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Environmental fate & pathways

Adsorption / desorption

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Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 2007-02-13 to 2007-02-15
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:
2007
Report Date:
2007

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))
Version / remarks:
AND Directive CE - methode C19 et OCDE 121
Deviations:
yes
Remarks:
The deviation was not considered to have compromised the validity or integrity of the study.
GLP compliance:
yes (incl. certificate)
Remarks:
2005-12-16
Type of method:
HPLC estimation method
Media:
soil

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
batch number: 173 JG-1 (at receipt), 173 JG1 (on the analytical certificate)
description: at receipt, gel
on anlaytical cetrificate yellox hard wax
received: 2006-12-12
storage conditions: at room temperature
purity: 99.7%
hydrosolubility 674 g/L at 20°C
expiry date: 2008-01-03
Radiolabelling:
no

Study design

Test temperature:
22 +/- 1°C

HPLC method

Details on study design: HPLC method:
chromatographic conditions
pump: 118 (Beckman)
Mobile phase (degazed): methanol 55%, water 45%
pH of mobile phase: 5.5
Flow rate: 1 mL/min
Column: Lichrospher 5 CN (Interchim)
particle size: 5um, length= 250mm
inner diameter: 4mm
Detector: Refractive Index Detector 2414 (Waters)
Injector: Spectra system AS3000 (TSP)
Injected volume: 50 uL
Software: Empower 2 (Waters)
Analysis time: 5 min

Batch equilibrium or other method

Computational methods:
As the retention time of the peak observed for the test item was close to the dead volume and below the retention time of acetanilide, reference item (Koc=1.25), the adsorption coefficient was demonstrated to be such as log Koc<1.25. In addition, when possible, an estimation using a calculation method on the non validated software PCKOC (v1.66) was performed.
The test item is a mixture.
The absortption coefficient of the test item was estimeted on the basis of the highest obtained value.

Results and discussion

Adsorption coefficient
Type:
Koc
Value:
<= 1
Temp.:
22 °C

Applicant's summary and conclusion

Conclusions:
Koc <= 1 according to an OECD test n°121
No further adsorption/desorption test is needed
Executive summary:

The aim of this study was to assess the absorption/desorption coefficient (Koc) of aquaxyl on soil. The estimation was carried out according to the test guidelines described in OECD guideline n° 121and directive 2001/59/EEC, C.19.

HPLC method was performed on an analytical column packed with a cyanopropyl solid phase containing lipophilic and polar moities. As the test item is not ionizable, a test was performed with the following mobile phase: methanol/water (55/45 v/v) at pH5.5

As the retention time of the peak observed for the test item was close to the dead volume and below the retention time of acetanilide, reference item (Koc=1.25), the adsorption coefficient was demonstrated to be such as log Koc<1.25. In addition, when possible, an estimation using a calculation method on the non validated software PCKOC (v1.66) was performed.

The test item is a mixture.

The absortption coefficient of the test item was estimeted on the basis of the highest obtained value.

the Koc of the test item was stated ≤1.