4''-butyl-4-[difluoro(3,4,5-trifluorophenoxy)methyl]-2',3,5-trifluoro-1,1':4',1''-terphenyl

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01.07.2016 - 07.09.2016

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. (dissolved fraction)

Temp.:

20 °C

pH:

6.9

Preliminary visual estimation of the water solubility

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.

Table 1: Results of the preliminary visual estimation of the water solubility

Amount of test item / mg	Total volume of dist. water / mL	Appearance of mixture
16.1	100	not dissolved
11.1	500	not dissolved
4.3	500	not dissolved

The preliminary visual experiments showed that the water solubility of the test item is < 10 mg/L. According to the preliminary visual estimation in the main test the water solubility was determined by
the column elution method.

Column elution method

107.1 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. 100 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 25 °C: 6.8). After a swelling time of 2 h pumps were started to rinse the test item coated sand with demineralized water. At the end of the study it was confirmed that residual test item remained on the columns. The residual test item was eluted with 50 mL acetone.

As blank value the used demineralized water was tested. No signal was detected in the range of the retention time of the test item. The concentration of the test item was quantified by HPLC.

Column 12.5 mL/h:

Rotation period of the fraction collector: 90 min per fraction

Duration of sampling: about 66 h (44 fractions)

Table 2: Column elution method, column 12.5 mL/h

Fraction no.	V / mL	pH	Water solubility / µg/L
27	18.6	7.1	<65.2
28	18.7	7.0	<65.2
29	18.1	7.0	<65.2
30	18.7	7.0	<65.2
31	18.8	7.2	<65.2

The water solubility was found to be below the quantification limit of 65.2 µg/L.

Column 25.0 mL/h:

Rotation period of the fraction collector:     45 min per fraction
Duration of sampling: about 66 h (88 fractions)

Table 3: Column elution method, column 25.0 mL/h

Fraction no.	V / mL	pH	Water solubility / µg/L
59	19.4	7.8	<65.2
60	19.6	7.3	<65.2
61	19.5	7.3	<65.2
62	19.3	7.2	<65.2
63	19.4	7.2	<65.2

The water solubility was found to be below the quantification limit of 65.2 µg/L.

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

Coating check:

Table 4: Coating check

	Amount of test item used for coating / mg	Measured concentration of test item in eluate / mg/L	Amount of test item eluted / mg
Column 12.5 mL/h	26.8	2.238 / 2.232	11.2
Column 25.0 mL/h		1.954 / 1.950	9.8

The coating check was successful. Enough test item remained on the columns.

The water solubility cs of the test item was below the quantification limit of 65.2 µg/L (mean value of the columns).

Conclusions:

The water solubility of the test substance was determined to be < 0.1 mg/L.

Executive summary:

The water solubility of the test item was determined according to OECD 105 and Regulation (EC) No. 440/2008 method A.6 using the column elution method with HPLC analysis. 107.1 mg of the test item were dissolved in 100 mL acetone. 25 mL of this solution were added to about 3 g of sea-shore sand and the mixture was shaken. The solvent was then removed under reduced pressure using a rotary evaporator (40 °C, approx. 100 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 25 °C: 6.8). After a swelling time of 2 h pumps were started to rinse the substance coated sand with demineralised water. At the end of the study it was confirmed that residual test item remained on the columns. The residual test item was eluted with 50 mL acetone. Two identical samples were prepared, one of them was exposed to a flow rate of 12.5 mL/h (column 1), the other one to 25.0 mL/h (column 2). The aqueous fractions were diluted 0.5 mL to 1 mL with acetonitrile / demineralised water 75:25 % (v/v) and measured by means of HPLC. The water solubility of the test item was determined to be <0.1 mg/L (<65.2 µg/L) at 20 °C (pH ~ 7).

Description of key information

The water solubility of the test substance was determined to be < 0.1 mg/L.

Additional information

The water solubility of the test item was determined according to OECD 105 and Regulation (EC) No. 440/2008 method A.6 using the column elution method with HPLC analysis. 107.1 mg of the test item were dissolved in 100 mL acetone. 25 mL of this solution were added to about 3 g of sea-shore sand and the mixture was shaken. The solvent was then removed under reduced pressure using a rotary evaporator (40 °C, approx. 100 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 25 °C: 6.8). After a swelling time of 2 h pumps were started to rinse the substance coated sand with demineralised water. At the end of the study it was confirmed that residual test item remained on the columns. The residual test item was eluted with 50 mL acetone. Two identical samples were prepared, one of them was exposed to a flow rate of 12.5 mL/h (column 1), the other one to 25.0 mL/h (column 2). The aqueous fractions were diluted 0.5 mL to 1 mL with acetonitrile / demineralised water 75:25 % (v/v) and measured by means of HPLC. The water solubility of the test item was determined to be <0.1 mg/L (<65.2 µg/L) at 20 °C (pH ~ 7) (reference 4.8-1).