3-cyclohexylaminopropane-1-sulphonic acid

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)

Rationale for reliability incl. deficiencies:

other: GLP -guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

see 'Principles of method if other than guideline'

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

yes

Remarks:

see 'Principles of method if other than guideline'

Principles of method if other than guideline:

Following the guideline, at least five times the amount which was determined in the preliminary study should be used for the main test. In this case, the mixtures with this loading rate did not deliver a filterable solution. The deviation is considered as uncritical, as several prepared solutions were saturated with test item.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

184 mg/L

Temp.:

20 °C

pH:

ca. 6

Remarks on result:

other: mean value ± standard deviation: 184.0 ± 5.6 g/L at 20.0 ± 0.5 °C

Conclusions:

Interpretation of results: very soluble (> 10000 mg/L)
Water solubility (at pH~6) = 184.0 ± 5.6 g/L at 20.0 ± 0.5 °C (mean value ± standard deviation)
The study was performed according to OECD TG105 and EU Method A.6 with only minor deviations considered as uncritical and therefore reliability of Klimisch 1 has been assigned.

Executive summary:

The water solubility of the test substance was determined (from measured concentrations in the filtrated and diluted test solutions) to be 184 g/L (mean value) at 20 °C and pH~6 in a GLP test according to OECD 105 resp. EU A.6 (flask method).

According to the guideline fivefold saturation of the test item water mixture for the main test is proposed. Because the mixture with nominal concentration 1000 g/L resulted in a high amount of dry test item and no filterable solution, a further pre-test was performed to find the highest possible loading rate. As the mixture with nominal load 542 g/L showed sufficient filterable solution, loading rates of 450 – 560 g/L were chosen for the main test.

During equilibration sampling was performed three times. The samples of the third sampling showed after sample preparation strongly scattering results. It was assumed, that this was caused by sample preparation. The sample preparation was changed therefore (dilution in two steps instead of one step). The precision was sufficient after this modification.

The modified sample preparation was applied to the samples of sampling 3 and sampling 4 (plateau). The samples of sampling 1 and sampling 2 were not taken into account for further evaluation, as they were regarded to be not reliable. The measurements of sampling 3 (7 – 9 days) showed, that equilibrium was achieved. On day 10 all flasks were sampled for the measurements at the plateau.

One measurement (flask 2) was stated as an outlier (Grubbs Test). The standard deviation of 5.6 g/L corresponding to a RSD of 3.1 % is sufficient.

No dependency of the solubility on the amount of the test item (nominal load) was perceived.

No observations arousing doubts concerning the accuracy of the results and the validity of the study were made.

Description of key information

The water solubility at 20 °C of the test material was determined to be 184 g/L (very soluble) [OECD Guideline 105, EU Method A.6]

Key value for chemical safety assessment

Water solubility:

184 g/L

at the temperature of:

20 °C