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Reference
Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
07 August 2013 to 25 November 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
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
GLP compliance:
yes
Type of method:
HPLC estimation method
Media:
other: Cyanopropyl solid phase
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- lot/batch No.of test material: E00031-633
- Retest date of the lot/batch: 30 January 2014

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Ambient temperature, in the dark
Radiolabelling:
no
Test temperature:
30 degrees Celsius
Details on study design: HPLC method:
EQUIPMENT
- Apparatus: Waters Alliance 2695 liquid HPLC
- Column: Zorbax CN, 250 x 4.6 mm, 5 µm
- Detection system: Waters 486 TUV detector; UV detection at 220 nm

MOBILE PHASES
- 55/45 (v/v) Methanol/0.01 M potassium citrate, pH 6.00

DETERMINATION OF DEAD TIME
- Method: by inert substances which are not retained by the column (formamide)

REFERENCE SUBSTANCES
- Aniline, supplied by Sigma-Aldrich, Lot No. 1389776, expiry date 28 May 2014.
- Acetanilide, supplied by Sigma-Aldrich, Lot No. STBB4338, expiry date 02 August
2016.
- Naphthalene, supplied by Sigma-Aldrich, Lot No. STBB0909, expiry date 10
September 2015.
- 1,2,3-Trichlorobenzene, supplied by Sigma-Aldrich, Lot No. 12912PF, expiry date 02
September 2015.
- Phenanthrene, supplied by Alfa-Aeser, Lot No. 10154844, expiry date 03 September
2015.
- 4,4’-DDT, also known as 1,1-Bis(4-chlorophenyl)-2, 2, 2-trichloroethane, supplied by
Sigma-Aldrich, Lot No. 02230KY, expiry date 01 October 2014.
- Formamide (un-retained for determination of dead time, t0), supplied by VWR, Lot
No. 08J290501, expiry date 03 September 2015.

DETERMINATION OF RETENTION TIMES
- 1 µL of each stock reference compound and stock test item solutions were injected individually. Single injections of 10 µL of the mixed reference solution and the test item solutions containing reference compounds were also performed.
- Quantity in a 25 mL volumetric falsk:
Formamide: 2.00 mL
Aniline: 0.25 mL
Acetanilide: 0.10 mL
Naphthalene: 0.02 mL
1,2,3-Trichlorobenzene: 0.25 mL
Phenanthrene: 0.20 mL
4, 4’-DDT: 0.93 mL
(Test item: 10.0 mL)

REPETITIONS
- Number of determinations: 2

EVALUATION
The capacity factors for each reference compound present in the mixed test item solutions
were calculated as follows:
k' = (tR - t0) / t0

Where k’ = capacity factor
tR = retention time of reference compound (min)
t0 = dead time of column (retention time of Formamide, min)
Log10 k’ was then calculated for each reference compound.
Following chromatography, a correlation graph was produced by plotting the Log10 k’ value versus the Log10 Koc value, for each compound. Literature Log10 Koc values were obtained from OECD Guideline 121.
A Log10 Koc value for the test item was then extrapolated from the correlation graph.
Sample No.:
#1
Type:
log Koc
Value:
> 10.03 dimensionless
pH:
6
Temp.:
30 °C
Sample No.:
#2
Type:
log Koc
Value:
> 10.05 dimensionless
pH:
6
Temp.:
30 °C
Details on results (HPLC method):
A typical chromatogram obtained from the mixed reference compound solution containing Formamide (un-retained compound) and six adsorption coefficient reference compounds was performed. Another chromatogram was obtained from each mixed test item solution containing Formamide (un-retained compound), six adsorption coefficient reference compounds and EXP0700332. A chromatogram for a blank injection of mobile phase was also performed.
The capacity factors (k’) for each reference compound present in the mixed test item solutions were calculated and used to determine the Log10 k’ for each reference compound.
Following chromatography, a correlation graph was produced by plotting the Log10 k’ value versus the Log10 Koc value, for each compound. Literature Log10 Koc values were obtained from OECD Guideline 121.
A Log10 Koc value for the test item was then extrapolated from the correlation graph.
The following correlation coefficients were obtained for each graph as follows:
Mixed Test Item Solution A: 0.9465
Mixed Test Item Solution B: 0.9468
No peaks were observed in the chromatogram in which the samples were injected. The test item was retained and eluted in later chromatograms. The adsorption coefficients for each test item solution were therefore calculated to be:
Replicate A Log10 Koc >10.03
Replicate B Log10 Koc >10.05
The adsorption coefficient of duplicate determinations of EXP0700332 test item was therefore determined to be as follows:
Log10 Koc of EXP0700332 >10.04 (retention time greater than 45 minutes run time)
Koc of EXP0700332 >1.10 x 10^10
Alternatively, the adsorption coefficient may be expressed as being greater than that of 4,4’-DDT, the latest eluting reference standard used. Since 4,4’-DDT has a theoretical adsorption coefficient of 5.63, it may be stated that for EXP0700332:
Log10 Koc >5.63
Koc >4.27 x 10^5
Validity criteria fulfilled:
yes
Conclusions:
During testing it was observed that these hydrocarbon structures did not elute from a cyanopropyl solid phase HPLC column during the 45 minute run time. The adsorption coefficient of duplicate determinations of EXP0700332 test item was therefore determined to be as follows:
Log10 Koc of EXP0700332 >10.04 (retention time greater than 45 minutes run time)
Koc of EXP0700332 >1.10 x 10^10
Alternatively, the adsorption coefficient may be expressed as being greater than that of 4,4’-DDT, the latest eluting reference standard used. Since 4,4’-DDT has a theoretical adsorption coefficient of 5.63, it may be stated that for EXP0700332:
Log10 Koc >5.63
Koc >4.27 x 10^5
Executive summary:

The registrant is currently undertaking registration studies with the test item EXP0700332, and have requested Charles River determine the adsorption coefficient. This study meets the requirements of the OECD Guidelines for the testing of chemicals, OECD 121. A summary of the findings is presented below:

During testing it was observed that these hydrocarbon structures did not elute from a cyanopropyl solid phase HPLC column during the 45 minute run time. The adsorption coefficient of duplicate determinations of EXP0700332 test item was therefore determined to be as follows:

Log10 Koc of EXP0700332 >10.04 (retention time greater than 45 minutes run time)

Koc of EXP0700332 >1.10 x 1010

Alternatively, the adsorption coefficient may be expressed as being greater than that of 4,4’-DDT, the latest eluting reference standard used. Since 4,4’-DDT has a theoretical adsorption coefficient of 5.63, it may be stated that for EXP0700332:

Log10 Koc >5.63

Koc >4.27 x 105

Description of key information

During testing, it was observed that these hydrocarbon structures did not elute from a cyanopropyl solid phase HPLC column during the 45 minute run time. The adsorption coefficient of duplicate determinations of EXP0700332 test item was therefore determined to be as follows:

Log10 Koc of EXP0700332 >10.04 (retention time greater than 45 minutes run time)

Koc of EXP0700332 >1.10 x 10^10

Alternatively, the adsorption coefficient may be expressed as being greater than that of 4,4’-DDT, the latest eluting reference standard used. Since 4,4’-DDT has a theoretical adsorption coefficient of 5.63, it may be stated that for EXP0700332:

Log10 Koc >5.63

Koc >4.27 x 105

Key value for chemical safety assessment

Additional information