2-ethyl-3-methylpyrazine

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 2017-02-21 to 2017-03-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Deviations:

no

GLP compliance:

no

Remarks:

The study was conducted under supervision of a quality assurance unit which had ensured e.g instrumentation validation, reagent/materials certification, analyst certification and providing standard operating procedures.

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

-33.1 °C

Atm. press.:

>= 997 - <= 1 003 hPa

Decomposition:

no

Sublimation:

no

In the temperature range of -40 to -20 °C an endothermic effect was observed.

Run No.	Sample weight (mg)	Onset of Effect (°C)	Range of effect (°C)	Weight loss (mg)	Atmospheric pressure (hPa)
PN12868	16.45	-33.16	-40 to -20 (endo)	16.45	1003.3
PN12884	15.24	-33.06	-40 to -20 (endo)	15.24	997.3

 

During the cooling phase, an exothermal effect in the temperature range of -75 to -70 °C was observed, which can be assigned to the freezing of the test item.

During the heating phase a distinct endothermic effect was observed in the temperature range of -40 to -20 °C, which can be assigned to the melting of the test item. The onset temperatures from both runs did not deviate with more than 0.5 K, therefore the mean value was the melting point of the test item: -33.1 °C.

Conclusions:

The test item has a melting point of -33.1 °C at atmospheric pressure (997 and 1003 hPa, respectively).

Executive summary:

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1 and EPA OPPTS test guideline 830.7200 to determine the melting point of the test item using differential scanning calorimetry (2017). The test item was weighed out into an aluminium crucible under an inert atmosphere. Two tests with about 15 – 16 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a liquid at ambient conditions. Therefore the crucibles were cooled down from ambient temperature to -100 °C with a constant cooling rate of 0.25 K/min under an inert atmosphere. After a waiting period of 30 min at -100 °C, the temperature was increased up to 500 °C at a constant heating rate of 10 K/min. In the temperature range of -40 °C – 20 °C, an endothermic effect were observed, which can be assigned to the melting of the test item. As the onset temperatures in both tests deviate by less than 0.5 K from their mean value of -33.11 °C, the test item has a melting point of -33.1 °C. No observations were made which cause doubt on the validity of the outcome of the study.

Description of key information

The melting point was determined to be -33.1 °C at 1013.25 hPa.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

-33.1 °C

Additional information

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1 and EPA OPPTS test guideline 830.7200 to determine the melting point of the test item using differential scanning calorimetry (2017). The test item was weighed out into an aluminium crucible under an inert atmosphere. Two tests with about 15 – 16 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a liquid at ambient conditions. Therefore the crucibles were cooled down from ambient temperature to -100 °C with a constant cooling rate of 0.25 K/min under an inert atmosphere. After a waiting period of 30 min at -100 °C, the temperature was increased up to 500 °C at a constant heating rate of 10 K/min. In the temperature range of -40 °C – 20 °C, an endothermic effect were observed, which can be assigned to the melting of the test item. As the onset temperatures in both tests deviate by less than 0.5 K from their mean value of -33.11 °C, the test item has a melting point of -33.1 °C. No observations were made which cause doubt on the validity of the outcome of the study.