Glycine hydrochloride

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 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 102 (Melting point / Melting Range)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.1 (Melting / Freezing Temperature)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

>= 173.34 - <= 177.56 °C

Atm. press.:

1 013.25 hPa

Decomposition:

no

Sublimation:

no

Pre-Test for melting range

The capillary tube containing the test item was set into the block at 20.9 °C. The block was heated until melting started. The temperature was noted at which the first signs of melting of the test item were observed. When the substance was completely melted, the temperature was noted again.

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 solution	180 °C

Security Pre-test for the DSC instrument

The test item was charred and escaped at the perforated position after 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]	Energy
Melting Point	173.34 (Onset)	177.75 [J/g]

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]	Energy
Melting Point	174.11 (Onset)	191.51 [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]	Energy
Melting Point	177.56 (Onset)	190.67 [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.

Presentation of final results

Table 7: Calculated Values

Melting Point	in °C	in K
First Determination	173.34	446.49
Second Determination	174.11	447.26
Third Determination	177.56	450.71
Min	173.34	446.49
Max	177.56	450.71

Conclusions:

The melting point of the test item was determined within the range of 173.34 and 177.56 °C (446.49 to 450.71 K), which was called the first event.

Executive summary:

A study was performed according to OECD TG 102 and Commission Regulation (EC). No. 440/2008 method A.1. in order to determine the melting point of the test item by using DSC method. Three determinations were performed since the deviation between the first and second determination was too high (> 0.5 K). Depending on the pre-test the melting point of the test item (first event) was determined to be within the range of 173.34 and 177.56 °C (446.49 to 450.71 K). Within the melting point range the test item melted to a clear colourless solution which returned to its original state after cooling down.

Description of key information

The melting point of the test item was determined within the range of 173.34 and 177.56 °C (446.49 to 450.71 K), which was called the first event.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

173.34 °C

Additional information

A study was performed according to OECD TG 102 and Commission Regulation (EC). No. 440/2008 method A.1. in order to determine the melting point of the test item by using DSC method. Three determinations were performed since the deviation between the first and second determination was too high (> 0.5 K). Depending on the pre-test the melting point of the test item (first event) was determined to be within the range of 173.34 and 177.56 °C (446.49 to 450.71 K). Within the melting point range the test item melted to a clear colourless solution which returned to its original state after cooling down (reference 4.2-1).