Registration Dossier

Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
calculation (if not (Q)SAR)
Remarks:
Migrated phrase: estimated by calculation
Adequacy of study:
key study
Study period:
18 April 2005 to 5 May 2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study was conducted in 2005 according to OECD Method # 19 and in accordance with GLP. The study material is well characterized.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report Date:
2006

Materials and methods

Test guideline
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:
yes
GLP compliance:
yes
Type of method:
HPLC estimation method
Media:
other: acetonitrile

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Test material is a extremely light tan colored powder which was received at testing laboratory on 15 February 2005 and stored at room temperature in the dark.
Radiolabelling:
no

Study design

Test temperature:
No data

HPLC method

Details on study design: HPLC method:
EQUIPMENT
- Apparatus: HPLC
- Type: Agilent Technologies 1100, incorporating autosampler and workstation
- Type, material and dimension of analytical (guard) column: column-Phenosphere Next 5u CN( 250X 4.6 mm id),
- column temperature 30 C
- flow-rate 1 mL/min
- Detection system: UV detector at 210 nm

MOBILE PHASES
- Type: acetonitrile:reverse osmosis water (55:45 v/v) adjusted to approximately neutral pH using 0.1M hydrochloric acid
- pH: 7.4
- Solutes for dissolving test and reference substances: test material dissolved in acteonitrile and reference substances in methanol

DETERMINATION OF DEAD TIME
- Method: Dead time was determined by measuring the retention time of formamide. (purity >=99.5%, 483 mg/L solution in methanol)

REFERENCE SUBSTANCES
- Identity: Reference standards were prepared in methanol for the following substances:
acetanilide, atrazine, triadimenol, linuron, naphthalene, endosulfan-diol, fenthion,alpha-endosulfan, phenanthrene, diclofop-methyl and DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 10 uL
- Quantity of reference substances: 10 uL
Calibration curves were developed from retention time data for formamide and reference standard solutions

REPETITIONS
- Number of determinations: duplicate

EVALUATION
- Calculation of capacity factors k: Yes- calculated from the equation k = tr-t0/t0 where tr is retention time ( min) and t0= dead time( min)
- Determination of the log Koc value: yes- with reference to the calibration curve
- mean retention time for dead time( formamide) = 3.113 (mins)

Batch equilibrium or other method

Computational methods:
- Adsorption coefficients was predicted using the chemical structure of the test material and the PCKOCWIN program. The program requires you to validate the program for functional groups found in the test material using reference substances of known adsorption coefficient and then to input the test material's chemical structure into the program. The software was validated for estimation of components of the test material as there were no systemic errors and the predictions were within +/- 1 log unit.

Results and discussion

Adsorption coefficientopen allclose all
Type:
Koc
Value:
< 17.8
Type:
log Koc
Value:
< 1.25

Results: HPLC method

Details on results (HPLC method):
Mean retention time for dead time( formamide) = 3.113 (mins)

Mean retention times for references substances used for calibration:
acetanilide 3.726 mins
atrazine, 3.897 mins
triadimenol, 4.032 mins
linuron, 4.136 mins
naphthalene, 4.394 mins
endosulfan-diol, 4.085 mins
fenthion, 4.666 mins
alpha-endosulfan, 5.279 mins
phenanthrene, 4.807 mins
diclofop-methyl, 5.076 mins
DDT, 6.634 mins

- Details of fitted regression line (log k' vs. log Koc): A= - 0.926, B=0.174, r=0.976
- Average retention data for test substance:
Injection 1: retention time: 2.2024 mins, capacity factor(k): <0.197, log10k:<-0.706, Log10 Koc: < 1.25
Injection 2: retention time: 2.190 mins, capacity factor(k): <0.197, log10k:<-0.706, Log10 Koc: < 1.25
Mean log 10 Koc: < 1.25
Adsorprtion coefficient: < 17.8

Any other information on results incl. tables

The guideline requires that the measurement of adsorption coefficient be performed on substances in their ionised and nonionised forms. This was not possible for the test material due to the dissociation constants of certain functional groups. Due to the presence of both the basic and acid functional groups, testing would be required at below pH 3.5 and greater than pH 14. As these are outside the environmental pH range for this test, the testing was carried out at neutral pH with the acidic group ionised.

Prediction values of adsorption coefficient for components of test material:

acid component: PCKOCWIN log10koc= 2.13 amine component: PCKOCWIN log10koc= 1.00

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The adsorption coeffcient of the components of the test material have been determined to be < 17.8 with log 10 Koc: < 1.25. The prediction values of adsorption coefficient for components of test material gave these results: acid component: PCKOCWIN log10koc= 2.13, amine component: PCKOCWIN log10koc= 1.00