Sodium ascorbate

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-12-21 to 2010-03-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Specific details on test material used for the study:

- Batch Number: TL00910581

Key result

Water solubility:

642.6 g/L

Temp.:

20 °C

pH:

ca. 6.5

The determination of the water solubility of the test item was performed according to the EEC Directive 92/69, A.6 Water Solubility (2008), Council Regulation (EC) No. 440/2008, A.6 Water Solubility and the OECD guideline No. 105, Water Solubility (1995) using the flask shaking method. The saturation concentration of the test item at 21.9 °C was estimated by a simplified flask method in the preliminary test to be higher than 10^-2 g/L. Therefore, the flask shaking test was performed.

After a shaking time of 24 hours, 48 hours and 72 hours, respectively, at 30 °C, the samples were equilibrated for another 24 hours at 20 °C. Afterwards, the samples were centrifuged, filtered, diluted and analyzed by HPLC. The water solubility of the test item at 20 °C was determined to be 642.6 g/L with a standard deviation of ± 6.0. The measured results differ by less than 15%. Therefore, the study is considered to be valid. The pH was measured to be in the range of 6.49 and 6.59. The results of the individual measurements of the main test are summarized in Table 3 below. The tabulated values represent rounded results, which were obtained by calculation using the exact raw data.

 

A typical chromatogram of a standard solution is given in the attached Figure 1. A typical chromatogram of a sample solution after 72 hours of incubation is given in the attached Figure 2. An HPLC chromatogram of a blank solution is shown in the attached Figure 3. The calibration data for test item-standards are given in the attached Figure 4 and Table 5. The r² fit was 0.9989 (optimum 1.0000). This reflects the linearity of the HPLC-system within the calibration range of 10.31 µg/mL to 103.1 µg/mL of the test item.

Table 3: Results of the Water Solubility of Sodium ascorbate crystalline

Sample No.	Shakingtime at30 °C	Concentration analyzed	Concentration calculated	Water solubility calculated (rounded)
		[mg/L]	[mg/L]	[g/L]
1	72	64.736	647359.24
2		64.765	647648.47
3	48	63.742	637422.08	642.58
4		63.309	633088.19	SD = 6.00
5	24	64.368	643679.79
6		64.626	646255.30

The saturation mass concentration is calculated from the bold values.

 SD = standard deviation

Conclusions:

Interpretation of results: very soluble (> 10000 mg/L)
The water solubility of the test item was determined to be 642.6 g/L at 20.0 °C and a mean pH of 6.5. The water solubility was not corrected for the purity of the test item.

Executive summary:

The water solubility of the test item was determined to be 642.6 g/L at 20.0 °C and a mean pH of 6.5 using the flask shaking method. The water solubility was not corrected for the purity of the test item.

Description of key information

The water solubility of the test item was determined to be 642.6 g/L at 20.0 °C and a mean pH of 6.5.

Key value for chemical safety assessment

Water solubility:

642.6 g/L

at the temperature of:

20 °C

Additional information

The water solubility of the test item was determined to be 642.6 g/L at 20.0 °C and a mean pH of 6.5 using the flask shaking method. The water solubility was not corrected for the purity of the test item.