Tetrasodium {5-[(4-chloro-6-{[4-(alkenylsulfonyl)phenyl]amino}-heteromonocycl-2-yl)amino]-4-(hydroxy-κO)-3-{[2-(hydroxy-κO)phenyl]diazenyl-κN}naphthalene-disulfonato(4-)}[3-(hydroxy-κO)-4-{[2-(hydroxy-κO)naphthalen-1-yl]diazenyl-κN}naphthalene-sulfonato(3-)]chromate(4-)

Adsorption / desorption

Description of key information

Determination of the partition coefficient of FAT 20341/A TE using HPLC screening method.

Key value for chemical safety assessment

Koc at 20 °C:

17.8

Additional information

The determination was carried out using the HPLC screening method, designed to be compatible with Method C19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001.

 

The test utilized a high performance liquid chromatograph. A commercially available cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties was used.

Discussion

As the test item was known to be an organic salt, testing was carried at approximately pH 7, with the test item in its fully ionized (salted) form.

 

The small peak at 2.2 minutes in the sample chromatograms was considered to be due to at least one of the impurities in the test item.

 

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 was consistent, the HPLC method was considered valid for the determination of adsorption coefficient.

 

Conclusion

The adsorption coefficient (K_oc) of the test item has been determined to be less than 17.8, log₁₀ K_oc less than 1.25. These values indicate that the test item has very high mobility.