Sodium 4-[4-[[2-methyl-4-[[(p-tolyl)sulphonyl]oxy]phenyl]azo]anilino]-3-nitrobenzenesulphonate

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:

May 02nd, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

adopted July 27, 1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Specific details on test material used for the study:

The test item was finely ground using a mortar and a pestle.

Decomposition:

yes

Decomp. temp.:

295.48 °C

APPEARANCE OF THE SAMPLES

Before the test the appearance of test item was orange-red powder. After the experiments the test item was cohered in the crucible and blackened.

MEASUREMENTS

During the heating the test item showed endothermic signals in the temperature range of approx. 60 - 170 °C that can be associated with the water evaporation of the test item.

Around 300 °C one exothermic peak could be observed, which was assumed to the decomposition of the test item.

Experiment 1

Sample weight [mg]	Loss of Mass of the Sample (%)	Onset of effect [°C]	Range of effect [°C]	Energy [J/g]
2.47	26	294	281-341	755 (exothermic)

Experiment 2

Sample weight [mg]	Loss of Mass of the Sample (%)	Onset of effect [°C]	Range of effect [°C]	Energy [J/g]
3.08	30	297	284 -343	687 (exothermic)

Experiment 3

Sample weight [mg]	Loss of Mass of the Sample (%)	Onset of effect [°C]	Range of effect [°C]	Energy [J/g]
3.24	24	295	281-343	698 (exothermic)

Conclusions:

Decomposition before melting (at 295.48 °C).

Executive summary:

The thermal behaviour of test item was assessed using the DSC analysis, according to the OECD guideline 102. A small amount of test item was weighed into a one-way 40 µl aluminum crucible and sealed with closed aluminum lid using a capsule presser. Thus prepared capsule was inserted into the furnace of the DSC device and heated from 25 °C to 500 °C with 10 K/minutes heating rate. The measurement was performed under nitrogen atmosphere. Before and after the test, the weight and the appearance of the sample were determined. The test was repeated three times.

During the heating the test item showed endothermic signals in the temperature range of approx. 60 - 170 °C that can be associated with the water evaporation of the test item. Around 300 °C one exothermic peak could be observed, which was assumed to the decomposition of the test item. The endotherm and exotherm peaks in the thermograms do not imply phase transition from a solid to liquid state.

Conclusion

Decomposition before melting (at 295.48 °C).

Description of key information

Decomposition before melting (at 295.48 °C)

Additional information

OECD 102 - DSC analysis