Registration Dossier

Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
December 18, 2013 - July 17, 2014
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was performed in accordance with OECD guideline 121. Non-GLP study. The substance is surface active and, according to the guideline, this method may not work for such a substance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2014
Report Date:
2014

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:
(2001)
GLP compliance:
no
Remarks:
non GLP study
Type of method:
HPLC estimation method
Media:
soil

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
Name of test material (as cited in study report): Disodium Isodecyl Sulfosuccinate
Description: white powder
Storage conditions of test material: at room temperature in well-sealed container
The substance was tested as received.
Radiolabelling:
no

Study design

HPLC method

Details on study design: HPLC method:
HPLC CONDITIONS
Instrument: Agilent 1200 with Chemstation Data system
Column: HALO ES-CN 2.7 µm (4.6 mm x 50 mm)
Column temperature: 30°C
Mobile phase: 55/45 (v/v) methanol/water (Milli-Q)
Flow: 0.8 mL/min
Injection volume: 5 µL
UV detection: 210 nm

SOLUTIONS
Test substance: 1 g/L of test substance in water
Unretained component: 3 g/L of formamide in water
Reference substances: 0.1 g/L solutions in 50/50 (v/v) methanol/water of benzamide, N,N-dimethylbenzamide, Phenol, 4-Nitrobenzamide, aniline, naphthalene, linuron, phenyl benzoate and fenthion.

PERFORMANCE OF THE STUDY
The unretained component, reference substance and test substance solutions were injected into the HPLC system. The capacity factor (k') of each substance was calculated from its retention time and the dead time (i.e. 0.682 minutes). The log k’ values of the references substances were plotted against the log Koc value provided by the OECD 121 guideline (based on soil adsorption data).

The equation of the calibration curve was calculated to be: log k’ = 0.663 x log Koc – 1.5573 (r^2=0.9388).

Using this equation, the log k' of the test substance was used to calculate the log Koc of the test substance.

Results and discussion

Adsorption coefficientopen allclose all
Type:
log Koc
Value:
1.59
Remarks on result:
other: See the remark below on the temperature.
Type:
Koc
Value:
36.3

Results: HPLC method

Details on results (HPLC method):
Calibration curve and HPLC chromatogram of the test substance solution are included in the attachment. The large peak at 0.896 minutes was assumed to be from the main constituent of the test substance.

Remark:
The test was performed at 30°C (i.e. the temperature of the column), but the log Koc value(s) obtained can be considered to represent the value(s) at an unspecified, probably ambient temperature (ca. 20°C) since no mention is made in the guidelines of the temperature at which the reference substance’s log Koc values were determined. Adsorption coefficients of the test and reference substances are assumed to vary with temperature in the same way.

Any other information on results incl. tables

Table: Koc determination results

 

Retention time

[min]

Capacity factor k'

log k’

log Koc

Formamide

0.682

 

 

 

Test substance

0.896

0.314

-0.503

1.59

Reference compounds

Benzamide1

0.799

0.172

-0.766

1.26

N,N-Dimethylbenzamide2

0.859

0.260

-0.586

1.52

Phenol2

0.91

0.334

-0.476

1.32

4-Nitrobenzamide1

0.913

0.339

-0.470

1.93

Aniline2

1.046

0.534

-0.273

2.07

Naphthalene2

1.855

1.720

0.236

2.75

Linuron2

2.176

2.191

0.341

2.59

Phenyl benzoate1

2.235

2.277

0.357

2.87

Fenthion2

3.583

4.254

0.629

3.31

 

1 From OECD TG 121 , Annex Table 1

2 From OECD TG 121, Annex Table 3

Applicant's summary and conclusion

Conclusions:
Using the HPLC method as described in OECD guideline 121 and using soil-adsorption-reference data, the log Koc for the test substance was determined to be 1.59.
Executive summary:

The HPLC method as described in OECD guideline 121, using 55/45 (v/v) methanol water as mobile phase and using soil-adsorption-reference data, was applied for the determination of the adsorption coefficient (Koc) of the test substance. The column temperature was 30°C. The dead time was determined by using formamide. The main constituent of the substance showed a large peak in the HPLC-UV chromatogram. From its retention time the log Koc of the substance was calculated to be 1.59 (Koc: 36.3). The result has to be treated with care as the surface active property of the substance might influence the outcome of this HPLC method.