1-Propanesulfonic acid, 3-(cyclohexylamino)-2-hydroxy-, sodium salt (1:1)

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 2012 - August 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes

Type of method:

flask method

Water solubility:

265.4 g/L

Conc. based on:

test mat.

Temp.:

10 °C

pH:

>= 11.7 - <= 11.8

Key result

Water solubility:

302.7 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

>= 11.7 - <= 11.8

Details on results:

The temperature of the water bath was 10.0 °C respectively 20.0 °C.
The pH of the solutions were 11.7 to 11.8 at 10 °C and 11.7 to 11.8 at 20 °C.
The difference between the concentrations of the test substance of day 1 to 3 at 10 °C and 20 °C was < 15 % and the concentrations of the test substance showed no relevant tendency. Therefore the mean of day 1 - 3 was taken as the solubility of the test substance at both temperatures, according to the guidelines.

The water solubility of the test item was determined to:
Mean: 265.4 g/L, standard deviation: 17.0, replicates of three days, temperature 10.0 °C.
Mean: 302.7 g/L, standard deviation: 11.7, replicates of three days, temperature 20.0 °C.
As the temperature coefficient of the solubility of the test substance was < 3 % (i.e. 1.3 %) per °C, the solubility was not determined at three temperatures, in agreement with the guideline.

Numerical data have been rounded for presentation, a manual recalculation therefore may yield slightly different results to those given in the tables.

Table 1: Water Solubility at 10 °C

Mass concentration of the test item determined at different times of stirring, two solutions were used.

 

nominal temperature	equilibrationtime	pH of the solutions		concentration (g/L)
		1st	2nd	1st	2nd	mean
10°C	1day	11.8	11.8	276.3	281.5	278.9
	2days	11.8	11.7	269.1	273.0	271.0
	3days	11.7	11.7	242.7	250.1	246.4
			mean (day1-3)			265.4
			SD			17.0

 

Table2: Water Solubility at 20°C

Mass concentration of the test item determined at different times of stirring, two solutions were used.

 

nominal temperature	equilibrationtime	pH of the solutions		concentration (g/L)
		1st	2nd	1st	2nd	mean
20°C	1day	11.8	11.8	313.0	313.8	313.4
	2days	11.8	11.8	306.9	302.0	304.5
	3days	11.7	11.7	288.8	291.5	290.1
			mean (day1-3)			302.7
			SD			11.7

 

Conclusions:

The water solubility of the test item was determined to be 302.7 g/L, standard deviation: 11.7, replicates of three days, temperature 20.0 °C.

Executive summary:

The water solubility was determined according to OECD 105 using the shake flask method with HPLC analysis. The investigations were performed with suspensions of 22.2785 g and 22.3005 g at 10 °C and 22.2730 g and 22.4170 g at 20 °C in 50 mL water. After fitting with glass stoppers the flasks were placed in different water baths where the solutions were stirred with approximately 300 rpm. One, 2 and 3 days after starting of stirring at the desired temperature, portions of the solutions were taken from the flasks and filtered. The pH values of the solutions were determined with a pH-meter. All samples were appropriately diluted with water to obtain concentrations within the calibration range and analysed at the same day by HPLC. The water solubility of the test item was determined to be 302.7 g/L at 20 °C.

Description of key information

The water solubility of the test item was determined to be 302.7 g/L, standard deviation: 11.7, replicates of three days, temperature 20.0 °C.

Key value for chemical safety assessment

Water solubility:

302.7 g/L

at the temperature of:

20 °C

Additional information

The water solubility was determined according to OECD 105 using the shake flask method with HPLC analysis. The investigations were performed with suspensions of 22.2785 g and 22.3005 g at 10 °C and 22.2730 g and 22.4170 g at 20 °C in 50 mL water. After fitting with glass stoppers the flasks were placed in different water baths where the solutions were stirred with approximately 300 rpm. One, 2 and 3 days after starting of stirring at the desired temperature, portions of the solutions were taken from the flasks and filtered. The pH values of the solutions were determined with a pH-meter. All samples were appropriately diluted with water to obtain concentrations within the calibration range and analysed at the same day by HPLC. The water solubility of the test item was determined to be 302.7 g/L at 20 °C.