4-Ethoxy-2,3-difluoro-4'-methyl-1,1'-biphenyl

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-03-23 to 2016-05-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

no

Type of method:

column elution method

Key result

Water solubility:

0.14 mg/L

Conc. based on:

test mat.

Incubation duration:

71 h

Temp.:

20 °C

pH:

>= 6.9 - <= 7

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.

 

Results of the preliminary visual estimation of the water solubility

Amount of test item / mg	Total volume of dist. water/mL	Appearance of mixture
8.8	100	not dissolved
11.6	500	not dissolved
4.4	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

102.2 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. 20 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: 6.1). 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 elution method, column 12.5 mL/h (fraction 21 to 25)

Fraction no.	V /mL	pH	water solubility /mg/L
21	19.0	6.9	0.131
22	19.0	6.9	0.132
23	18.7	6.9	0.133
24	18.7	6.9	0.133
25	18.7	6.9	0.137

Due to the slight tendency of the results five additional fractions have been analysed.

 

Column elution method, column 12.5 mL/h (fractions 37 to 41)

Fraction no.	V /mL	PH	water solubility /mg/L
37	18.7	6.7	0.130
38	18.7	6.9	0.133
39	18.7	6.8	0.134
40	18.7	6.9	0.135
41	18.7	6.9	0.137

 

As the water solubility was in the same range for each of the five fraction series (both starting at 0.13 mg/L and going to 0.14 mg/L) the observed tendency was evaluated as not significant. The water solubility was found to be 0.133 mg/L.

 

Column 25.0 mL/h:

Rotation period of the fraction collector: 45 min per fraction Duration of sampling: about 47 h (63 fractions)

 

Column elution method, column 25.0 mL/h

Fraction no.	V /mL	pH	water solubility /mg/L
48	19.8	6.9	0.145
49	19.8	7.0	0.138
50	19.8	6.9	0.137
51	20.0	6.9	0.140
52	20.0	7.0	0.141

 

The water solubility was found to be 0.140 mg/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 0.140 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. About 102.2 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. 20 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: 6.1). 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 concentration of test item was determined by means of HPLC. The pH of each sample was recorded. The water solubility of the test item was determined to be 0.140 mg/L at 20 °C (pH = 6.9 – 7.0).

Description of key information

The water solubility of the test item at a temperature of 20 °C was determined to be 0.140 mg/L.

Key value for chemical safety assessment

Water solubility:

0.14 mg/L

at the temperature of:

20 °C

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. About 102.2 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. 20 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: 6.1). 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 concentration of test item was determined by means of HPLC. The pH of each sample was recorded. The water solubility of the test item was determined to be 0.140 mg/L at 20 °C (pH = 6.9 – 7.0).