Sodium 2-biphenylate

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

yes (incl. QA statement)

Remarks:

Staatstoezicht op de Volksgezondheid, Veterinaire Hoofdinspectie

Type of method:

flask method

Water solubility:

> 1 000 g/L

Temp.:

20 °C

pH:

13.6

Remarks on result:

other: in preliminary test

After 3 days of stirring the test substance in water at a nominal concentration of about 1300 g/L, undissolved test substance was present in the water phase. After 1, 2, 3 and 4 centrifugation steps, the test substnace concentration in the war phase was determined to be 1043, 1101, 1118 and 1020 g/L, respectively. The pH of the water phase after 4 centrifugation steps was 13.6.

After 6 days of stirring, the test substance concentration after 1, and 2 centrifugation steps was detemined to be 1055 and 1078 g/L, respectively.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

Cited as Directive 92/69/EEC, A.6

GLP compliance:

yes

Type of method:

flask method

Specific details on test material used for the study:

The test was performed with 2-phenylphenol, the conjugate acid of sodium 2-biphenylate.
Content of test substance 2-phenylphenol: 99.9%

Water solubility:

0.53 - 0.64 g/L

Temp.:

20 °C

pH:

5 - 9

Water Solubility (g/liter):
1. In water       at 10/20/30 degree C: 0.51/0.62/0.80 g/L;
2. In buffer pH 5 at 10/20/30 degree C: 0.43/0.53/0.70 g/L;
3. In buffer pH 7 at 10/20/30 degree C: 0.45/0.56/0.73 g/L;
4. In buffer pH 9 at 10/20/30 degree C: 0.52/0.64/0.84 g/L.

Description of key information

> 1000 g/L at pH 13.6 and 20 °C (given as sodium 2-biphenylate tetrahydrate), (OECD 105, preliminary test)

Additionally for the environmental relevant pH range (pH 5 - 9) a test was performed with 2-phenylphenol:

0.53 mg/L (pH 5, 20 °C), 0.56 mg/L (pH 7, 20°C) and 0.64 mg/L (pH 9, 20 °C) 2-phenylphenol (EU Method A.6, flask method).

Key value for chemical safety assessment

Water solubility:

1 000 g/L

at the temperature of:

20 °C

Additional information

Sodium 2-biphenylate dissociates in water and is transformed to 2-phenylphenol and sodium and hydroxyl ions. The ratio of 2-biphenylate and 2-phenylphenol in water only depends on the pH value. Due to the measured dissociation constant pKa(2-phenylphenol) = 9.5, in environmental relevant pH ranges (pH 5 - 9) only the uncharged form, o-phenylphenol, occurs. Therefore additionally the determination of water solubility in environmental relevant pH ranges was performed with 2-phenylphenol.