Indium, cake

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:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Principles of method if other than guideline:

Principle of the test method
In a measurement with differential scanning calorimetry (DSC) a sample of the test item and a reference material (identical crucible without the test item) are subjected to the same controlled temperature program. The difference in the temperatures of the test item and the reference material is recorded and applying a calibration function converted to a heat flow signal. When the sample undergoes a transition involving a change in enthalpy (endothermic on melting), that change is indicated by a departure from the base line of the heat flow record.
Thermogravimetry (TG) is based on continuous recording of mass changes of a sample as a function of temperature (with first derivative curve DTG).
Simultaneous Thermal Analysis (STA) generally refers to the simultaneous application of Thermogravimetry (TG) and Differential scanning calorimetry (DSC) to one and the same sample in a single instrument. The test conditions are perfectly identical for the TG and DSC signals (same atmosphere, gas flow rate, vapor pressure of the sample, heating rate, thermal contact to the sample crucible and sensor, radiation effect, etc.). The analyzability of the signals is improved, since two or more sets of information concerning sample behavior are always simultaneously available (differentiation between phase transformation and decomposition, between addition and condensation reactions, recognition of pyrolysis, oxidation, and combustion reactions, etc.).

GLP compliance:

not specified

Type of method:

other: simultaneous thermal analysis - simultaneous appication of thermogravity and differential scanning calorimetry

Test material

Test material information

Constituent 1

Reference substance name:

Indium, cake

EC Number:

273-794-1

EC Name:

Indium, cake

Cas Number:

69029-48-7

IUPAC Name:

Insoluble indium-containing residue after precipitation of indium bearing solutions

Test material form:

other: solid pellet-like

Details on test material:

substance as put on the market

Results and discussion

Melting / freezing point

Melting / freezing pt.:

> 1 100 °C

Atm. press.:

1 atm

Decomposition:

yes

Sublimation:

yes

Remarks on result:

other: No melting point was found up to 1100 °C The decomposition/sublimation of the sample starts with the beginning of heating.

Any other information on results incl. tables

The first two DSC measurements were combined with a thermogravimetric (TG) measurement.

Measurement 1:

The first STA measurement shows a decomposition/sublimation in several steps and in a very complex manner. Beginning at room temperature there is a permanent weight loss till ca. 1000 °C. Then there is a small increase in weight, caused by precipitation through sublimation. After cooling down the sample crucible as well as the reference crucible is covered with a grey precipitation. The residue is discoloured dark-grey, but still a powder, so there are no visible indications of melting. There are two endothermic peaks which can be assigned to phase changes, possibly partial melts. A very weak maximum at 127 °C (onset temperature: 125 °C) and a sharp peak with maximum at 663 °C (onset temperature: 659 °C).

Measurement 2:

The second STA measurement was stopped at 680 °C, directly after the sharp endothermic peak. Up to this temperature the curves show the same course as in the first measurement. After cooling down, the sample holder, the reference crucible as well as the sample crucible are covered with a red-brown precipitation. The residue is discoloured olive-green, but still a powder, so there are no visible indications of melting. There are two endothermic peaks which can be assigned to phase changes, possibly partial melts. A very weak maximum at 128 °C (onset temperature: 125 °C) and a sharp peak with maximum at 663 °C (onset temperature: 659 °C).

Measurement 3:

Because the first weak phase change is overlapped by the strong starting deflection of the STA apparatus, a pure DSC measurement is realized, to detect the reaction more precisely. The DSC curve shows a small but very sharp peak with an onset temperature at 125 °C and a maximum at 126 °C.

In summary:

Right from the beginning the sample shows decomposition and sublimation. Up to 1100 °C there is no unambiguous proof of melting, but the curves show two endothermic phase changes in varying degrees, which possibly refer to partial melt. Melting temperature: No melting point was found up to 1100 °C The decomposition/sublimation of the sample starts with the beginning of heating.

Phase changes: 125 °C (possibly partial melt), 659 °C (possibly partial melt)

Applicant's summary and conclusion

Conclusions:

study according to standard OECD protocol

Executive summary:

Right from the beginning the sample shows decomposition and sublimation. Up to 1100 °C there is no unambiguous proof of melting, but the curves show two endothermic phase changes in varying degrees, which possibly refer to partial melt.

Melting temperature: No melting point was found up to 1100 °C, the decomposition/sublimation of the sample starts with the beginning of heating.

Phase changes: 125 °C (possibly partial melt), 659 °C (possibly partial melt)