5-potassium hydrogen L-glutamate

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Test material

Test material information

1

Reference substance name:

5-potassium hydrogen L-glutamate

EC Number:

243-094-0

EC Name:

5-potassium hydrogen L-glutamate

Cas Number:

19473-49-5

Molecular formula:

C5H9NO4.K

IUPAC Name:

potassium 5-oxido-5-oxo-L-norvaline

Test material form:

solid

Results and discussion

Water solubility

Key result

Water solubility:

ca. 1 136.11 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

5.877 g/L

Incubation duration:

ca. 3 d

Temp.:

30 °C

pH:

>= 8.53 - <= 8.58

Applicant's summary and conclusion

Conclusions:

The solubility of Test item at pH 8.53 – 8.58 in water is 1136.11 g/l.

Executive summary:

Description of the method

The study of the determination ofL-GLUTAMIC ACID MONOPOTASSIUM SALT MONOHYDRATEsolubility in water at one pH valueusing shake flask methodwas carried out according to the method EC A.6. COUNCIL REGULATION (EC) No 440/2008 (Method A.6. Water solubility; p.57) and (EC) No 260/2014 (Method A.6. Water solubility; p.3) which is in conformity with OECD Guideline 105 and concluded in SPO/BS/08/b, edition 6.

3.5.2. Course of the study

The preliminary test of a small sample (~ 0.1g) ofTest itemwasperformed in a10 ml measuring cylinder, ingradually increased volume of distilledwater. Starting from 0.1 g of water after addition of the sample, the solution was vigorously mixed for 10 minutes and it was visually determined if insoluble parts ofTest itemwas in solution. In that way, an approximate solubility ofTest itemwas determined at the solventvolume in which the whole substance was dissolved.

About 46 g of test item was weighed into each of three 50 ml glass vessels fitted with glass stoppers. 17 ml of double distilled water was added to each vessel. The volume of water was chosen on the basis of the analytical method and solubility range. 

These closed vessels were agitated in an incubator at 30^oCwith magnetic stirrers.

After one day, one of the flasks was equilibrated for 24 h at the test temperature (20 ± 0.5)^oC with occasional shaking. The other two flasks were treated similarly after initial equilibration at 30^oC for two and three days,respectively.

The samples taken during saturation were separated using a vial-centrifuge to give the clear liquid phase andthe concentration of test substance in the clear solvent phase was determined by a suitable HPLCmethod.

If the concentrations measured in at least the two last flasks did not differ by more than 15%, the test was satisfactory. If the results from vessels 1, 2 and 3 show a tendency of increasing values, the whole test should be repeated using longer equilibration times.

The pH of each sample was measured using a calibrated pH electrode.

If the measured concentration exceeded 100 g/l, the density of the solution was determined (SPO/BS/16/t, edition 2) to recalculate the analytical study results which were obtained in g/kg.