Iron titanium trioxide

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 Oct - 24 Oct 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

GLP compliance:

no

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

Iron titanium trioxide

EC Number:

234-667-6

EC Name:

Iron titanium trioxide

Cas Number:

12022-71-8

Molecular formula:

FeO3Ti

IUPAC Name:

4-oxo-1,3-dioxa-2-ferra-4-titanacyclobutane

Test material form:

solid

Results and discussion

Water solubility

Water solubility 1

Key result

Water solubility:

0.23 mg/L

Conc. based on:

element (dissolved fraction)

Remarks:

Iron

Loading of aqueous phase:

1 g/L

Temp.:

20 °C

pH:

>= 6.8 - <= 7

Water solubility 2

Key result

Water solubility:

0.12 mg/L

Conc. based on:

element (dissolved fraction)

Remarks:

Titanium

Loading of aqueous phase:

1 g/L

Temp.:

20 °C

pH:

>= 6.8 - <= 7

Details on results:

Preliminary test
Three preliminary tests were carried out with specified amounts of the test item and 100 ml and 500 ml demineralized water, respectively. After each addition of an amount of water, the mixture was stirred for at least 24 hours, and visually checked for any undissolved particles.
The preliminary test showed that the water solubility of the test item is < 10 mg/L. ln this range the water solubility of organic test items should be determined with the column elution method. However as the present test item is an inorganic substance the suitable method according to ECHA guidance R.7a is the flask method with two loading rates.

Flask method
As the test item is an inorganic compound the concentration of lron and Titanium in the water extracts was determined in this study as representative parameters for the solubility of the complete test item.
The main test was performed with two loading rates (0.1 g/l and 1 g/l). Therefore, three flasks (experiment A - C) were prepared with about 10 mg of the test item and 100 ml demineralized water and three flasks (experiment E - G) with about 100 mg of the test item and 100 ml demineralized water, respectively. The batches were stirred for different times at 30°C (experiments A and E for 24 h, experiments B and F for 48 h, experiments C and G for 72 h) in tightly closed flasks.
After equilibration (further stirring for 24 h at 20"C) precipitate was observed in the flasks of the experiments excluding the blank experiment.
One other experiment was performed according to this procedure but without test item ("blank" = D).

All measured lron and Titanium concentrations were at or below the quantification limit of the analytical method for a loading rate of 0.1 g/L.
The mean concentrations for a loading rate of 1.0 g/l were 0.23 mg/l lron and 0.12 mgll Titanium.
The concentrations found in the experiments with different loading rates were in different orders of magnitude for both elements. Therefore a dependency of the loading rate was observed. All results for one loading rate and one element did not differ more than 15 o/o. Therefore the results fulfilled the requirement from guideline OECD 105.

Any other information on results incl. tables

Table 1: Water solubility experiments of the test item (loading rate 1.0 g/L)

Experiment	E	F	G	D (blank)
amount of test item / g	127.5	103.2	112.8	--
amount of demineralized water / mL	100	100	100	100
stirring time at 30 °C / h	24	48	72	72
pH at 25 °C	6.9	6.8	7.0	6.3
measured iron concentration / mg/L	0.25	0.19	0.24	<0.025*
measured titanium concentration / mg/L	0.13	0.13	0.10	<0.005*

*indicates below the quantification limit

Applicant's summary and conclusion

Conclusions:

The water solubility of the test item at a temperature of 20 °C was determined according to the flask method. The mean concentrations for a loading rate of 1.0 g/lLwere 0.23 mg/L lron and 0.12 mg/L Titanium.