1-(methylamino)-4-[(3-methylphenyl)amino]anthraquinone

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental starting date: 17 October 2017. Experimental completion date: 17 January 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (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:

1-(methylamino)-4-[(3-methylphenyl)amino]anthraquinone

EC Number:

229-059-2

EC Name:

1-(methylamino)-4-[(3-methylphenyl)amino]anthraquinone

Cas Number:

6408-50-0

Molecular formula:

C22H18N2O2

IUPAC Name:

1-(methylamino)-4-[(3-methylphenyl)amino]-9,10-dihydroanthracene-9,10-dione

Test material form:

solid: particulate/powder

Details on test material:

Identification: 1-(methylamino)-4-[(3-methylphenyl)amino] anthraquinone
Physical state/Appearance: dark red powder
Batch: 702W01
Purity: 99.4%
Expiry Date: 08 February 2020
Storage Conditions: room temperature in the dark
Intended use/Application: industrial chemical

Results and discussion

Water solubility

Key result

Water solubility:

< 0.02 mg/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

>= 5.5 - <= 5.9

Any other information on results incl. tables

Preliminary Test

The preliminary estimate of the water solubility at 20.0 ± 0.5 °C was less than 2.0 x 10^-5g/L. The solution had a pH of 8.9.

Definitive Test

The mean peak areas relating to the standard and sample solutions are shown in the following table:

Solution	Mean Peak Area
Standard 1.01 x 10^-2mg/L	8.5194 x 10^4
Standard 1.02 x 10^-2mg/L	8.6700 x 10^4
Matrix blank	None detected
Sample 1A	None detected
Sample 1B	None detected
Sample 2A	None detected
Sample 2B	None detected
Sample 3A	None detected
Sample 3B	None detected
Standard 1.01 x 10^-2mg/L (filtered)[1]	2.1954 x 10^4

The concentration (g/L) of test item in the sample solutions is shown in the following table:

Sample Number	Time Shaken at ~ 30 ºC (hours)	Concentration (g/L)	Solution pH
1	24	<2.0 x 10^-5	5.9
2	48	<2.0 x 10^-5	5.5
3	72	<2.0 x 10^-5	5.6

Mean concentration   :          Less than 2.0 x 10^-5 g/L at 20.0 ± 0.5 ºC

 Validation

The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 0.0025 to 0.10 mg/L. The results were satisfactory with a first-order correlation coefficient (r) of 0.9997 being obtained.

  Discussion

On completion of the equilibration period, the samples were colorless solutions with excess test item attached to the glass of the flasks above the solutions, floating on top of the solutions with a small amount in suspension. The solutions were decanted, avoiding excess test item prior to centrifugation and filtration. After centrifugation and filtration, the supernatants were taken for analysis. The supernatants were clear, colorless and free from excess, undissolved test item.

As the preliminary test indicated a water solubility of less than 10 mg/L, this indicated that the column elution method would be more appropriate. However, during method development, it was noted that the solubility of the test item in suitable volatile solvents for coating the glass beads with test item, was extremely low. It was therefore, concluded that the column elution was not feasible in this instance and therefore, it would be more appropriate to use the flask method.

From the results for the standard solutions, blank solution and sample solutions, it was considered that the water solubility should be expressed as a limit value based on the filtered standard solution’s results. This filtered standard solution provided an acceptable level of response for a limit value to be reported. All the sample solutions demonstrated no response and therefore the water solubility was concluded to be less than 2.0 x 10^-5g/L.

Applicant's summary and conclusion

Conclusions:

The water solubility of the test item has been determined to be less than 2.0 x 10-5 g/L of solution at 20.0 ± 0.5 °C.