Bontron E-108

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 March 2002 to 07 March 2002.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, that do not affect the quality of relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

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

Remarks:

In accordance with UK Principles of GLP (UK GLP Regulations 1999) which are in accordance with OECD Principles of GLP., revised 1997 (ENV/MC./CHEM(98)17).

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): S178207
- Physical state: White solid
- Analytical purity: 91.4% total ligand
- Lot/batch No.: NBZ 0155/44
- Stability under test conditions: Stable
- Storage condition of test material: In the dark at ambient temperature.

Radiolabelling:

no

Study design

Test temperature:

20.3 - 22.9°C

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Analytical column packed with a silica matrix
- Type, material and dimension of analytical (guard) column: 25 cm x 4.6 mm i.d. column packed with a 5 µm CN phase
- Detection system: photo diode array (PDA)


MOBILE PHASES
- Type: methanol:water (55:45)
- Experiments with additives carried out on separate columns: no
- pH: 2.00 and 10.02
- Solutes for dissolving test and reference substances: All substances injected onto the HPLC were dissolved in the mobile phase.


DETERMINATION OF DEAD TIME
- Method: by means of homologous series


REFERENCE SUBSTANCES
Acetanilide, Atrazin, Isoproturon, Linuron, Naphthalene, 1,2,3-Trichlorobenzene, Fenthion, Phenanthrene, p,p-DDT - all present at a concentration of 20 mg/l.


DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 100 µl
- Quantity of reference substances: 100 µl
- Intervals of calibration: at least once daily


REPETITIONS
- Number of determinations: 2


EVALUATION
- Calculation of capacity factors k': The capacity factor was determined using the calculation below:

K' = (tr - to)/to

Where:
k' = capacity factor
tr = retention time of the test substance
to = column dead time (retention time of an inert substance)

- Calculation of retention times: retention time measured in seconds

- Determination of the log Koc value:Koc calculated using the calibration curve (Please refer to Attachment 1)

Batch equilibrium or other method

Computational methods:

Not applicable

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

Koc

Value:

1 995.26

Adsorption coefficient 2

Type:

log Koc

Value:

3.3

Results: HPLC method

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
Please refer to Attachment 2

- Details of fitted regression line (log k' vs. log Koc): Please refer to Attachment 1

- Graph of regression line attached: Yes

- Average retention data for test substance:
pH 2 = 237 seconds
pH 10 = 71 seconds

Results: Batch equilibrium or other method

Transformation products:

no

Statistics:

Not applicable

Any other information on results incl. tables

From the experimetally dervied k' measurements and the literature Koc values of the reference substances, the equation of the fitted regression line was determined as:

log10 koc = a.log10 k' + b

where at pH 2, a = 5.11 and b = 2.18 and at pH 10 a = 7.38 and b = 2.16. The coefficient of determination (r2) of these data was calculated as 0.953 and 0.944 at pH2 and pH10, respectively, indicating a linear relationship between log10 Koc and log10 k'.

At pH 2 the log10 k' for S178207 was 0.220, therefore, the estimated log10 Koc for S178207 is 3.30. At pH 10 the log10 koc for S178207 could not be calculated and the estimated log10 Koc is therefore <1.5.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The test described has been validated for the quantitative estimation of log10 koc values in the range 1.5 to 5.0. In those instances where the statistical treatment of the experimental data produces a calculated log10 koc value outside this range then th

Conclusions:

The log10 Koc at pH 2 has been determined to be 3.30 and at pH 10 it has been determined to be less than 1.5.

Executive summary:

The guideline followed was OECD 121 Estimation of the Adsorption Coefficient (Koc) on Soil and Sewage Sludge using High Performance Liquid Chromatography (HPLC).

The log10 Koc at pH 2 has been determined to be 3.30 and at pH 10 it has been determined to be less than 1.5.