Boronic acid, (4-ethylphenyl)-

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28.02. - 16.03.2007

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:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

1 190 mg/L

Conc. based on:

test mat.

Incubation duration:

>= 29 - <= 77 h

Temp.:

20 °C

pH:

6.2

Preliminary Test

Amounts of the test item and water were stirred at room temperature until the mixture appeared dissolved or the water solubility could be estimated to be below 10 mg/L.

Table 1: Appearance of the test mixtures

Amount of the test item in mg	Total volume in mL	Appearance of mixture
105.0	0.1	undissolved
	0.5	undissolved
	1.0	undissolved
	2.0	Undissolved^1)
	10.0	Undissolved^1)
	100.0	Undissolved^2)
11.5	100.0	Dissolved^3)

¹⁾: After adding the indicated amount of water, the solution was treated with ultrasound for 2 minutes.

²⁾: After adding the indicated amount of water, the solution was treated with ultrasound for 5 minutes.

³⁾: After adding the indicated amount of water, the solution was treated with ultrasound for 20 minutes and stirred over night.

 

Flask method

Table 2: Water solubility of the test item - experiments A to D

 

Experiment	A	B	C	D (blank)
Amount of test item (mg)	246.0	274.2	277.2	—
Stirring time at 30 °C (h)	29	53	77	77
pH at 25°C	6.6	6.2	6.2	6.4
aliquot of the flasks(mL)	0.2	0.2	0.2	0.2
end volume (mL)	1	1	1	1
Measured concentration (mg/L)	240.3 / 239.8	239.8/241.7	244.0 / 247.1	— / —
Mean concentration (mg/L)	240.0	240.8	245.5	—
Water solubility (mg/L)	1200	1204	1228	—

 

Average experiments A to C (without correction for the purity):	1211 mg/L
Standard deviation:	15 mg/L
Relative standard deviation:	1.2 %

The water solubility of the test item increases from flask A to C for about 30 mg/L. Due to the low relative standard deviation, this increase is not related to an increasing tendency of the water solubility according to consolidated version of Guideline 67/548/EEC Annex V (Council Directive 92/69/EEC) method A.6.. Therefore the test has not been repeated.

Conclusions:

The water solubility of the test substance was determined to be 1190 mg/L at 20 °C (with correction for the purity).

Executive summary:

The water solubility of the test item was determined according to OECD 105 and the consolidated version of Guideline 67/548/EEC Annex V (Council Directive 92/69/EEC) method A.6 using the shake flask method with HPLC analysis. For the main test three flasks were prepared with about 246 mg, 274 mg and 277 mg of the test item and 50 mL distilled water. The batches were stirred for different times at 30 °C. After equilibration for 19.5 h at 20 °C aliquots of the saturated aqueous phase were taken and centrifuged. Aliquots of the aqueous phases were filtered and diluted. The concentration of the test item was determined by means ofHPLC. The pH of each sample was recorded. The water solubility of the test item at a temperature of 20 °C was found to be 1190 mg/L ± 14.3 mg/L (with correction of the purity).

Description of key information

The water solubility of the test substance was determined to be 1190 mg/L at 20 °C (with correction for the purity) (reference 4.8-1).

Key value for chemical safety assessment

Water solubility:

1 190 mg/L

at the temperature of:

20 °C

Additional information

The water solubility of the test item was determined according to OECD 105 and the consolidated version of Guideline 67/548/EEC Annex V (Council Directive 92/69/EEC) method A.6 using the shake flask method with HPLC analysis. For the main test three flasks were prepared with about 246 mg, 274 mg and 277 mg of the test item and 50 mL distilled water. The batches were stirred for different times at 30 °C. After equilibration for 19.5 h at 20 °C aliquots of the saturated aqueous phase were taken and centrifuged. Aliquots of the aqueous phases were filtered and diluted. The concentration of the test item was determined by means ofHPLC. The pH of each sample was recorded. The water solubility of the test item at a temperature of 20 °C was found to be 1190 mg/L ± 14.3 mg/L (with correction of the purity) (reference 4.8-1).