4-Ethoxy-4'-(trans-4-ethylcyclohexyl)-2,3-difluor-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:

06.-13.02.2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

2008

Deviations:

no

GLP compliance:

no

Type of method:

column elution method

Key result

Water solubility:

< 0.049 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

5.6

Preliminary visual estimation of the water solubility

Different amounts of the test item and water were stirred at room temperature until the mixture appeared dissolved or the water solubility could be estimated to be below 10 mg/L.

Table 1: Appearance of the test mixtures

Amount of the test item in mg	Total volume In mL	Appearance of mixture
9.0	100	Undissolved 1)
9.6	500	Undissolved 1)
3.8	500	Undissolved 1)

1) After adding the indicated amount of water, the solution was stirred at room temperature for about 1 day.

The solubility of the test item in water is below 7.6 mg/L (without correction of the purity). Therefore, the water solubility had to be determined by the "column elution method".

 

Column elution method

Individual conditions

Column 1:

Rotation period of the fraction accumulator: 90 min per fraction

Average fraction volume: 17.9 mL

Flow rate: between 11.3 mL/h and 12.7 mL/h

Duration of sampling: about 48 h (32 fractions)

 

Column 2:

Rotation period of the fraction accumulator: 45 min per fraction

Average fraction volume: 18.5 mL

Flow rate: between 22.0 mL/h and 26.0 mL/h

Duration of sampling: about 48 h (64 fractions)

 

Column 3 (blank):

Rotation period of the fraction accumulator: 45 min per fraction

Average fraction volume: 18.2 mL

Flow rate: between 22.0 mL/h and 25.3 mL/h

Duration of sampling: about 44 h (59 fractions)

 

Concentration and pH

Table 2: Column-elution method: Column 1

Fraction no.	V in mL	pH	water solubility in µg/L
23	17.5	5.6	<49.0 2)
24	17.5	5.6	<49.0 2)
25	17.5	5.5	<49.0 2)
26	17.5	5.7	<49.0 2)
27	17.0	5.7	<49.0 2)

2) < indicated below quantification limit

According to the guideline the run can be stopped if the concentrations of five fractions do not differ more than ± 30 % without any raising or descending tendency.

The water solubility was found to be below the quantification limit of 49.0 µg/L.

 

Table 3: Column-elution method: Column 2

Fraction no.	V in mL	pH	water solubility in µg/L
51	17.5	5.7	<49.0 2)
52	17.5	5.6	<49.0 2)
53	17.5	5.7	<49.0 2)
54	17.5	5.6	<49.0 2)
55	17.0	5.6	<49.0 2)

2) < indicated below quantification limit

According to the guideline the run can be stopped if the concentrations of five fractions do not differ more than ± 30 % without any raising or descending tendency.

The water solubility was found to be below the quantification limit of 49.0 µg/L.

 

Table 4: Column-elution method: Column 3 (blank)

Fraction no.	V in mL	pH	water solubility in µg/L
51	17.5	5.7	<49.0 2)
52	17.0	5.6	<49.0 2)
53	17.0	5.6	<49.0 2)
54	17.0	5.5	<49.0 2)
55	17.0	5.6	<49.0 2)

2) < indicated below quantification limit

The blank concentration was found to be below the quantification limit of 49.0 µg/L.

 

Standards for recheck

Table 5: Concentrations of standards for recheck:

Standard	Measured concentration (µg/L)	% Recovery (mean value)
Standard i (c = 24.5 µg/L)	22.6/22.3 22.6/22.3	91.7 91.7
Standard H (c = 44.4 µg/L)	40.5/40.3	90.9
Standard G (c = 196.0 µg/L)	182.1/181.9	92.9
Standard J (c = 196.0 µg/L)	188.0/188.2	96.0
Standard K (c = 444.0 µg/L)	429.8/429.8	96.8

The recovery of the 'recheck samples' is between 90.9 % and 96.8 %, indicating a good accuracy of the analytical method.

All recovery values are calculated from the measured and unrounded concentration values and not from the rounded values given in table 5.

 

Coating check

Table 6: Coating check:

	Amount used for coating in mg	Measured concentration in mg/L	Amount eluted per column in mg
Column 1	28.5	0.446/0.466	23.3
Column 2	28.5	0.447/0.446	22.3

The coating check was successful.

Conclusions:

The water solubility cs of the test item at a temperature of 20 °C was determined to be cs < 0.049 mg/L.

Executive summary:

A study was conducted in accordance with OECD 105 and Regulation (EC) No 440/2008 method A.6 to determine the water solubility of the test substance using the column elution method. The preliminary test showed that the water solubility of the test item is < 7.6 mg/L. The water solubility cs of the test item at a temperature of 20 °C was determined to be cs < 0.049 mg/L (without correction for the purity).  

Description of key information

The water solubility cs of the test item at a temperature of 20 °C was determined to be cs < 0.049 mg/L.

Key value for chemical safety assessment

Water solubility:

0.049 mg/L

at the temperature of:

20 °C

Additional information

A study was conducted in accordance with OECD 105 and Regulation (EC) No 440/2008 method A.6 to determine the water solubility of the test substance using the column elution method. The preliminary test showed that the water solubility of the test item is < 7.6 mg/L. The water solubility cs of the test item at a temperature of 20 °C was determined to be cs < 0.049 mg/L (without correction for the purity).