Glycine hydrochloride

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 2017-10-16 to 2017-11-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 103 (Boiling Point)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.2 (Boiling Temperature)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Key result

Boiling pt.:

229.59 °C

Atm. press.:

1 013.25 hPa

Decomposition:

yes

Decomp. temp.:

201.01

Remarks on result:

other: boiling point: start of boiling under decomposition (lowest of two values); decomposition: start of decomposition (lowest of three values)

Pre-test for boiling point following Siwoloboff

Table 1: Results of the pre-test

Observations	Temperature
The test item began to melt	176 °C
The test item was completely melted to a clear colourless liquid, colour getting darker	200 °C
Started to boil	210 °C
Colour was yellow-brown and became darker, lots of bubble, burner was turned off	220 °C
No more bubbles visible, colour was dark brown	180 °C

After cooling down a green-brown solid was visible.

Security Pre-test for the DSC instrument

The test item was charred and escaped at the perforated positionafter reaching a temperature of 420 °C. The weight was recorded with 47.50 mg. For the additional crucible no visually change after reaching a temperature of 250 °C was visible. The weight was recorded with 46.77 mg.

Calibration

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

Table 2: Values DSC indium

Expected Melting point	Measured Melting point	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 3: Values DSC test item first determination

	Temperature [°C]	Heat flow
Beginning of decomposition	205.45 (Event Mark)	26.53 (mW)

The temperature program was adopted in order to cover all expected events for the second and the third determinations.

Table 4: Values DSC test item second determination

	Temperature [°C]	Heat flow
Beginning of decomposition	201.01 (Event Mark)	27.99 (mW)
	Temperature [°C]	Energy
Boiling under decomposition	229.59 (Onset)	543.08 [J/g]
Boiling point of decomposition product	285.09 (Onset)	27.52 [J/g]

The deviation between the first and second determination was too high (> 0.5 K); therefore, a third measurement was performed.

Table 5: Values DSC test item third determination

	Temperature [°C]	Heat flow
Beginning of decomposition	202.06 (Event Mark)	30.07 (mW)
	Temperature [°C]	Energy
Boiling under decomposition	233.48 (Onset)	316.44 [J/g]
Boiling point of decomposition product	281.93 (Onset)	35.08 [J/g]

Observations

Table 6: Values Observations

	Mass test item	Mass crucible (before measurement):	Mass crucible (after measurement):	Observations
First Measurement	1.01 mg	46.83 mg	46.49 mg	The crucible was visually unchanged after measurement
Second Measurement	2.16 mg	47.59 mg	46.38 mg	The crucible was visually unchanged after measurement. The crucible was opened: the test item was charred and the crucible was discolored into black.
Third Measurement	2.18 mg	48.05 mg	46.83 mg	The crucible was visually unchanged after measurement

Referring to observations in the pre-tests the first endothermic event was stated as melting point. Second endothermic event in second and third determinations is stated as boiling under decomposition and the third endothermic event is stated as boiling point of the decomposition product. The beginning of decomposition was evaluated with an event marker. In the muffle furnace pre-test the change of test item was observed, which is an indication of decomposition.

Presentation of final results

Table 7: Calculated Values

Begin of decomposition	in °C	in K
First Determination	205.45	478.60
Second Determination	201.01	474.16
Third Determination	202.06	475.21
Min	201.01	474.16
Max	205.45	478.60
Boiling under decomposition	in °C	in K
Second Determination	229.59	502.74
Third Determination	233.48	506.63
Min	229.59	502.74
Max	233.48	506.63
Boiling point of the decomposition product	in °C	in K
Second Determination	285.09	558.24
Third Determination	281.93	555.08
Min	281.93	555.08
Max	285.09	558.24

Conclusions:

The beginning of decomposition of the test item was stated at a temperature of 201.01 °C (lowest value of three determinations).
The boiling under decomposition (2nd endothermic event) started at 229.59 °C (lowest value of two determinations).
The boiling of the decomposition product (third endothermic event) was stated at a temperature of 281.93 °C (lowest value of two determiations).

Executive summary:

A study was performed according to OECD TG 103 and Commission Regulation (EC) No. 440/2008 method A.2. in order to determine the boiling point of the test item by using the differential scanning calometry method. Refering to the pre-test following Siwoloboff decomposition of the test item was observed after melting. The boiling under composition was indicated as second endothermic event and the boiling point of the decomposition product was indicated as third endothermic event. Three determinations were performed since the deviation between the first and second determination was too high (> 0.5 K). At second determination the crucible with the test item was opened and the test item was charred.

The temperature at beginning of decomposition was evaluated with event marker function of the differential scanning calometry to be 201.01 °C (lowest value of three determinations). The boiling under decomposition (second event) was evaluated with onset function and started at 229.59 °C (lowest value of two determinations). The boiling point of the decomposition product was determined with onset function to be 281.93 °C (lowest value of two determiations).

Description of key information

The beginning of decomposition of the test item was stated at a temperature of 201.01 °C (lowest value of three determinations).

The boiling under decomposition (2nd endothermic event) started at 229.59 °C (lowest value of two determinations).

The boiling of the decomposition product (third endothermic event) was stated at a temperature of 281.93 °C (lowest value of two determiations).

Additional information

A study was performed according to OECD TG 103 and Commission Regulation (EC) No. 440/2008 method A.2. in order to determine the boiling point of the test item by using the differential scanning calometry method (reference 4.3-1). Refering to the pre-test following Siwoloboff decomposition of the test item was observed after melting. The boiling under composition was indicated as second endothermic event and the boiling point of the decomposition product was indicated as third endothermic event. Three determinations were performed since the deviation between the first and second determination was too high (> 0.5 K). At second determination the crucible with the test item was opened and the test item was charred. The temperature at beginning of decomposition was evaluated with event marker function of the differential scanning calometry to be 201.01 °C (lowest value of three determinations). The boiling under decomposition (second event) was evaluated with onset function and started at 229.59 °C (lowest value of two determinations). The boiling point of the decomposition product was determined with onset function to be 281.93 °C (lowest value of two determiations).