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Physical & Chemical properties

Water solubility

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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 guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.6 (Water Solubility)
Deviations:
no
GLP compliance:
no
Type of method:
column elution method

Test material

Reference
Name:
Unnamed
Type:
Constituent
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 cS 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:

cS< 0.04 mg/l