Xylose

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

The melting behaviour was studied with conventional Differential Scanning Calorimetry (DSC). Decomposition examined by Thermo Gravimetric Analysis.

GLP compliance:

not specified

Type of method:

differential scanning calorimetry

Melting / freezing pt.:

142.4 °C

Decomposition:

yes

Decomp. temp.:

> 138.5 °C

Remarks on result:

other: Peak temperature of melting was 142.4°C, onset of decomposition at 138.5°C

The melting can be said to be anomalous if a change of the conformation of molecules occurs during melting. Also a decomposition taking place in the melting temperature range causes the melting to be anomalous.

The melting of the test substance was anomalous because, besides the melting, also partial thermal decomposition and mutarotation occurred. At slow heating rates the decomposition began before melting ended.

Conclusions:

Melting point = 142.4°C

Executive summary:

The melting temperature of the test substance was determined with DSC. Decomposition was examined by TG. The melting of the test substance was anomalous because, besides the melting, also partial thermal decomposition and mutarotation occurred. The experiments were conducted at a range of temperatures and heating rates. The peak temperature of melting was determined to be 142.4°C and decomposition began at 138.5°C.

 

Description of key information

Peak temperature of melting was 142.4°C with onset of decomposition at 138.5°C

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

142.4 °C