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Reference
Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2002-05-08 to 2002-05-13
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))
Version / remarks:
2001
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC estimation method
Media:
soil
Radiolabelling:
no
Test temperature:
25°C
Details on study design: HPLC method:
REAGENTS
Methanole, Chromasolv Riedel de Haen
Distilled water, Roth
Potassium phosphate monobasic, Fluka (KH2PO4)
Sodium hydroxide, Riedel de Haen
Hydrochloric acid, Merck
Buffer pH 6: 13.61g KH2PO4 dissolved in distilled water and filled up to a volume of 1000 mL. 100 ml of this solution and 30 mL sodium hydroxide solution (c = 1 mole/L) diluted with distilled water and filled up to a volume of 1000 mL with distilled water, the pH value was adjusted to 6.0.
Dead time marker: Uracil, Riedel de Haen
Calibration substances

INSTRUMENTS
- Chromatographic apparatus
- Analytical balance Sartorius R160 P
- Ultrasonic bath Branson 3200
- General laboratory glassware

EQUIPMENT
- Apparatus:
HPLC pump G1311A
Autosampler G1313A
Column oven G1316A
UVA/IS detector G1314A by Agilent
Type: stationary phase: LiChrospher 100 CN 5µm by Duratec (18804-02)
Type, material and dimension of analytical (guard) column: Reversed phase column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties, dimensions: 125 mm x4.6 mm; column temperature: 25 °C

MOBILE PHASES
- Type: methanol / buffer (pH 6.0) 55:45 (v/v), isocratic elution
- Experiments with additives carried out on separate columns: no
- Flow rate: 1.0 mL/min
- Detection wavelength: 220 nm

DETERMINATION OF DEAD TIME

- Method: by inert substances which are not retained by the column. The dead time marker was injected in triplet as solutions in acetonitrile/distilled water (50:50) (v/v). The calibration substances were dissolved in acetonitrile and diluted 0.1 to 1 in the mobile phase and injected as single standards twice a time. The test substance was dissolved in methanol and diluted 0.1 to 1 in the mobile phase and injected twice a time

REFERENCE SUBSTANCES
- Identity: Benzamide, Acetanilide, Monuron, Aniline, 3,5-Dinitrobenzamide, Triadimenol, Linuron, Tertbutryn, Naphthalene, Trifluralin, Diclofop-methyl and Quintozen.

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 9.31 µg
- Quantity of reference substances:
Dead time marker: 2.72 µg
Calibration substances: 0.66-2.75 µg
Test item: 9.31 µg

REPETITIONS
- Number of determinations: 2
Key result
Sample No.:
#2
Type:
Koc
Value:
501.187 dimensionless
Temp.:
25 °C
Key result
Sample No.:
#1
Type:
log Koc
Value:
2.7 dimensionless
Temp.:
25 °C
Details on results (HPLC method):
- Retention times of reference substances used for calibration:
4 Measurement:
Benzamide: 1.95
Acetanilide: 2.17
Monuron: 2.55
Aniline: 2.19
3,5-Dinitrobenzamide: 2.55
Triadimenol: 2.99
Linuron: 3.54
Terbutryn: 2.99
Naphthalene: 3.91
Trifluralin: 8.75
Diclofop-methyl: 6.19
Quintozen: 6.73


5 Measurement:
Benzamide: 1.96
Acetanilide: 2.18
Monuron: 2.57
Aniline: 2.20
3,5-Dinitrobenzamide: 2.56
Triadimenol: 3.00
Linuron: 3.58
Terbutryn: 3.03
Naphthalene: 3.96
Trifluralin: 8.97
Diclofop-methyl: 6.36
Quintozen: 6.91
- Details of fitted regression line (Log k vs Log Koc)
4. Measurement: y = 2.2778x + 2.8473; R2 = 0.9154
5. Measurement: y = 2.2727x + 2.8213; R2 = 0.9167
- Graph of regression line attached: yes
- Average retention data for test substance: 3.18 min
- The adsorption coefficient of the test item was found to be: log Koc: 2.7

Table 1: Determination of the Dead Time to

Dead time marker

Retention time of substances “tr” in min

Measurement

Measurement

Measurement

Mean

Uracil

1.70

1.69

1.69

1.69

Dead time to = 1.69 min

Table 2: Calibration Data - 4. Measurement (*from OECD guideline 121, adopted January 2001)

Calibration substance

Inj. Retention time  in min

K

log K

log Koc*

Benzamide

1.95

0.15

-0.82

1.00

Acetanilide

2.17

0.28

-0.55

1.25

Monuron

2.55

0.51

-0.30

2.21

Aniline

2.19

0.29

-0.54

2.07

3,5-Dinitrobenzamide

2.55

0.50

-0.30

2.31

Triadimenol

2.99

0.76

-0.12

2.40

Linuron

3.54

1.09

0.04

2.59

Terbutryn

2.99

0.76

-0.12

2.68

Naphthalene

3.91

1.31

0.12

2.75

Trifluralin

8.75

4.17

0.62

3.94

Diclofop-methyl

6.19

2.66

0.42

4.20

Quintozen

6.73

2.97

0.47

4.34

Regression: log Koc = a + bx logk

Parameters: a = 2.847; b = 2.278; r2 = 0.9154

Table 3: log Koc of the Test Substance - 4. Measurement

Test substance

Inj. Retention time in min

K

log K

log Koc

1-Ethoxy-2,3-difluorbenzol

3.16

0.86

-0.06

2.70

Table 4: Calibration Data - 5. Measurement (*from OECD guideline 121, adopted January 2001)

Calibration substance

Inj. Retention time in min

K

log K

log Koc *

Benzamide

1.96

0.16

-0.80

1.00

Acetanilide

2.18

0.29

-0.54

1.25

Monuron

2.57

0.52

-0.29

2.21

Aniline

2.20

0.30

-0.53

2.07

3,5-Dinitrobenzamide

2.56

0.51

-0.29

2.31

Triadimenol

3.01

0.78

-0.11

2.40

Linuron

3.58

1.11

0.05

2.59

Terbutryn

3.03

0.79

-0.10

2.68

Naphthalene

3.96

1.34

0.13

2.75

Trifluralin

8.97

4.30

0.63

3.94

Diclofop-methyl

6.36

2.75

0.44

4.20

Quintozen

6.91

3.08

0.49

4.34

Regression: log Koc = a + bx logk

Parameters: a = 2.821; b = 2.273; r2 = 0.9167

Table 5: log Koc of the Test Substance - 5. Measurement

Test substance

Inj. Retention time in min

K

log K

log Koc

1-Ethoxy-2,3-difluorbenzol

3.18

0.88

-0.06

2.69

Table 6: log Koc of the Test Item

 

Log Koc

4. Measurement

2.70

5. Measurement

2.69

Mean

2.70

RSD %

< 0.01

 

 

 

Validity criteria fulfilled:
yes
Conclusions:
The adsorption coefficient of the test substance has been determined according to the "HPLC- method" described in guideline 67/548/EEC, annex C.19 and OECD 121 (2001). The adsorption coefficient was found to be: log Koc = 2.7.
Executive summary:

The HPLC method is based on the correlation between the retention of a substance on a reversed phase column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties and the adsorption coefficient Koc. The dead time is determined by using a "dead time marker". For calibration the retention times of a series of substances with known adsorption coefficients were measured and a calibration graph was established. The adsorption coefficient of the test substance was derived from its retention time and the calibration graph. The adsorption coefficient was found to be: log Koc = 2.7.

Description of key information

The adsorption coefficient of the test substance has been determined according to the "HPLC- method" described in guideline 67/548/EEC, annex C.19 and OECD 121 (2001). The adsorption coefficient was found to be: Koc = 501.187.

Key value for chemical safety assessment

Koc at 20 °C:
501.187

Additional information

The HPLC method is based on the correlation between the retention of a substance on a reversed phase column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties and the adsorption coefficient Koc. The dead time is determined by using a "dead time marker". For calibration the retention times of a series of substances with known adsorption coefficients were measured and a calibration graph was established. The adsorption coefficient of the test substance was derived from its retention time and the calibration graph. The adsorption coefficient was found to be: Koc = 501.187