Registration Dossier

Diss Factsheets

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
June 09, 2015 to July 07, 2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
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))
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))
GLP compliance:
yes (incl. QA statement)
Type of method:
HPLC estimation method
Media:
soil/sewage sludge
Specific details on test material used for the study:
Name (as stated in the report): GR-88-0778
Lot No: Batch 6
Aspect: Colourless liquid
Expiration date: March 29, 2017
Radiolabelling:
no
Test temperature:
The determination was performed at 35 °C (temperature of the column), but the value obtained above can be considered to represent the value at an unspecified, probably ambient temperature since no mention is made in the guidelines of the temperature at which the tabulated reference substances log KOC values were determined. Adsorption coefficients of the test and reference substances are assumed to vary with temperature in the same way.
Details on study design: HPLC method:
Reverse phase High Performance Liquid Chromatography on cyanopropyl-modified silica stationary phase, containing lipophilic and polar moieties, is used.

While passing through the column among with the mobile phase the test substance interacts with the stationary phase. As a result of the partitioning between the mobile and stationary phase the test substance is retarded. The dual-composition of the stationary phase having polar and non-polar sites allows for interaction of polar and non-polar groups of a molecule in a similar way as it is the case for organic matter in soil or sewage sludge matrices. This enables the relationship between the retention time on the column and the adsorption coefficient on organic matter to be established.
A solution of the test substance was prepared (10.0 mg in 25 ml methanol/water 55/45 v/v).

After equilibration of the HPLC system, the calibration mixture was injected first, followed by the test chemical solution twice and the calibration mixture again. See Appendixes 3 and 4 for examples of the chromatograms obtained.

Retention times tR were measured and averaged and the decimal logarithms of the capacity factors k were calculated. The linear regression parameters of the relationship

log KOC = f(log k)

were also calculated from the data obtained with the calibration mixture and, therewith, log KOC of the test substance was determined from its measured capacity factor.

Finally solutions of the reference substances were injected individually to confirm the peak assignment.
Key result
Sample No.:
#1
Type:
log Koc
Value:
3.3
pH:
7
Temp.:
35 °C
Details on results (HPLC method):
The determination was performed at 35 °C (temperature of the column), but the value obtained above can be considered to represent the value at an unspecified, probably ambient temperature since no mention is made in the guidelines of the temperature at which the tabulated reference substances log KOC values were determined. Adsorption coefficients of the test and reference substances are assumed to vary with temperature in the same way.


Therefore: Adsorption coefficient (KOC) of GR-88-0778:

log KOC = 3.3
Validity criteria fulfilled:
yes
Conclusions:
The chromatograms of GR-88-0778 show one peak at an average retention time of 5.594 minutes, corresponding to an adsorption coefficient (log value) of 3.3.
Therefore: Adsorption coefficient (KOC) of GR-88-0778:
Log KOC = 3.3

Executive summary:

The Adsorption coefficient (KOC) on soil and on sewage sludge of GR-88 -0778 was determined by the Reverse Phase High Performance Liquid Chromatographic Method according to the OECD Guidelines for Testing of Chemicals, Method No. 121.

 

The result is: Adsorption coefficient (KOC) of GR-88 -0778 :

log KOC= 3.3

 

 

 


Description of key information

TheAdsorption coefficient (KOC) on soil and on sewage sludgeof GR-88 -0778 was determined by the Reverse Phase High Performance Liquid Chromatographic Method according to the OECD Guidelines for Testing of Chemicals, Method No. 121.

 

Key value for chemical safety assessment

Koc at 20 °C:
1 995

Additional information