Sodium hydrogen L-aspartate

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14.07.2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

> 140 - < 149 °C

Atm. press.:

1 013.25 hPa

Decomposition:

no

Values of the DSC run

Sample weight [mg]	Loss of Mass of the Sample (%)	Onset of effect [°C]	Endset of effect [°C]	Peak Maxium [°C]	Energy [J/g]
3.03	50	141	147	144	- 200 (endothermic)
1.89	43	140	151	145	- 223 (endothermic)
1.79	77	140	149	145	- 223 (endothermic)

 

Summary of the DSC Test of Test Item

	Experiment 1	Experiment 2	Experiment 3	Mean
Onset of effect [°C]	141	140	140	140
Endset of effect [°C]	147	151	149	149

 

 

Using a linear heating rate of 10 °C/min the melting point of L-aspartic acid sodium salt monohydrate was determined to be in the range of 140 - 149 °C (414 - 422 K). In a non-GLP study, the melting point of the test item was measured with the capillary method and was visually determined that the test item starts to directly melt at around 140 °C and no dehydration can be observed.

 

Conclusions:

The melting range of the test item was determined to be 140-149 °C at 1013.25 hPa.

Executive summary:

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1 and EPA OCSPP test guideline 830.7200 to determine the melting point of the test item using differential scanning calorimetry. The test item was weighed out into an aluminium crucible under an inert atmosphere (nitrogen). Two tests with about 1.7 – 3 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a solid at ambient conditions. Therefore the crucibles were heated from room temperature up to 500 °C at a constant heating rate of 10 K/min. The onset temperatures in the three tests deviate less than 0.5 K from their mean value. The melting range of the test item was determined to be 140-149 °C at 1013.25 hPa. No observations were made which cause doubt on the validity of the outcome of the study.

Description of key information

The melting range of the test item was determined to be 140-149 °C at 1013.25 hPa.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

140 °C

Additional information

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1 and EPA OCSPP test guideline 830.7200 to determine the melting point of the test item using differential scanning calorimetry (reference 4.2 -1). The test item was weighed out into an aluminium crucible under an inert atmosphere (nitrogen). Two tests with about 1.7 – 3 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a solid at ambient conditions. Therefore the crucibles were heated from room temperature up to 500 °C at a constant heating rate of 10 K/min. The onset temperatures in the three tests deviate less than 0.5 K from their mean value. The melting range of the test item was determined to be 140-149 °C at 1013.25 hPa. No observations were made which cause doubt on the validity of the outcome of the study.