Registration Dossier

Administrative data

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

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

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))
Deviations:
yes
Remarks:
The reference item 4,4-DDT was expired since 31 October 2009
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC estimation method
Media:
soil/sewage sludge

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
impurity

Study design

Test temperature:
The temperature during the analytical phase was around 22 °C.

HPLC method

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.

Results and discussion

Adsorption coefficient
Type:
log Koc
Value:
3.75
Temp.:
22 °C

Results: HPLC method

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.

Any other information on results incl. tables

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

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The adsorption / desorption coefficient of 2-ETHYLHEXYL NITRATE is equal to 3.75