3-methyl-6-(p-toluidino)-3H-dibenz[f,ij]isoquinoline-2,7-dione

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

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))

Version / remarks:

(adopted, May 2008)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

(adopted, January 2001)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

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.

Details on study design: HPLC method:

I. Preparation of the test solutions:
- The dead time marker sodium nitrate was dissolved in acetonitrile / demineralized water 9:1 and diluted with acetonitrile
- The calibration substances were dissolved and diluted with acetonitrile
- The test item was dissolved in 5 ml tetrahydrofuran and diluted with acetonitrile
- The concentration for the calibration substances was approximately 0.03 to 0.1 mg/mL; the concentration for the test item was approximately 0.19 mg/mL

II. Equipment and chromatographic conditions
- Chromatograph: High Performance Liquid Chromatograph, HP 1100
- Column type: length: 250 mm, inner diameter: 4 mm
- Stationary Phase: LiChrospher 100 CN, particle diameter: 5 μm
- Supplier: Fa. Merck
- Mobile Phase: A: 830 mL demineralized water (Millipore) + 170 mL buffer pH 6 (Fluka, Art. No. 33545); B: Acetonitrile
- Flow rate: 1.0 mL/min
- Column temperature: 40 °C
- Detection: UV, 220 nm
- Injection volume: 3 μL

III pH determination (aqueous part of the mobile phase):
- Method no.: determined using a calibrated pH-meter with a single-rod glass electrode
- Result: 6.4

IV: Calibration substances:
- Sodium nitrate
- 2-Nitrobenzamide
- 3,5-Dinitrobenzamide
- Triazoxide
- 1,2,3-Trichlorobenzene
- Phenanthrene
- 9,10-Dimethyl-1,2-benz-anthracene

Key result

Sample No.:

#1

Type:

log Koc

Value:

4.29

pH:

6.4

Temp.:

25 °C

Remarks on result:

other: Retention time [tr]: 8.8 minutes

Remarks:

Mean value of 3 single values

Type:

log Koc

Value:

4.2

Remarks on result:

other: calculated

Remarks:

KOCWIN v. 2.00

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient of Solvent Red 52 was log Koc 4.29 measured at 25 °C and pH 6.4.

Executive summary:

The adsorption coefficient (Koc) of Solvent Red 52 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 - 5.37 are established in the EG-test method. The chromatogram of Macrolex Rot 5B showed the main signal eluting at 8.8 minutes. Because the non-ionic form of Solvent Red 52 exists at a pH value > 1.5 the test was carried out at approx. pH 6. The adsorption coefficient (log Koc) of Solvent Red 52 was 4.29 measured at 25 °C and pH 6.4.

Description of key information

The adsorption coefficient was determined by HPLC and the chromatogram showed

1 signal eluting at 8.8 minutes. The log Koc was calculated to be 4.29.

Key value for chemical safety assessment

Koc at 20 °C:

19 498

Additional information

"Should read: log Koc 4.29 at 25 °C"

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.

[LogKoc: 4.29]