Nitric acid, ammonium calcium salt

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:

15 April 2010- 06 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other 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

Specific details on test material used for the study:

Experiment 1 was performed with fine particles in the test substance. Experiments 2-4 were performed with ground test substance. Grinding was performed using a mortar and pestle.

Key result

Remarks on result:

other: Melting was not observed up to 400°C

TGA

From approximately 150°C upwards the weight of the sample decreased significantly. After the experiment, a white molten residue remained in the sample container (original colour: white).

DSC EXP. 1

A first endothermic effect was observed at the start of the experiment. Between 75°C and 125°C, a second effect was observed with peaks at 94°C and 104°C. A third endothermic effect was observed at a temperature of 168°C. After the experiment, a white coalesced residue remained in the sample container.

 

DSC EXP. 2

During the second experiment, a closed sample container was used in order to determine evaporation. A lower start temperature was used in order to investigate the endothermic peak at the start of the first experiment. The first endothermic peak was observed at 39°C. The second endothermic effect was observed at 104°C. Because this is comparable with the first experiment, it indicated that the (second) peak was not due to evaporation. The third endothermic peak shifted significantly to a higher temperature (i.e. to 237°C) which indicates that the peak was caused by evaporation. After the experiment, a white coalesced residue remained in the sample container. DSC curve: see illustration below.

 

DSC EXP. 3

With the third experiment a repeated heating cycle was used in order to determine if melting caused one or both of the first two peaks observed during the second experiment. During the first heating two endothermic peaks were observed at 41°C and 109°C. Cooling showed no effects which were caused by crystallization. Second heating shows no effects which can be allocated to melting. After the experiment, the residue appeared to be unchanged.

DSC EXP. 4

A lower heating rate was used in order to determine reaction and/or decomposition. The endothermic peaks shifted to a lower temperature which indicates that the peaks were due to reaction and/or decomposition. After the experiment, the residue appeared to be unchanged.

Conclusions:

Using differential scanning calorimetry (DSC), melting of CN-Nitcal was not observed up to 400°C.

Executive summary:

No melting point was determined in this study. The temperature range in two DSC experiments was up to 400°C. Therefore it was concluded that the substance does not have a melting point up to 400°C. In the study report it was also concluded that the endothermic effect between ca 75 and 125°C was caused by reaction/decomposition.

Description of key information

A DSC study according to OECD 102 and EC A.1 guideline was performed showing no melting of CN-Nitcal up to 400°C.

Additional information

No melting point was determined in this study. The temperature range in two DSC experiments was up to 400°C. Therefore it was concluded that the substance does not have a melting point up to 400°C. In the study report it was also concluded that the endothermic effect between ca 75 and 125°C was caused by reaction/decomposition.