Absolute of Cistus ladaniferus (Cistaceae) obtained from labdanum concrete by ethanol extraction

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 November 2017 - 22 January 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

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 but restrictions apply considering the difficulty to determine the initial boiling point & temperature of decomposition of the substance. Therefore a validation with restrictions applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling point/boiling range)

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 15 and 16 November 2017 / signed on 15 May 2018

Type of method:

method according to Siwoloboff

Key result

Decomposition:

ambiguous

Remarks on result:

not determinable

Table 4.3.1 Observations Pre-test for the boiling point following Siwoloboff

Observations	Temperatures
Test items colour became lighter	45 °C
Some bubbles	85 °C
Bubbles inside of the liquid of the test item rose up	103 °C
More bubbles	110,120,160 °C
Many bubbles	180 °C
Superheating occured twice	192 °C
Superheating with sizzle	197, 204, 212, 214, 216, 220, 222, 224, 226 °C
Test terminated for safety reason. Immediately no bubbles anymore.	226 °C

Superheating was indicated by the substance (strongly) spraying out of the container.

After cooling down the test item appeared slightly darker.

 

Table 4.3.2 Observations Main-test for the boiling point following Siwoloboff

Observations	Temperatures
	First determination atmospheric pressure 99031 Pa		Second determination atmospheric pressure 99039 Pa
Test start Some bubbles visible after setting in the block	100.0 °C
Test item getting clearer	102 °C
No bubbles anymore	Since 105 °C
Some bubbles in large interval. Colour of test item getting darker	110 °C Since 110°C	105 °C Since 110°C
More bubbles	Since 200 °C
Test item boils with vapour and superheating. No boiling chain. Test stopped for safety reasons.	220 °C	215 °C

After cooling down the test item appeared as a clear, viscous red-brown liquid, whereas the original test item was a yellow-brown liquid. Signs of decomposition (colour change) were considered.

Finally no boiling point could be determined up to 220°C using the SIWOLOBOFF method. Decomposition of the substance was suspected during the test : Small bubbles observed from 100°C and colour change observed from 105°C (lowest temperature) may be either the signs of decomposition of the substance or the sign of releasing of trapped more volatile compounds in the matrix.

 

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:

No boiling point can be determined using standard method conducted in this study (Siwoloboff method).
Signs of potential decomposition of the substance were observed during the test.

Executive summary:

A study was conducted to determine the boiling point of the test substance under GLP according to OECD 103 / EU A2 guideline.

The Siwoloboff method was performed to determine the initial boiling point of the substance. However, No boiling point can be determined. Signs of potential decomposition of the substance were observed during the experiments: Small bubbles observed from 100°C and colour change observed from 105°C (lowest temperature) may be either the signs of decomposition of the substance or the sign of releasing of trapped more volatile compounds in the matrix.

Finally, no temperature of initial boiling point or initial decomposition of the test item can be determined using the Siwoloboff method.

Description of key information

No boiling point can be determined using standard method conducted in this study (Siwoloboff method).

Signs of potential decomposition of the substance were observed during the test.

Additional information

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

It is considered as a key study.