Propanenitrile, 3-[[4-[[5,6(or 6,7)-dichloro-2-benzothiazolyl]azo]phenyl]ethylamino]-

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

September 17, 2021 - October 07, 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

EC No. 260/2014

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Key result

Water solubility:

< 0.087 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

>= 6.3 - <= 7

Water solubility:

< 0.048 mg/L

Conc. based on:

test mat.

Remarks:

Constituent 1

Temp.:

20 °C

pH:

>= 6.3 - <= 7

Remarks on result:

not determinable because of methodological limitations

Key result

Water solubility:

< 0.039 mg/L

Conc. based on:

test mat.

Remarks:

Constituent 2

Temp.:

20 °C

pH:

>= 6.3 - <= 7

Remarks on result:

not determinable because of methodological limitations

Individual results:

Preliminary test:

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 6: Results of the preliminary test

Amount of test item / mg	Total volume of demineralized water / mL	Appearance of mixture
14.4	100	not dissolved
13.1	500	not dissolved
3.0	500	not dissolved

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

Column elution method:

101.5 mg of the test item were dissolved in 100 mL tetrahydrofuran using the ultrasonic bath for 10 min. 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 (50 °C, approx. 10 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: 5.9). 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 with 50 mL 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 quantified by HPLC. Refer to Table 7 to Table 9 for results.

Column 3:

Rotation period of the fraction collector: 90 min per fraction

Duration of sampling: about 48 h (32 fractions)

Table 7: Column elution method, column 1 (approximately 12.5 mL/h)

Fraction no.	V / mL	pH	water solubility Peak 1 / mg/L	water solubility Peak 2 / mg/L
19	19.5	6.3	< 0.048	< 0.039
20	19.5	6.3	< 0.048	< 0.039
21	19.5	6.5	< 0.048	< 0.039
22	19.5	7.0	< 0.048	< 0.039
23	19.5	6.9	< 0.048	< 0.039

The water solubility was found to be below the quantification limit of 0.048 mg/L (peak 1) and 0.039 mg/L (peak 2).

Column 4:

Rotation period of the fraction collector: 45 min per fraction

Duration of sampling: about 48 h (64 fractions)

Table 8: Column elution method, column 2 (approximately 25.0 mL/h)

Fraction no.	V / mL	pH	water solubility Peak 1 / mg/L	water solubility Peak 2 / mg/L
44	16.5	6.6	< 0.048	< 0.039
45	16.5	6.3	< 0.048	< 0.039
46	16.5	6.8	< 0.048	< 0.039
47	16.5	6.4	< 0.048	< 0.039
48	16.5	6.8	< 0.048	< 0.039

The water solubility was found to be below the quantification limit of 0.048 mg/L (peak 1) and 0.039 mg/L (peak 2).

In both columns the concentration of five consecutive fractions was constant within ± 30 %.

Coating check:

Table 9: Coating check (peak 1)

	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	25.4	0.322 / 0.322	3.22
Column 25.0 mL/h	25.4	0.203 / 0.203	2.03

Table 10: Coating check peak 2

	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	25.4	0.360 / 0.360	3.60
Column 25.0 mL/h	25.4	0.229 / 0.217	2.23

After eluating the residual test item with tetrahydrofuran 2 additional peaks were detected in the HPLC chromatograms. These additional peaks had a peak area comparable to the peak area of peak 1 and peak 2. As the sea sand coated with the test item was still red coloured before eluating the residual test item, it was assumed that this had no influence on the final result. The coating check was successful. Enough test item remained on the columns.

The water solubility c_S of the test item was below the quantification limit of 0.048 mg/L (peak 1) and 0.039 mg/L (peak 2).

Conclusions:

The water solubility of the test item at a temperature of 20 °C was determined to be < 0.087 mg/L

Executive summary:

The water solubility of the test item at a temperature of 20 °C was determined according to the column elution method (European Commission Regulation (EC) No. 440/2008 and No. 260/2014, method A.6. and OECD 105 (1995)). It was found to be below the quantification limit of the HPLC measurement:

Peak 1: < 0.048 mg/L

Peak 2: < 0.039 mg/L

Description of key information

The water solubility of the test item at a temperature of 20 °C was determined to be < 0.087 mg/L

Key value for chemical safety assessment

Water solubility:

0.087 mg/L

at the temperature of:

20 °C

Additional information

The water solubility of the test item at a temperature of 20 °C was determined according to the column elution method (European Commission Regulation (EC) No. 440/2008 and No. 260/2014, method A.6. and OECD 105 (1995)). It was found to be below the quantification limit of the HPLC measurement:

Constituent 1: < 0.048 mg/L

Constituent 2: < 0.039 mg/L