1,3-Benzenediamine, 4-methyl-, reaction products with 4-nitrobenzenamine, p-phenylenediamine and sodium sulfide (Na2(Sx))

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-06-22 to 2017-06-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

July 27, 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

19 March 2014

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Version / remarks:

March, 1998

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

>= 0.91 - <= 0.99 mg/L

Conc. based on:

act. ingr.

Loading of aqueous phase:

5 g/L

Incubation duration:

>= 24 - <= 72 h

Temp.:

20 °C

pH:

>= 2.25 - <= 2.27

Details on results:

The measured concentrations were constant within ± 15 % and thus within the range required by the guidelines.

Table: Brown 3 in water was analysed by the previously validatedspectrophotometric

method; results of the method validation

Measurement repeatability (7 parallels)	CV% < 1 %
Repeatability of the Preparation (n=5)	< 2 %
Linear range	0.1 - 20 µg/mL
Correlation coefficients	> 0.999
Limit of Quantification	0.1 µg/mL
Limit of Detection	0.1 µg/mL
Recovery from ISO medium		100 %
Recovery from20X AAPmedium		102 %
Recovery from ultra-pure water		100 %
Accuracy (samples used for calibration)		≤ 6 % (14 % at LOQ)
Precision		≤ 10 %
Stability of the test item in ISO medium at the temperature 18-22°C for 2 days		71 % at the test conditions
Stability of the test item in 20X AAP medium at the temperature 22-26°C for 7 days		75 % at the test conditions
Stock solution stability (1 mg/ml), after dissolution, dye complexation and color development		for at least 4 days at 5±3 °C

Regression data

Analytical occasion	Constant	X Coefficient	R. Squared
June 27, 2017	0.0092	0.0943	0.9999

Results of the determination of Brown 3 concentrations

Sampling time	Measured concentrationofBrown 3(mg/L )		Measured pH
	Test vessels	Mean withthe 95% confidence intervals
After 24h	1.02	0.95 ± 0.20	2.25
	0.86		2.26
	0.98		2.26
After 48h	0.92	0.91 ± 0.06	2.26
	0.88		2.27
	0.93		2.27

Results of the determination of Brown 3 concentrations (continued)

Sampling time	Measured concentrationofBrown 3(mg/L )				Measured pH
	Test vessels		Mean withthe 95% confidence intervals
After 72h	0.99		0.98 ± 0.03		2.26
	0.97				2.25
	0.99				2.25
Solubility ofthe test item (mg/L)	0.95 ± 0.04	-
RSD%	6	-
Ultra-pure water			< LOQ	5.94

Conclusions:

The water solubility of the test item was assessed according to OECD Guideline 105, EU Method A.6 and US EPA OPPTS 830.7840 under GLP conditions. The water solubility of the test item was determined to be 0.95 ± 0.04 mg/L (95% confidence interval) at 20 °C ± 1 °C using the shake-flask method for the performance.

Executive summary:

The water solubility of the test item was assessed according to OECD Guideline 105, EU Method A.6 and US EPA OPPTS 830.7840 under GLP conditions. The solubility of the test item is below 10^-2 g/L, so the column elution method should be applied according to the guideline. However, column elution method is not feasible with this test item, because coating of the support material is not possible due to the low solubility of the test item in any solvent. Therefore, the shake-flask method was applied. In result, the water solubility of the test item was determined to be 0.95 ± 0.04 mg/L (95% confidence interval).

Description of key information

The water solubility of Brown 3 was determined to be 0.95 ± 0.04 mg/L (95% confidence interval)  at 20 °C ± 1 °C using the shake-flask method for the performance.

Key value for chemical safety assessment

Water solubility:

0.95 mg/L

at the temperature of:

20 °C