Bis (3‐(diethylamino)‐7‐hydroxy‐5‐phenylphenazinium) sulphate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 July 2019 - 12 July 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

2.23 g/L

Conc. based on:

test mat.

Incubation duration:

72 h

Temp.:

20 °C

pH:

>= 5.16 - <= 5.46

Table 1. Results of the preliminary test

0.1g in x ml of solution	0.1	0.5	1	2	10	100	> 100
Soluble (+/-)	-	-	-	-	-	+	+
Approximate solubility, g/l	> 1000	1000 to 200	200 to 100	100 to 50	50 to 10	10 to 1	<1

Table 2. Calibration solution

Day	Weight [mg]	Dilution [ml]	Cw [mg/ml]	Average absorbance Aw	f	Average  f
1	8.11	25-0.1-10	0.00114448	0.0792	14.45054545	14.28924516
		25-0.5-10	0.00572242	0.3992	14.33470942
		25-1-10	0.01144483	0.8127	14.08248062
2	8.11	25-0.1-10	0.00114448	0.0801	14.28817978	14.23246749
		25-0.5-10	0.00572242	0.3987	14.35268623
		25-1-10	0.01144483	0.8142	14.05653648
3	8.11	25-0.1-10	0.00114448	0.0814	14.05999017	14.15558581
		25-0.5-10	0.00572242	0.4010	14.27036409
		25-1-10	0.01144483	0.8096	14.13640316

Table 3. Study solution in water

Sample day/ flask		Weight of the sample [mg]	Dilution [mL]	Cp [mg/mL]	Average absorbance Ap	X [g/kg]
1	1	983.65	25-1-25	1.5738	0.2259	2.0510
	2	991.21		1.5859	0.2396	2.1588
2	3	986.57	25-1-25	1.5785	0.2488	2.2433
	4	983.50		1.5736	0.2623	2.3724
3	5	983.86	25-1-25	1.5742	0.2425	2.1807
	6	983.24		1.5732	0.2633	2.3692

Table 4. Results of test item solubility in water

Mixing time at 30 ºC [days, flasks]	1		2		3
Samples	1	2	3	4	5	6
Temperature, ºC	19.9		19.5		20.1
pH	5.38		5.46		5.16
Concentration of Violet LCC6D dried, g/kg	2.05	2.16	2.24	2.37	2.18	2.37
Average concentration of Violet LCC6D dried, g/kg	2.10		2.31		2.27
Average concentration of Violet LCC6D dried, g/kg	2.23

The solubility of Violet LCC6D dried in water is 2.23 g/kg. The density of this solution is about 1 kg/l (about water density).

After recalculation: The solubility of Violet LCC6D dried at pH 5.16 – 5.46 in water is 2.23 g/l.

Conclusions:

Solubility of the test item in water at 20 ± 0.5ºC and at pH ranging 5.16–5.46 is 2.23 g/L.

Executive summary:

The water solubility determination of the test item was performed in accordance with EU method A.6 and OECD TG 105. About 5 times the quantity necessary to saturate the desired volume of water, estimated in a preliminary test, was weighed into each of three glass vessels at 100 ml fitted with glass stoppers. 70 ml of double distilled water was added to each vessel. These closed vessels were agitated in an incubator at 30 ºC with magnetic stirrers. After one day, one of the flask was equilibrated for 24 h at the test temperature 20 ± 0.5 ºC with occasional shaking. The other two flasks were treated similarly after initial equilibration at 30 ºC for two and three days respectively. Two replicates were performed. The samples taken during saturation were then separated using a vial-centrifuge to give the clear liquid phase and the concentration of the test substance in the clear solvent phase was determined by a validated UV-VIS spectrophotometric method. The solubility of the test item in distilled water at pH 5.16 -5.46 was determined to be 2.23 g/L at 20 ± 0.5 °C.

Description of key information

Key study: Test method EU A.6 and OECD 105. GLP study. The solubility of the test item in distilled water at pH 5.16 -5.46 was determined to be 2.23 g/L at 20 ± 0.5 °C.

Key value for chemical safety assessment

Water solubility:

2.23 g/L

at the temperature of:

20 °C