2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar-heptyl ar',ar''-Me derivs.

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

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:

no

Type of method:

flask method

Specific details on test material used for the study:

Identification: C.I. Solvent Red 164 Solid
Appearance/Physical state: dark red /dark purple solid
Batch: ZA07192016
Purity: >99%
Expiry date: 18 July 2019
Storage conditions: room temperature in the dark

Key result

Water solubility:

< 0 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

5.93

Preliminary Test Results:

The preliminary estimate of the water solubility at 20.0 ± 0.5 °C was less than 5.0 x 10^-5g/L. The solution had a pH of 5.93.

Definitive Test Results:

The mean peak areas relating to the standard and sample solutions are shown in the following table:

Solution	Mean Peak Area
Standard 5.06 mg/L	2.0504 x 10^6
Standard 5.01 mg/L	2.0917 x 10^6
Sample 1A	none detected
Sample 1B	none detected
Sample 2A	none detected
Sample 2B	none detected
Sample 3A	none detected
Sample 3B	none detected

Reported Result         :          less than 5.0 x 10^-5g/L

Discussion:

On completion of the equilibration period, the samples were clear and colorless with excess test item present at the bottom of the test vessels. The solutions were decanted, avoiding excess test item prior to centrifugation. After centrifugation, the supernatant was taken for analysis. The supernatant was visually observed to be clear/colorless and free from un-dissolved test item.

The preliminary water solubility test indicated that the column elution method should have been performed as the solubility was less than 1x10^-2g/L. However, due to the large sample volume required for analysis, the column elution method was impractical. Therefore the flask method was used.

No test item was detected in the samples during analysis therefore the result has been reported as a limit value. The limit used is the level at which the recoveries were performed, given that the results from these recoveries showed good precision and accuracy.

Validation:

The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 1 to 10 mg/L. The results were satisfactory with a correlation coefficient (r) of 1.000 being obtained.

Assessment of the sample recovery procedure was performed and proved adequate for the test; at a nominal concentration of 0.05 mg/L, a mean percentage recovery of 99.1% was obtained (range 98.4 to 100.0%).

Test sample concentrations have not been corrected for the recovery of analysis.

Conclusions:

The water solubility of the test item has been determined to be less than 5.0 x 10^-5 g/L of solution at 20.0 ± 0.5 °C.

Executive summary:

Water Solubility. Less than 5.0 x 10^-5g/L of solution at 20.0 ± 0.5 °C, using the flask method, designed to be compatible with Method A.6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.

Description of key information

Water Solubility. Less than 5.0 x 10^-5g/L of solution at 20.0 ± 0.5 °C, using the flask method, designed to be compatible with Method A.6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.

Key value for chemical safety assessment

Water solubility:

0 g/L

at the temperature of:

20 °C

Additional information

Less than 5.0 x 10^-5g/L of solution at 20.0 ± 0.5 °C, using the flask method, designed to be compatible with Method A.6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995.