4-[[2-[[2,5-dimethoxy-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-1,3-dioxobutyl]amino]-5-methoxy-2-methylbenzenesulphonic acid, sodium 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:

April 06, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

no

Type of method:

differential scanning calorimetry

Key result

Decomposition:

yes

Decomp. temp.:

> 280 °C

Two DSC measurements in aluminium crucibles with a hole showed endothermal effects in the temperature range of 35 – 45 °C and 115 – 150 °C with no clear melting point (onset). Above 280 °C an exothermal decomposition followed. Visual inspection of the crucible of the experiment which was stopped before the decomposition showed an unchanged test item. Thus no melting was observed.

The results of the DSC measurements are summarized in Table 1.

Table1: Melting point (DSC measurements)

Ident No.	Test item / mg	Starting temperature / °C	Final test temperature / °C	Temperature range (endo-thermal) / °C	Onset (melting) / °C	Crucible	Observations after the measurement
36932	11.25	25	500	115 – 145	-	Aluminium with a hole	Test item was a black residue: 50 % mass loss
36933	9.90	25	180	35 – 45 115 – 150	-	Aluminium with a hole	Test item was unchanged: 5 % mass loss

Executive summary:

The test item had no melting point and no boiling point at atmospheric conditions. Decomposition started at approx. 280 °C.

Description of key information

The test item had no melting point and no boiling point at atmospheric conditions. Decomposition started at approx. 280 °C.