2-(2-methoxyethoxy)ethyl 4-[(5-cyano-1-ethyl-1,6-dihydro-2-hydroxy-4-methyl-6-oxopyridin-3-yl)azo]benzoate

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 05, 2016 - December 08, 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

no

Type of method:

column elution method

Test material

Test material information

Constituent 1

Reference substance name:

p-[(5-cyano-1,6-dihydro-2-hydroxy-1,4-dimethyl-6-oxo-3-pyridyl)azo]-N-(2-ethylhexyl)benzamide

EC Number:

250-205-6

EC Name:

p-[(5-cyano-1,6-dihydro-2-hydroxy-1,4-dimethyl-6-oxo-3-pyridyl)azo]-N-(2-ethylhexyl)benzamide

Cas Number:

30449-81-1

Molecular formula:

C23H29N5O3

IUPAC Name:

4-[(5-cyano-2-hydroxy-1,4-dimethyl-6-oxo-1,6-dihydropyridin-3-yl)diazenyl]-N-(2-ethylhexyl)benzamide

Test material form:

solid: particulate/powder

Results and discussion

Water solubility

Key result

Water solubility:

< 0.04 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

4.9

Any other information on results incl. tables

 Individual 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 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

Table4: Results of the preliminary visual estimation of the water solubility

Amount of test item / mg	Total volume of dist. water / ml	Appearance of mixture
11.3	100	not dissolved
10.4	500	not dissolved
4.0	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

102.5 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 24 °C: 5.5). 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 12.5 ml/h:

Rotation period of the fraction collector:                 90 min per fraction

Duration of sampling:                                             about 68 h (45 fractions)

Table5: Column elution method, column 12.5 ml/h

Fraction no.	V / ml	pH	water solubility /µg/l
28	17.0	4.9	< 33.6
29	17.0	4.9	< 33.6
30	17.0	4.9	< 33.6
31	17.0	4.9	< 33.6
32	17.0	4.8	< 33.6

The water solubility was found to be below the quantification limit of 33.6 µg/l.

 Column 25.0 ml/h:

Rotation period of the fraction collector:       45 min per fraction

Duration of sampling:                                    about 68h(90 fractions)

Table6: Column elution method, column 25.0 ml/h

Fraction no.	V / ml	pH	water solubility /µg/l
56	16.5	5.0	< 33.6
57	16.5	5.0	< 33.6
58	16.5	5.0	< 33.6
59	16.5	5.0	< 33.6
60	16.5	5.0	35.8

The water solubility was found to be below 40 µg/l.

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

Coating check:

Table7: 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	27.5	0.188 / 0.189	15.7
Column 25.0 ml/h	27.5	0.191 / 0.192	16.0

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

Applicant's summary and conclusion

Executive summary:

The water solubility c_S of the test item Disperse Yellow 198 at a temperature of 20 °C was determined according to the column elution method. It was found to be below the quantification limit:

c_S< 0.04 mg/l