alkoxy substituted aryl diazo heterocyclic aryl nitrile

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 16, 2015 - January 22, 2015

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:

yes (incl. QA statement)

Type of method:

column elution method

Water solubility:

< 15 µg/L

Temp.:

20 °C

pH:

5.8 - 6.6

Results:

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 distilled water, respectively. After each addition of an amount of water, the mixture was stirred for 24 hours, and visually checked for any undissolved particles

Table 4: Results of the preliminary visual estimation of the water solubility

Amount of the test item / mg		Total volume / mL		Appearance of mixture
9.8		100		undissolved
9.7		500		undissolved
2.3		500		undissolved

The solubility of the test item in water was found to be below 4.6 mg/L (without correction for the purity). According to the guideline the column elution method is the appropriate method for solubilities below 10 mg/L therefore this method was used for the main test.

Column elution method

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: 5.5). After a swelling time of 2 h pumps were started to rinse the test item coated sand with distilled water.

The data of the fractions 1 to 5 were not taken into account for the following evaluation. The values for the water solubility were calculated from fractions 21 to 25 for the 12.5 mL/h column and from the fractions 47 to 51 for the 25.0 mL/h column.

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. The eluate was diluted from 0.5 mL to 5 mL with acetonitrile and again from 0.1 mL to 1.0 mL with acetonitrile / distilled water (50 % / 50 %). The concentration of the test item was quantified by HPLC.

As blank value the used distilled water was tested by means of HPLC. No signal was detected in the range of the retention time of the test item.

Column 12.5 mL/h:

Rotation period of the fraction collector:      90 min per fraction

Duration of sampling:                                    about 66 h (44 fractions)

Table 5: Column elution method, column 12.5 mL/h

Fraction no.	V / mL	pH	water solubility /µg/L
21	19.0	6.2	<15
22	19.0	5.8	<15
23	19.0	6.2	<15
24	19.0	6.2	<15
25	19.0	6.0	<15

Evaluation of the fractions 21 to 25:

The water solubility was found to be below the quantification limit of 15 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 6: Column elution method, column 25.0 mL/h

Fraction no.	V / mL	pH	water solubility /µg/L
47	15.6	6.6	<15
48	15.6	6.3	<15
49	15.4	6.1	<15
50	15.4	6.1	<15
51	15.4	6.1	<15

Evaluation of the fractions 47 to 51:

The water solubility was found to be <15 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 7: 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	9.7	1.676 / 1.677	8.4
Column 25.0 mL/h	9.7	1.496 / 1.496	7.5

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

The water solubility was found to be below the quantification limit of 15 µg/L.

Conclusions:

The water solubility of the test item at a temperature of 20 °C was below the limit of quantification of 15 µg/L

Executive summary:

The water solubility c_S of the test itemat a temperature of 20 °C was determined according to the column elution method described in the European Commission Regulation (EC) No. 440/2008. It was found to be: c_S < 15 µg/L

Description of key information

The water solubility of the test item was determined by the column elution method according to the European Commission Regulations (EC) No. 440/2008 and No. 260/2014, A.6. Water solubility; column elution method and according to the OECD test guideline, OECD 105 Water solubility.

Additional information

The water solubility c_S of the test item at a temperature of 20 °C was determined according to the column elution method described in the European Commission Regulation (EC) No. 440/2008. It was found to be below the quantification limit of 15 µg/l:

c_S < 15 µg/l