Bile, extract

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:

from 2018-05-23 to 2019-02-05

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:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Key result

Atm. press.:

1 013.25 hPa

Decomposition:

yes

Decomp. temp.:

ca. 180 °C

In the temperature range of 80 – 150 °C, a first endothermic effect was observed. Between 310 – 410 °C a second endothermic effect could be detected.

Table 1: Results of the DSC-measurements

No.	Sample weight / mg	Onset of Effect / °C	Range of effect / °C	Weight loss / mg	Atmospheric pressure / hPa
PN15782	6.34	78.8 310.0	80 – 150 (endo) 310 – 410 (endo)	4.30	1001.9

For a verification of the DSC measurement the capillary method was performed. In two of three capillaries the light brown test item started foaming and ascending in the capillary at approx. 140 °C. In the third capillary the test item showed this behavior at approx. 160 °C. In one of the capillaries, the darkened test item flowed back to the bottom of the capillary at approx. 180 °C.

Combining the results of the DSC measurements and of the capillary method, none of the endothermic effects can be assigned to the melting of the test item.

The test item started to decompose at approx. 180 °C.

Conclusions:

The test item decomposes before melting.

Executive summary:

A study was conducted according to OECD TG 102, Regulation (EC) No 440/2008 method A.1 and EPA OPPTS 830.7200 to determine the melting point of the test item using differential scanning calorimetry DSC. The test item was weighed into an aluminium crucible. One test with about 6 mg of the test item was performed. As reference crucible, an empty aluminium crucible was used. The substance is a solid at ambient conditions. Therefore, the test was started at ambient temperature. The temperature was increased up to 500 °C at a constant heating rate of 10 K/min under air. In the temperature range of 80 – 150 °C, a first endothermic effect was observed. Between 310 – 410 °C a second endothermic effect could be detected. For a verification of the DSC measurement the capillary method was performed. Three capillaries were prepared and measured. In the first one foaming formation at ca. 140 °C was observed. In the second at ca. 160 °C and in the third the darkened test item flowed back to the bottom of the capillary at ca. 180 °C. Combining the results of the DSC measurement and the capillary method, none of the endothermic effects can be assigned to the melting of the test item. The test item started to decompose at ca. 180 °C before melting.

Description of key information

The test item decomposes at ca. 180 °C before melting.

Additional information

A study was conducted according to OECD TG 102, Regulation (EC) No 440/2008 method A.1 and EPA OPPTS 830.7200 to determine the melting point of the test item using differential scanning calorimetry DSC. The test item was weighed into an aluminium crucible. One test with about 6 mg of the test item was performed. As reference crucible, an empty aluminium crucible was used. The substance is a solid at ambient conditions. Therefore, the test was started at ambient temperature. The temperature was increased up to 500 °C at a constant heating rate of 10 K/min under air. In the temperature range of 80 – 150 °C, a first endothermic effect was observed. Between 310 – 410 °C a second endothermic effect could be detected. For a verification of the DSC measurement the capillary method was performed. Three capillaries were prepared and measured. In the first one foaming formation at ca. 140 °C was observed. In the second at ca. 160 °C and in the third the darkened test item flowed back to the bottom of the capillary at ca. 180 °C. Combining the results of the DSC measurement and the capillary method, none of the endothermic effects can be assigned to the melting of the test item. The test item started to decompose at ca. 180 °C before melting.