Haematoxylin

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Test material

Test material information

Constituent 1

Reference substance name:

Haematoxylin

EC Number:

208-237-3

EC Name:

Haematoxylin

Cas Number:

517-28-2

Molecular formula:

C16H14O6

IUPAC Name:

haematoxylin

Results and discussion

Melting / freezing point

Key result

Melting / freezing pt.:

>= 267 °C

Atm. press.:

ca. 1 013 hPa

Decomp. temp.:

ca. 267 °C

Remarks on result:

not determinable

Any other information on results incl. tables

A first pre-test was conducted and the test item appeared to be degraded at the end of measurements. To determine if peaks observed during this pre-test correspond to thermal degradation and not to transition phases, three more tests were performed and corresponding thermograms were obtained. Moreover the crucible was observed and opened at the end of each trial and the appearance of the test item was checked.

A first peak was observed near 140°C and seems to correspond with the boiling of the water contained in the test item as a mass loss of about 5.3% is observed and comply with the quantity of water (5.3%) given by the certificate of analysis.

A second peak was observed near 210°C. It seems the test item under powder form melts at this temperature and becomes “vitrified”. However, if the test item is cooled and then heated again, the transition peak is no longer observed.

A third peak is observed near 267°C and corresponds to the degradation of the test item. The test item changes into a black carbonised powder. In addition the test item mass decreases and thus indicates an emission of volatile compounds during the degradation process.

Moreover, the melting point of the Indium respects the checking cards limits (156.6°C for a reference value of 156.6°C) so as its enthalpy (29.31 J/g for a reference value of 28.6 J/g).

Applicant's summary and conclusion

Conclusions:

No melting point or boiling point of the substance were observed up to 267°C as the test item starts to degrade at this temperature.
However, the following observations can be noticed. The water contained into the test item vaporizes near 140°C. The test item is “vitrified” near 210°C.

Executive summary:

No melting point or boiling point of the substance were observed up to 267°C as the test item starts to degrade at this temperature.

However, the following observations can be noticed. The water contained into the test item vaporizes near 140°C. The test item is “vitrified” near 210°C.