Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guidelineopen allclose all
according to guideline
EU Method A.8 (Partition Coefficient - HPLC Method)
according to guideline
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
GLP compliance:
Type of method:
HPLC method
Partition coefficient type:

Test material

Constituent 1
Chemical structure
Reference substance name:
ethyl (2S)-3-[3,5-diamino-4-(4-methoxyphenoxy)phenyl]-2-acetamidopropanoate
Cas Number:
Molecular formula:
ethyl (2S)-3-[3,5-diamino-4-(4-methoxyphenoxy)phenyl]-2-acetamidopropanoate
Test material form:
solid: particulate/powder

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficient
Key result
log Pow
Partition coefficient:
25 °C
> 5 - < 6

Applicant's summary and conclusion

The log POW of the test item L-Tyrosine, N-acetyl-3,5-diamino-O-(4-methoxyphenyl)-, ethyl ester is stated as 0.9 (mean).
Executive summary:

The study was performed using a HPLC with a C18 column. Six reference items with differ-ent retention times and thiourea for the determination of the dead time were used to pro-duce a calibration curve, since retention time on hydrophobic columns and POW are corre-lated. The reference items were chosen based on the results of the pre-test.

One vial was filled with the reference item mix and one vial with the test item solution. The vials were analysed using the HPLC with the program described below (chapter 4.3.2). First one injection from the solvent blank methanol/water 65/35 (v/v) was made. Then three in-jections were measured from the reference item mix, three injections from the test item and again three injections from the reference item mix. The pH of the eluent was 5 6, deter-mined with indicator paper.

For each reference item, the capacity factor k was calculated from the retention time of thiourea and the retention time of the respective reference item.
A calibration function (log k versus log POW, linear fit) was determined using the literature values for POW of the reference items and the retention times in the six determinations.

The chromatogram of the test item L-Tyrosine, N-acetyl-3,5-diamino-O-(4-methoxyphenyl)-, ethyl ester gave one peak with a retention time of 2.206 min (mean).
With the calibration function log k versus log POW, the corresponding log POW of the peak was calculated with: 0.912 ± 0.002 (mean ± standard deviation).
Therefore, the log POW of the test item L-Tyrosine, N-acetyl-3,5-diamino-O-(4-methoxyphenyl)-, ethyl ester is stated as 0.9 (mean).