C.I. Solvent Red 119

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 2017 - January 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

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:

yes (incl. QA statement)

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

C.I. Solvent Red 119

EC Number:

602-676-8

Cas Number:

12237-27-3

Molecular formula:

C32H22N10O8Cr

IUPAC Name:

C.I. Solvent Red 119

impurity 1

Reference substance name:

Unknown impurities

Cas Number:

not available

IUPAC Name:

Unknown impurities

impurity 2

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

water

Test material form:

solid: particulate/powder

Results and discussion

Water solubility

Key result

Water solubility:

>= 0.1 - <= 1.56 mg/L

Conc. based on:

test mat. (dissolved fraction)

Temp.:

20 °C

pH:

>= 6 - <= 7

Applicant's summary and conclusion

Conclusions:

For the determination of test item concentrations in Algal and Daphnia test medium, a
method was validated (validation study 17042601G926). This method was adapted to the
determination of the test item concentration in demineralised water by also measuring accuracy
and specificity.
All conditions for the range of 0.1 – 10 mg/L Solvent Red 119 in demineralised water were
fulfilled as the quadratic function was used for calculation of the test item concentration. As
the correlation coefficient was > 0.99 and the accuracy of calibration standards lay in the
demanded ranges of 100 ± 15 % and 100 ± 20 % (low concentration), the working range of
0.1 – 10 mg/L Solvent Red 119 could be used.
A minimal absorption was measured in the blank with 1.0 % of the lowest calibration level.
Therefore, the condition “< 20 % of the lowest calibration level” was fulfilled.
As the accuracy lay in the range of 100 ± 5 % (mean value 101 %), no recovery rate was
used for calculation in the study. The relative standard deviation was 2.9 % and 0.7 % for
0.4 mg/L and 6 mg/L test item solution, respectively.
Filtration had an enormous influence on the measured concentration. But it was assumed
that the presence of a minimal amount of undissolved particles was a possible reason for a
low recovery rate after filtration instead of adsorption of the test item on the filter. Filtration
of the solutions was performed in both main tests as a Tyndall effect was observed in centrifuged
solutions. No Tyndall effect was observed in filtrated solutions. Therefore, the solubility
of Solvent Red 119 in water was stated from the measured concentrations of the
test item in the filtrated test solutions only.
Two main tests were performed: with the range of 1 – 10 g/L (main test 1) and 100 –
1000 mg/L (main test 2) as the first main test in the range of 1 – 10 g/L provided fluctuating
results probably due to a high nominal load.
During main test 1, a dependency of the solubility on the amount of the test item (nominal
load) was perceived in the flasks 1 – 4 only (1 – 6 g/L nominal load). During main test 2, a
dependency of the solubility on the amount of the test item (nominal load) was also perceived
in the flasks 4 – 6, as the values in the flasks 1 – 3 lay below the LOQ of the method
(< 0.1 mg/L) and were not used in the evaluation.
The results from the flasks 1 and 3 – 4 of main test 1 and from the flasks 4 – 6 from main
test 2 were used in the evaluation.
As solubility was dependent on the nominal concentration, no exact value for the solubility
of the test item in water can be stated. The solubility range for the tested nominal concentration
601 – 6001 mg/L was 0.10 – 1.56 mg/L, corresponding to 0.02 % of the test item
relating to the nominal concentration of the test item.
No observations arousing doubts concerning the accuracy of the results and the validity of
the study were made.

Executive summary:

The solubility of the test item Solvent Red 119 in water was determined by measurement

of the test item concentration in the filtrated test solutions using a photometer.

In the preliminary test, concentrations lower than the LOQ (< 0.1 mg/L) and 0.4 mg/L were

measured in 100 mg/L and 1 g/L nominal loads, respectively. Therefore, the slow-stirring

flask method was used.

For the main test 1, six different loading rates in the range of 1 – 10 g/L were chosen: 1, 3,

5, 6, 8 and 10 g/L. The three flasks 1A – 1C with the same loading rate (5 g/L) were used

during equilibration. Six vessels (1C (for the sampling point 72 h) and 2 – 6) were set onto

the stirrer immediately and stirring at 100 rpm was started. After 24 ± 2 hours, flask 1B (for

the sampling point 48 h) and after 48 ± 2 hours, flask 1A (for the sampling point 24 h) were

set on the stirrer and all flasks were stirred for further 24 ± 2 hours at room temperature.

Then, flasks 1A – 1C were taken from the stirrer, tempered at 20.0 ± 0.5 °C, samples were

taken, centrifuged and membrane filtered and analysed using a photometer. Because of a

difference of more than 15 % in the concentrations on days 2 and 3 in the centrifuged and

filtrated solutions each, the test was prolonged, and the flasks 1A-1C were measured on

days 4 – 7. Due to a difference of less than 15 % in the concentrations on days 6 and 7

and no upward tendency in the last three values in the filtrated solutions, the test was finished.

The final measurement was performed as determination from flasks 2 – 6 on day 7.

The additional main test 2 in the low range 100 – 1000 mg/L was necessary as the first

main test in the range of 1 – 10 g/L (nominal) provided fluctuating results probably due to a

high nominal load. The following nominal loads were tested 100, 300, 500, 600, 800 and

1000 mg/L. The same procedure was performed as described above (main test 1). Because

of a difference of more than 15 % in the concentrations on days 2 and 3 in the centrifuged

solutions, the test was prolonged, and the flasks 1A-1C were measured on days 4

– 7. The values in the filtrated solutions lay below the LOQ of the method (< 0.1 mg/L).

Due to a difference of less than 15 % in the concentrations on days 4 and 5 and no upward

tendency in the last three values in the centrifuged solutions, the test was finished.

The final measurement was performed as determination from flasks 2 – 6 on day 8.

A Tyndall effect was present in the centrifuged solutions. After filtration of the centrifuged

solutions no Tyndall effect was observed.

During main test 1, a dependency of the solubility on the amount of the test item (nominal

load) was perceived in the flasks 1 – 4 only (1 – 6 g/L nominal load). During main test 2, a

dependency of the solubility on the amount of the test item (nominal load) was also perceived

in the flasks 4 – 6 only, as the values in the flasks 1 – 3 lay below the LOQ of the

method (< 0.1 mg/L) and were not used in the evaluation.

The results from flasks 1 and 3 – 4 of main test 1 and from flasks 4 – 6 from main test 2

were used in the evaluation.

Table 3.2-a       Measurements used for Calculation of Solubility (Filtrate)

Main Test       Flask#             Measured Conc.* Test Item [mg/L]       Nominal Conc. Test Item [mg/L]       Dissolved Part [%]

2                     4                                   0.10                                                        601                                          0.02

5                                   0.14                                                        800                                           0.02

6                                   0.32                                                        1000                                          0.03

1                     3                                   0.72                                                        3001                                          0.02

1                                   0.88                                                        5002                                          0.02

4                                   1.56                                                        6001                                          0.03

* Conc. = concentration

As the solubility was dependent on the nominal concentration, no exact value for the solubility

of the test item in water can be stated.

The concentration of Solvent Red 119 in water was in the range of:

0.10 – 1.56 mg/L at 20.0 ± 0.5 °C

0.10 – 1.56 * 10-3 kg/m3 (SI units).

for the following nominal concentration range of the test item in water: 601 – 6001 mg/L,

corresponding to a dissolved part of 0.02 % of the test item (mean value) relating to the

nominal concentration of the test item.