Essential oil camphor-rich of Artemisia herba-alba (Asteraceae) obtained from herb 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 9th May to 7th June 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. The substance is considered to be 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:

inspected on 13 and 14 October 2014 / signed on 08 April 2015

Type of method:

differential scanning calorimetry

Key result

Boiling pt.:

ca. 96.22 °C

Atm. press.:

ca. 101 325 Pa

Remarks on result:

other: As the test item is an UVCB substance the lowest temperature value under these circum-stances will be stated as the initial boiling point for the possibly minor constituent as: 96.22 °C (369.37 K).

Pre-Test following Siwoloboff

Individual bubble was visible since 60 °C, a colourless condensate was noticed.

Constant bubbles were observed at 170 °C and a boiling chain at 172 °C. The heating was switched off at 182 °C. The boiling chain broke at 167 °C.

After cooling down no signs of changes were visible.

Security Pre-test for the DSC instrument

The crucible was heated up to 420°C. After cooling down the crucible was visual unchanged. The weight was recorded with 46.08 mg, then the crucible was heated to 600 °C. After cooling down the crucible was visual unchanged. The weight was recorded with 46.01 mg. After that the crucible was opened and no test item was visible.

Calibration

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

  Table.- Values DSC Indium

Expected Melting point	Measured Melting point	Expected Energy	Measured Energy	Assessment
156.6 ± 1.0°C	156.31 °C	28.45 ± 1.0 J/g	29.02 J/g	OK

The measurement of indium after calibration met the validity criteria.

DSC Measurement of the Test Item

First determination:

The peak in this measurement was caused through a contamination; therefore this determination will not be evaluated.

Second determination:

No event could be detected therefore the temperature range was adopted and more test item was used.

Third dertermination:

	Temperature[°C]	Energy
First endothermic event	103.07 (Onset)	0.84[J/g]
Second endothermic event	197.26	14.92[J/g]

Forth determination:

	Temperature[°C]	Energy
First endothermic event	96.22 (Onset)	2.89[J/g]
	Temperature[°C]	Heat Flow
Second endothermic event	182. 33	40.35[mW]

Observations:

	Mass test item	Mass crucible (before measurement):	Mass crucible (after measurement):	Observations
First Determination	A contamination occurred; therefore this determination will not be evaluated.
Second Determination	1.52 mg	47.05 mg	46.31 mg	After the test the crucible was visually unchanged
Third Determination	2.20 mg	48.15 mg	45.96 mg	After the test the crucible was visually unchanged
Forth Determination	2.01 mg	48.24 mg	46.36 mg	After the test the crucible was visually unchanged

Interpretation of the measurements:

Four determinations were performed.

The first determination can be discarded, because the measured peak was caused through contamination of the instrument.

No event could be detected in the second determination, therefore the temperature range was adapted and more test item was used.

The third determination showed three endothermic events. Only the first two events were evaluated because the last event can be related to a decomposition product.

Both events were evaluated with the “onset” function.

The forth determination, where less test item than in the third determination was used, showed three endothermic events as well. Also only the first two events were evaluated because the last event can be related to a decomposition product. The first and third event are endothermic and the second slightly exothermic. The first event was evaluated with the “onset” function. The second event only could be evaluated with the “event marker” function.

In the Pre-test following Siwoloboff a colourless condensate was noticed at >60 °C. Boiling was observed at 170 °C, the boiling chain broke at 167 °C.

 

Based on these facts the first event of the second and third determination can be related to colourless condensate.

The first event might be partial evaporation of one constituent.

As the test item is an UVCB substance the lowest temperature value under these circumstances should be stated as the initial boiling point with composition changes.

Presentation of results

Table.- Values DSC measurements

	in °C	in K
1Determination	Not evaluated through contamination
2Determination	No Event
3Determination
1 Event	103.07	376.22
2 Event	197.26	470.41
4Determination
1 Event	96.22	369.37
2 Event	182.33	455.48

Validity

As decomposition was stated no valid criteria need to consider.

Discussion

The boiling point was determined via DSC (differential scanning calorimetry).

Considering the test item is an UVCB substance, the transition is expected to vary from batch-to-batch, therefore it is considered more appropriate to express the final result as an approximate initial boiling point, instead of a range, considering the range would apply to the present batch only, and is not specifications, which is the responsibility of the manufacturer.

 

Considering both the preliminary test according to Siwoloboff, and the two main DSC determinations, the first thermal event, recorded at 103.07°C and 96.22°C in the main test, is supposed related to the first bubbles and condensate observed with the capillary. Therefore, it is not considered representative of the substance (possibly minor constituent).

 

Thus, the result of the preliminary test according to Siwoloboff (boiling chain broke at 167 °C) and the second event of the main tests (197.26°C and 182.33°C) can be considered more representative of the substance.

 

The initial boiling point can be stated as the lowest value of the main DSC tests. The initial boiling point under these circumstances is therefore 96.22 °C (369.37 K)

with composition changes.

 

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 initial boiling point was determined as the lowest value under these circumstances as: 96.22 °C (369.37 K).

Executive summary:

The study was performed in order to determine the boiling point of test item according OECD 103, resp. EU A.2 guideline, usind Differential Scanning Calorimetry.

Considering both the preliminary test according to Siwoloboff, and the two main DSC determinations, the first thermal event, recorded at 103.07°C and 96.22°C in the main test, is supposed related to the first bubbles and condensate observed with the capillary. Therefore, it is not considered representative of the substance (possibly minor constituent).

Thus, the result of the preliminary test according to Siwoloboff (boiling chain broke at 167 °C) and the second event of the main tests (197.26°C and 182.33°C) can be considered more representative of the substance.

 

The initial boiling point can be stated as the lowest value of the main DSC tests. The initial boiling point under these circumstances is therefore 96.22 °C (369.37 K)

with composition changes.

 

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 initial boiling point was determined as the lowest value under these circumstances as: 96.22 °C (369.37 K)

Key value for chemical safety assessment

Boiling point at 101 325 Pa:

96.22 °C

Additional information

A fully reliable experimental study, conducted according to OECD 103/ EU A2 guideline is available.

It is considered as a key study, and the result is retained as key data.