Sodium metaphosphate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Testing was conducted between 02 October 2009 and 24 December 2009.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: 2009-09-15 / Date of Signature: 2009-11-26

Type of method:

flask method

Remarks:

The determination was carried out using the flask method, Method A6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008.

Key result

Water solubility:

>= 54.8 - <= 59.7 other: w/w

Conc. based on:

test mat.

Temp.:

20 °C

pH:

7.2

Details on results:

Please see section remarks on results including tables and figures, as the results are mostly tables.

Results

Preliminary test

The sample concentrations, observations recorded and sample solution pH are shown in the following table:

Sample Identity	Loading Rate (% w/w)	Observations	Solution pH
1	20.6	clear colourless mobile liquid	7.5
2	31.3	clear colourless mobile liquid	7.4
3	39.8	clear colourless slightly viscous liquid	7.3
4	50.6	clear colourless slightly viscous liquid	7.2
5	60.1	opaque viscous liquid	7.0
6	22.2	clear colourless liquid with no excess test material	7.6
7	30.3	clear colourless liquid with no excess test material	7.4
8	40.3	clear colourless slightly viscous liquid with no excess test material	7.3
9	49.5	clear colourless slightly viscous liquid with no excess test material	7.2
10	59.3	opaque viscous liquid with excess test material	7.0
11	18.8	clear colourless liquid with no excess test material	7.4
12	29.8	clear colourless liquid with no excess test material	7.2
13	40.3	clear colourless slightly viscous liquid with no excess test material	7.1
14	49.3	clear colourless slightly viscous liquid with no excess test material	7.0
15	59.4	opaque viscous liquid with excess test material	6.9

Preliminary test result:         Solubility at 20.0°C: In the range 50.6 to 60.1 % w/w
                                             Solubility at 30.0°C: In the range 49.5 to 59.3 % w/w
                                             Solubility at 10.0°C: In the range 49.3 to 59.4 % w/w

 

1.1.2               Definitive test

The sample concentrations, observations recorded and solution pH are shown in the following table:

Table5.4

Sample Identity	Loading Rate (% w/w)	Observations	Solution pH
1	40.0	clear colourless liquid with no excess test material	7.2
2	44.8	clear colourless liquid with no excess test material	7.2
3	50.2	clear colourless liquid with no excess test material	7.2
4	54.7	slightly translucent liquid with excess test material	*
5	60.5	slightly translucent liquid with excess test material	*
6	39.5	clear colourless liquid with no excess test material	7.2
7	45.0	clear colourless liquid with no excess test material	7.2
8	50.0	clear colourless liquid with no excess test material	7.2
9	54.8	clear colourless liquid with no excess test material	7.2
10	59.7	slightly translucent liquid with excess test material	*
11	39.6	clear colourless liquid with no excess test material	7.2
12	45.2	clear colourless liquid with no excess test material	7.2
13	50.8	clear colourless liquid with no excess test material	7.2
14	55.2	clear colourless liquid with no excess test material	7.2
15	60.0	slightly translucent liquid with excess test material	*

Definitive test result:           Solubility at 10.0°C: In the range 50.2 to 54.7 % w/w
                                          Solubility at 20.0°C: In the range 54.8 to 59.7 % w/w
                                          Solubility at 30.0°C: In the range 55.2 to 60.0 % w/w

* Insufficient sample solution for pH measurement

Conclusions:

Interpretation of results: very soluble (> 10000 mg/L)

The water solubility of the test material has been visually assessed to be in the range of 54.8 to 59.7 % w/w at 20.0 ± 0.5°C. The temperature range 10 to 30°C had no significant influence on the observed solubility of the test material.

Executive summary:

Method

The determination was carried out using a flask method, based on Method A6 Water Solubility of Commission Regulation (EC) No 440/2008 of 30 May 2008.

Conclusion

The water solubility of the test material has been visually assessed to be in the range of 54.8 to 59.7 % w/w at 20.0 ± 0.5°C. The temperature range 10 to 30°C had no significant influence on the observed solubility of the test material (see following table).

Test Temperature	Water Solubility	Typical Solution pH
30.0±0.5°C	In the range 55.2 to 60.0 % w/w	7.2
20.0±0.5°C	In the range 54.8 to 59.7% w/w	7.2
10.0±0.5°C	In the range 50.2 to 54.7 % w/w	7.2

Description of key information

The water solubility was determined according to EU Method A.6 (Water solubility) and under the conditions of GLP.

Additional information

The water solubility of the test material has been visually assessed to be in the range of 54.8 to 59.7 % w/w at 20.0 ± 0.5°C.  The temperature range 10 to 30°C had no significant influence on the observed solubility of the test material.