Sodium Nickel Manganese Magnesium Titanium Dioxide (Crystal phase: O3/P2/RS)

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Jul. 25, 2019 to Jul. 28, 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: HT/T 153

Version / remarks:

2004

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

2000

GLP compliance:

yes

Type of method:

column elution method

Test material

Test material information

Constituent 1

Reference substance name:

Sodium Nickel Manganese Magnesium Titanium Dioxide (Crystal phase: O3/P2/RS)

EC Number:

951-477-5

Molecular formula:

Na1-δNivMnwMgxTiyO2, where the ranges are 0 < δ < 0.2, 0.2 < v < 0.4, 0.4 < w < 0.6, 0.02 < x < 0.2, 0.02 < y < 0.2

IUPAC Name:

Sodium Nickel Manganese Magnesium Titanium Dioxide (Crystal phase: O3/P2/RS)

Test material form:

solid: particulate/powder

Results and discussion

Water solubility

Key result

Water solubility:

>= 19.6 - <= 69 200 µg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

ca. 7.2

Applicant's summary and conclusion

Conclusions:

The results indicated that, under test temperature (20±0.5 ºC), the concentration of element sodium and nickel were 13724 μg/L and 3.86 μg/L, respectively. And the element magnesium, manganese and titanium were not detected. The water solubility of test substance calculated by sodium was 69.2 mg/L, the water solubility of test substance calculated by nickel was 19.6 μg/L, and the water solubility of test substance calculated by elements (magnesium, manganese, and titanium) were undissolved. So, the water solubility of test substance was between 19.7 μg/L and 69.2 mg/L

Executive summary:

According to “The guidelines for the testing of chemicals” (HJ/T 153-2004), “The Guidelines for the Testing of Chemicals – Physical-Chemical Properties and Physical Hazards” (the 2^nd edition, Beijing: China Environment Press. 2013) and with reference to Procedure 105 of the “Guidelines for Testing of Chemicals” of the OECD: “Water Solubility” (2000), the water solubility test for the substance was conducted.

Because the solubility of the test substance was less than 10^-2 g/L in the preliminary test, column elution method was adopted to test the water solubility of the test substance. According to the information provided by the sponsor, what will happen is an ion-exchange with the sodium-ion in the material and hydrogen from the water to create sodium hydroxide. What is left is a sodium poor substance with birnessite structure. It is expected that around 40-50% of the original sodium is extracted from the structure. So this means that we would have Sodium hydroxide, our original substance and same sodium poor substance with birnessite structure.

The results indicated that, under test temperature (20±0.5 ºC), the concentration of element sodium and nickel were 13724 μg/L and 3.86 μg/L, respectively. And the element magnesium, manganese and titanium were not detected. The water solubility of test substance calculated by sodium was 69.2 mg/L, the water solubility of test substance calculated by nickel was 19.6 μg/L, and the water solubility of test substance calculated by elements (magnesium, manganese, and titanium) were undissolved. So, the water solubility of test substance was between 19.7 μg/L and 69.2 mg/L.