Graphene

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 Oct 2019 - 20 Feb 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

Version not mentioned

Deviations:

yes

Remarks:

temperature and pH measurement is missing flow rate lower than in OECD 105

Principles of method if other than guideline:

- Principle of test: The test item was evaluated using the equilibrated-column technique for water saturation and then total carbon analysis was performed to determine the carbon concentration followed prolonged periods of continuous column perfusion. The OECD 105 “column elution method” was developed to establish equilibrium conditions for determining the test substance solubility in water within a 7 to 11 day total equilibration time.
- Parameters analysed / observed: Total carbon analysis was conducted to determine the percent carbon of the test substance and the measured solubility of the test substance in water.

GLP compliance:

yes

Remarks:

no certificate included in report

Type of method:

column elution method

Water solubility:

< 3 mg/L

Conc. based on:

other: Net Total Carbon

Loading of aqueous phase:

500 other: mg

Incubation duration:

>= 5 - <= 11 d

Remarks on result:

other: not determinable due to low solubility of test substance (< LOD)

Remarks:

Temperature and pH not specified

Details on results:

The experimentally determined carbon content of the test substance was 8.5 ppm +/- 4.1 ppm; Blank Sample TC was 9.3 ppm, net total carbon was below the LOD of 3 ppm.

Conclusions:

The water solubility of the test item was determined to be <3 mg/L based on net total carbon according to OECD 105 using the column equilibration method (modified).

Executive summary:

Water solubility was determined for the test item based on a saturation equilibrium using the column elution method. Total carbon analysis was performed following 5 to 11 days of equilibration. Total carbon measured from the equilibrated test item was 8.5 (+/- 4.1) ppm and total carbon measured from a blank DDI control was 9.8 ppm. From this assessment, no net carbon was recovered above the 3 ppm LOD for the test system. Approximately 9.3 ppm of  total carbon was measured from the blank equilibration mobile phase following 10 days of continuous equilibration, which is considered to have been derived from the test system, tubing or atmospheric sources. A separate validation check of the total carbon reference standard was conducted following the total carbon calibration and sample analysis. The independent reference solution of 10 ppm provided a mean reference value of 11.5 ppm in the same analytic setup, providing independent validation of the TC calibration curve.

The water solubility of the test item was determined to be <3 mg/L based on net total carbon according to OECD 105 using the column equilibration method (modified).

Description of key information

Water Solubility was determined for the test item based on a saturation equilibrium using the column elution method. Total carbon analysis was performed following 5 to 11 days of equilibration. Total carbon measured from the equilibrated test item was 8.5 (+/- 4.1) ppm and total carbon measured from a blank DDI control was 9.8 ppm. From this assessment, no net carbon was recovered above the 3 ppm LOD for the test system. Approximately 9.3 ppm of  total carbon was measured from the blank equilibration mobile phase following 10 days of continuous equilibration, which is considered to have been derived from the test system, tubing or atmospheric sources. A separate validation check of the total carbon reference standard was conducted following the total carbon calibration and sample analysis. The independent reference solution of 10 ppm provided a mean reference value of 11.5 ppm in the same analytic setup, providing independent validation of the TC calibration curve.

The water solubility of the test item was determined to be <3 mg/L based on net total carbon according to OECD 105 using the column equilibration method (modified).