5-amino-2-nitrobenzoic acid

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 - 09 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 105 (Water Solubility)

Version / remarks:

1995

Deviations:

yes

Remarks:

The temperature in the equilibration phase was 19.2–19.8 °C with a mean of 19.5 °C and was thus out of the range of 20 ± 0.5 °C. No impact on the study is expected, as the deviation was minor, and the overall mean was in the range given by the guideline.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

Regulation (EC) No 440/2008

Deviations:

yes

Remarks:

The temperature in the equilibration phase was 19.2–19.8 °C with a mean of 19.5 °C and was thus out of the range of 20 ± 0.5 °C. No impact on the study is expected, as the deviation was minor, and the overall mean was in the range given by the guideline.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

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

Results and discussion

Water solubility

Key result

Water solubility:

>= 1.88 g/L

Conc. based on:

test mat. (dissolved fraction)

Temp.:

20 °C

pH:

2.3

Details on results:

Preliminary test
This preliminary test indicated a water solubility of 1 to 10 g/l, as about 0.1 g of the test item could be dissolved in 100 ml of water.

Main test
The results are given in the table in the next section. The individual results of the test vessels, which were deemed constant, were averaged and are given in mass per volume of solution. The test is satisfactory if the concentrations of at least the last two vessels do not differ by more than 15%.

Any other information on results incl. tables

HPLC determinations:

Test vessel	Incubation time at 30 °C (d)	Equilibration time at 20 °C (h)	pH	Determined concentration A (g/L)	Determined concentration B (g/L)	Determined concentration C (g/L)	Mean (g/L)	Considered for calcu- lation of the final result
No. 1	1	24	2.3	1.88	1.86	1.83	1.86	yes
No. 2	2	24	2.3	1.94	1.92	1.92	1.93	yes
No. 3	3	24	2.3	1.85	1.83	1.85	1.84	yes
						Overall Mean (g/L)	1.88
						Variation (%)	4.6

The concentrations of the three vessels differed by 4.6% (validity criterion given by OECD is met).

Applicant's summary and conclusion

Conclusions:

The water solubility of 5-Amino-2-Nitrobenzoic Acid (CAS no. 13280-60-9) was determined according to the OECD guideline 105
The water solubility of the test item at 20°C was 1.88 g/L. The pH of the aqueous samples was 2.3.

Executive summary:

The water solubility of 5-Amino-2-Nitrobenzoic Acid (CAS no. 13280-60-9) was determined according to the OECD guideline 105.

Several test vessels containing ultra-pure water mixed with test item in great excess (initial amount of test item about 50 g per liter water) were incubated and stirred for different periods of time at 30 °C (saturation phase), and then transferred to about 20 °C for 24 hours (equilibration phase). Undissolved test item was subsequently separated by centrifugation. The concentration of the test item in the clear aqueous phase was analysed with HPLC.

The determined concentrations were as follows:

1.86 g/l after one day at 30 °C, followed by 24 hours at ca. 20 °C, pH 2.3

1.93 g/l after two days at 30 °C, followed by 24 hours at ca. 20 °C, pH 2.3

1.84 g/l after three days at 30 °C, followed by 24 hours at ca. 20 °C, pH 2.3

No significant variation of the concentrations and pH values was observed in the three respective test vessels after one, two and three days of incubation at 30 °C (followed by 24 hours equilibration at about 20 °C).

The water solubility of 5-Amino-2-Nitrobenzoic Acid (CAS no. 13280-60-9), calculated as the mean of the three test vessels, is 1.88 g/l at a pH of 2.3 and about 20 °C.

The validity criterion was fulfilled.