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Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Experimental starting date: 28 March 2017 Experimental completion date: 22 June 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method A.8 (Partition Coefficient - Shake Flask Method)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of method:
flask method
Partition coefficient type:
octanol-water

Test material

Constituent 1
Chemical structure
Reference substance name:
Sodium glyoxylate
EC Number:
220-298-8
EC Name:
Sodium glyoxylate
Cas Number:
2706-75-4
Molecular formula:
C2H2O3.Na
IUPAC Name:
sodium oxoacetate
Specific details on test material used for the study:
Identification: Safelink SPM-01
Appearance/Physical state: colorless to slightly yellow powder
Batch: G150201
Purity: 99.9%
Expiry date: not supplied
Storage conditions: room temperature, in the dark

Study design

Analytical method:
photometric method

Results and discussion

Partition coefficient
Key result
Type:
log Pow
Partition coefficient:
2.2
Temp.:
22 °C
pH:
6.8
Details on results:
Preliminary Estimate
The log10 Pow was calculated to be: -5.21

Discussion
The determination of partition coefficient was performed using the shake-flask method. This
was due to the expected partition coefficient obtained in the preliminary assessment.
The stock solution was prepared in n-octanol saturated water in place of water saturated
n-octanol. This was due to the insolubility of the test item in the organic phase. This issue
has been considered to have had a negligible impact on the overall result and has been
considered to be more appropriate to obtain a realistic partition coefficient value.
As there was no definitive test item detected in the organic phases, a limit valve for the
sample concentrations was taken based on the organic phase sample with the highest
absorbance. This result was corrected for the absorbance of the organic phase matrix blank
extract. This approach provided a worst case scenario and resulted in the final result being a
limit value. Although the test item was a complex mixture, it is considered that the test result
represents the test item as a whole.

Validation
The linearity of the detector response with respect to concentration was assessed over the
nominal concentration ranges of 5 to 50 mg/L (organic phases) and 50 to 500 mg/L (aqueous
phases). The results were satisfactory with a correlation coefficient (r) of 0.998 and 0.999
being obtained respectively.

Any other information on results incl. tables

Results

The partition coefficient determined for each flask is shown in the following table:

Flask Organic/ Aqueous
Volume Ratio		 Partition Coefficient Log10 Pow Mean Partition Coefficient
1 02:01 ≤6.00 x 103 ≤2.22 ≤2.22
2 ≤5.98 x 103 ≤2.22
3 04:01 ≤5.82 x 103 ≤2.24 ≤2.22
4 ≤6.08 x 103 ≤2.22
5 08:01 ≤6.02 x 103 ≤2.22 ≤2.22
6 ≤6.30 x 103 ≤2.22

Overall Pow : ≤6.30 x 10-3

Overall log10 Pow : ≤2.20

Applicant's summary and conclusion

Conclusions:
The partition coefficient of the test item has been determined to be less than or equal to be
6.30 x 10-3 at 22.0 ± 0.5 °C, log10 Pow of ≤2.20.
Executive summary:

Less than or equal to be 6.30 x 10-3 at 22.0 ± 0.5 °C,

log10 Pow of ≤2.20, using the shake-flask method, designed to be compatible with Method A.8

Partition Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and

Method 107 of the OECD Guidelines for Testing of Chemicals, 13 April 2004.