Reaction mass of hydrogen [1-[(2-hydroxy-4-nitrophenyl)azo]-2-naphtholato(2-)][1-[(2-hydroxy-5-nitrophenyl)azo]-2-naphtholato(2-)]chromate(1-) , compound with 3-[(2-ethylhexyl)oxy]propylamine (1:1) and hydrogen bis[1-[(2-hydroxy-4-nitrophenyl)azo]-2-naphtholato(2-)]chromate(1-) , compound with 3-[(2-ethylhexyl)oxy]propylamine (1:1) and hydrogen bis[1-[(2-hydroxy-5-nitrophenyl)azo]-2-naphtholato(2-)]chromate(1-) , compound with 3-[(2-ethylhexyl)oxy]propylamine (1:1)

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 September 2017 to 03 October 2017

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:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

374 g/L

Conc. based on:

test mat.

Incubation duration:

3 d

Temp.:

20 °C

pH:

>= 6.7 - <= 6.84

Remarks on result:

other: ± 19.3 mg/mL (95 % confidence interval)

Details on results:

CALIBRATION
- Seven concentration levels were used: 0.1, 0.2, 0.5, 2, 5, 10 and 20 μg/mL. The calibration graph was calculated applying weighted linear regression using 1/concentration as weighting factor.
- Intercept: -0.139
- Slope: 24.9
- Correlation Coefficient: 0.9999

SHAKE FLASK METHOD
- pH of the samples varied in the range of 6.70 – 6.84.
- The concentration in the clear solvent phase of samples were analysed with the above HPLC method. The newer dilution from the filtered samples compared to the first dilution shows obviously, that the samples were stable on the applied condition.
- Measured concentrations are summarised in Table 1.

Table 1: Results of the determination of test material concentrations

Measured concentration after 1 day (mg/L)	pH	Measured concentration after 2 days (mg/L)	pH	Measured concentration after 3 days (mg/L)	pH	Solubility of the test material (mg/L)
339	6.84	367	6.81	395	6.71	374 ± 19.3
342	6.81	382	6.77	401	6.71
400	6.79	352	6.73	391	6.70
Mean: 360	-	Mean: 367	-	Mean: 396	-	RSD % = 6.7 %

Conclusions:

Under the conditions of this study, the water solubility of the test material was determined to be 374 ± 19.3 mg/mL (95 % confidence interval) at 20 ± 0.5 °C using the shake-flask method.

Executive summary:

The water solubility of the test material was investigated in accordance with the standardised guidelines OECD 105 and EU Method A.6, under GLP conditions.

As the expected water solubility is above 10^-2 g/L, the flask method was applied and the concentration of the samples was determined by HPLC.

pH of the samples varied in the range of 6.70 – 6.84. The concentration in the clear solvent phase of samples were analysed using the HPLC method. The newer dilution from the filtered samples compared to the first dilution shows that the samples were stable on the applied condition.

Under the conditions of this study, the water solubility of the test material was determined to be 374 ± 19.3 mg/mL (95 % confidence interval) at 20 ± 0.5 °C using the shake-flask method.

Description of key information

Under the conditions of this study, the water solubility of the test material was determined to be 374 ± 19.3 mg/mL (95 % confidence interval) at 20 ± 0.5 °C using the shake-flask method.

Key value for chemical safety assessment

Water solubility:

374 g/L

at the temperature of:

20 °C

Additional information

The water solubility of the test material was investigated in accordance with the standardised guidelines OECD 105 and EU Method A.6, under GLP conditions. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

As the expected water solubility is above 10^-2 g/L, the flask method was applied and the concentration of the samples was determined by HPLC.

pH of the samples varied in the range of 6.70 – 6.84. The concentration in the clear solvent phase of samples were analysed with the HPLC method. The newer dilution from the filtered samples compared to the first dilution shows obviously, that the samples were stable on the applied condition.

Under the conditions of this study, the water solubility of the test material was determined to be 374 ± 19.3 mg/mL (95 % confidence interval) at 20 ± 0.5 °C using the shake-flask method.