Potassium isobutyrate

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 Jan 2020 - 24 Jan 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

Potassium isobutyrate

EC Number:

243-077-8

EC Name:

Potassium isobutyrate

Cas Number:

19455-20-0

Molecular formula:

C4H8O2.K

IUPAC Name:

potassium 2-methylpropanoate

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: Sponsor / 181101001
- Expiration date of the lot/batch: 31 Oct 2020
- Purity test date: 09 Nov 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room Temperature (20 ± 5 °C); keep away from humidity; keep under inert gas
- Stability under storage conditions: stable

Results and discussion

Water solubility

Key result

Water solubility:

>= 945.02 - <= 990.96 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

11

Details on results:

Flasks 1A-C were used for determination of the equilibration phase only. The water solu-bility of the test item was determined from flasks 2 – 4 at 20.0 ± 0.5 °C and a pH value of 11 as 967.99 ± 22.97 g/L, corresponding to a relative standard deviation of 2.4 %.

Any other information on results incl. tables

The following table gives an overview on the determined solubility of the test item in demineralised water.

Table 4. Determined Solubility in Demineralised Water

Flask	Temperature [°C]	pH	Nominal Concentration [g/L]	Measured Concentration [g/L]
1A	20.0	11	3000.9	1012.34
1B	19.9	11	3001.8	974.70
1C	19.8	11	3002.8	880.37
2	19.8	11	2999.3	992.66
3	20.1	11	3000.2	964.10
4	19.9	11	3003.5	947.22

Applicant's summary and conclusion

Conclusions:

At the plateau, the concentration of Potassium isobutyrate in water had reached:

967.99 ± 22.97 g/L at 20.0 ± 0.5 °C and a pH value of 11
= 967.99 ± 22.97 kg/m3 (SI units)

(mean value ± standard deviation of three individual vessels)

Executive summary:

 

Findings and Results:

The solubility of the test item Potassium isobutyrate in water using the flask method was determined using a validated method for HPLC-UV measurements.

For determination of the solubility of the test item, the preliminary test described in the guideline was performed and to 103 mg of the test item, water was added stepwise. Al-ready after addition of 0.1 mL of water, the test item was completely dissolved. Thus, the solubility was estimated to be higher than 1000 g/L. Additional preliminary tests were per-formed to find the concentration where the test was is completely moistened and a filterable mixture was formed. The highest nominal concentration fulfilling these criteria was 3000 g/L. The solution was filtered using PTFE membrane filters (0.45 µm) and measured using HPLC-UV. The solubility of the test item was estimated as 973.71 g/L. As the solubility of the test item was very high, the nominal concentration of 3000 g/L was chosen for the main test since at this concentration, the test item was completely moistened and the solution was still filterable.

Five vessels (flasks 1C (for the sampling point 72 h) and flasks 2 – 4, blank sample) were set onto the shaking apparatus immediately and shaking was started. After 24 ± 2 h, flask 1B (for the sampling point 48 h) and after 48 ± 2 h, flask 1A (for the sampling point 24 h) were set on the shaker and all flasks were shaken for further 24 ± 2 h at room temperature. Then, flasks 1A-C were taken from the shaker and tempered at 20.0 ± 0.5 °C. Aliquots were taken, membrane filtrated (0.45 µm, PTFE) and diluted to reach the calibrated range.

Because of a difference of less than 15 % in the concentrations on days 2 and 3 and no upward tendency in the three values, the test was finished on day 3.

The final measurement was performed as determination from flasks 2 – 4. None of the filtrated test solutions showed a Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid).

 

At the plateau, the concentration of Potassium isobutyrate in water had reached

 

967.99 ± 22.97 g/L at 20.0 ± 0.5 °C and a pH value of 11

= 967.99 ± 22.97 kg/m3 (SI units)

 

(mean value ± standard deviation of three individual vessels)