Magnesium hydroxide sulfate (Mg6(OH)10(SO4)), hydrate (1:3)

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 June 2006 and 24 July 2006.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of inspection: 30/08/06; Date of signature: 04/09/2006

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

483-390-9

EC Name:

-

Cas Number:

12508-61-1

Molecular formula:

H16Mg6O17S

IUPAC Name:

hexamagnesium(2+) trihydrate decahydroxide sulfate

Results and discussion

Water solubility

Key result

Water solubility:

0.046 g/L

Temp.:

20 °C

Remarks on result:

other: no pH vlaue available

Any other information on results incl. tables

The mean absorbances relating to the standard and sample solutions for samples 1 to 3 are shown in the following table:

Solution	Mean Absorbance
Standard 1.98 mg/l	0.344
Standard 1.58 mg/l	0.270
Standard 1.19 mg/l	0.239
Standard 0.396 mg/l	0.139
Standard 0.198 mg/l	7.945 x 10^-2
Standard 9.90 x 10^-2mg/l	6.650 x 10^-2
Sample 1A	0.154
Sample 1B	0.157
Standard 1.98 mg/l	0.285
Standard 1.58 mg/l	0.231
Standard 1.19 mg/l	0.176
Standard 0.792 mg/l	0.128
Standard 0.396 mg/l	6.69 x 10^-2
Standard 0.198 mg/l	4.75 x 10^-2
Standard 9.90 x 10^-2mg/l	3.28 x 10^-2
Sample 2A	0.126
Sample 2B	0.138
Sample 3A	0.161
Sample 3B	0.140

The concentration of magnesium in the sample solutions is shown in the following table:

Table 7.3

Sample Number	Time Shaken at ~ 30ºC (hours)	Time Equilibrated at 20ºC (hours)	Concentration (g/l)	Solution pH
1^*	24	24	3.32 x 10^-2	5.9
2	48	24	4.31 x 10^-2	6.1
3	72	24	4.98 x 10^-2	6.3

Mean concentration:    4.64 x 10^-2 g/l at 20.0 ± 0.5ºC
Range:                        4.31 x 10^-2 to 4.98 x 10^-2 g/l

^*Not used in calculation of mean due to inconsistency with other samples.

Applicant's summary and conclusion

Conclusions:

The concentration of magnesium observed in saturated test solutions has been determined to be 4.64 x 10-2 g/l of solution at 20.0 ± 0.5°C.

Executive summary:

For substance MOS-HIGE in project number 1456 -0064, the determination was carried out using the flask method, Method A6 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).As the test material was essentially insoluble in typical reverse phase solvents, it was deemed not possible to perform any analysis of the sulphate component within the test material.The concentration of magnesium observed in saturated test solutions has been determined to be 4.64 x 10^-2 g/l of solution at 20.0 ± 0.5°C.