1-amino-4-hydroxy-2-phenoxyanthraquinone

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

other: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

The complete read across justification is detailed in section 13. Source study has reliability 1.

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))

GLP compliance:

yes

Type of method:

HPLC estimation method

Test temperature:

20 °C.

Details on study design: HPLC method:

The determination was carried out using the HPLC screening method, designed to be compatible with EU method C19 (2008) and OECD guidelines 121 (2001).
The test system utilized a high performance liquid chromatograph. A commercially available cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties was used.

The sample, dead time and reference standard solutions were injected in duplicate using the following HPLC parameters:
HPLC System: Agilent Technologies 1200 series
Column: Luna Cyano 5 μm 100 Å (150 x 4.6 mm id)
Column temperature: 20 ºC
Mobile phase: methanol: purified water (55:45 v/v)
pH of mobile phase:7.0
Flow-rate: 1.0 ml/min
Injection volume: 10 μl
UV detector wavelength: 210 nm dead time and standards & 520 nm sample

Analytical monitoring:

yes

Type:

Koc

Value:

21 700 dimensionless

Temp.:

20 °C

Type:

log Koc

Value:

4.34 dimensionless

Temp.:

20 °C

Validity criteria fulfilled:

not specified

Conclusions:

The adsorption coefficient (Koc) of the test item has been determined to be 2.17 x 10E4, log10 Koc 4.34. These values indicate that the test item will demonstrate immobility in the environment.

Executive summary:

A key study was performed to determine the adsorption of test substance according to OECD guideline 121.

The test item has no dissociation constants relevant to this test, therefore manipulation of the mobile phase pH was unnecessary. Testing performed at approximately neutral pH with the test item in a non-ionised form. As the slope of the calibration curve for the reference standards showed good first order correlation and as the retention times between duplicate injections for each solution were consistent, the HPLC method was considered valid for the determination of adsorption coefficient.

The adsorption coefficient (K_oc) of the test item has been determined to be 2.17 x 10⁴, logK_oc 4.34. These values indicate that the test item will demonstrate immobility in the environment.

Description of key information

Log Koc = 4.34 at 20 °C.

Key value for chemical safety assessment

Koc at 20 °C:

21 700

Additional information

No experimental data on Disperse Red 060 was available, nevertheless, based on the physicochemial properties, the substance can be expected to have a low potential for adsorption (log Kow < 3). In order to support this evaluation a read across approach was followed. Details are attached in section 13.

HPLC method based on OECD guideline 121 and EU method C.19.

Data on Similar Substance 01 was used to assess the adsorption/desorption potential of the test item, as the two substances show similar chemical structure and properties. The two species are anthraquinone rings substituted by polar and apolar groups, leading to low water solubility and similar partition coefficients, i.e. log K_ow values in the range of ca. 1.8 - 2.3.

Test item has no dissociation constants relevant to this test, thus manipulation of the mobile phase pH was unnecessary. Test was performed at approximately neutral pH with the test item in a non-ionised form. As the slope of the calibration curve for the reference standards showed good first order correlation and retention times between duplicate injections for each solution were consistent, the HPLC method was considered valid for the determination of adsorption coefficient.

The adsorption coefficient (K_oc) of the test item was determined to be 2.17 x 10⁴, log K_oc 4.34. These values indicate that the test item will demonstrate immobility in the environment.

[LogKoc: 4.34]