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Reference
Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
23 June 1997 - 01 July 1997
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
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))
GLP compliance:
yes
Type of method:
HPLC estimation method
Media:
soil
Radiolabelling:
no
Test temperature:
20˚C in a temperature controlled room
Details on study design: HPLC method:
Experimental Conditions
Equipment
- normal laboratory glassware and instrumentation
- Waters 6OOE HPLC pump
- Waters 486 UV detector
- Waters WISP 71 7 autosampler
- Hypersil CPS, 5 pm panicle size, 21-0 s 4 mm, Batch 3756, Bischoff, Germany
Reagents
- Water, bidistilled grade
- Potassium dihydrogencitrate (Merck 4848, Germany)
- Sodium hydroxide (Merck 9136.9025, Germany)
- Methanol (Baker 9262-03, Germany)
- Helium 5.0, 99.999 Vol O;b for degassing (SWF, Germany)

High Performance Liquid Chromatographic Determination
A liquid chromatograph, fitted with a pulse-free pump and a UV detector has used. The injection was performed by a valve with an injection loop as given by autosamplers Commercial microparticulate bonded resins on a silica basis was used. A guard column was positioned between the injection system and the analytical column
HPLC grade methanol, distilled water and citrate buffer were used to prepare the eluting solvent, which was degassed before use lsocratic elution was employed. No additives such as ion pair reagents were used, because they would change the properties of the stationary phase Since these changes may be irreversible. The column was never used with additives. before Because the test substance contains protonable functional groups the use of buffer solution to stabilise pH was
recommended

The samples were directly injected from methanol solution. The method was based on the following parameters:
Pump: Waters 600E
Injector: Waters WISP 717
Detector: Waters 486
Column specification: Hypersil-CPS, 5 µm. 220 x 40 mm including precolumn
Column temperature: 20˚C
Injection volume: 10 µL for the reference substances, 20 µL for the test substances
Detection wavelength: 223 nm for the reference substances, 276 nm for the test substance
Mobile phase: Methanol / 0.1 M citrate-buffer pH 6.0 (60 / 40; v / v)
Flow rate: 1 mL/min

Solutes
The test and reference compounds were the purest available. Compounds used for the test or calibration purposes were dissolved in methanol, a solvent also part of the mobile phase To minimise effects of pure methanol on the column, the injection volume was 10 µL for the reference substances and 20 µl for the test substance at each injection, only.

Test Conditions
The measurements was performed at 20˚C in a temperature controlled room
Key result
Type:
Koc
Value:
> 5
Temp.:
20 °C
Remarks on result:
other: Based on impurity
Details on results (HPLC method):
The retention times of all reference substances were analysed four times and met with the requirements of the method.
The concentration of the ANOX BF solution injected for the determination of retention times was 4240 mg/L This was 84800 ng injected in 20 uL.
The retention times of the first peak of the test substance showed minor ditierences The second peak L\as not detectable in a mobile phase composed by nlethanoli 0.1 M citrate-buffer; 60/40;v lv, only in a mobile phase composed by methanol/0 1 M citrate-bufer, 70130; vlv The second peak was rlie mean peak and had a percentage of 93.33% in peak area.
The calibration curve was calculated wilh the seven references.
The single determinations did not give any significant variation in calculated log K,values from determination to determination. The confidence limits indicate that the
determined log K., values were within the limits of the method for the impurity assigned . The log Koc value of the major compound of the test substance was out of the limits ofthe method and estimated to be >5.0.

Determination of Dead Time t0

The dead time of the chromatographic system was determined by injection of 10 uL

Thiourea. The solution had a concentration of 1/1000 of a saturated solution prepared by dissolving thiourea in the mobile phase of the chromatographic system.

The retention times were as follows.

Dead time of chromatographic system

Repetition

1

2

3

4

Thiourea

2.19

2.19

2.19

2.19

Mean

2.19

Standard deviation

0.0

The mean value was taken for the calculation of calibration curves

 

Retention Times of Reference Substances

The retention times were determined by injection of four different solutions. The solutions were composed as follows:

 

Composition of reference solutions

 

Mix

References

GAB-Code

Injection volume (µl)

Concentration (mg/L)

Amount injected (ng)

1

Triadimenol

97162

10

36.13

361.3

Fenthion

97161

10

57.73

577.3

Sulprofos

97075

10

89.20

892.0

2

Azinphosmethyl

97163

10

11.02

110.2

Trifluralin

96103

10

35.35

353.5

3

Linuron

96087

10

27.76

277.6

4

Fenamiphos

97164

10

53.00

560.0

The amount injected was calculated after pre-test to get peak heights nor differing more than a factor of two from each other.

 

The retention times of all references substances were analysed four times. The following table gives the results of the individual determinations which are taken for the calculation of the regression analysis of the calibration graphs.

 

Retention times of the reference substances

Names

GAB-Code

Log Koc

RT (min)

RT

K1

Mean

Standard deviation

Triadimenol

97162

2.40

3.19

3.19

0

0.46

2.40

3.19

0.46

2.40

3.19

0.46

2.40

3.19

0.46

Fenthion

97161

3.31

4.62

4.63

0.01

1.11

3.31

4.63

1.11

3.31

4.62

1.11

3.31

4.63

1.11

Sulprofos

97075

4.46

6.97

6.98

0.02

2.18

4.46

6.97

2.18

4.46

6.96

2.18

4.46

7.00

2.20

Azinphosmethyl

97163

2.94

3.77

3.76

0.01

0.72

2.94

3.76

0.72

2.94

3.76

0.72

2.94

3.76

0.72

Trifluralin

96103

3.94

6.16

6.14

0.01

1.81

3.94

6.14

1.80

3.94

6.13

1.80

3.94

6.13

1.80

Linuron

96087

2.59

3.48

3.48

0

0.59

2.59

3.48

0.59

2.59

3.48

0.59

2.59

3.48

0.59

Fenamiphos

97164

2.44

3.21

3.21

0

0.47

2.44

3.21

0.47

2.44

3.21

0.47

2.44

3.21

0.47

 

The retention times of the references did only show minor differences from run to run.

 

Retention time of ANOX BF

The concentration of the ANOX BF solution injected for the determination of retention times was 2440 mg/L. This was 84800 ng injected in 20µl.

 

Retention time of ANOX BF

Name

GAB-CODE

RT (min)

RT Mean

Standard Deviation

K1

ANOX BF

97151

4.41

4.43

0.01

1.01

 

 

4.42

 

 

1.02

 

 

4.43

 

 

1.02

 

 

4.44

 

 

1.03

 

Also the retention times of the first peak of the test substance showed minor differences. The second peak was not detectable in a mobile phase composed by methanol/0.1 M citrate-buffer; 60/40; v/v, only in a mobile phase composed by methanol/0.1  citrate-buffer, 70/30; v/v. The second peak was the mean peak and had a percentage of 93.33% in peak area.

 

 

Calculation of Calibration Curve

The calibration curve was calculated with the seven references. The following table represents the calibration calculations using the curve parameters

 

K1 values determined against log Koc values of literature

Name

GAB-Code

Log Koc

Literature

K1 determined

Log Koc

Calculated

Confidence limits +/-

Triadimenol

97162

2.40

0.46

2.47

0.19

2.40

0.46

2.47

0.19

2.40

0.46

2.47

0.19

2.40

0.46

2.47

0.19

Fenthion

97161

3.31

1.11

2.23

0.19

3.31

1.11

2.23

0.19

3.31

1.11

2.23

0.19

3.31

1.11

2.23

0.19

Sulprofos

97075

4.46

2.18

4.47

0.19

4.46

2.18

4.47

0.19

4.46

2.18

4.47

0.19

4.46

2.20

4.49

0.19

Azinphosmethyl

97163

2.94

0.72

2.77

0.19

2.94

0.72

2.77

0.19

2.94

0.72

2.77

0.19

2.94

0.72

2.77

0.19

Trifluralin

96103

3.94

1.81

4.04

0.19

3.94

1.80

4.03

0.19

3.94

1.80

4.03

0.19

3.94

1.80

4.03

0.19

Linuron

96087

2.59

0.59

2.62

0.19

2.59

0.59

2.62

0.19

2.59

0.59

2.62

0.19

2.59

0.59

2.62

0.19

Fenamiphos

97164

2.44

0.47

2.48

0.19

2.44

0.47

2.48

0.19

2.44

0.47

2.48

0.19

2.44

0.47

2.48

0.19

 

Calculation of the Adsorption/Desorption Coefficient of ANOX BF

The parameters of calibration curve were taken for the calculation of log Koc value ANOX BF I

 

log Koc value calculated from calibration curve

Name

GAB-Code

K1 determined

Log Koc

Calculated

Confidence limits +/-

ANOX BF I

97151

1.01

3.11

0.19

 

 

1.02

3.12

0.19

 

 

1.02

3.12

0.19

 

 

1.03

3.13

0.19

The single determinations did not give any significant variation in calculated log koc values from determination to determination. The confidence limits indicate that the determined log Koc values were within the limits of the method for the impurity assigned as ANOX BF I. The log Koc value of major compound of the test substance was out of the limits of the method and estimated to be > 5 0.

Validity criteria fulfilled:
yes
Conclusions:
The log Koc value of ANOX BF is above 5.0. Only log Koc value for the impurity, represented by peak I could be determined to be 3.12 by this method.
Executive summary:

The aim of this study was the determination of the adsorption-coefficient of ANOX BF on soil (Koc). The test was performed following the proposal "Screening Method for the Determination of the Adsorption-Coefficient on Soil"

The log Koc was above 5.0 for the test substance ABOX BF at a temperature of 20˚C , determined by the HPLC screening method in a mobile phase composed by methanol 0.1M citrate-buffer, 60/40; v/v with Hypersl CPS as stationary phase. 

Description of key information

The log Koc was above 5.0 for the test substance ANOX BF at a temperature of 20˚C , determined by the HPLC screening method in a mobile phase composed by methanol 0.1M citrate-buffer, 60/40; v/v with Hypersl CPS as stationary phase. Koc is set at > 100,000

Key value for chemical safety assessment

Koc at 20 °C:
100 000

Additional information