Methyl (R)-2-(4-(3-chloro-5-trifluoromethyl-2-pyridyloxy)phenoxy)propionate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: IBAMA, Brazil, according to the protocol for evaluation of ecotoxicological effects of chemicals, paragraph E.2.

Deviations:

no

GLP compliance:

no

Type of method:

other: thin-layer chromatography (TLC)

Media:

soil

Specific details on test material used for the study:

DE-535
Lot # AGR 259822
Purity: 99.5%

Radiolabelled test substance
Haloxyfop-R-Pyr-3,4,5,6-14C
Inventory # R 006
Specific activity: 11.2 mCi/mmole
Radiochemical Purity: > 99.0%

Radiolabelling:

yes

Test temperature:

24±2°C

Analytical monitoring:

no

Matrix no.:

#1

Matrix type:

other: LE (Typic Haplorthox)

% Clay:

84

% Silt:

9

% Sand:

7

pH:

4.1

CEC:

9.6 other: meq/100cm³

Matrix no.:

#2

Matrix type:

other: LR (Typic Haplorthox)

% Clay:

69

% Silt:

13

% Sand:

18

pH:

4.1

CEC:

14.9 other: meq/100cm³

Matrix no.:

#3

Matrix type:

other: PV (Arenic Abruptic PaIeudalf)

% Clay:

15

% Silt:

2

% Sand:

83

pH:

3.5

CEC:

9.1 other: meq/100cm³

Details on matrix:

COLLECTION AND STORAGE
- Geographic location: The PV soil was collected at 19th km SP 304 Rd. The LE soil was collected at 14th km Piracicaba-Rio Claro Rd. The LR soil was collected at 6th km Piracicaba-Tupi Rd.
- Sampling depth: 0-20 cm
- Soil preparation: Air dried and sieved on 250 mesh screen

Details on test conditions:

The test was carried out using soil samples air-dried and sieved on 250 Mesh screen. Water was added to wet soil until a smooth, moderately fluid slurry was obtained. Thus, the soil paste was quickly spread evenly on a clean glass plate in order to get 0.5 mm soil layer thickness (adsorbent phase). Glass plates dimensions were 10.0 x 15.0 cm. After slowly air-drying the plates, 5 µL of test-substance solution containing carbon-14 were spotted with a micro syringe 2 cm above the base line. In a third spot was applied the standard solution (2,4-D-14C). The final concentration of test solution was 165 µg/mL and radioactivity 5 µCi/mL. The glass plates were immersed down in a vertical position, inside a chamber containing clean water (mobile phase), keeping the water layer up to 1 cm depth. After migration of water for 12 cm, plates were removed, dried, and involved with X-ray film in a cold dark box for 15 days. The plates are then assayed by autoradiography. The distance travel by each of the compound were measured.

Key result

Sample No.:

#1

Type:

other: coefficient of mobility (Rf)

Value:

0.76 dimensionless

pH:

4.1

Temp.:

24 °C

Matrix:

LE (Typic Haplorthox) soil

Key result

Sample No.:

#2

Type:

other: coefficient of mobility (Rf)

Value:

0.63 dimensionless

pH:

4.1

Temp.:

24 °C

Matrix:

LR (Typic Haplorthox) soil

Key result

Sample No.:

#3

Type:

other: coefficient of mobility (Rf)

Value:

0.58 dimensionless

pH:

3.5

Temp.:

24 °C

Matrix:

PV (Arenic Abruptic PaIeudalf) soil

Conclusions:

The coefficients of mobility from LE, LR and PV were 0.76, 0.63 and 0.58, respectively.

Executive summary:

This study was conducted to determine the mobility of the test substance on three Brazilian soils of different textures, by the measurement of the Rf on soil thin-layer chromatography plates.

The test substance showed high mobility on LE (Typic Haplorthox) soil, and intermediate mobility on LR (Typic Haplorthox) and PV (Arenic Abruptic PaIeudalf) soils. The coefficients of mobility from LE, LR and PV were 0.76, 0.63 and 0.58, respectively.

Description of key information

The study was conducted to determine the mobility of the test substance. The coefficients of mobility ranged from 0.58 to 0.76 with intermediate to high moblity in soil.