Benzoin Sumatra resinoid

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 18 July to 23 August 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was conducted according to an internationally recognised method, and under GLP. The substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Version / remarks:

2008

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

GLP compliance programme (inspected on 13-14 October 2014 / signed on 8 April 2015)

Type of method:

capillary method

Key result

Melting / freezing pt.:

>= 53.4 - <= 60.7 °C

Remarks on result:

other: main of 2 determinations with capillary method

RESULTS

Different methods were performed to determine the melting point of this substance: DSC and capillary method pre-tests. Then capillary method as a main test was chosen.

Pre-test for melting range following capillary method

Table 4.2.1.-  Values Pre-Test for melting range following capillary method

Begin of melting process	End of melting process
60.0 °C	72.0°C

The test item melted to a red-brownliquid. After cooling down the test item was a red-brown solid. Some of the test item was taken to grind, the test item was visually looked like the original state.

Security Pre-test for the DSC instrument

The crucible was found visually unchanged after reaching a temperature of 420°C. The weight was recorded with 48.81 mg (2.72 mg residue). After further heating to 600°C and cooling down the crucible was bloated. The weight was recorded with 46.47 mg (0.38 mg residue). After heating and weighing of 600 °C the crucible was opened, a black residue (like charcoal) was visible.

Calibration

After calibration with indium and zinc the measurement of indium yielded the following values:

Table 4.2.2.-Values DSC Indium

ExpectedMelting point	Measured Melting point	Expected Energy	Measured Energy	Assessment
156.6 ± 1.0°C	156.29 °C	28.45 ± 1.0 J/g	28.78 J/g	OK

 

The measurement of indium after calibration met the validity criteria.

Results with DSC method

Table 4.2.3.- Values Observations

	Mass test item	Mass crucible (before measurement):	Mass crucible (after measurement):	Observations
First Measurement	1.10 mg	46.29 mg	46.22 mg	After the test the crucible was visually unchanged. The crucible was opened, a red-brown glassy mass was visible.
Second Measurement	2.96 mg	48.88 mg	48.84 mg	After the test the crucible was visually unchanged
Third Measurement	3.12 mg	49.08 mg	48.97 mg	After the test the crucible was visually unchanged
Fourth Measurement	3.00 mg	48.76 mg	48.63 mg	After the test the crucible was visually unchanged

 

DSC measurements show no reliable results, the determination of the Melting Point with the Capillary Method was performed.

Results Melting Point with the Capillary Method (main test)

Table 4.2.4.- Values Melting Point with the Capillary Method

Melting point/range	Begin	End
First Determination	53.5 °C (326.7 K)	60.6 °C (333.8 K)
Second Determination	53.3 °C (326.5 K)	60.7 °C (333.9 K)

 

The test item melted to a red-brown liquid. After cooling down the test item was a red-brown solid looked like the original state.

 

Melting range: 53.4 °C to 60.7 °C (326.6 K to 333.9 K)

Standard deviation: 0.14 (begin); 0.07 (end)

Estimated accuracy: ± 0.2 °C

Validity melting point

All validity criteria are presented in the following table.

Table 4.2.5.- Validity melting point

Parameter	Criterion	Found	Assessment
Difference between duplicate determinations	<=0.5 K	0.1 K	valid
Difference between begin and end of melting process	<=0.5 K	5.2 K	melting range is stated

 

The validity criterion “difference between duplicate determinations” was met. The test item showed a melting range, no melting point. As the test item consists of a mixture, this is considered as normal.

Conclusions:

The melting range was determined as 53.4 °C to 60.7 °C (326.6 K to 333.9 K)

Executive summary:

The melting point test with the substance was performed under GLP according to OECD 102 / EU A1 guideline, using capillary method.

At first one experiment was conducted via DSC (differential scanning calorimetry). As no significant events were observed, the capillary method was conducted as a main test. The melting range was determined as 53.4 °C to 60.7 °C (326.6 K to 333.9 K) with capillary method. These values are the means from two independent determinations.

Description of key information

The melting range was determined as 53.4 °C to 60.7 °C (326.6 K to 333.9 K)

Additional information

A reliable GLP experimental study, conducted according to a recognized OECD/EC guidelines using capillary method, is available.

It is considered as a key study. The result is retained as key data.