Reaction mass of sodium hydrogen N-(1-oxooctadecyl)-L-glutamate and sodium hydrogen N-(1-oxohexadecyl)-L-glutamate

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:

24 April 2008 and 19 September 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with GLP and agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of relevant results.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of Signature: 15/10/2007; Date of Inspection: 21/08/2007

Type of method:

capillary method

Melting / freezing pt.:

448 K

Atm. press.:

other: Not stated

Decomposition:

yes

Decomp. temp.:

> 448 K

Sublimation:

no

Melting / freezing pt.:

438 K

Atm. press.:

other: Not stated

Decomposition:

yes

Decomp. temp.:

> 438 K

Sublimation:

no

Preliminary Test

The preliminary test indicated that the test material started to melt with decomposition at approximately 473K.

Definitive Test

The temperatures shown in the following tables are those of the liquid bath.

Determination 1

Temperature (K)	Observations
323	White Powder
393	Condensation. The test material had become a waxy solid
448	The test material had started to shrink.
460	The test material had started to become discoloured.
478	The test material had started to liquefy.
498	The test material had turned into a white foam, with brown foam on the surface and brown liquid at the bottom.
513	The foam breaks down to a brown liquid.
531	The test material was an opaque liquid with a brown surface

Determination 2

Temperature (K)	Observations
328	White powder
333	The test material was sticking to the side of the tube.
400	Condensation
438	The test material had started to shrink.
458	The test material started to become discoloured
478	The test material had turned into a white foam
508	The test material was a brown liquid with some foam.
531	The test material was a brown opaque liquid.

Discussion

The test material went through several stages of physical change during the test. The test material became waxy at approximately 333K, the start of melting (indicated by shrinkage) started at approximately 438K, decomposition started at 458K and the end of melting was at approximately 508K.

A preliminary test was performed using the DSC under air and nitrogen atmospheres to give an assessment of thermographic profiles including whether any decomposition observed may be due to thermal or oxidative. Similar endotherms were obtained using air and nitrogen atmospheres, indicating that no oxidative decomposition occurred. An additional DSC showed an endotherm starting at ambient to approximately 70°C corresponding to the test material becoming waxy and an endotherm at approximately 209°C corresponding to melting with decomposition. The DSC thermogram was consistent with the observations made in the liquid bath experiment.

Conclusions:

The test material has been determined to melt with decomposition from 438 to 508K.

Executive summary:

The melting point/freezing point determination for the test material was carried out using the capillary method/melting temperature devices with liquid bath, Method A1 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directice 67/548/EEC.

The test material has been determined to melt with decomposition from 438 to 508K.)

Description of key information

438 to 508 K (164.85 to 234.85 °C), decomposes with melting, EU method A.1, Butler & White (2008)

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

164.85 °C

Additional information

The melting point of the test material was determined in accordance with EU method A.1 under GLP conditions in the key study (Butler & White 2008). The study was performed using the capillary method. Under the conditions of the test, the test material was found to melt with decomposition from 438 to 508 K. The study was assigned a reliability score of 1 in accordance with the criteria for assessing data quality outlined in Klimisch et al. (1997).