Phosphoric acid, butyl ester, sodium salt

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:

2018-02-22 to 2018-03-20

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7200 (Melting Point / Melting Range)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

differential scanning calorimetry

Key result

Melting / freezing pt.:

>= -20 - <= 8 °C

Atm. press.:

1 013.25 hPa

Decomposition:

yes

Decomp. temp.:

> 230 °C

In the temperature ranges of -70 - 30 °C, 60 - 210 °C, 220 – 320 °C and 370 - 410 °C, four and five, respectively, endothermic effects were observed.

Results of the DSC-measurements

No.	Sample weight / mg	Onset of Effect / °C	Range of effect / °C	Weight loss / mg	Atmospheric pressure / hPa	Remark
PN15006	16.74	-23.96 113.27 169.67 220.33 382.31	30 – 80 (endo) 110 – 180 (endo) 190 – 250 (endo) 300 – 350 (exo) 350 – >500 (exo)	11.13	1006.6
PN15108	10.92	-28.93 111.05 225.34 377.86	-70 – 30 (endo) 70 – 210 (endo) 220 – 320 (endo) 370 – 410 (endo)	7.23	979.8

During the cooling phase, no thermic effect could be observed in the DSC-measurements. During the subsequent heating phase four and five, respectively, broad endothermic effects were observed, which can’t be clearly assigned to a melting or boiling of the test item. Thus, the test item was additionally investigated in a test tube.

The test tube with the test item was cooled with liquid nitrogen. The temperature measurement could be started at -20.3 °C. At this temperature, the test item was solid. During the warming up, it could be observed that the test item melted at a temperature of 7.6 °C and boiled at 112.7 °C. At 121.3 °C the test item evaporated. The measurement was stopped at 143.2 °C.

Combining the results of the measurements, the first endothermic effect in the DSC can be assigned to the softening and melting of the test item. Since, the effect is very broad, and the test item was solid in the test tube at -20.3 °C, the test item has a melting range of approx. ‑20 to 8 °C.

The second endothermic signal in the temperature range of 60 to 210 °C can be assigned to the boiling of the test item. The visual observed boiling of the test item in the test tube was in good correlation with the onset temperatures of the DSC-measurements. As the onset temperatures in both tests deviate by more than 0.5 K from their mean value of 112.16 °C, the test item has a boiling range of 111 to 113 °C.

The other two to three endothermic effects in the DSC may be caused by the evaporation of the test item.

 

Conclusions:

The melting range of the test item was determined to be in range from -20 to 8 °C.

Executive summary:

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1 and EPA OCSPP test guideline 830.7200 to determine the melting point of the test item using differential scanning calorimetry. The test item was weighed out into an aluminium crucible under an inert atmosphere (nitrogen). Two tests with about 11 – 17 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a liquid at ambient conditions. The crucibles were cooled down to approx. -80 K at a constant cooling rate of 0.25 K/min. Subsequently, the temperature was increased up to 500 °C at a constant heating rate of 10 K/min under an inert atmosphere. During the cooling phase, no thermic effect could be observed in the DSC-measurements. During the subsequent heating phase four and five, respectively, broad endothermic effects were observed, which can’t be clearly assigned to a melting or boiling of the test item. Thus, the test item was additionally investigated in a test tube.Combining the results of the measurements, the first endothermic effect in the DSC can be assigned to the softening and melting of the test item. Since, the effect is very broad, and the test item was solid in the test tube at -20.3 °C, the melting range of the test item was determined to be in range from -20 to 8 °C.

Description of key information

The melting range of the test item was determined to be in range from -20 to 8 °C.

Additional information

A study was conducted according to OECD test guideline 102, Regulation (EC) No 440/2008 method A.1 and EPA OCSPP test guideline 830.7200 to determine the melting point of the test item using differential scanning calorimetry. The test item was weighed out into an aluminium crucible under an inert atmosphere (nitrogen). Two tests with about 11 – 17 mg of the test item were performed. As reference crucible, an empty aluminium crucible was used. The substance is a liquid at ambient conditions. The crucibles were cooled down to approx. -80 K at a constant cooling rate of 0.25 K/min. Subsequently, the temperature was increased up to 500 °C at a constant heating rate of 10 K/min under an inert atmosphere. During the cooling phase, no thermic effect could be observed in the DSC-measurements. During the subsequent heating phase four and five, respectively, broad endothermic effects were observed, which can’t be clearly assigned to a melting or boiling of the test item. Thus, the test item was additionally investigated in a test tube.Combining the results of the measurements, the first endothermic effect in the DSC can be assigned to the softening and melting of the test item. Since, the effect is very broad, and the test item was solid in the test tube at -20.3 °C, the melting range of the test item was determined to be in range from -20 to 8 °C.