[No public or meaningful name is available]

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:

12 March 2018 to 03 April 2018

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:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

>= 31.18 - <= 68.69 °C

Decomposition:

yes

Decomp. temp.:

148 °C

Remarks on result:

other: Atmospheric pressure not specified

Pre-Test for Melting Range

Table 1: Results of the Pre-Test

Observations	Temperature (°C)
The test material began to melt	65
The test material completely melted to a yellow-white liquid. Capillary sank down to the bottom.	86
Liquid became clear	89
Liquid completely clear, slightly yellow	98
Some bubbles rising	134
Colour of liquid more yellow, less bubbles	148
Colour of liquid strong yellow, no bubbles anymore	156
Colour of liquid slightly orange	181
Gas burner switched off, colour of liquid getting darker and darker	190

 

- Decomposition of the test material occurred after melting but before boiling. Decomposition started at approx. 148 °C indicated by colour change.

 

Security Pre-Test for the DSC Instrument

- The crucible was black coloured and stuck on the ground after reaching a temperature of 420 °C.

- The weight was recorded with 33.68 mg.

- The second crucible was visually unchanged and the weight was recorded with 36.16 mg after heating to 100 °C.

 

Calibration

- After calibration with indium and zinc the measurement of indium yielded the following values:

Expected melting point: 156.6 ± 1.0 °C; measured melting point: 156.68 °C

Expected energy: 28.45 ± 1.0 J/g; measured energy: 28.69 J/g

Assessment: OK

- The measurement of indium after calibration met the validity criteria.

 

DSC Measurement of the Test Material

Table 2: Values of DSC Test Material First Determination

	Temperature (°C)
Melting Range	Begin	End
	31.49	67.21
Onset	37.68
Peak Maximum	53.25

 

Table 3: Values of DSC Test Material Second Determination

	Temperature (°C)
Event Range	Begin	End
	25.67	60.28

 - As this measurement showed an odd curve a third measurement with a new crucible was prepared.

 

Table 4: Values of DSC Test Material Third Determination

	Temperature (°C)
Melting Range	Begin	End
	31.18	68.69
Onset	39.97
Peak Maximum	53.51

 

 Observations

- The crucible was visually unchanged after all three measurements.

 

Interpretation

- In all three runs an endothermic behaviour was detected. In the first and third measurement a clear melting range peak is visible in line with pre-test findings.

- As the peak was wide and flat and not sharp and high like the indium measurement for the beginning of the melting range the start and the end of the event was used for evaluation rather than the onset value. The start and end of the event were evaluated with the Event Mark function of the DSC software.

- As the repetition measurement was not reproducible, the determination was discarded.

 

Table 5: Summary of Results

Melting Range	°C	K
First Determination
Begin	31.49	304.64
End	67.21	340.36
Peak Maximum	53.25	326.40
Onset	37.68	310.83
Repeat Second Determination
Begin	25.67	298.82
End	60.28	333.43
Third Determination
Begin	31.18	304.33
End	68.69	341.84
Peak Maximum	53.51	326.66
Onset	39.97	313.12
Min.	31.18	304.33
Max.	68.69	341.84
Peak Maximum	53.51	326.66

  

Validity

- As the deviation between the evaluated determinations (onset value) was above 0.5 K a melting range is stated.

 

Discussion

- The determination of the melting point of the test material was performed via DSC (differential scanning calorimetry).

- In all runs an endothermic behaviour was detected. In the first and third measurement a clear melting range peak is visible.

- Therefore the melting range was determined under these circumstances as: 31.18 °C (304.33 K) to 68.69 °C (341.84 K).

A peak maximum was detected with 53.51 °C (326.66 K).

The onset values were calculated in a range of 37.68 – 39.97 °C.

- These values are the results of two independent determinations.

- A melting point range has been reported in keeping with the UVCB nature of the test material.

- No observations were made which might cause doubts on the validity of the study outcome. Therefore, the result of the study is considered valid.

Conclusions:

Under the conditions of this study, the melting range of the test material was 31.18 to 68.69 °C.

Executive summary:

The melting point of the test material was investigated in accordance with the standardised guidelines OECD 102 and EU Method A.1, under GLP conditions.

The determination of the melting point of the test material was performed via DSC (differential scanning calorimetry). In all runs an endothermic behaviour was detected. In the first and third measurement a clear melting range peak is visible.

The melting range was determined under these circumstances as: 31.18 °C (304.33 K) to 68.69 °C (341.84 K). A peak maximum was detected with 53.51 °C (326.66 K). The onset values were calculated in a range of 37.68 – 39.97 °C. These values are the results of two independent determinations.

A melting point range has been reported in keeping with the UVCB nature of the test material. No observations were made which might cause doubts on the validity of the study outcome. Therefore, the result of the study is considered valid.

Under the conditions of this study, the melting range of the test material was 31.18 to 68.69 °C.

Description of key information

Under the conditions of this study, the melting range of the test material was 31.18 to 68.69 °C.

Additional information

The melting point of the test material was investigated in accordance with the standardised guidelines OECD 102 and EU Method A.1, under GLP conditions. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

The determination of the melting point of the test material was performed via DSC (differential scanning calorimetry). In all runs an endothermic behaviour was detected. In the first and third measurement a clear melting range peak is visible.

The melting range was determined under these circumstances as: 31.18 °C (304.33 K) to 68.69 °C (341.84 K). A peak maximum was detected with 53.51 °C (326.66 K). The onset values were calculated in a range of 37.68 – 39.97 °C. These values are the results of two independent determinations.

A melting point range has been reported in keeping with the UVCB nature of the test material. No observations were made which might cause doubts on the validity of the study outcome. Therefore, the result of the study is considered valid.

Under the conditions of this study, the melting range of the test material was 31.18 to 68.69 °C.