7-ethoxy-4,6-difluoro-dibenzothiophen-3-ol

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-11-15 to 2018-11-21

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:

no

Type of method:

column elution method

Key result

Water solubility:

0.1 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

>= 6 - <= 6.3

Details on results:

Preliminary test
Three preliminary tests were carried out with specified amounts of the test item and 100 mL and 500 mL demineralized water, respectively. After each addition of an amount of water, the mixture was stirred for at least 24 hours, and visually checked for any undissolved particles. The prelíminary test showed that the water solubility of the test item was < 10 mg/L. According to the preliminary test the water solubility was determined by the column elution method in the main test.

Column elution method
The water solubility of the test item at a temperature of 20 °C was determined according to the column elution method to be 0.1 mg/L.

Column 1:

Rotation period of the fraction collector: 90 min per fraction

Duration of sampling: about 48 h (32 fractions)

Column elution method, column 1 (approximately 12.5 mL/h)

Fraction no.	V /mL	pH	water solubility µg/L
25	15.5	6.0	125
26	15.5	6.3	122
27	15.5	6.0	124
28	16.0	6.1	122
29	16.0	6.1	121

The water solubility was found to be 123 µg/L (+ 2 µg/L)

Column 2:

Rotation period of the fraction collector: 45 min per fraction
Duration of sampling: about 48 h (64 fractions) 

Column elution method, column 2 (approximately 25.0 mL/h)

Fraction no.	V /mL	PH	water solubility / µg/L
50	16.5	6.0	97
51	16.5	6.0	75
52	16.5	6.1	78
53	16.5	6.1	92
54	16.5	6.0	92

 

The water solubility was found to be 87 µg/L (± 10 µg/L).

In both columns the concentration of five consecutive fractions was constant within ± 30 %. No increasing or decreasing tendency was observed.

Conclusions:

The water solubility of the test item at a temperature of 20 °C was determined to be 0.1 mg/L.

Executive summary:

The water solubility was determined according to OECD 105 using the column elution method with HPLC analysis. 100.6 mg of the test item were dissolved in 100 mL acetone. For charging the columns in each case 25 mL of the test item solution was added to about 3 g of sea sand and the mixtures were shaken. The solvent was then removed under reduced pressure using a rotary evaporator (40 °C, approx. 30 mbar). The dry residues were placed into the columns of the test apparatus, which have afterwards been filled with water (test temperature: 20 °C; water pH at 23 °C: 6.0). After a swelling time of 2 h pumps were started to rinse the test item coated sand with distilled water. The values for the water solubility were calculated from fractions 25 to 29 for the 12.5 mL/h column and from the fractions 50 to 54 for the 25.0 mL/h column. In both columns the concentration of five consecutive fractions was constant within ± 30 %. No increasing or decreasing tendency was observed. The water solubility of the test item was determined to be 0.1 mg/L.

Description of key information

The water solubility of the test item at a temperature of 20 °C was determined to be 0.1 mg/L (reference 4.8 -1)

Key value for chemical safety assessment

Water solubility:

0.1 mg/L

at the temperature of:

20 °C

Additional information

The water solubility was determined according to OECD 105 using the column elution method with HPLC analysis. 100.6 mg of the test item were dissolved in 100 mL acetone. For charging the columns in each case 25 mL of the test item solution was added to about 3 g of sea sand and the mixtures were shaken. The solvent was then removed under reduced pressure using a rotary evaporator (40 °C, approx. 30 mbar). The dry residues were placed into the columns of the test apparatus, which have afterwards been filled with water (test temperature: 20 °C; water pH at 23 °C: 6.0). After a swelling time of 2 h pumps were started to rinse the test item coated sand with distilled water. The values for the water solubility were calculated from fractions 25 to 29 for the 12.5 mL/h column and from the fractions 50 to 54 for the 25.0 mL/h column. In both columns the concentration of five consecutive fractions was constant within ± 30 %. No increasing or decreasing tendency was observed. The water solubility of the test item was determined to be 0.1 mg/L.