5-amino-2-nitrobenzoic acid

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 - 21 August 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Version / remarks:

1995

Deviations:

yes

Remarks:

Based on the guideline, this test should be conducted with the non-ionised form. However, in the environmentally relevant pH range of 5 to 9, the amount of the non-charged species is negligible as the negatively charged species dominates.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Version / remarks:

Regulation (EC) No 440/2008

Deviations:

yes

Remarks:

Based on the guideline, this test should be conducted with the non-ionised form. However, in the environmentally relevant pH range of 5 to 9, the amount of the non-charged species is negligible, as the overall once negatively charged species dominates.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

5-amino-2-nitrobenzoic acid

EC Number:

236-283-4

EC Name:

5-amino-2-nitrobenzoic acid

Cas Number:

13280-60-9

Molecular formula:

C7H6N2O4

IUPAC Name:

5-amino-2-nitrobenzoic acid

impurity 1

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

Oxidane

impurity 2

Reference substance name:

Unknown impurities.

Molecular formula:

Not available as unknown impurities.

IUPAC Name:

Unknown impurities.

Test material form:

solid

Details on test material:

Batch / Lot No. 10044431

Specific details on test material used for the study:

Batch no.: 10044431
Storage: At room temperature, protected from light

Study design

Analytical method:

liquid chromatography

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

< -1.48

pH:

7

Remarks on result:

other: The temperature was 21-22 °C.

Details on results:

CALCULATION METHOD
The log Pow value of the non-charged test item species was calculated to be 1.01 (EPI Suite™ v4.11).

FLASK METHOD
The determined log Pow values were in the range of <-1.47 to <-1.48 for all three volume ratios and all replicates. For each replicate, the mass balance calculation showed that the experiment was reliably conducted, as the recovery rates ranged from 99 to 100%. The log Pow of the test item is given as the mean value of all measurements. Detailed results are given in the table in the field 'Any other information on results incl. tables'.

Any other information on results incl. tables

DETAILED RESULTS TABLE

Ratio 1-octanol:water (v:v)	Determined concentration 1-octanol (mg/L)	Determined concentration water (mg/L)		Pow	log Pow	pH
1:4	<47.7	1439	<0.0331		<-1.48	7.0
1:4	<47.7	1423	<0.0335		<-1.47	7.0
1:8	<47.7	1426	<0.0334		<-1.48	7.0
1:8	<47.7	1431	<0.0333		<-1.48	7.0
1:16	<47.7	1428	<0.0334		<-1.48	7.0
1:16	<47.7	1422	<0.0335		<-1.47	7.0
Mean					<-1.48

FURTHER REMARKS

According to the guideline, this test should be conducted with the non-ionised form. However, in the environmentally relevant pH range of pH 5 to 9, the amount of the non-ionised test item species is negligible. Instead, the overall once negatively charged species dominates (see https://chemicalize.com/#/calculation). Therefore, a lower log Pow than for the non-ionised test item species of 1.01 was expected.

To ensure defined pH conditions during the test, a 10 mM phosphate buffer was used at pH 7.0±0.1.

Applicant's summary and conclusion

Conclusions:

The shake flask method according to the OECD guideline 107 was applied for the determination of the log Pow of 5-Amino-2-Nitrobenzoic Acid (CAS no. 13280-60-9). The determined log Pow value of 5-Amino-2-Nitrobenzoic Acid at 21-22 °C and pH 7.0 is <-1.48.

Executive summary:

The log Pow of the test item 5-Amino-2-Nitrobenzoic Acid (CAS no. 13280-60-9) was determined according to the OECD guideline 107.

Phosphate buffer at pH 7.0, 1-octanol and the test item were equilibrated in test vessels by shaking, applying three different volume ratios of the two solvents. Subsequently, the test item concentrations were determined in both solvent phases.

The determined log Pow values were in the range of <-1.47 to <-1.48 for all three volume ratios and all replicates. For each replicate, the mass balance calculation showed that the experiment was reliably conducted, as the recovery rates ranged from 99 to 100%.

The determined log Pow value of 5-Amino-2-Nitrobenzoic Acid at pH 7.0 and 21–22 °C is <-1.48.

The validity criterion was fulfilled.