α,α,α-trifluoro-4-nitro-m-cresol

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 1999-04-16 to 2000-03-02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7860 (Water Solubility Generator Column Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

Directive 92/69/EEC

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes

Type of method:

flask method

Specific details on test material used for the study:

Batch No.: FB 079

Key result

Water solubility:

8.26 g/L

Conc. based on:

test mat.

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

4.3

Key result

Water solubility:

15.05 g/L

Conc. based on:

test mat.

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

6.1

pH	Flask	Measured pH-value	Dilution factor	Measured peak area 1st injection [µV*s]	Mean measured peak area [µV*s]	Measured water solubility [g/L]
4	1a 1b	4.3	25	6992511 7021295	7003130.5 7030234.0	8.341 8.370
	2a 2b	4.3	25	6855004 5699700	6856187.0 5694736.5	8.143 6.737
	3a 3b	4.3	25	6870592 5622521	6877107.0 5623488.0	8.180 6.666
7	1a 1b	6.1	50	6714022 6135081	6723601.5 6144551.5	16.008 14.621
	2a 2b	6.1	50	6127805 6098871	6122605.0 6104782.0	14.499 14.509
	3a 3b	6.2	50	5016500 5825077	5062933.5 5831794.0	12.208 13.859
9	1a 1b	6.1	50	6429751 6424536	6425602.5 6422198.5	15.229 15.230
	2a 2b	6.1	50	6486710 6397131	6477246.0 6392985.0	15.328 15.151
	3a 3b	6.1	50	6561830 6548024	6560694.0 6525787.5	15.567 15.526

The results show, that the applied buffer capacity was not sufficient to stabilize the pH at the planned values 4, 7 and 9. Therefore, the water solubilities are given at the measured pH-values. Because pH 7 as well as pH 9 both resulted in a measured pH of 6.1, all allowed values of both tests were used to calculate the solubility at this pH. The water solubility of the test substance do not depend on time of equilibration.

Measured pH	Number of allowed values	Mean water solubility [g/L]	Standard deviation	Relative standard deviation [%]
4.3	4	8.26	0.11	1.4
6.1	11	15.05	0.61	4.1

Additional testing at pH 9

The capacity of the standard buffer solution pH 9 was not sufficient to stabilize the pH of the solution at this pH. Therefore, in an additional test it was tried to readjust the pH back to 9 using NaOH (1 mol/L). But it was impossible to obtain a two phase system when the pH was 9. This effect was independent from the ratio of combined volumina (test substance / added aqueous solution). Therefore, at pH 9 the test substance is mixable with water at all ratio.

Conclusions:

The water solubility of the test item was determined at three different pH - at pH 4.3 was 8.26 g/L, at pH 6.1 was 15.05 g/L and at pH 9 was determined to be mixable with water at all ratio.

Executive summary:

The water solubility of the test item was determined according to EEC-guideline 92/69/EWG A.6, Flask-method. Therefore, samples of the test substance were added with 80 mL of the corresponding standard buffer solution with pH 4, 7 and 9, and subsequently mixed and thermostated at 30 °C for 24, 48 and 72 hours. Afterwards all flasks were incubated at 20 °C for 24 hours. After phase separation at 20 °C, the concentration of the test substance in the samples was determined by HPLC.

The water solubility of the test item was determined at three different pH - at pH 4.3 was 8.26 g/L, at pH 6.1 was 15.05 g/L and at pH 9 was determined to be mixable with water at all ratio.

Description of key information

The water solubility of the test item was determined at three different pH - at pH 4.3 was 8.26 g/L, at pH 6.1 was 15.05 g/L and at pH 9 was determined to be mixable with water at all ratio. As key value the water solubility at pH 6.1 was chosen, as this pH is relevant for the environment.

Key value for chemical safety assessment

Water solubility:

15.05 g/L

at the temperature of:

20 °C

Additional information

The water solubility of the test item was determined according to EEC-guideline 92/69/EWG A.6, Flask-method. Therefore, samples of the test substance were added with 80 mL of the corresponding standard buffer solution with pH 4, 7 and 9, and subsequently mixed and thermostated at 30 °C for 24, 48 and 72 hours. Afterwards all flasks were incubated at 20 °C for 24 hours. After phase separation at 20 °C, the concentration of the test substance in the samples was determined by HPLC.

The water solubility of the test item was determined at three different pH - at pH 4.3 was 8.26 g/L, at pH 6.1 was 15.05 g/L and at pH 9 was determined to be mixable with water at all ratio.