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Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
18 May 2007
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted in GLP compliance and in accordance with several internationally established guidelines (OECD, EEC, see below).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report date:
2007

Materials and methods

Test guidelineopen allclose all
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:
not specified
Qualifier:
according to guideline
Guideline:
EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))
Deviations:
not specified
GLP compliance:
yes (incl. QA statement)
Type of method:
HPLC estimation method

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
480-420-2
EC Name:
-
Cas Number:
144702-27-2
Molecular formula:
C33 H29 N5
IUPAC Name:
4'-{[4-methyl-6-(1-methyl-1H-1,3-benzodiazol-2-yl)-2-propyl-1H-1,3-benzodiazol-1-yl]methyl}-[1,1'-biphenyl]-2-carbonitrile
Test material form:
other: solid
Details on test material:
- Name of test material (as cited in study report): BIBR 277 Nitril
- Physical state: Solid
- Analytical purity: 99.7%
- Purity test date: 20 March 2007
- Lot/batch No.: 80A
- Expiration date of the lot/batch: 08 March 2008
- Stability under test conditions: yes
- Storage condition of test material: At room temperature, dark and dry
Radiolabelling:
no

Study design

Test temperature:
25°C

HPLC method

Details on study design: HPLC method:
Eight chemicals for which log K oc has been reported were used to calibrate the elution time in units of log K oc .
Reference substances used were:

Sodium nitrate / Acetanilide / Methyl benzoate / Triazophos / Naphthalene / Fenthion / Pyrazophos / α-Endosulfan / DDT

The reference substances were dissolved in methanol. The concentration of the stock solutions was about 1 mg/ml. These stock solutions were diluted with the eluent resulting concentrations of the test solutions of approximately 50 μg/ml.

The test item was dissolved in methanol. The concentration of this solution was about 1 mg/ml. It was diluted with eluent to 50 µg/ml.

Three series were measured which contained the above reference solutions and the test item solution. The series of the solution were measured with two parallel injections, each. The retention times were determined. The three calibration series and three test item series were measured alternately.
For the determination of t0 (t0 = retention time of the unretarded component) Sodium Nitrate solution was measured three times. The retention time of the test item was shorter than the retention time of any reference substance. Therefore, the Koc of the test item was estimated.

The adsorption coefficient Koc was determined based on a calibration curves using 8 reference items. The capacity factors k’ were calculated from the dead time and retention times of the reference substances. The log k’ data of the reference substances were plotted against their log Koc values.
Under the HPLC circumstances applied for this test BIBR 277 Nitril elutes in two peaks from the column. Both retention times were evaluated.

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HPLC system:

Merck-Hitachi LaChrom HPLC system:
D-7000 Interface, No.: 1442-122
L-7100 HPLC pump, No.: 1516-030
L-7200 Autosampler, No.: 1406-005
L-7400 UV Detector, No.: 1502-017
L-7360 Column Oven, No.: 00107295
L-7614 Degasser, No.: 14412YA0500

Stationary Phase Analytical column: LiChrospher 100 CN (5µm) 250x4
No.: 638212

HPLC Conditions Detector: UV at 225 nm
Flow: 1 ml/min.
Injection volume: 5 μl
Temperature: 25 °C

Mobil Phase: Methanol : Water at a ratio of 55 : 45 (v/v)




Results and discussion

Adsorption coefficient
Type:
log Koc
Value:
< 1.25
Temp.:
25 °C

Results: HPLC method

Details on results (HPLC method):
- Retention times of reference substances used for calibration:
Sodium Nitrate: 1.24 min; Acetanilide: 3.16 min; Methyl Benzoate: 3.61 min; Triasophos: 5.31 min; Naphthalene: 5.28 min; Fention: 7.09 min; Pyrazophos: 6.27 min; α-Endosulfan: 7.5 min; and DDT: 14.83 min.

- Details of fitted regression line (log k' vs. log Koc):
The equation of the curve fitted to the calibration points is as follows:
log k' = 0.190 * log Koc – 0.030 (R sq = 0.984)

- Graph of regression line attached: see attached study

- Average retention data for test substance: 2.44 min (mean)

Applicant's summary and conclusion

Conclusions:
n the course of this study the adsorption coefficient (Koc) of BIBR 277 Nitril was estimated, using high performance liquid chromatography.
Both retention times of the test item are lower than the retention times of any reference substance. Therefore, the Koc of the test item is below the calibration range. In conclusion, the estimated log Koc: < 1.25.
The quality criteria were met, as values of log Koc derived from individual measurements
fell within a range of ± 0.25 log units and the correlation coefficient R was >0.95.