Registration Dossier

Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 2010-02-18 to 2010-05-07
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study, OECD guideline

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
2009-08-17
Type of method:
HPLC estimation method
Media:
soil/sewage sludge

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Identification LCE10027
Identification of the flask LCE10027
Expiry date 27 may 2011
Supplier SEPPIC
Appearance Beige pearls
Packaging 1 white plastic flask with blue stopper
Quantity received 300 g
Date of the reception 15 March 2010
Storage In darkness at room temperature
Identification number for the study 10-041

Study design

Test temperature:
22° C

HPLC method

Details on study design: HPLC method:
Instrumental analysis
The experimental conditions used for the determination of the retention times of the
analytical reference items and of the test item by high pressure liquid chromatography
equipped with an ultraviolet detector are as following:
Column
Column Supelco Length (cm) 25
Particle size (μm) 5.0 Internal diameter (mm) 4.6
Stationary phase Supelcosil LC-CN
Mobile phase Methanol / water 45/55 v/v
Flow rate (mL/min) 0.9
Injected volume (μL) 40 Wave length analysis (nm) 210
Injection sequence
Mixture of the analytical reference items, test item, mixture of the analytical reference
items, test item, mixture of the analytical reference items, individual analytical reference
items.
The temperature during the analytical phase was around 22°C.

Batch equilibrium or other method

Details on sampling:
Preparation of the test item solution
A quantity of about 1000 mg of LCE10027 was accurately weighed into a 100-mL
volumetric flask. The volume was made with up methanol. The solution was treated with
ultrasounds for 15 minutes before analysis.
Computational methods:
The following discussion provides elements to define the adsorption/desorption coefficient of the test item.

The structure of the substances which make up the test item have a long non-polar chain and a hydrophilic part. Thus, the substances might exhibit surface-active properties.

The partition coefficients of the substances present in the test item as calculated during DEFITRACES’s study 10-919003-001 are very high; this is an indication of the hydrophobic nature of them.

A linear relationship exists between the adsorption/desorption coefficient and the partition coefficient of chemical substances. In the case of hydrophobic substances the relationship is given by the formula:

logKoc = 0.81 x log Pow + 0.10

The following table gives the calculated values of the adsorption/desorption coefficient of the substances defined in the test item.


Substances contained in
LCE10027 % in LCE10027 Value of log Pow Value of log Koc
Dodecanol < 0.5 4.8 4.0
Tetradecanol About 1.5 5.8 4.8
Hexadecanol About 30 6.7 5.5
Octadecanol About 34 7.7 6.3
Dodecylmonoglucoside About 7 2.9 2.4
Tetradecylmonoglucoside About 2.5 3.9 3.3
Hexadecylmonoglucoside About 9 4.9 4.1
Octadecylmonoglucoside About 8.5 5.8 4.8


The adsorption/desorption coefficient of LCE10027 can be estimated to be higher then 2.4 which represents the lowest value of Koc found for the substances which make up the test item. The calculated coefficients indicate that the more hydrophobic the substance is the more it tends to partition into the organic components of the soil and the sewage sludge and becomes associated with these materials.

Results and discussion

Adsorption coefficient
Type:
log Koc
Value:
> 2.4
Temp.:
22 °C
Remarks on result:
other: Based on the relationship existing between log Koc and log Pow, the adsorption/desorption coefficient of LCE10027 on soil and on sewage sludge can be estimated to be higher then 2.4.

Results: HPLC method

Details on results (HPLC method):
No peaks related to the test item could be observed on the chromatographic trace in the interval limited by the reference substances using the method as described in the Guideline.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The adsorption / desorption coefficient of LCE10027 is lower than 1.25.
Executive summary:

Determination of the adsorption / desorption coefficient of LCE10027

In compliance with OECD Guideline No. 121 (2001)

The objective of this study was to estimate the adsorption/desorption coefficient on soil and on sewage sludge using (HPLC) High Performance Liquid Chromatography following the test method (OECD Guideline No. 121, 2001).

The adsorption/desorption coefficient is defined as the ratio between the concentration of the test substance in the soil/sludge and the concentration of the test substance in the aqueous phase at adsorption equilibrium. The adsorption coefficient Koc normalised to the organic carbon of the soil is a useful indicator of the binding capacity of a substance on organic matter of soil or sewage sludge.

No peaks related to the test item could be observed on the chromatographic trace in the interval limited by the reference substances using the method as described in the Guideline.

 

Based on the relationship existing between log Kocand log Pow,the adsorption/desorption coefficient of LCE10027 on soil and on sewage sludge can be estimated to be higher then 2.4.