Essential oil of Cinnamomum camphora (Lauraceae) obtained from leaves by steam distillation

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 9 to 11 Octobre 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 test substance is adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling 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:

differential scanning calorimetry

Key result

Boiling pt.:

>= 178.26 - <= 179.13 °C

Atm. press.:

ca. 1 013 hPa

Remarks on result:

other: atmospheric pressure not provided but assumed to be normal atmospheric pressure (1013 hPa)

Results

Pre-Test following Siwoloboff

A small amount of the test item was heated in a test tube with a Bunsen burner.

The following observations were noted:

Table 4.3/1.- Values Observations

Observation	Temperatures
Formation of single bubbles	52 °C
Bubbles came faster	83°C
Bubbles came fast and in series	110°C
Building of a chain of bubbles	143°C
Many chains of bubbles (heating stopped)	150°C
Broke of the chain of bubbles	136°C
After broke of the chain of bubbles, test item was heated again to 200 °C
Many chains of bubbles, volume of liquid expanded	200 °C
After cooling down no visual changes and no signs for decomposition or polymerisation were visible.

Security Pre-test for the DSC instrument

The crucible was found visual unchanged after reaching a temperature of 420°C. After cooling down the weight was recorded with 46.05 mg, leaving a residue of 0.14 mg.

Calibration

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

Table 4.3/2.-Values DSC Indium

Expected Melting point	Measured Melting point (Onset)	Expected Energy	Measured Energy	Assessment
156.6 ± 1.0°C	156.60 °C	28.45 ± 1.0 J/g	27.72 J/g	OK

 

The measurement of indium after calibration met the validity criteria.

DSC Measurement of the Test Item

Table 4.3/3.- Values results

Event	in °C	in K
First Determination	no event	-
Second Determination	178.26	451.41
Third Determination	179.13	452.28
Min	178.26	451.41

Table 4.3/4.-Values Observations

	Mass test item	Mass crucible (before measurement):	Mass crucible (after measurement):	Observations
First Measurement	3.17 mg	48.43 mg	47.54 mg	After the test the crucible was visually unchanged
Second Measurement	4.66 mg	50.44 mg	45.91 mg	After the test the crucible was visually unchanged
Third Measurement	4.98 mg	50.64 mg	45.80 mg	After the test the crucible was visually unchanged

Validity

As the criterion of≤0.5 K was not fulfilled a boiling range was stated.

Discussion

The determination of the boiling point of the test item was performed via DSC (differential scanning calorimetry).

 

A preliminary test conducted according the Siwoloboff method, showed the formation of bubbles from about 52°C, building of bubbles’ chain at about 143°C, many chains of bubbles at about 150°C (stop of heating) and break of the bubbles’ chain at about 136°C.

 

Three determinations were performed using the DSC method. The first in the range from 15°C to 165°C, but no event could be detected. Therefore, the range of tested temperatures was adapted.

In the two other runs, conducted in the range from 15°C to 420°C,one small endothermic event was detected with a slightly shift of the baseline.This event was considered to be a representative boiling point value for the test substance.

 

As the replicates were not within accuracy limits of the method, the result is stated as a range.

 

Finally the boiling point of the substance was determined under these circumstances within the following range:

(178.26 – 179.13 °C) (451.41 – 452.28 K)

 

These values are the results of two independent measurements using DSC method.

We noted a large difference with the result obtained during the preliminary test, which may be due to the volatilisation of the most volatile constituents of the substance. Note also that these results may vary with the substance composition and should therefore be considered with caution.

 

No observations were made which might cause doubts on the validity of the study outcome. Therefore, the result of the study is considered valid.

Conclusions:

The boiling point of the substance was determined under experimental circumstances within the following range: (178.26 – 179.13 °C) (451.41 – 452.28 K) using DSC method.

Executive summary:

The boiling point of the test item was measured under GLP according to OECD 103 / EU A2 guideline, by DSC.

3 runs were performed. One event could be detected in the second and the third run. The event was endothermand was considered to be a representative boiling point value for the test substance.

As the replicates were not within accuracy limits of the method, the result is stated as a range. Finally the boiling point of the substance was determined under these circunstances within the following range: (178.26 – 179.13 °C) (451.41 – 452.28 K).

These values are the results of two independent measurements using DSC method.

We noted a large difference with the result obtained during the preliminary test which may be due to the volatilisation of the most volatile constituents of the substance. Note also that these results may vary with the substance composition and should therefore be considered with caution.

 

No observations were made which might cause doubts on the validity of the study outcome. Therefore, the result of the study is considered valid.

Description of key information

The boiling range of the substance was determined under experimental circumstances within the following range: (178.26 – 179.13 °C) (451.41 – 452.28 K) using DSC method.

Additional information

A reliable experimental study, conducted according to a recognized OECD/EC method and under GLP, is available. It is considered as a key study. The result being expressed as a range, it cannot be retained as (single) key data.