5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenyl)-4-benzopyrone

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 May 23rd to May 25th, 2016.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Key result

Water solubility:

0.19 mg/L

Conc. based on:

test mat.

Incubation duration:

72 h

Temp.:

20 °C

pH:

>= 5.98 - <= 6.02

Details on results:

Solubility of the test item in distilled water is 0.019 ± 0.005 mg/L at pH = 6.04 - 6.08.

Table 1. Results of the preliminary test

0.01 g in x mL of water	0.05	0.1	0.2	1	10	100	200	1000	>1000
Soluble (+/-)	-	-	-	-	-	-	-	-	+
Approximate solubility, g/L	> 200	200 to 100	100 to 50	50 to 10	10 to 1	1 to 0.1	0.1 to 0.05	0.05 to 0.01	< 0.01

The final approximate solubility was found to be < 0.01 g/L.

 

Table 2. Study solution – first run.

Sample	Sample volume	Absorbance Ap	X [mg/L]
1	15	0.259	0.228
2	15	0.26	0.229
3	15	0.254	0.224
4	15	0.253	0.223
5	15	0.247	0.218
6	15	0.246	0.217

Table 3. Study solution – second run.

Sample	Sample volume	Absorbance Ap	[mg/L] X
1	15	0.191	0.168
2	15	0.191	0.168
3	15	0.187	0.164
4	15	0.187	0.164
5	15	0.183	0.161
6	15	0.188	0.165

Table 4. Results of Diosmetin solubility at 20 ± 0.5 ºC in distilled water, column elution with recirculating pump method.

		1	2	3	4	5	6	Average concentration of Diosmetin on successive runs, mg/L	Average concentration of Diosmetin, mg/L
1 run	Concentration of Diosmetin, mg/L	0.23	0.23	0.22	0.22	0.22	0.22	0.22 ± 0.01	0.19 ± 0.04
	pH	6.01	6.00	6.00	6.02	6.01	6.00
2 run	Concentration of Diosmetin, mg/L	0.17	0.17	0.16	0.16	0.16	0.17	0.17 ± 0.003
	pH	5.99	5.98	6.00	5.98	6.01	5.99

Conclusions:

The solubility of the test item at 20 ± 0.5 ºC and at pH ranging 5.98 - 6.02 in water is 0.19 ± 0.004 mg/L.

Executive summary:

The study of the water solubility of the test item was performed by the column elution method, according to OECD 105 / EU Method A.6 (GLP study). The test item was dissolved in acetone and added to innert support material. Then, the solvent was evaporated, and the loaded support material was soaked for 2h in 5 ml of water. This suspension was added to a micro-column and the test item was eluted until the concentration reached a plateau. The mass concentration of the eluate at this time was determined by UVVIS spectrophotometry, and taken as the water solubility value. Based on the test results, the solubility of the test item in water of the test item at 20 ± 0.5 ºC and at pH ranging 5.98 - 6.02 in water was found to be 0.19 ± 0.004 mg/L.

Description of key information

Key study. Method according to OECD 105 / EU Method A.6 (column elution method), GLP study. The solubility of the test item in water of the test item at 20 ± 0.5 ºC and at pH ranging 5.98 - 6.02 in water was found to be 0.19 ± 0.004 mg/L.

Key value for chemical safety assessment

Water solubility:

0.019 mg/L

at the temperature of:

20 °C

Additional information

The study of the water solubility of the test item was performed by the column elution method, according to OECD 105 / EU Method A.6 (GLP study). The test item was dissolved in acetone and added to innert support material. Then, the solvent was evaporated, and the loaded support material was soaked for 2h in 5 ml of water. This suspension was added to a micro-column and the test item was eluted until the concentration reached a plateau. The mass concentration of the eluate at this time was determined by UV-VIS spectrophotometry, and taken as the water solubility value. Based on the test results, the solubility of the test item in water of the test item at 20 ± 0.5 ºC and at pH ranging 5.98 - 6.02 in water was found to be 0.19 ± 0.004 mg/L.