2-oxoglutaric acid

Melting point / freezing point

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-10-31 to 2016-12-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

adopted 27 July, 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

30 May, 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

115 °C

Atm. press.:

1 013 Pa

Decomposition:

yes

Decomp. temp.:

> 180 °C

Sublimation:

no

A preliminary thermogravimetric measurement was performed over a temperature range from room temperature to approx. 600 °C. Two steps were registered with maxima at 226 °C resp. 427 °C. A total mass loss of 86.3 % at the final temperature could be observed (mass change in the range until 360 °C: - 77.1 %; mass change in the range from 360 to 600 °C: -9.2 %). No significant mass loss occurred due to purging. The course of the thermogravimetric curve suggests decomposition of the test item. After cooling the residue looked black and shiny. The DSC measurements were performed twice in the temperature range from 20 - 400 °C. A sharp endothermic peak indicating a melting point could be observed (peak maximum: 119 °C /119 °C; extrapolated onset temperature: 115.20 °C/ 115.22 °C; rounded mean of both determinations: 115 °C). Upon further heating the DSC-curve showed no more sharp peaks but the typical fluctuating course of decomposition starting at approx. 180 °C. Reweighing after the measurement showed that the sample had lost 74.7 %/ 74.8 % of its mass. The residue was brown-black discoloured and bloated coming out of the 50 µm hole.

Conclusions:

The melting temperature of 2-oxoglutaric acid was determined by differential scanning calorimetry according to OECD Test Guideline 102 and EU test method A.1
The melting temperature is 115 °C.

Reference 2

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Version / remarks:

handbook data

Principles of method if other than guideline:

- Principle of test: Not specified/handbook data
- Short description of test conditions: Not specified/ handbook data

GLP compliance:

not specified

Other quality assurance:

other: not specified

Type of method:

other: not specified, handbook data

Melting / freezing pt.:

115.5 °C

Decomposition:

no

Sublimation:

no

Conclusions:

The melting point of 2-oxoglutaric acid is115.5°C according to CRC: Handbook of Chemistry and Physics: A Ready-Reference Book of Chemical and Physical Data.

Description of key information

Melting point: 115°C, OECD guideline 102, GLP, RL1

CRC handbook of chemistry and physics: melting point: 115.5°C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

115 °C

Additional information

In a Study according to OECD guideline 102, GLP, the melting point of 2-oxoglutaric acid was determined to be 115°C. This result is in line with the published literature data.