Magnesium titanate

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From July 12, 2017 to August 03, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

no

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

Calcium titanium trioxide

EC Number:

234-988-1

EC Name:

Calcium titanium trioxide

Cas Number:

12049-50-2

Molecular formula:

Ca.O3Ti

IUPAC Name:

Calcium titanium trioxide

impurity 1

Reference substance name:

Titanium dioxide

EC Number:

236-675-5

EC Name:

Titanium dioxide

Cas Number:

13463-67-7

Molecular formula:

O2Ti

IUPAC Name:

dioxotitanium

impurity 2

Reference substance name:

Silicon dioxide

EC Number:

231-545-4

EC Name:

Silicon dioxide

Cas Number:

7631-86-9

Molecular formula:

O2Si

IUPAC Name:

dioxosilane

impurity 3

impurity 4

Reference substance name:

Magnesium oxide

EC Number:

215-171-9

EC Name:

Magnesium oxide

Cas Number:

1309-48-4

Molecular formula:

MgO

IUPAC Name:

magnesium oxygen(-2) anion

impurity 5

Reference substance name:

Diniobium pentaoxide

EC Number:

215-213-6

EC Name:

Diniobium pentaoxide

Cas Number:

1313-96-8

Molecular formula:

Nb2O5

IUPAC Name:

diniobium pentoxide

Test material form:

solid: nanoform, surface-treated

Results and discussion

Water solubility

Key result

Water solubility:

< 0.3 mg/L

Conc. based on:

test mat.

Temp.:

25 °C

pH:

7.59

Remarks on result:

other: pH is calculated mean of Day 1 - 3

Details on results:

Comparison of individual test results for calcium from tests 1, 2, and 3 indicated that there was no increasing solubility over time and the concentrations of all test solutions do not differ by more than 15 %; therefore, the mean results from tests 1, 2, and 3 were reported as the water solubility value to 1 decimal place. Spike sample recoveries lie within acceptable limits (nominal 100 ± 20 %).
No levels of titanium were observed in any test solutions and spike sample recoveries lie within acceptable limits (nominal 100 ± 20 %).
The lack of observable titanium concentration when compared to the calcium concentrations measured suggests that calcium titanate is soluble at <0.1 mg/L in water. The origin of the 5 mg/L calcium measured (rounded to the nearest mg/L) is unknown. Due to the structure of calcium titanate it is not felt that this level is caused by any dissociation from the calcium titanate molecule and is likely due to residual calcium or impurities.
From the titanium result, the water solubility of calcium titanate in solution is estimated based on correction for molecular weight as 0.1 x 135.4 / 47.87 = 0.28 rounded to <0.3 mg/L.
Analysis of test solutions by Malvern Zetasizer indicated that the test substance did not appear to be dispersed in the test solutions and that the values reported are indicative of solubilised test substance.

Applicant's summary and conclusion

Conclusions:

Calcium titanate has a water solubility of <0.3 mg/L at 25°C.

Executive summary:

A study was undertaken to establish the water solubility of calcium titanate according to the shake flask technique described in OECD Guideline 105 (Water Solubility). No deviation from the protocol was reported. Test item dispersion within the solution was analysed with Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and by Malvern Zetasizer, rendering a water solubility of <0.3 mg/L for calcium titanate at 25°C (corrected for molecular weight). Calcium titanate did not appear dispersed in the test solution and the reported value is indicative of solubilised test material.