N-[4-(2',7'-ditert-butyl-9,9'-spirobi[fluorene]-2-yl)phenyl]-9,9-dimethyl-N-(2-phenylphenyl)fluoren-2-amine

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05.-06.08.2019

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)

Version / remarks:

2014

Deviations:

no

GLP compliance:

no

Type of method:

column elution method

Key result

Water solubility:

< 0.05 mg/L

Conc. based on:

test mat.

Temp.:

25 °C

pH:

4.9

Preliminary test

For the present test item a preliminary test was not conducted, as the test item is known to have a very non-polar molecular structure and will therefore not be soluble in water. This assumption was supported by a calculated value of the water solubility of 9E-7 mg/l (Software "KOWWIN" v1.68, EPI Suite v4.10). Therefore, the water solubility of the test item was assumed to be < 10 mg/l and the water solubility was determined by the column elution method in the main test.

Column elution method

102.5mg of the test item were dissolved in100 mL in tetrahydrofuran. 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 24°C:4.9). 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 with50 mL tetrahydrofuran. The eluate was diluted from 0.1 mL to 10 mL and again from 0.5 mL to 1.0 mL with tetrahydrofuran. As blank value 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 quantifiedby HPLC.

 

Column 1:

Rotation period of the fraction collector:         90min per fraction

Duration of sampling:                           about72h (49fractions)

 

Table column elution method, column 1 (approx. 12.5 mL/h)

Fraction no	V / mL	pH	Water solubility /µg/L
36	18.0	6.5	< 48
37	18.0	6.5	< 48
38	18.0	6.6	< 48
39	18.0	6.5	< 48
49	18.0	6.5	< 48

 

The water solubility was found to bebelow the quantification limit of 48 µg/L.

 

Column 2:

Rotation period of the fraction collector:         45min per fraction

Duration of sampling:                           about72h (98fractions)

 

Table column elution method, column 2 (approx. 25.0 mL/h)

Fraction no	V / mL	pH	Water solubility /µg/L
72	18.5	6.5	< 48
73	18.5	6.5	< 48
74	18.5	6.6	< 48
75	18.5	6.6	< 48
76	18.5	6.5	< 48

 

The water solubility was found to bebelow the quantification limit of 48 µg/L.

 

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

 

Table Coating check

	Amount of test item used for coating /mg	Measured concentration of  test item in eluate /mg/L	Amount of test item  eluated /mg
Column 12.5 mL/h	25.6	1.652/1.631	16.4
Column 25.0 mL/h	25.6	1.283/1.294	12.9

 

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 of48 µg/L(mean value of the columns) in both columns.

Conclusions:

The water solubility cs of the test item at a temperature of 20°C was determined according to the column elution method. It was found to be below the quantification limit: cs < 0.05 mg/L.

Executive summary:

The water solubility was determined according to OECD 105 using the column elution method. Calculation showed that the water solubility of the test item is < 10 mg/L. The column elution method showed a solubility: cs< 0.05mg/L.

Description of key information

The water solubility cs of the test item at a temperature of 20°C was determined according to the column elution method was found to be cs < 0.05 mg/L.

Key value for chemical safety assessment

at the temperature of:

20 °C

Additional information

The water solubility was determined according to OECD 105 using the column elution method. Calculation showed that the water solubility of the test item is< 10 mg/L. The column elution method showed a solubility below the quantification limit:cs < 0.05 mg/L.