Reaction products of 4,4'-methylenebis(2,6-dimethylaniline) and 4-aminobenzenesulfonic acid with 2,4,6-trichloro-1,3,5-triazine, diazotised and subsequently coupled with N-(2-methoxyphenyl)-3-oxobutanamide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 October 2006 and 20 November 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

other: Column elution and shake flask methods

Key result

Water solubility:

1.8 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

6

Details on results:

During the preliminary test the water solubility of the test material at room temperature was estimated by a simplified flask method to be lower than the smallest calibration point of 1.608 µg/mL. Therefore, at first, the column elution method was used for the performance of the main test.
During the main test six samples have been analysed in the first run (0.52 mL/min) and six samples during the second run (0.26 mL/min), each with a sampling interval of 1 h. Total elution time was about 94 h. The sample measurement was performed by HPLC.
The concentration of the test material was found to be about 25 mg/L with a flow of 0.52 mL/min and about 68 mg/L with half the flow (0.26 mL/min).
The obtained values are above the limits of the column elution method. Therefore the second main test was performed using the shake flask method.
For this, the concentrations were determined after a shaking time of 24 h, 48 h and 72 h at 30 °C followed by an equilibration for another 24 h at 20 °C. The measured values differed by less than 15 %. Therefore the study is considered to be valid. The water solubility was found to be 1.8 mg/L using the shake flask method.
Additionally the water solubility was estimated by a model calculation based on the molecular formula to be 0.001 mg/L.
The model calculation and the result obtained during the preliminary test as well as the observations made during the preliminary test indicate that the results obtained using the flask shaking method is more reliable than the results obtained using the column elution method.
The higher water solubility obtained using the column elution method might be caused by microscopic particles of the test material because the eluted samples were not filtered prior to analysis. It could also be caused by a component of the test material that has accumulated during the elution and has the same retention time.

Column Elution Method
The R² fit was 1.0000 (optimum). This reflects the linearity of the HPLC system within the calibration range of 0.4829 mg/L to 112.91 mg/L of the test material.

Shake Flask Method
The R² fit was 1.0000 (optimum). This reflects the linearity of the HPLC system within the calibration range of 0.3698 mg/L to 18.49 mg/L of the test material.

Under the conditions of the study the water solubility of the test material at 20 °C was determined to be 1.8 mg/L using the shake flask method.

Water Solubility Results Using the Column Elution Method

Experiment No.	Flow rate [mL/h]	Sample No.	Concentration analysed [µg/L]	Water solubility calculated [mg/L]		pH
1	31	1	20.28	25.041 SD = ± 5.30	48.61 SD = ± 24.08	6.22
		2	18.34			6.49
		3	28.15			6.26
		4	29.53			6.41
		5	0.23*			6.30
		6	28.91			6.21
2	16	7	61.67	68.523 SD = ± 9.37		6.27
		8	73.38			6.35
		9	80.26			6.29
		10	54.46			6.40
		11	73.71			6.31
		12	66.03			6.25

SD = Standard deviation

* Outlier not used for the calculation

 

Data of the Performance Using the Flask-Shaking Method

Sample solution No.	1	2	3	4	5	6
Weighed sample of the test material [mg]	15.14	15.59	15.88	16.55	18.82	18.31
Added volume of water [mL]	25	25	25	25	25	25
Agitation time at 30 °C [h]	72	72	48	48	24	24
Equilibration time at 20 °C [h]	24	24	24	24	24	24
pH values of test material solution	5.32	5.36	5.30	5.22	5.13	5.06

 

Water Solubility Results

Sample No.	Shaking time at 30 °C	Concentration analysed [mg/L]	Concentration calculated [mg/L]	Water solubility calculated (rounded) [mg/L]
1	72	1.655	1.65	1.80 SD = 0.25
2	72	2.226	2.23
3	48	1.733	1.73
4	48	0.948	0.95*
5	24	1.803	1.80
6	24	1.587	1.59

The saturation mass concentration is calculated from the bold values.

SD = Standard deviation

* Outlier not used for calculation

Conclusions:

Under the conditions of the study the water solubility of the test material at 20 °C was determined to be 1.8 mg/L using the shake flask method.

Executive summary:

The water solubility of the test material was assessed according to OECD Test Guideline 105 and EU Method A.6. and in compliance with GLP.

During the preliminary test the water solubility of the test material at room temperature was estimated by a simplified flask method to be lower than the smallest calibration point of 1.608 µg/mL. Therefore, at first, the column elution method was used for the performance of the main test.

During the main test six samples have been analysed in the first run (0.52 mL/min) and six samples during the second run (0.26 mL/min), each with a sampling interval of 1 h. Total elution time was about 94 h. 

The concentration of the test material was found to be about 25 mg/L with a flow of 0.52 mL/min and about 68 mg/L with half the flow (0.26 mL/min). 

The obtained values are above the limits of the column elution method. Therefore the second main test was performed using the shake flask method.

For this, the concentrations were determined after a shaking time of 24 h, 48 h and 72 h at 30 °C followed by an equilibration for another 24 h at 20 °C. The measured values differed by less than 15 %. Therefore the study is considered to be valid. 

Under the conditions of the study the water solubility of the test material at 20 °C was determined to be 1.8 mg/L using the flask shaking method.

Description of key information

Under the conditions of the study the water solubility of the test material at 20 °C was determined to be 1.8 mg/L using the shake flask method.

Key value for chemical safety assessment

Water solubility:

1.8 mg/L

at the temperature of:

20 °C

Additional information

The water solubility of the test material was assessed according to OECD Test Guideline 105 and EU Method A.6. and in compliance with GLP. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

During the preliminary test the water solubility of the test material at room temperature was estimated by a simplified flask method to be lower than the smallest calibration point of 1.608 µg/mL. Therefore, at first, the column elution method was used for the performance of the main test.

During the main test six samples have been analysed in the first run (0.52 mL/min) and six samples during the second run (0.26 mL/min), each with a sampling interval of 1 h. Total elution time was about 94 h. 

The concentration of the test material was found to be about 25 mg/L with a flow of 0.52 mL/min and about 68 mg/L with half the flow (0.26 mL/min). 

The obtained values are above the limits of the column elution method. Therefore the second main test was performed using the shake flask method.

For this, the concentrations were determined after a shaking time of 24 h, 48 h and 72 h at 30 °C followed by an equilibration for another 24 h at 20 °C. The measured values differed by less than 15 %. Therefore the study is considered to be valid. 

Under the conditions of the study the water solubility of the test material at 20 °C was determined to be 1.8 mg/L using the flask shaking method.