[No public or meaningful name is available]

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:

19/08/2008-03/07/2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to the OECD guideline and it sis GLP

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))

Deviations:

no

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

Principles of method if other than guideline:

This method utilizes a high performance liquid chromatograph with UV/VIS and ELSD detector, reversed phase column and an aqueous mobile phase.

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

not specified

Test temperature:

25ºC

Details on study design: HPLC method:

Apparatus:
Merck-Hitachi Sampler L-7200
Merck-Hitachi Pump L-6200
Sedex ELSD Detector 85
Merck-Hiachi UV/VIS-Detector L-4000
Crococil LCSOF 55

Column:
Luna CN, particle size 5µm, 50 mm x 4.6 mm
Pre-Colimn: CN
HPLC Eluent: Water / Methanol (45:55; v/v); pH 6.06
Detection: Test item: ELSD
Reference items: 220nm
Sodium nitrate: 220 nm
Temperature: 25ºC
Injection Volume: 10µL
Flow: 1.0 mL/min
Run Time: 12 minutes

Analytical monitoring:

not required

Details on sampling:

The substance (58.45mg) was dissolved in methanol (50mL) to prepare a stock solution of 1169µg/mL. The stock solution (5mL) was diluted with a solvent mixture of water and methanol (45:55; v/v) to 10mL to obtain a test item solution of 584.5µg/mL. The pH value of the test item solution was determined to be 6.48. This test item solution was injected three times.

Type:

Koc

Value:

6 423

Type:

log Koc

Value:

3.8

Validity criteria fulfilled:

yes

Conclusions:

The log of the adsorption coefficient (Koc) of the substance was calculated to be logKoc=3.8 which is equal to a Koc value of 6423 using the HPLC method. This value indicates that the susbtance is immobile.

Executive summary:

The determination of the adsorption coefficient (KOC) of AA 15 was performed according to the OECD Guideline for the Testing of Chemicals, No.121, Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge using High Performance Liquid Chromatography (HPLC), January, 2001 and the EC Directive 2001/59, C.19.

The detection of the reference items were performed using UV detection. Isoproturon, pyrazophos and diclofop-methyl were detectable using ELSD. The substance was not detectable using UV detection. Therefore, the test item was measured using ELSD.

The chromatography of the test item resulted in one main peak with a well-defined and reproducible retention time. The HPLC method was therefore considered to be suitable for the purpose of the study. Based on the chromatographic data, the substance was  considered to be  stable during the test procedure.

The log of the adsorption coefficient (Koc) of the substance was calculated to be logKoc = 3.8 which is equal to a Koc value of 6423 using the HPLC method. Because of the high Koc value of the substance it can be said thar the test item is immobile in organic matter.

This study is considered as relevant. All the validity criteria were fulfilled and no deviations were observed from the OECD 301B guideline.

Description of key information

The determination of the adsorption coefficient (KOC) of AA 15 has been investigated in a study according to the OECD Guideline for the Testing of Chemicals, No.121, Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge using High Performance Liquid Chromatography (HPLC), January, 2001 and the EC Directive 2001/59, C.19. This study was assessed as a key study.

The log of the adsorption coefficient (Koc) of the substance was calculated to be logKoc = 3.8 at 20°C which is equal to a Koc value of 6423 using the HPLC method.

Because of a Koc value > 5000, the substance test item is considered immobile in organic matter according to McCall et al. (1980) scale of mobility classes.

Key value for chemical safety assessment

Koc at 20 °C:

6 423

Additional information

The determination of the adsorption coefficient (KOC) of AA 15 was performed according to the OECD Guideline for the Testing of Chemicals, No.121, Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge using High Performance Liquid Chromatography (HPLC), January, 2001 and the EC Directive 2001/59, C.19.

The detection of the reference items were performed using UV detection. Isoproturon, pyrazophos and diclofop-methyl were detectable using ELSD. The substance was not detectable using UV detection. Therefore, the test item was measured using ELSD.

The chromatography of the test item resulted in one main peak with a well-defined and reproducible retention time. The HPLC method was therefore considered to be suitable for the purpose of the study. Based on the chromatographic data, the substance was  considered to be  stable during the test procedure.

The log of the adsorption coefficient (Koc) of the substance was calculated to be logKoc = 3.8 which is equal to a Koc value of 6423 using the HPLC method. Because of the high Koc value of the substance it can be said thar the test item is immobile in organic matter.