7-acetamido-4-hydroxy-3-[[4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]naphthalene-2-sulphonic 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:

2013-10-02 - 2013-10-17

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:

other: OECD 113 (1981) Screening test for thermal stability and stability in air

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Type of method:

capillary method

Remarks:

and thermal analysis

Key result

Melting / freezing pt.:

> 400 °C

Atm. press.:

ca. 1 013 hPa

Decomposition:

yes

Decomp. temp.:

>= 140 °C

Remarks on result:

other: The test item has no melting point. The test item decomposed.

Thermal stability (DSC)

Two DSC-measurements in a closed glass crucible with the test item showed multistage exothermal effects in the temperature range 140 - 165°C with an energy release of 40 J/g and in the temperature range 175 - 225 °C with an energy release of 195 J/g, and in the temperature range 135 - 165°C with an energy release of 39 J/g and in the temperature range 170 - 225 °C with an energy release of 187 J/g.

Melting point / melting range (DSC)

Two measurements in a closed glass crucible with the test item showed a broad endothermal effect in the temperature range 110 to 160°C. Two exothermal effects were detected in the temperature ranpe 175 - 195°C with an energy release of 11 J/g (1st measurement) and 14 J/g (2nd measurement), and in the temperature range 245 - 295°C with an energy release of 250 J/g (1st measurement) and 243 J/g (2nd measurement). About 2/3 of the weight of the test item remained in the crucible after measurement showing a black residue.

Capillary Method:



No.	Set point	Heating rate	End point	Melting point/range	Remarks
1	50 °C	10 K/min	310°C	Not detected	Starting at approx. 91°C some liquid distilled off, and condensed at the cool part of the capillary outside the heating block. The solid material remained unchanged without melting up to approx. 249°C. Starting above 249 °C the red test item discoloured to black up to 279°C.
1	50°C	10 K/min	310°C	Not detected	Starting at approx. 91°C some liquid distilled off, and condensed at the cool part of the capillary outside the heating block. The solid material remained unchanged without melting up to approx. 245°C. Starting above 245 °C the red test item discoloured to black up to 277°C.

Thus it was concluded, that the test item showed no melting. The test item decomposed

Conclusions:

The test item has no melting point. The test item decomposed.

Executive summary:

At ambient temperature the test item is solid.

Two measurements in a closed glass crucible with the test item showed a broad endothermal effect in the temperature range 110 to 160°C. Two exothermal effects were detected in the temperature ranpe 175 - 195°C with an energy release of 11 J/g (1 st measurement) and 14 J/g (2nd measurement), respectively, and in the temperature range 245 - 295°C with an energy release of 250 J/g (1st measurement) and 243 J/g (2nd measurement), respectively. About 2/3 of the weight of the test item remained in the crucible after measurement showing a black residue

The endothermal effect was further investigated with the capillary method.

Starting at approx. 91°C some liquid distilled off, and condensed at the cool part of the capillary outside the heating block. The solid material remained unchanged without melting up to approx. 245-249°C. Starting above 245 °C the red test item discoloured to black up to 277-279°C. 

Thus it was concluded, that the test item showed no melting. The test item decomposed

Description of key information

Substance decomposes prior to melting.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

400 °C

Additional information

At ambient temperature the test item is solid.

Two measurements in a closed glass crucible with the test item showed a broad endothermal effect in the temperature range 110 to 160°C. Two exothermal effects were detected in the temperature range 175 - 195°C with an energy release of 11 J/g (1^st measurement) and 14 J/g (2^nd measurement), respectively, and in the temperature range 245 - 295°C with an energy release of 250 J/g (1st measurement) and 243 J/g (2nd measurement), respectively. About 2/3 of the weight of the test item remained in the crucible after measurement showing a black residue

The endothermal effect was further investigated with the capillary method.

Starting at approx. 91°C some liquid distilled off, and condensed at the cool part of the capillary outside the heating block. The solid material remained unchanged without melting up to approx. 245-249°C. Starting above 245 °C the red test item discoloured to black up to 277-279°C. 

Thus it was concluded, that the test item showed no melting. The test item decomposed