Registration Dossier

Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
October 4, 2007 - January 24, 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guidelineopen allclose all
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
Qualifier:
according to
Guideline:
EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC estimation method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Corsair Clear #34
- Substance type: Clear white lumpy solid
- Physical state: Solid
- Stability under test conditions: Stable
- Storage condition of test material: At room temperature in the dark
Radiolabelling:
no

Study design

Test temperature:
35°C

HPLC method

Details on study design: HPLC method:
According to the guidelines, the determination of the Koc for test substances that are ionized for at least 10% within pH 5.5 to 7.5 should be performed with both the ionized and non-ionized form. Therefore, the pKa values of the test substance were calculated using the Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International San Francisco, CA, USA). Based on the calculations, the HPLC analysis was performed at neutral pH.

Analytical conditions:
Instrument: Alliance Separation Module 2695 (Waters, Milford, MA, USA)
Detector: Photodiode Array Detector 2996 (Waters)
Column: Hypersil BDS-CN, 150 mm x 4.6 mm i.d., dp = 5 µm (Thermo, San Jose, CA, USA)
Column temperature: 35°C +/- 1.0°C
Mobile phase: A - 55/45 (v/v) methanol/water B - Methanol

Since it proved not possible to elute the test substance with the recommended mobile phase composition of 55/45 (v/v) methanol/water under isocratic conditions, a gradient (to 100% methanol) was applied in order to elute the test substance and rinse the column.

Gradient
Time [minutes] %A %B
0 100 0
10 100 0
10.1 0 100
40 0 100
40.1 100 0
50 100 0

Flow: 1 ml/min
Injection volume: 10 µl
UV detection: 210 nm

Test solution:
From earlier experiments it was known that the test substance could not be dissolved in mobile phases containing > 25 volume % of water. Therefore, a 1774 mg/l test solution of the test substance was prepared in methanol. In order to dissolve the test substance completely the stock solution was ultrasonicated for 5 minutes.

Results and discussion

Adsorption coefficient
Type:
log Koc
Value:
> 4.5

Results: HPLC method

Details on results (HPLC method):
In the chromatogram of the test substance solution, six test substance peaks were observed. The peaks between 0.9 and 3.6 minutes and at 27.6 minutes were also observed in the chromatogram of the blank solution. Therefore, it was assumed that these compounds did not derive from the test substance.

Any other information on results incl. tables

Substance

tr,1

tr,2

mean tr
(n=2)

log Koc

Koc

Area
%

Formamide (t0)

2.594

2.863

2.729

Phenol

3.036

3.390

1.32

N,N-Dimethylbenzamide

2.840

3.150

1.52

Methylbenzoate

3.228

3.626

1.80

3,5-Dinitrobenzamide

3.556

3.945

2.31

Naphthalene

4.171

4.690

2.75

Fenthion

6.146

6.819

3.31

Phenanthrene

5.954

6.683

4.09

2,4-DDT

9.514

10.537

5.63

NS179082 peak 1

7.164

7.865

7.515

4.52

3.3x104

0.2

NS179082 peak 2

7.795

8.847

8.321

4.72

5.3x104

3

NS179082 peak 3

9.243

10.547

9.895

5.05

1.1x105

6

NS179082 peak 4*

11.438

12.857

12.148

> 5.63

> 4.3x105

0.5

NS179082 peak 5*

15.351

18.525

16.938

> 5.63

> 4.3x105

9

NS179082 peak 6*

27.019

27.445

27.232

> 5.63

> 4.3x105

81

* These peaks were eluted from the column under gradient conditions.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The Koc and log Koc values of the majority of the UV-active components of Corsair Clear #34, i.e. 90.8%, are: >4.3 x 10^5 and >5.63, respectively.
Three components with an area percentage between 0.2% and 6% had log Koc values between 4.52 and 5.05.