Methyl toluene-4-sulphonate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 September 2017 to 08 September 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

Commission Regulation (EC) No 440/2008 of 30 May 2008 laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), Part A, A.6 Water Solubility

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

Organisation for Economic Co-operation and Development (OECD), OECD Guidelines for Testing of Chemicals, Guideline No. 105, "Water Solubility", adopted July 27, 1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

No further details specified in the study report.

Key result

Water solubility:

0.865 other: mg/mL

Conc. based on:

test mat.

Temp.:

20 °C

pH:

>= 1.63 - <= 1.72

Details on results:

Results of the Shake Flask Method
pH of the samples varied in the range of 1.63 – 1.72.
Samples were analysed with the HPLC method.
Based on the measured concentrations the test mixtures were homogeneous and the whole amount of the added test substance was dissolved.

Results of the determination of test item concentrations

Measured concentration after 1 day (mg/mL)	pH	Measured concentration after 2 days (mg/mL)	pH	Measured concentration after 3 days (mg/mL)	pH	Solubility of the test item (mg/mL)
0.850	1.72	0.884	1.68	0.865	1.65	0.865 ± 0.004
0.871	1.71	0.873	1.67	0.863	1.63
0.881	1.70	0.838	1.67	-*	1.63
Mean: 0.867	-	Mean: 0.865	-	Mean: 0.864	-	RSD%=0.19

*The measurement of this sample was not successful due to technical reasons, but considering the results of other samples, it does not affect the study results.

Conclusions:

In conclusion, the water solubility of PTSM was determined to be 0.865 ± 0.004 mg/mL (95% confidence interval) at 20°C ± 0.5°C using the shake-flask method.

Executive summary:

The purpose of this study was to determine the water solubility of PTSM, which is specified by the saturation mass concentration of the test item in water at 20 ± 0.5 °C.

As the expected water solubility is above 10^-2g/L, the flask method was applied.

 

The substance was dissolved in water at a temperature somewhat above the test temperature. When saturation was achieved the mixture was cooled and kept at the test temperature, as long as necessary to reach equilibrium. Subsequently, the mass concentration of the substance in the aqueous solution was determined by a suitable analytical method.

 

About 200 mg test item measured into stoppered Erlenmeyer flasks (three parallel). After the addition of 25 mL ultrapure water, the flasks were agitated at 30 °C.

After one and two days 3-3 similarly prepared flasks were agitated at 30 °C.

After one day, the vessels were removed and re-equilibrated at 20 °C for 24 hours. The all samples were dissolved in water and diluted before the analysis (three parallel dilutions and two injections each). The concentration of the samples was determined by HPLC.

 

Based on the measured concentrations the test mixtures were homogeneous and the whole amount of the added test substance was dissolved.

 

In conclusion, the water solubility of PTSM was determined to be 0.865 ± 0.004 mg/mL (95% confidence interval) at 20 °C ± 0. 5 °C using the shake-flask method.

Description of key information

The water solubility of PTSM was determined to be 0.865 ± 0.004 mg/mL at 20 °C ± 0. 5 °C.

Key value for chemical safety assessment

Water solubility:

865 mg/L

at the temperature of:

20 °C

Additional information

The substance was dissolved in water at a temperature somewhat above the test temperature. When saturation was achieved the mixture was cooled and kept at the test temperature, as long as necessary to reach equilibrium. Subsequently, the mass concentration of the substance in the aqueous solution was determined by a suitable analytical method.

 

Based on the measured concentrations the test mixtures were homogeneous and the whole amount of the added test substance was dissolved.

 

In conclusion, the water solubility of PTSM was determined to be 0.865 ± 0.004 mg/mL (95% confidence interval) at 20 °C ± 0. 5 °C using the shake-flask method.