Grape, red, ext.

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

Grape, red, ext.

EC Number:

284-511-6

EC Name:

Grape, red, ext.

Cas Number:

84929-27-1

IUPAC Name:

5-[(1E)-2-(4-hydroxyphenyl)ethenyl]benzene-1,3-diol; 5-[(2R,3R)-6-hydroxy-2-(4-hydroxyphenyl)-4-[(1E)-2-(4-hydroxyphenyl)ethenyl]-2,3-dihydro-1-benzofuran-3-yl]benzene-1,3-diol

Test material form:

solid

Results and discussion

Water solubility

Key result

Water solubility:

>= 0.32 - <= 1.56 mg/L

Conc. based on:

test mat.

Temp.:

19.5 °C

Remarks on result:

other: The solubility of the test item was also stated as 0.013 % relating to the nominal concentration of the test item (mean value).

Applicant's summary and conclusion

Conclusions:

As solubility was dependent on nominal concentration, no exact value for the solubility of
the test item in water can be stated:
0.32 – 1.56 mg/L at 19.5 °C
0.32 – 1.56 * 10-3 kg/m3 (SI units)
for the following nominal concentration range of the test item in water: 3 – 10 g/L.
The solubility of the test item was also stated as 0.013 % relating to the nominal concentration
of the test item (mean value).

Executive summary:

The solubility of the test item Palmitoyl grapevine shoot extract in water was determined by

measurement of DOC concentration in the filtrated test solutions using TOC analyser.

In the pre-test, flasks with nominal concentrations 10 mg/L and 1000 mg/L were shaken at

room temperature for 96 h and measured for DOC after membrane filtration (0.45 μm,

PTFE) and acidification. Undissolved particles were observed in the flasks. The measured

DOC concentration lay at 0.15 mg/L and below the LOQ of TOC (< 0.1 mg/L) in the flasks

with the nominal concentrations 1000 mg/L and 10 mg/L, respectively. As dependency of

the water solubility on the amount of the test item added was perceived, different loading

rates were used in the main test. According to the guideline the slow-stirring flask method

was used for the determination of the solubility of the test item in water.

In the main test, six different loading rates of the test item were chosen to study the effect

of the loading rate on the measured water solubility: 1, 3, 5, 6, 8 and 10 g/L. Three flasks

1A - C with the same loading rate (5 g/L) were used during equilibration. Seven vessels

(flasks blank, 1C (for the sampling point 72 h) and 2 – 6) were set onto the shaking apparatus

immediately and shaking at 100 rpm was started. After 24 ± 2 hours, flask 1B (for the

sampling point 48 h) and after 48 ± 2 hours, flask 1A (for the sampling point 24 h) were set

on the shaker and all flasks were shaken for further 24 ± 2 hours at room temperature.

Then, flasks 1A - 1C were removed from the shaker, tempered at 20 ± 0.5 °C, samples

were taken, membrane filtered and analysed for DOC via TOC analyser. Because of an

upward tendency, the test was prolonged and the flasks 1A – 1C were measured on days

4 – 8. Due to a difference of less than 15 % in the concentrations on days 7 and 8 and no

upward tendency in the last three values, the test was finished on day 8. The final measurement

was performed on day 8 as determination from flasks 2 – 6. DOC was measured

via TOC analyser in the saturated aqueous solutions.

No Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid)

could be observed indicating that no colloidal dispersed particles were present.

As solubility was dependent on nominal concentration, no exact value for the solubility of

the test item in water can be stated:

0.32 – 1.56 mg/L at 19.5 °C

0.32 – 1.56 * 10-3 kg/m3 (SI units)

for the following nominal concentration range of the test item in water: 3 – 10 g/L.

The solubility of the test item was also stated as 0.013 % relating to the nominal concentration

of the test item (mean value).