1-(5,6,7,8-tetrahydro-3,5,5,6,8,8-hexamethyl-2-naphthyl)ethan-1-one

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes

Type of method:

flask method

Water solubility:

1.31

Temp.:

25 °C

pH:

5

Remarks on result:

other: Average water solubility (mg active/l) of 14C-AHTN after 7 days of equilibration.

Water solubility:

1.22

Temp.:

25 °C

pH:

7

Remarks on result:

other: Average water solubility (mg active/l) of 14C-AHTN after 7 days of equilibration.

Water solubility:

1.22

Temp.:

25 °C

pH:

9

Remarks on result:

other: Average water solubility (mg active/l) of 14C-AHTN after 7 days of equilibration.

Water solubility:

1.25 mg/L

Temp.:

25 °C

pH:

> 5 - < 9

Remarks on result:

other: Overall average water solubility (mg active/L) of 14C-AHTN after 7 days of equilibration.

Details on results:

The average water solubility (+/- % relative standard deviation) of 14C-AHTN calculated after 7 days equilibration in pH buffer solutions of 5, 7, and 9 were 1.31 mg active/L +/-13.0%, 1.22 mg active/L +/-8.20%, and 1.22 mg active/L +/-14.8%, respectively, with an overall average water solubility of 1.25 mg active/L. pH did not seem to affect water solubility.

Table 1 Average Water Solubility (mg active/l). Average of three replicates for each pH/centrifuge speed.

pH		5			7			9
		Centrifuge speed
Sampling day		0	5,000	10,000	0	5,000	10,000	0	5,000	10,000
1		1.15	1.02	1.04	1.06	0.96	1.08	0.98	1.03	1.08
2		1.17	1.12	1.30	1.11	1.14	1.07	1.15	1.18	1.31
5		1.19	1.30	1.28	1.07	1.20	1.15	1.22	1.29	1.29
7		1.44	1.32	1.18	1.24	1.19	1.22	1.33	1.29	1.06

Conclusions:

Interpretation of results (migrated information): slightly soluble (0.1-100 mg/L)
The water solubility is determined to be 1.25 mg/l (at 25°C) and seemed independent on the pH.

Executive summary:

A rough approx of water solubility was made by adding a series of masses of non-radiolabelled AHTN samples in deionised (DI) water and noting phase separation after overnight agitation. Using this procedure 10 mg active/l of (14)C-AHTN was estimated to be "well in excess" of the water solubility. The test apparatus consisted of 9 Teflon centrifuge tubes. AHTN was initially dissolved in ethanol (EtOH). The EtOH solution was added to tubes in volumes sufficient to deliver (14)C-AHTN in excess of the estimated water solubility (10 mg active/l). The EtOH was removed by evaporation, leaving the test material as tiny droplets on the bottom of the tubes. 3 buffer solutions (pH 5, 7 and 9) was added to triplicate tubes. Tubes were sealed and agitated overnight at 25°C. Agitation was ceased and water samples withdrawn from near bottom of tubes following 1 hour holding time, then following 30 min of centrifugation at 5,000 rpm (2,655 x g), and finally following 30 min of centrifugation at 10,000 rpm (10,620 x g). Concentration of test substance was determined by liquid scintillation counting. This procedure was repeated 2, 5, and 7 days after set-up. After 7 days of equilibration average water solubilities of (14)C-AHTN (±% relative standard deviation) were 1.31 mg active/l ±13.0%, 1.22 mg active/l ±8.20% and 1.22 mg active/l ±14.8% in pH buffers of pH 5, pH 7 and pH 9, respectively. pH of buffer solution did not appear to affect water solubility of (14)C-AHTN. Overall average water solubility was 1.25 mg active/l.

Description of key information

The water solubility of the test item has been established with radio labelled form of the test item in a OECD guideline 105 study under GLP compliance. Water solubilty was determined to be 1.25 mg/L.

Key value for chemical safety assessment

Water solubility:

1.25 mg/L

at the temperature of:

25 °C