Disodium 4,5-dihydroxybenzene-1,3-disulphonate

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 Feb 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EU A.24

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht Kaiser-Friedrich-Straße 7, 55116 Mainz, Germany

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 4,5-dihydroxybenzene-1,3-disulphonate

EC Number:

205-741-5

EC Name:

Disodium 4,5-dihydroxybenzene-1,3-disulphonate

Cas Number:

149-45-1

Molecular formula:

C6H6O8S2.2Na

IUPAC Name:

disodium 4,5-dihydroxybenzene-1,3-disulphonate

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

< 0.3

Temp.:

25 °C

pH:

6.5

Any other information on results incl. tables

Final Results

With the calculated capacity factors for the test item, each log Pow from the three determinations should be calculated. Finally, mean and standard deviation of the log Pow should be calculated.

This was not feasible here because k is negative. The retention time of the test item is lower than the retention time of thiourea, which was used for the determination of the dead time of the method. Therefore, the log Pow of the test item AF-378 is not calculable and stated as < 0.3.

Individual Results

Test Item AF-378: Measurement Data -

The retention times of the test item are presented in the following table:

Measurement	RT
	min
Measurement 1	1.344
Measurement 2	1.344
Measurement 3	1.335
Mean	1.341
Standard deviation	0.005

Calculated Values

The calculated values are presented in the following table:

Measurement	k	log k	log POW
Measurement 1	-0.0918	not calculable*	not calculable*
Measurement 2	-0.0918	not calculable*	not calculable*
Measurement 3	-0.0978	not calculable*	not calculable*

* Not calculable, because k is negative. The retention time of test item is lower than the retention time of thiourea, which was used for the determination of the dead time of the method.

 

For each reference item, the calculated capacity factors are presented in the following table.

Compound	Retention Time Mean	Retention T ime Stand.Dev.	RetentionTime Relative Stand. Dev.	k
	min	min	%
Thiourea	1.480	0.003	0.214	0.0000
2-Butanone	1.967	0.003	0.144	0.3292
Benzylalcohol	2.373	0.005	0.214	0.6038
Acetophenone	2.970	0.010	0.347	1.0069
Nitrobenzene	3.535	0.016	0.457	1.3891
Benzene	5.031	0.029	0.581	2.4000
Toluene	8.065	0.066	0.815	4.4502

Validity of Results

The test item showed one peak with a retention time 1.341 min with a very low standard deviation of 0.005 min. The determination was precise. The calculation of the log Pow of the test item peak is not possible, because the retention time of the test item peak was lower than the retention time of thiourea (1.480 min). The log Pow of the test item AF-378 is stated as < 0.3.

 

Discussion of Results

Variations in the retention times of reference items and test item are very small. Therefore, a stable configuration of the HPLC-column can be assumed. As the calculated log Pow of the test item peak lay below the lowest log Pow of the reference items (2-Butanone with log Pow 0.3), the log Pow of this peak is stated as < 0.3. No observations were made which might cause doubts concerning the validity of the study outcome.