Disodium hydrogen citrate

Boiling point

Link to relevant study record(s)

Reference

Endpoint:

boiling point

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

from 2017-03-22 to 2017-04-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same 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

Atm. press.:

1 013.25 hPa

Decomposition:

yes

Decomp. temp.:

158.03 °C

Remarks on result:

other: boiling point of decomposed product - 310.26 °C

Pre-test for boiling point following Siwoloboff

The pre-test was not carried out as the test item showed decomposition in the melting point pre-test.

Additional test

A colourless condensate was observed. The condensate dropped back and reacted with the still solid test item. The formed liquid turned to yellow and boiled.

DSC measurement (main test)

Table 1: Values and Observations from DSC Measurements

	Mass test item	Mass crucible (before measurement):	Mass crucible (after measurement):	Observations
First measurement	1.75 mg	46.89 mg	46.20 mg	After the test the crucible was visually unchanged, the crucible was opened and a brown residue was visible.
Second Measurement	1.73 mg	47.63 mg	46.97 mg	After the test the crucible was visually unchanged.

Based on the observations of the pre-test and the additional test the second event (endothermic) was indicated as boiling point of the decomposition product. The lowest value of measurement 1 and 2 is stated as start of boiling of the decomposition product.

Table 2: Results from DSC Measurements

Boiling point of the decomposition product	in °C	in K
1st Determination	316.30	589.45
2nd Determination	310.26	583.41
Beginning of event	310.26	583.41

Conclusions:

The substance decomposes before boiling.

Executive summary:

A study was conducted according to OECD test guideline 103 and Regulation (EC) No 440/2008 method A.2 to determine the boiling of the test item usingdifferential scanning calorimetry(DSC). In the preliminary test, decomposition of the test item was observed. Furthermore, in an additional testcolourless condensate was observed. The condensate dropped back and reacted with the still solid test item. The formed liquid turned to yellow and boiled. No boiling point of the test item could be determined under these circumstances. However, based on the observations of the pre-test and the additional test the boiling point of the decomposed product was determined by DSC method (second event). Two measurements were performed and the lower temperature was stated as start of boiling of the decomposition product. The decomposition temperature was determined to be 158.03 °C and the boiling point of the decomposed product 310.26 °C (reference 4.3-2).

As the test item decomposed the validity criteria according to the guideline are not applicable for the determination of the decomposition temperature.

Description of key information

The substance decomposes before boiling.

Additional information

A study was conducted according to OECD test guideline 103 and Regulation (EC) No 440/2008 method A.2 to determine the boiling of the test item using differential scanning calorimetry (DSC). In the preliminary test, decomposition of the test item was observed. Furthermore, in an additional test colourless condensate was observed. The condensate dropped back and reacted with the still solid test item. The formed liquid turned to yellow and boiled. No boiling point of the test item could be determined under these circumstances. However, based on the observations of the pre-test and the additional test the boiling point of the decomposed product was determined by DSC method (second event). Two measurements were performed and the lower temperature was stated as start of boiling of the decomposition product. The decomposition temperature was determined to be 158.03 °C and the boiling point of the decomposed product 310.26 °C (reference 4.3-2).

As the test item decomposed the validity criteria according to the guideline are not applicable for the determination of the decomposition temperature.