(2S)-2-amino-3-(4-{[bis(sodiooxy)phosphoryl]oxy}phenyl)propanoic acid

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:

from 2020-02-24 to 2020-04-27

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

Remarks:

and capillary method

Key result

Atm. press.:

> 984 - < 993 hPa

Decomposition:

yes

Decomp. temp.:

ca. 200 °C

Sublimation:

no

Starting at a temperature of 160 °C a first endothermic effect could be observed, which was directly followed by an exothermic effect starting at a temperature of 200 °C with an energy release of -60 J/g. The exothermic effect was directly followed by an endothermic effect starting at a temperature of 240 °C. A third endothermic effect was observed in the temperature range of 310 °C – 430 °C.

 

Table1: Results of the DSC-measurements

No.	Sample weight / mg	Onset of Effect / °C	Range of effect / °C	Weight loss / mg	Atmospheric pressure / hPa
PN19190	7.38	175.95 --- 262.69 325.06	160 – 200 (endo) 200 – 240 (exo) 240 – 300 (endo) 310 – 430 (endo)	2.70	993.3
PN19198	8.28	175.90 --- 262.30 320.16	160 – 200 (endo) 200 – 240 (exo) 240 – 300 (endo) 310 – 420 (endo)	2.98	983.5

As none of the endothermic effects could be clearly assigned to a melting or boiling of the test item, the capillary method was performed in order to visually investigate if there is a melting or boiling up to a temperature of 400 °C.

The test item turned from white to brown starting at a temperature of approx. 275 °C. At this temperature the test item was still solid. Starting at a temperature of approx. 320 °C a partial liquefaction could be observed. At a temperature of 400 °C there were still residues of solid matter in the partial liquefied test item.

Due to the observations in the measurements using the capillary method, it can be stated that the test item has no melting or boiling point up to its decomposition starting at a temperature of approx. 200 °C.

Conclusions:

For the test item no melting point was found at atmospheric pressure (984 – 993 hPa) until the decomposition starting at a temperature of approx. 200 °C as determined by differential scanning calorimetry and confirmed by the capillary method.

Executive summary:

A study was conducted according to OECD TG 102, Regulation (EC) No 440/2008 method A.1 and EPA OPPTS 830.7200 to determine the melting point/range of the test item using differential scanning calorimetry (DSC). The test item was weighed into an aluminium crucible under air. Two tests with about 7 – 8 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is solid at ambient conditions. The crucible was heated from room temperature to 500 °C with 10 K/min heating rate under air. Several exothermic and endothermic effects were observed in the temperature range of 160 – 420 °C.As none of the endothermic effects could be clearly assigned to a melting of the test item, the capillary method was performed in order to visually investigate if there is a melting or boiling up to a temperature of 400 °C. The test item did not melt completely up to the maximum temperature of 400 °C. Due to the observations in the measurements using the capillary method, it can be stated that the test item has no melting point up to its decomposition starting at a temperature of approx. 200 °C.

Description of key information

For the test item no melting point was found at atmospheric pressure (984 – 993 hPa) until the decomposition starting at a temperature of approx. 200 °C as determined by differential scanning calorimetry and confirmed by the capillary method (reference 4.2-1).

Additional information

A study was conducted according to OECD TG 102, Regulation (EC) No 440/2008 method A.1 and EPA OPPTS 830.7200 to determine the melting point/range of the test item using differential scanning calorimetry (DSC). The test item was weighed into an aluminium crucible under air. Two tests with about 7 – 8 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is solid at ambient conditions. The crucible was heated from room temperature to 500 °C with 10 K/min heating rate under air. Several exothermic and endothermic effects were observed in the temperature range of 160 – 420 °C.As none of the endothermic effects could be clearly assigned to a melting of the test item, the capillary method was performed in order to visually investigate if there is a melting or boiling up to a temperature of 400 °C. The test item did not melt completely up to the maximum temperature of 400 °C. Due to the observations in the measurements using the capillary method, it can be stated that the test item has no melting point up to its decomposition starting at a temperature of approx. 200 °C.