N-glycylglycine

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 June - 23 October 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Version / remarks:

1998

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

EC No. 440/2008

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Test material

Test material information

Constituent 1

Reference substance name:

N-glycylglycine

EC Number:

209-127-8

EC Name:

N-glycylglycine

Cas Number:

556-50-3

Molecular formula:

C4H8N2O3

IUPAC Name:

N-glycylglycine

Test material form:

solid: crystalline

Details on test material:

Batch Number: S119 0711
Storage conditions: room temperature

Specific details on test material used for the study:

Batch No.: S119 0711
Storage: At room temperature (approx. 15-25°C), dry

Results and discussion

Melting / freezing point

Key result

Melting / freezing pt.:

228.8 °C

Atm. press.:

>= 1 002 - <= 1 006 hPa

Decomposition:

yes

Decomp. temp.:

ca. 230 °C

Any other information on results incl. tables

During the heating phase a first endothermic effect was observed in the temperature range of 220 – 270 °C, which could be assigned to the melting of the test item. A second endothermic effect was observed in the temperature range of 280 – 390 °C.

No.	Sample weight / mg	Onset of Effect / °C	Range of effect / °C	Weight loss / mg	Atmospheric pressure / hPa
PN19899	7.78	228.63 289.79	220 – 270 (endo) 280 – 390 (endo)	4.47	1005.6
PN19902	7.65	228.87 287.03	220 – 270 (endo) 280 – 390 (endo)	4.26	1002.0

Optical verification using the capillary method:

To verify the results of the DSC measurement, three additional measurements in melting capillaries were performed in the temperature range of 180 °C to 290 °C at a heating rate of 10 K/min. The test item melted and turned brown starting at a temperature of approx. 220 °C. At a temperature of 240 °C the test item was completely molten and dark brown.

Due to this result, the first endothermic effect can be assigned to the melting of the test item accompanied by its decomposition. As the onset temperatures in both tests do not deviate by more than 0.5 K from their mean value of 228.75 °C, this temperature can be used as melting point. The test item has a melting point of 228.8 °C accompanied by its decomposition, which could be confirmed by the capillary method.

Applicant's summary and conclusion

Conclusions:

The test item Glycyl glycine (CAS no. 556-50-3) has a melting point of 228.8°C at atmospheric pressure (1002 – 1006 hPa) accompanied by its decomposition as determined by Differential Scanning Calorimetry according to Regulation (EC) No 440/2008 Method A.1. and OECD Test Guideline 102 (1995).

Executive summary:

The test item Glycyl glycine (CAS no. 556-50-3) has a melting point of 228.8°C at atmospheric pressure (1002 – 1006 hPa) accompanied by its decomposition as determined by Differential Scanning Calorimetry according to Regulation (EC) No 440/2008 Method A.1. and OECD Test Guideline 102 (1995).