1,4-bis[(2-ethyl-6-methylphenyl)amino]anthraquinone

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption, other

Remarks:

(Q)SAR calculated endpoint

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

28th April 2022

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
Estimation Programme Interface (EPI) Suite programme for Microsoft Windows v4.11.


2. MODEL (incl. version number)
KOCWIN v2.00


3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
SMILES: CCc1cccc(C)c1Nc2ccc(Nc3c(C)cccc3CC)c4C(=O)c5ccccc5C(=O)c24


4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
Please refer to attached justification.


5. APPLICABILITY DOMAIN
Please refer to attached justification.


6. ADEQUACY OF THE RESULT
Please refer to attached justification.

Qualifier:

according to guideline

Guideline:

other: ECHA's Guidance on information requirements and chemical safety assessment Chapter R.6: QSARs and grouping of chemicals

Version / remarks:

May 2008

Principles of method if other than guideline:

The prediction of Koc for the registered substance was performed using the model KOCWIN v.2.00 (September 2008). The KOCWIN program estimates the organic carbon-normalised sorption coefficient for soil and sediment using two different models: the first based on the Sabljic molecular connectivity index and the second a QSAR applied to a measured log Kow value for the substance (attributed to McCall et al., 1981).

- Software tool(s) used including version:
Estimation Programme Interface (EPI) Suite programme for Microsoft Windows v4.11.

- Model(s) used:
KOCWIN v2.00

GLP compliance:

no

Remarks:

not relevant

Specific details on test material used for the study:

SMILES: CCc1cccc(C)c1Nc2ccc(Nc3c(C)cccc3CC)c4C(=O)c5ccccc5C(=O)c24
Log Kow=8.6

Type:

log Koc

Value:

6.5 dimensionless

Remarks on result:

other: QSAR based on KOCWIN v2.00 log KOW method: see QPRF for justification as key value.

Type:

Koc

Value:

3 456 000 L/kg

Remarks on result:

other: QSAR based on KOCWIN v2.00 log KOW method: see QPRF for justification as key value.

Type:

log Koc

Value:

7.7 dimensionless

Remarks on result:

other: QSAR based on KOCWIN v2.00 MCI method.

Type:

Koc

Value:

48 560 000 L/kg

Remarks on result:

other: QSAR based on KOCWIN v2.00 MCI method.

Table 1: KOC predictions for the test substance obtained with KOCWIN v.2.00

KOCWIN v2.00
test substance; SMILES: CCc1cccc(C)c1Nc2ccc(Nc3c(C)cccc3CC)c4C(=O)c5ccccc5C(=O)c24
Method 1: Sabljic molecular connectivity index
KOC(L/kg):	48 560 000
Method 2: log Kow methodology determined from KOWWIN estimated values
KOC(L/kg):	3 456 000

Conclusions:

KOCWIN predicts a logKOC value of 7.6863 (KOC =48 560 000L/kg) for the registered substance, based on the first-order Sabljic molecular connectivity index (MCI), and a logKOC value of 6.5386 (KOC=3 456 000 L/kg) based on the log Kow methodology using the experimental value (8.6) as input in the model.

Executive summary:

The adsorption coefficient (KOC) of the registered substance was estimated using the KOCWIN v2.00 QSAR model available from the US EPA. The estimated adsorption coefficient of the registered substance, based on the first-order Sablljic molecular connectivity index is 48 560 000 L/kg.

Additionally, log Kow methodology predicted a KOC value of 3 456 000 L/kg, calculated from an experimentally measured log Kow value for the registered substance that was used as an input into the QSAR model.

Reference 2

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Deviations:

no

Principles of method if other than guideline:

The reference Koc-values in the OECD-guideline presumably refer to 25 °C. Even though the column temperature was 40 °C, this temperature is without influence on the result of the determination. The calibration was done referring to Koc- values of reference substances determined at 25 °C.

For the determination of the adsorption coefficient (Koc) four calibration standards with log Koc from 1.45 - 4.09 are established in the EG-test method. Additional a new reference substance 9,10-Dimethyl-1,2-benzanthracene (7,12-Dimethylbenzanthracene) was used in this test. The experimental value of log Koc = 5.37 for 9,10-Dimethyl-1,2-benzanthracene was published by Donald A. Bahnick and William J. Doucette in the “Chemosphere, Vol. 17, No. 9, pp 1703-1715, 1988”.

Although the determined value does not exactly meet the range of application of the test guideline (1.3 – 5), the value is considered as valid (measurement uncertainty +/- 0,5 log units).

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

In order to ensure a stable performance of the HPLC column, the column temperature was set to 40°C. The reference Koc-values in the OECD guideline presumably refer to 25°C. Even though the column temperature was 40°C, this temperature has no influence on the result of the determination. Therefore the Koc -value of the test item determined within this study also refers to 25 °C.

Details on study design: HPLC method:

Determination of the pH-value of the aqueous part of the mobile phase:
- Procedure: calibrated pH-meter with a single-rod glass electrode
- Result: pH 6.4

PREPARATION OF THE TEST SOLUTIONS:
- The dead time marker sodium nitrate and the calibration substances were dissolved in acetonitrile/demineralized water 9:1; the concentration for the calibration substances was approximately 0.01 to 0.06 mg/ml
- Test item: dissolved in acetonitrile, test concentration approximately 0.1 mg/ml

HPLC-METHOD PARAMETERS:
- Chromatograph: High Performance Liquid Chromatograph, Agilent 1200
Chromatographic conditions:
- Column type: length: 250 mm, inner diameter: 4 mm
- Stationary Phase: LiChrospher 100 CN, particle diameter: 5 μm
- Supplier: Fa. Merck
- Mobile Phase: A: 373.5 ml demineralized water (Millipore) + 76.5 ml buffer pH 6 (Fluka, Art. No. 33545) + 550 ml acetonitrile
- Solvent program: Isocratic 100 % A and 0 % B
- Flow: 1.0 ml/min
- Column temperature: 40 °C
- Detection: UV, 220 nm
- Injection volume: 5 μL

Analytical monitoring:

yes

Key result

Type:

log Koc

Value:

6.2

Temp.:

25 °C

Remarks on result:

other: measured

Type:

log Koc

Value:

6.6

Temp.:

25 °C

Remarks on result:

other: calculated with the software PCKOCWIN v1.66, U.S.EPA

Details on results (HPLC method):

In order to ensure a stable performance of the HPLC column, the column temperature was set to 40°C. The reference Koc-values in the OECD guideline presumably refer to 25°C. Even though the column temperature was 40°C, this temperature has no influence on the result of the determination. Therefore the Koc-value of the test item determined within this study also refers to 25 °C.

The chromatogram of the test item showed 1 signal eluting at 5.5 minutes. No calibration substance with a Koc–value above the value for the signal of the test item was available. For this reason the results for this signal was extrapolated. Although the determined value does not exactly meet the range of application of the test guideline (1.3 – 5), the value is considered as valid (measurment uncertainity +/-0.5 log units).

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient (logKoc) of the test item is 6.2, measured at 25 °C and pH 6.

Executive summary:

The adsorption coefficient (Koc) of Macrolex Blau 3R was determined according to the HPLC method at 40 °C. In order to comply with the guideline OECD 121 and considering environmental relevance, pH 6 was chosen as pH value for the buffer. The reference Koc-values in the OECD-guideline presumably refer to 25 °C. Even though the column temperature was 40 °C, this temperature is without influence on the result of the determination. The calibration was done referring to Koc- values of reference substances determined at 25 °C. For the determination of the adsorption coefficient (Koc) five calibration standards with log Koc from 1.45 - 4.09 are established in the EG-test method. Additional a new reference substance 9,10-Dimethyl-1,2-benzanthracene (7,12-Dimethylbenzanthracene) was used in this test. Although the determined value does not exactly meet the range of application of the test guideline (1.3–5), the value is considered as valid (measurement uncertainty +/- 0,5 log units). A logKoc of 6.2 was determined for the test material measured at 25 °C and pH 6..

Description of key information

Reinblau RLW, Key, Rel 1,OECD-TG 121,GPL; Currenta(2012): Koc = 1 584 893 - log Koc=6.2

Key value for chemical safety assessment

Koc at 20 °C:

1 584 893

Additional information

As the adsorption coefficient (Koc) of Reinblau RLW was measured to be 1 584 893 (Currenta, 2012). The result indicates that the substance is immobile in soils according to McCall et al. (1981).

Range of Koc	Mobility class
0-50	Very high
50-150	High
150-500	Medium
500-2000	Low
2000-5000	Slightly
>5000	Immobile

McCall P.J., Laskowski D.A., Swann R.L., and Dishburger H.J., (1981), “Measurement of sorption coefficients of organic chemicals and their use, in environmental fate analysis”, in Test Protocols for Environmental Fate and Movement of Toxicants. Proceedings of AOAC Symposium, AOAC,Washington DC. 

 

Category approach:

A category approach has been defined (see attached justification document in section 13). The category consists of substances all having the diamino-anthraquinone structure as a common moiety which is linked to phenyl groups via the amino groups. Differences within the category are described by various alkyl groups bound to the phenyl groups. All substances included in the category approach are poorly water soluble with high adsorption coefficient (log Koc>6), high partition coefficient (logKow>8) and not readily biodegradable.

Data available on other members of the category confirmed the immobile behavior of the substances:

Reinblau BLW (CAS n°32724-62-2)	QSAR (EPI) Suite v4.11	logKoc value = 6.5 / Koc= 3456000 L/kg (Log Kow method) logKoc value = 8.7 / Koc= 454 800 000 L/kg (MCI method)
Green 3 (CAS n° 128-80-3)	QSAR (EPI) Suite v4.11	logKoc value =6.3 / Koc= 2100000 L/kg (Log Kow method) logKoc value = 6.7 / Koc= 4800000 L/kg (MCI method)
Violet 36 (CAS n° 82-16-6)	QSAR (EPI) Suite v4.11	logKoc value = 6.4 / Koc=2400000 L/kg (Log Kow method) logKoc value = 6.7 / Koc=4 800 000 L/kg (MCI method)
Green 28 (CAS n° 4851-50-7)	QSAR (EPI) Suite v4.11	logKoc value = 8.0 / Koc=110000000 L/kg (Log Kow method) logKoc value = 8.2 / Koc=150000000 L/kg (MCI method)
Blue 104 (Cas n° 116-75-6)	QSAR (EPI) Suite v4.11	logKoc value = 6.7 / Koc=5 100 000 L/kg  (Log Kow method) logKoc value = 7. 5 / Koc=34 000 000 L/kg (MCI method)