phosphonic acid, [2-(4-aminophenyl)-1-hydroxyethylidene]bis-, monosodium salt

Melting point / freezing point

Administrative data

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 12 September 2018 and 17 November 2018.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

no

Test guideline 2

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

Test material

Test material information

Constituent 1

Reference substance name:

phosphonic acid, [2-(4-aminophenyl)-1-hydroxyethylidene]bis-, monosodium salt

EC Number:

828-215-2

Cas Number:

172796-84-8

Molecular formula:

C8H12NO7P2Na

IUPAC Name:

phosphonic acid, [2-(4-aminophenyl)-1-hydroxyethylidene]bis-, monosodium salt

impurity 1

Reference substance name:

4-aminophenylacetic acid

EC Number:

214-828-7

EC Name:

4-aminophenylacetic acid

Cas Number:

1197-55-3

Molecular formula:

C8H9NO2

IUPAC Name:

4-aminophenylacetic acid

impurity 2

Reference substance name:

EBP dimer

Molecular formula:

C16H22N2O12P4

IUPAC Name:

EBP dimer

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Identification: Phosphonic acid, [2-(4-aminophenyl)-1-hydroxyethylidene]bis-, monosodium salt (“EBP”)
Appearance/Physical state: Beige colored powder
Batch: CHPC071917EBP
Purity: > 90%
Expiry date: 01 July 2019
Storage conditions: Room temperature in the dark

Results and discussion

Melting / freezing point

Key result

Decomposition:

yes

Decomp. temp.:

220 °C

Remarks on result:

not determinable

Any other information on results incl. tables

Thermal Analysis

Determination 1

Loss on heating: 37%

Determination 2

Loss on heating: 35%

Determination 3

Loss on heating: 33%

Determination 4

Loss on heating: 33%

Atmospheric pressure: 100.0 kPa

Overall result: Decomposed from approximately 240 °C (513 K)

Visual Evaluation -Modified Liquid Bath

Significant sample observations and temperatures are summarized in the following table:

Visual Evaluation on Heating

Temperature (°C)	Observation
26	Test item is a very pale yellow fine powder.
165	Small amount of shrinkage, barely visible.
220	Test item has darkened slightly, still a pale yellow fine powder.
231	Test item continues to darken, now a beige fine powder.
235	Black tar like material at base of test item. Test item is melting into a wax-like dark brown mass with black, tar-like material where test item touches the glass. Large amount of shrinkage, which occurred very quickly (a few seconds). Small amounts of brown powder can be seen.
245	Test item is now is black, near spherical mass of wax-like material which contains brown globules, possibly bubbles or brown powder. Some brown powder on the surface.
255	Test item is expanding up the tube, then gas being released and test item collapsing back down, happening repeatedly. Test item on surface of glass is now dark brown (with a slightly red hue).
275	Test item has now expanded (as it tends to only partly collapse each time) to ~ 25 mm in height. Test item is very dark brown with a red hue.
281	Column still expanding (~ 30 mm now). The test item on the glass surface is now full of “holes” from the bubbles. Cannot determine if bubbles are still forming.
283	Column is now hollow due to bubbles popping. Column is no longer expanding, bottom ~ 10 mm is almost free of test item, only very small patches left on the glass as a very dark brown liquid.
290	All except the top ~ 5 mm of test item contaminated area of the tube has only small dark brown/black liquid patches and bubbles on the glass. Top 5 mm has a mass of test item forming, popping and re-forming; this is also a dark brown/black liquid.
302	Many tiny bubbles have formed in the test item on the side of the glass, giving an appearance of white patches among the dark brown/black liquid. The mass of test item at the top has reduced to only covering part of the diameter of the tube. Testing halted.

Result:            Decomposed from approximately 220 °C (513 K)

Applicant's summary and conclusion

Conclusions:

The test item has been determined to decompose from approximately 220 °C (493 K). As the test item decomposed, no values for melting/freezing point and boiling point could be determined.

Executive summary:

Melting/Freezing Point and Boiling Point. Decomposed from approximately 220 °C (493 K),at 100.0 kPa, by differential scanning calorimetry and using a modified liquid bath method, designed to be compatible with Methods A.1 Melting/Freezing Temperature and A.2 Boiling Temperature of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Methods 102 and 103 of the OECD Guidelines for Testing of Chemicals, 27 July 1995. As the test item decomposed, no values for melting/freezing point and boiling point could be determined.