2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3,8-bis[[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]azo]-, trisodium salt

Melting point / freezing point

Administrative data

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

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:

according to OECD 102 / 103 resp. EU A.1 / A2

Deviations:

no

GLP compliance:

no

Type of method:

differential scanning calorimetry

Specific details on test material used for the study:

The test substance was ground and dried in an agate mortar. Drying was done in an des-iccator at least overnight

Key result

Decomposition:

yes

Decomp. temp.:

>= 158.81 °C

Remarks on result:

not determinable

Aone-way aluminum crucible with perforated lid was prepared. 1.18 mg test substance was weighed into a one-way aluminium crucible. The weight of the crucible with the test substance was recorded with 47.49 mg. The crucible was heated in the muffle furnace from room temperature to 420 °C.

A second crucible was prepared without perforation with 1.26 mg test substance. The weight of the closed crucible was recorded with 34.00 mg.

After cooling down the crucibles was inspected for visual changes and the weight of the crucibles were recorded

The crucible containing the test substance was heated under inert gas from 15 to 350 °C using a heating rate of 10 K/min. As reference an empty crucible of the same kind was used. The heat flow and temperature were recorded by the DSC during the test. After the test the crucible was inspected for visual changes.

Observations Pre-test for melting and boiling point

Performances	Temperature in °C
Capillary with test item was set in an Aluminium block	20.4
No changes visible	At 124, 144 and 167 °C
Getting darker	197 °C
No further changes	220°C
More dark colour	280°C
Test terminated. Test sample completely black	350°C

 

No melting was visible, therefore the determination of the boiling point is not possible.

 

Conclusions:

No melting or boiling point of Blendazol Red could be determined via DSC (differential scanning calorimetry) under these circumstances, because of decomposition of the test substance.
In all runs small endothermic and exothermic were detected.
Referring to the pre-test, beginning decomposition was observed at 197 °C indicated by colour change. The bloated crucible after the DSC measurements and the remained black residue confirm the decomposition.
Therefore, beginning decomposition should be stated as:

158.81 °C (431.96 K)

Executive summary:

No melting or boiling point of Blendazol Red could be determined via DSC (differential scanning calorimetry) under these circumstances, because of decomposition of the test substance.

Description of key information

No melting or boiling point of Blendazol Red could bedetermined via DSC (differential scanning calorimetry) under these circumstances, because of decomposition of the test substance.