Selenium disulphide

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:

Started and finished on the 02 March 2017

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:

not specified

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Type of method:

capillary method

Specific details on test material used for the study:

Name: Selenium Disulphide
Batch/Lot number: PMC/285/16
Appearance: Orange/yellow powder
CAS number: 7488-56-4
Purity: 100%
Retest date: 24 November 2019
Storage conditions: Protected from light, room temperature
Safety precautions: Enhanced safety precautions were applied considering the supplied safety data sheet to assure personnel health and safety.

Key result

Melting / freezing pt.:

106.5 °C

  PRELIMINARY TEST

The following preliminary tests were performed:

 

- from 30°C to 400°C at 10°C/min heating rate with three parallel samples:

At about 110°C the colour of test item changed rapidly and continuously then the test item began to melt. At about 117°C in a part of glass tube the test item seemed to be black, the other part of tube seemed to be empty, thereafter the remaining part of test item glowed with rose colour. At about 160°C the whole test item was black, under the black part the tube seemed to be empty, above the black part a purple vapour-like substance appeared then later disappeared. At about 250°C shiny drops or bubbles appeared in the tube. Amount of these parts increased at about 280°C. Above 300°C the amount of black part increased continuously in the tube. The preliminary test was repeated with a slower heating rate to obtain more accurate results.

 

- from 100°C to 115°C at 2°C/min heating rate with two parallel samples:

At about 107°C the test item began to be dark, then at about 109°C it began to melt, at about 110°C the liquid phase appeared in the capillary. At about 111°C one part of test item was bright, the other part was dark in the tube. At about 114°C the tube contained liquid, but a dark part remained. The test was repeated with a slower heating rate to obtain more accurate results.

 

- from 105°C to about 120°C at 1°C/min heating rate with three parallel samples:

At about 107°C the test item began to be dark, then the test item started to melt at about 108°C, thereafter the liquid phase

appeared in the tube. At about 109°C a black part appeared that prevented further observations.

 

- from 105°C to 120°C at 0.5°C/min heating rate with three parallel samples:

At about 106°C the test item began to be dark, then at about 106.9°C it began to melt.

At about 108°C the liquid phase appeared in the tube. At 108.7°C the bottom of the tube contained empty part and above this a black part appeared. At 109.6°C on the wall of tube was a black part and besides this some liquid shone brightly.

At 110.7°C a mixture of a black part, a pinkish brightly liquid and above this vapour, was visible in the capillary. Thereafter the colour of test item became gradually dark. The amount of black part increased at about 115°C. At about 116°C the bottom of capillary seemed to be empty, above this the tube contained black test item and purple vapour.

 

MAIN TEST

For the main study three capillaries containing test item were placed into the apparatus, the block was heated from 105°C to 115°C at 0.5°C/min heating rate. The transformations of the test item were observed, visually through the magnifying glass. Two parallel experiments were carried out and in each case three parallel samples were measured. The observations were same in both experiments: At about 106°C the test item began to be dark, then at about 106.5°C the test item began to melt, the liquid phase appeared, meanwhile the colour of test item changed from vermilion to claret red. At about 108°C the major part of the sample was liquid, but an appreciable amount remained solid. At about 108.2°C a dark part appeared on the wall of capillary. At about 109°C the liquid shon brightly, mixed with the black part. At about 115°C the liquid phase became darker and the black part remained.

Conclusions:

The test item began to melt at about 106.5°C, but the accurate melting point cannot be assessed due to the continuously colour changes and the appearance of black parts, which indicate a visual evidence of degradation simultaneous with melting.

Executive summary:

The purpose of the study was to determine the melting point for selenium disulphide

 

For the determination of the melting point or melting range, the capillary method using a metal block was applied.

Using a linear heating rate of 0.5°C/min the melting point of Selenium Disulphide began to melt at about 106.5°C, although visual

evidence of degradation simultaneous with melting was observed.

 

Description of key information

Key value determined in a GLP accredited laboratory study using capillary method, in accordance with EU Method A.1 and OECD Guideline102.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

106.5 °C

Additional information

The purpose of the study was to determine the melting point for selenium disulphide For the determination of the melting point or melting range, the capillary method using a metal block was applied. Using a linear heating rate of 0.5°C/min the melting point of Selenium Disulphide began to melt at about 106.5°C, although visual evidence of degradation simultaneous with melting was observed.