Registration Dossier

Diss Factsheets

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
04 March 2010 to 21 April 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: compliant to GLP and testing guideline; adequate coherence between data, comments and conclusions
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:
yes
Remarks:
The reference item 4,4-DDT was expired since 31 October 2009
GLP compliance:
yes (incl. QA statement)
Type of method:
HPLC estimation method
Media:
soil/sewage sludge
Test temperature:
The temperature during the analytical phase was around 22 °C.
Details on study design: HPLC method:
EQUIPMENT
- Apparatus: Autosampler, HPLC pump, Ultrasonic tank, Magnetic stirrer, Balance, Usual laboratory apparatus
- Column: Supelco - Length: 25 cm
- Particle size: 5.0 µm - Internal diameter: 4.6 mm
- Stationary phase: Supelcosil LC-CN
- Flow rate: 0.9 mL/min
- Injected volume: 40 µL - Wave length analysis: 210 nm
- Detection system: UV visible detector Hitachi L-4250

MOBILE PHASES
- Type: Methanol / water 45/55 v/v
- Solutes for dissolving test and reference substances: methanol

DETERMINATION OF DEAD TIME
- Method: by inert substances which are not retained by the column
Preparation of the thiourea solution

REFERENCE SUBSTANCES
- Identity: Acetanilide, methylbenzoate, isoproturon, 1,2,3-trichlorobenzene, pyrazophos and 4,4'-DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 100 mg
- Quantity of acetanilide, 1,2,3-trichlorobenzene, pyrazophos or 4,4'-DDT introduced in the column: 10 mg
- Quantity of methylbenzoate introduced in the column: 20 mg
- Quantity of isoproturon introduced in the column: 5 mg

REPETITIONS
- Number of determinations: 2

EVALUATION
- The adsorption / desorption coefficient is given by the following equation: Logk' = a log Koc + b where k' is the capacity factor of the chromatographic column, a and b the coefficient of the calibration curve
The coefficients of the calibration curve are obtained through the chromatographic analysis of at least six analytical reference items with known adsorption coefficient.
Type:
log Koc
Value:
3.75
Temp.:
22 °C
Details on results (HPLC method):
The results of the adsorption coefficient determination of 2-ETHYLHEXYL NITRATE are given in tables (see below).

First run: Using the Capacity factor and the adsorption coefficient of the reference items, the following calibration curve was obtained: log k' = 0.380 logKoc - 0.878

Second run: Using the Capacity factor and the adsorption coefficient of the reference items, the following calibration curve was obtained: log k' = 0.382 logKoc - 0.881

Variation in the retention times of the reference items are very small. Therefore a stable configuration of the HPLC column can be assumed.

First run:

Products  Mean Retention Time (min)  Value of the Capacity factor k'  Value of log k'  Value of log Koc 
Acetanilide  4.68  0.28  -0.55   1.25
Methyl benzoate  5.80  0.59  -0.23   1.80
Isoproturon  6.73  0.84   -0.074  1.86
1,2,3 -trichlorobenzene  12.22  2.35   0.37  3.16
Pyrazophos  20.15  4.52   0.66  3.65
4,4' DDT  55.37  14.2   1.15  5.63
Test item  16.45  3.51   0.54  3.74

Second run:

roducts  Mean Retention Time (min)  Value of the Capacity factor k'  Value of log k'  Value of log Koc 
Acetanilide  4.67  0.28 -0.55   1.25
Methyl benzoate  5.80 0.59 -0.23   1.80
Isoproturon  6.74 0.85  -0.072  1.86
1,2,3 -trichlorobenzene  12.32 2.38  0.38  3.16
Pyrazophos  20.41 4.59  0.66  3.65
4,4' DDT  56.19 14.4  1.16  5.63
Test item  16.63 3.56  0.55  3.75
Validity criteria fulfilled:
yes
Conclusions:
The adsorption / desorption coefficient of 2-ETHYLHEXYL NITRATE is equal to 3.75

Description of key information

Key value for chemical safety assessment

Koc at 20 °C:
5 623

Additional information