractions were detected in the HPLC system, several detectable components were found with log Pow values between 1 and 2.2.

Under the conditions of the study it is considered that the main (or major) component is very strongly hydrophobic. Water soluble minor fractions were detected in the HPLC system, with log Pow value between 1 and 2.2. The HPLC estimation method is suitable within the range of 0 and 6.5. It is concluded that the main test material substance has a log Pow of >> 6.5.