Antimony nickel titanium rutile

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-03-21 to 2017-07-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and OECD guideline compliant study

Qualifier:

according to guideline

Guideline:

OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media

Principles of method if other than guideline:

The transformation/dilution of antimony nickel titanium oxide yellow (Sicotan Yellow K 1010) in environmentally relevant test medium was estimated according to the OECD Series on Testing and Assessment 29: Guidance document on transformation/dissolution of metals and metal compounds in aqueous media ENV/JM/MONO(2001)9. The transformed/dissolved amount of the test item was quantified by assessing the elemental nickel and antimony concentrations in the test media.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

0.383 µg/L

Element analysed:

Ni

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH 6, 0.2 µm filtration

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

0.598 µg/L

Element analysed:

Ni

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 6, 0.2 µm filtration

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

0.48 µg/L

Element analysed:

Ni

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 6, 0.2 µm filtration

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

0.732 µg/L

Element analysed:

Sb

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

ph 6, 0.2 µm filtration

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

1.61 µg/L

Element analysed:

Sb

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH 6, 0.2 µm filtration

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

1.851 µg/L

Element analysed:

Sb

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH 6, 0.2 µm filtration

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

2.645 µg/L

Element analysed:

Ni

Loading of aqueous phase:

10 mg/L

Incubation duration:

7 d

Test conditions:

pH 6, 0.2 µm filtration

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

2.084 µg/L

Element analysed:

Sb

Loading of aqueous phase:

10 mg/L

Incubation duration:

7 d

Test conditions:

pH 6, 0.2 µm filtration

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

24.949 µg/L

Element analysed:

Ni

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH 6, 0.2 µm filtration

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

24.414 µg/L

Element analysed:

Ni

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

ph 6, 0.2 µm filtration

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

1.893 µg/L

Element analysed:

Sb

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH 6, 0.2 µm filtration

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

7.72 µg/L

Element analysed:

Sb

Loading of aqueous phase:

100 mg/L

Incubation duration:

7 d

Test conditions:

pH 6, 0.2 µm filtration

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

16.407 µg/L

Element analysed:

Ni

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH 8.5, 0.2 µm filtration

Type of test:

screening transformation/dissolution test - sparingly soluble metal compounds

Mean dissolved conc.:

1.607 µg/L

Element analysed:

Sb

Loading of aqueous phase:

100 mg/L

Incubation duration:

24 h

Test conditions:

pH 8.5, 0.2 µm filtration

Details on results:

All data presented above including the screening test ("solubility of metal ions in aqueous media") are corrected for background if practical (i.e. measured mean elemental concentrations in method blanks > LOQ). For Ni and Sb background levels used for correction, please refer to "any other information on results incl. tables, Table 4: Relevant dissolved (0.2 µm filtration) Ni and Sb concentrations in method blanks".

Solution pH, oxygen concentrations, temperature:
Mean temperature was 22.7 ± 0.1 °C during the screening test at pH 6 and 21.5 ± 0.1 °C during the screening test at pH 8.5. Mean temperatures during the full test were 21.4 ± 0.1 °C (loadings of 10 and 100 mg/L) and 21.4 ± 0.3 °C (1 mg/L loading).
In the 100 mg/L screening tests, pH values at pH 6 and pH 8.5 (target pH) in sample and blank vessels were in the range of 5.9 – 6.1 and 8.6 – 8.7, respectively.
In the 1, 10 and 100 mg/L full tests, pH values at pH 6 (target pH) in sample and blank vessels were in the range of pH 5.8 – 6.3.
Oxygen levels of all test solutions were in the range recommended by the OECD Test Guidance 29 during the test (> 70 % of oxygen saturation at 8.5 mg/L (70 % of 8.5 mg/L = 6 mg/L).

Within and between vessel variations in titanium and antimony concentrations
At some samples, the within-vessel variation in transformation data and the between vessel variation exceeded 10 and 20 %, respectively. This can be explained by formation of particles which have passed the filter membrane. However, these variations have no impact on the overall results.

The 24 h screening measurements were performed with a concentration of the test item of 100 mg/L. At pH = 6, approx. 24.95 µg/L Ni and 1.89 µg/L Sb were found in the solution, after 24 hours of leaching time. The same procedure was performed at pH = 8.5 and the concentration of Ni and Sb were found to be 16.52 and 1.62 µg/L (no background correction performed), respectively. Therefore, the full tests were conducted at the most relevant pH with respect to ecotoxicology, i.e. at pH 6. Slight nickel and antimony background concentrations were measured. If dissolved metal amounts of test item loaded samples were in the range of background levels, the mean background concentrations per day were additionally subtracted.

The results are presented in following tables:

Table 1:  Mean nickel and antimony concentrations at a loading rate of 1 mg/L at pH 6

Sample time [h]	Metal average concentration at a loading rate of 1 mg/L
	Ni [µg/L]*	Sb [µg/L]
2	0.0918*	0.0171
6	0.1506*	0.0705
24	0.3825*	0.7319
96	0.5706*	1.4724
168	0.5976*	1.6103*
336	0.6246*	1.8915*
504	0.5374*	1.9001*
672	0.4800*	1.8508*

 * data corrected for elemental background in method blanks

 

Table 2: Mean nickel and antimonyconcentrations at a loading rate of 10 mg/L at pH 6

Sample time [h]	Metal average concentration at a loading rate of 10 mg/L
	Ni [µg/L]	Sb [µg/L]
2	1.8842	0.0765
6	2.1810	0.1841
24	2.6592	0.9173
96	2.6848	1.7635
168	2.7948	2.0954

 

 Table 3: Mean nickel and antimonyconcentrations at a loading rate of 100 mg/L at pH 6

Sample time [h]	Metal average concentration at a loading rate of 100 mg/L
	Ni [µg/L]	Sb [µg/L]
2	17.2499	0.3881
6	20.5698	0.7481
24	23.1046	2.0195
96	24.2053	5.3368
168	24.5638	7.7312

 

 

Table 4: Full test - Relevant dissolved (0.2 µm filtration) Ni and Sb concentrations in method blanks at pH 6

Sample time [h]	pH	Ni [µg/L]	Sb [µg/L]
24 h	6	0.1505	< LOQ (0.027)
7 d	6	0.1501	0.0110
28 d	6	0.3110	0.0112

 

Conclusions:

The transformation/dissolution test (OECD Series on Testing and Assessment Number 29, 2001) of antimony nickel titanium oxide yellow (Sicotan Yellow K 1010) at a loading of 1 mg/L at pH 6, the pH which maximises dissolution, resulted after 1, 7 and 28 days in dissolved nickel concentrations (0.2 µm filtration) of 0.383, 0.598 and 0.480 µg Ni/L, respectively. In addition, dissolved antimony concentrations after 1, 7 and 28 days at pH 6, the pH which maximises dissolution, were determined with 0.732, 1.610 and 1.851 µg Sb/L, respectively. At loadings of 10 and 100 mg/L test item, dissolved nickel concentrations after 7 days amounted to 2.645 and 24.414 µg Ni/L whereas dissolved antimony concentrations were determined with 2.084 and 7.720 µg Sb/L, respectively. Thus, the extent to which antimony nickel titanium oxide yellow (Sicotan Yellow K 1010) can produce soluble available ionic and other metal-bearing species in aqueous media is limited.

Description of key information

Antimony nickel titanium rutile (Sicotan Yellow K 1010) is practically insoluble in water (<0.1 mg/L at 20 °C). In addition, the extent to which antimony nickel titanium rutile can produce soluble available ionic and other metal-bearing species in aqueous environmental media is limited. According to a transformation/dissolution test (OECD Series on Testing and Assessment Number 29, 2001) by Klawonn (2017), measured dissolved antimony and nickel concentrations (0.2 µm fraction) after 7 and 28 days at a loading of 1 mg/L at pH 6 (i.e. the pH which maximizes dissolution) amount to 0.60 µg/L and 0.48 µg/L nickel and 1.61 µg/L and 1.85 µg/L antimony, respectively. At loadings of 10 and 100 mg/L test item, dissolved nickel concentrations after 7 days amounted to 2.65 and 24.41 µg Ni/L whereas dissolved antimony concentrations were determined with 2.08 and 7.72 µg Sb/L, respectively. Thus, the dissolution of antimony nickel titanium rutile in environmental media is limited.

Additional information

<0.1 mg/L at 20 °C

Transformation/dissolution of the substance according to OECD 29:

(i): 24 h, loading 100 mg/L: 24.95 µg/L Ni and 1.89 µg/L Sb at pH 6 and 16.41 µg/L Ni and 1.61 µg/L Sb at pH 8.5

(ii): 7 d, loading 1, 10 and 100 mg/L at pH 6: 0.60, 2.65 and 24.41 µg/L for Ni and 1.61, 2.08 and 7.72 µg/L for Sb

(iii): 28 d, loading 1 mg/L at pH 6: 0.48 µg/L for Ni and 1.85 µg/L for Sb