5-potassium hydrogen L-glutamate

Boiling point

Administrative data

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

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.2 (Boiling Temperature)

GLP compliance:

yes (incl. QA statement)

Type of method:

method according to Siwoloboff

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

Specific details on test material used for the study:

Test item: L-GLUTAMIC ACID MONOPOTASSIUM SALT
MONOHYDRATE
CAS No.: 6382-01-0
Appearance: White powder
Batch number: SLCJ1327
Manufacturing date: 15.12.2020
Expiry date: 01.12.2022
Producer: Sigma-Aldrich Handels GmbH
Sample code: 46/21
Storage temperature range: 10-25 ̊C

Results and discussion

Boiling point

Key result

Atm. press.:

ca. 101 325 Pa

Decomposition:

yes

Decomp. temp.:

ca. 205 °C

Remarks on result:

not determinable because of methodological limitations

Applicant's summary and conclusion

Conclusions:

Boiling point was not determined – test item decomposes and the decomposition process
starts at about 205 °C.

Executive summary:

Boiling point was not determined – test item decomposes and the decomposition process
starts at about 205 °C.

Determination of the boiling point was performed in accordance with the Standard Operating
Procedure SPO/BS/26/b (edition 5). The boiling point determination using capillary tube in
metal block was performed according to EC method A.2 “Boiling temperature” (1.4.4.
Method according to Siwoloboff), which is in conformity with the OECD Guideline for
Testing of Chemicals no. 103 “Boiling point”.
The capillary tube in heated metal block method and BÜCHI Melting Point M-565 apparatus
was used. A sample of the test item was poured into a boiling point tube. The level of sample
was 5-10 mm. A boiling point capillary was inserted into the boiling point tube with its open
end. The capillary tube with a sample of test item and an inner capillary was placed in a
heated metal block.
The sample of test item was heated in a boiling point tube under atmospheric pressure. In the
preliminary test the temperature was increased at a rate of 10 °C/min to determine
approximate value of boiling point. The sample has not achieved the boiling point, it started
to decompose. During the final test the initial test temperature was 120 °C and the heating rate
was decreased to 5 °C/min to observe the changes of the sample more precisely.

Preliminary test
The study was carried out in order to determine the boiling temperature range for LGLUTAMIC ACID MONOPOTASSIUM SALT MONOHYDRATE (in the range of 110.0 –
400.0 °C). The boiling point was not determined due to the decomposition process which was
observed during the study execution. Detailed observation of the sample was carried out
during the ‘final test’.
Final test
The sample was heated in the temperature range of 120-400 °C. At about 130 °C some gas
bubbles started to liberate – the hydration water was expelled from the sample. At about 154
°C the process stopped and the substance became solidified. Then, at about 205 °C, the
sample melted and gas bubbles were very slowly liberated from the capillary – the
decomposition process was initiated. At about 275 °C tint of the sample started to change to
straw. The decomposition process was observed until about 350 °C, when the sample was
dark brown and started to raise in the capillary.