Asphalt, sulfonated, sodium salt

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-08-20 to 2004-09-19

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP study performed according to Method 105 of the OECD Guidelines however; due to the complex nature of the test material no determination of water solubility was possible . No substance specific method of analysis could be obtained. During method development, the test material failed to dissolve in any solvent suitable for use with high performance liquid chromatography (HPLC) or gel permeation chromatography (GPC). Therefore, a visual and gravimetric assessment was used.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

no guideline followed

Principles of method if other than guideline:

No determination of water solubility was possible using Method 105 of the OECD Guidelines, due to the complex nature of the test material. No substance specific method of analysis could be obtained. During method development, the test material failed to dissolve in any solvent suitable for use with high performance liquid chromatography (HPLC) or gel permeation chromatography (GPC). Therefore, a visual and gravimetric assessment was used. The sponsor stated that the water solubility was 70% wt, a visual assessment to determine the approximate solubility was considered sufficient.

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Type of method:

flask method

Water solubility:

ca. 48.5 other: portion of test material soluble when prepared at approx. 5-10% w/w

Temp.:

20 °C

pH:

10

Details on results:

- Gravimetric analysis showed that approx. 48.5% of the test material as a whole was water-soluble at 20 +/- 0.5 deg C, when prepared at approx. 5-10% w/w.

- The percentage of test material that was soluble was calculated by the following equation:
% soluble = [(mean residue (% w/w)) / (prepared sample concentration (% w/w))] x 100

Visual Assessment Results
Sample Number	Concentration (% w/w)	Observations
1	49.8	Very dark brown/black viscous solution.  All test material wetted, but evidence of excess particulate material present.
2	60.0	Very dark brown/black viscous solution.  All test material wetted, but evidence of excess particulate material present, but sample immobile.  Excess test material present.
3	69.8	Very dark brown/black viscous solution.  All test material wetted, but evidence of excess particulate material present, but small amount of powdery test material present.
4	79.7	Much non-wetted test material present in excess.  Small amount of wetted suspension/solution.
5	89.9	Much non-wetted test material present in excess.  Small amount of wetted suspension/solution.  Much excess test material present.
6	94.7	Much non-wetted test material present in excess.  Small amount of wetted suspension/solution.  Much excess test material present.
7	5.00	Brown liquid with excess test material present.
8	10.1	Brown liquid with excess test material present.
9	20.1	Brown liquid with large amount of excess test material present.
10	30.0	Brown liquid with large amount of excess test material present.
11	39.9	Brown liquid with large amount of excess test material present.

.

Calculated Percentage Residues for Each Sample
Sample Number	Percent Residue	Mean Percent Residue
1A	2.41	2.44
1B	2.47
2A	4.82	4.84
2B	4.86

.

Percentage of Test Material that was Soluble
Sample Number	Prepared Sample Concentration (% w/w)	Mean Residue (% w/w)	Portion of Test Material Soluble (%)
1	5.01	2.44	48.6
2	9.98	4.84	48.4

Conclusions:

No determination of water solubility was possible using method 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995, due to the complex nature of the test material. However, using visual and gravimetric assessment, approx. 48.5% of the test material as a whole was found to be soluble at 20.0 +/- 0.5 degrees C at approx. 5 to 10% w/w. Visual assessment suggests that this will be the case at other prepared concentrations also.

Executive summary:

N/A

Description of key information

No determination of water solubility was possible using method 105 of the OECD Guidelines for Testing of Chemicals, 27 July 1995, due to the complex nature of the test material.  However, using visual and gravimetric assessment, approx. 48.5% of the test material as a whole was found to be soluble at 20.0 +/- 0.5 degrees C at approx. 5 to 10% w/w.  Visual assessment suggests that this will be the case at other prepared concentrations also.