kresoxim-methyl (ISO);methyl (E)-2-methoxyimino-[2-(o-tolyloxymethyl)phenyl]acetate

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)

GLP compliance:

yes

Type of method:

batch equilibrium method

Media:

soil

Test material

Test material information

Constituent 1

Reference substance name:

methyl (2E)-2-methoxyimino-2-[2-[(2-methylphenoxy)methyl]phenyl]acetate

EC Number:

604-351-6

Cas Number:

143390-89-0

Molecular formula:

C18 H19 N O4

IUPAC Name:

methyl (2E)-2-methoxyimino-2-[2-[(2-methylphenoxy)methyl]phenyl]acetate

Details on test material:

- Name of test material (as cited in study report): LAB 242 009. BAS 490 F
- Analytical purity: 99.6%
- Batch: Prep.-No. 353.01
- Radiochemical purity (if radiolabelling): > 99%
- Specific activity (if radiolabelling): 3566.0 MBq/g
- Locations of the label (if radiolabelling): (E)-2-[2-(2-Methylphenoxy)-methyl]phenyl-[phenyl-U- 14C]-2-(methoxyimido)acetic acid methyl ester
- Lot No.: 39/149-1

Radiolabelling:

yes

Study design

Batch equilibrium or other method

Analytical monitoring:

yes

Details on matrix:

PROPERTIES
- Four soil were used with the following properties:
- #Soil 1:
- Origin: Lufa Speyer German Standard Soil 2.1
- Type: sand
- Carbon content: 0.7%
- pH-value: 6.1
- Particle < 20 µm: 7.9%
- Cation-exchange Capacity [mVal/100 g soil]: 4.9

- #Soil 2:
- Origin: Lufa Speyer German Standard Soil 2.2
- Type: loamy sand
- Carbon content: 2.29%
- pH-value: 6.0
- Particle < 20 µm: 10.7%
- Cation-exchange Capacity [mVal/100 g soil]: 9.7

- #Soil 3:
- Origin: Lufa Speyer German Standard Soil 2.3
- Type: sandy loam
- Carbon content: 1.2%
- pH-value: 6.2
- Particle < 20 µm: 23%
- Cation-exchange Capacity [mVal/100 g soil]: 12.7

- #Soil 4:
- Origin: Limburgerhof Bruch Ost
- Type: clayey loam
- Carbon content: 2.7%
- pH-value: 7.5
- Particle < 20 µm: 53%
- Cation-exchange Capacity [mVal/100 g soil]: 46.1

Details on test conditions:

STOCK SOLUTION
- 4.0 mg test substance was dissolved in 25 ml CH3OH.
- Concentration of the test substance in the stock solution: 0.2 mg/ml CH3OH
- Specific radioactivity: 43209 dpm/µg

RECOVERY TEST IN AQUEOUS SOIL EXTRACTS
- Pretreatment: 50 g soil were shaken with 250 ml 0.01 M aqueous CaCl solution and the water extract was decanted.
- Testing concentrations: 25 ml of the water extract were fortified with stock solution in four different concentrations equal to 0.008, 0.04, 0.2 and 1 mg/L.
- Analysis: LSC

ADSORPTION SCREENING TEST
- 5 g soil were shaken with 25 ml 0.01 M aqueous CaCl solution containing 1 mg/L test substance. Water extract was decanted and analyzed by LSC

DESORPTION SCREENING TEST
- Pretreatment: Soil residue from adsorption screening test was made up with 25 ml 0.01 M aqueous CaCl solution and agitated for 16 hours. The supernatant was stored and the procedure was repeated. Both water extracts were combined and brought up to 50 ml with aqueous CaCl solution.
- Analysis: LSC

ADSORPTION EQUILIBRIUM TEST
- A series of samples for each soil with 1 mg/L test substance concentration were prepared. The samples were analyzed after 1, 2, 4, 8, 16 and 24 hours.

ADSORPTION ISOTHERM DETERMINATION
- Following the procedures of the adsorption screening test four initial test substance concentrations of to 0.008, 0.04, 0.2 and 1 mg/L were used for each soil. Agitation time = 1 h.

MATERIAL BALANCE
- Pretreatment: The amount of test substance adsorbed to soil was determined. Soil residue of the 1 mg/L samples from the adsorption isotherm determination was extracted by shaking with 25 ml methanol. After decanting the supernatant, the soil residues were extracted again. An aliquot of 1 ml from the combined extracts were analyzed.
- Analysis: LSC

Results and discussion

Adsorption coefficient

Type:

Koc

Value:

219 - 372

Results: Batch equilibrium or other method

Adsorption and desorption constants:

Adsorption constant KA = 2.6 - 7.7
Adsorption exponent 1/n = 0.95 - 0.99

Recovery of test material:

Recovery ranges from 100.0 to 112.6%

Details on results (Batch equilibrium method):

ADSORPTION SCREENING TEST
- after 16 hours 35.6 – 53.7% of the test substance adsorb to soil
- moderate adsorption tendency

DESORPTION SCREENING TEST
- 75 -81 % of the adsorbed test substance was desorbed from the soils

MATERIAL BALANCE
- recovered radioactivity ranged from 92.3 -100.7%

TLC-MEASUREMENTS
- Radiolabelled test substance was stable in methanolic solution
- In contact with moist soil the radiolabelled test substance hydrolyzes to acid metabolites