N-[2-[bis(carboxymethyl)amino]ethyl]-N-(1-oxononyl)Glycine

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:

2022-01-17 to 2022-04-04

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)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Version / remarks:

1998

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

183.7 °C

Atm. press.:

1 022 hPa

Decomposition:

yes

Decomp. temp.:

> 183.7 °C

Remarks on result:

other: Melting process is directly followed by a decomposition process

Results of the DSC measurements are summarised in Table 1.

Table 1: Results of the DSC measurements

Measurement	Sample weight [mg]	Onset of effect [°C]	Range of effect [°C]	Weight loss [mg]	Atmospheric pressure [hPa]
1	8.28	163.45 183.67 -	160-170 (endo) 180-240 (endo) 290-350 (exo)	7.05	1022.8
2	7.93	163.46 183.71	160-170 (endo) 180-240 (endo) 290-350 (exo)	6.70	1021.7

The test item showed a first small endothermic effect in the temperature range of 160 – 170 °C and a second larger endothermic effect in the temperature range of 180 – 240 °C. An exothermic effect was detected in the temperature range of 290 – 350 °C. No further thermal effects were observed up to the test end temperature of 500 °C.
During the verification measurements with the capillary method it was observed that the test item started to melt at approx. 180 °C. During the melting process the formation of gas bubbles (foaming) was observed. At 200 °C the test item was completely molten and had turned into a clear yellow liquid. 

The first endothermic effect is too small to be assigned to the melting of the test item which was verified optically by the capillary method. Therefore, the second endothermic effect is assigned to the melting process. As the onset temperatures in both measurements do not deviate by more than 0.5 K from their mean value of 183.69 °C, this temperature can be used as melting point.

The test item did not show a separate distinct endothermic signal which could be assigned to the boiling of the test item above the melting temperature of the test item. Nevertheless, gas formation directly following the melting process was observed by capillary method. However, the cause for the formation of gas can be based on a decomposition process of the test item instead of boiling. If the test item had been boiling the weight loss at the end of the DSC measurement would have been approx. 100 % instead of only approx. 85 %. This means that decomposition product probably remained as residue in the crucible. Furthermore, the liquid in the capillary had turned yellow at 200 °C. This indicates a chemical reaction at these temperatures.

In conclusion, the melting point of the test item was determined at 183.7 °C by DSC measurement and confirmed by the capillary method. The melting process is directly followed by a decomposition process accompanied by gas evolution.

Conclusions:

The melting point of the test item is 183.7 °C

Executive summary:

The test item has a melting point of 183.7 °C at atmospheric pressure (1022 hPa) as determined by DSC and confirmed by the capillary method according to EU Method A.1. and OECD Test Guideline 102 under GLP.

Description of key information

The test item has a melting point of 183.7 °C at atmospheric pressure (1022 hPa) as determined by DSC and confirmed by the capillary method according to EU Method A.1. and OECD Test Guideline 102 under GLP.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

183.7 °C