(1R)-2-[5-(2-halo-3-methoxyphenyl)-3-[2-halo-6-(trihalomethyl)benzyl]- 4-alkyl-2,6-dioxoheterocyclyl]-1-phenylethanaminium salicylate

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3rd September 2018 to 30th October 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

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))

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: MEP The Guidelines for the Testing of Chemicals No. 121 Estimation of the adsorption coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC) (2013)

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: MEP (2103) The Guidelines for the testing of chemicals No.106. Adsorption - Desorption Using a Batch Equilibrium Method (2013)

Test guideline 5

Qualifier:

according to guideline

Guideline:

other: GB/T 21851-2008, Chemicals-Adsorption-desorption using a batch equilibrium method

GLP compliance:

yes

Type of method:

batch equilibrium method

Media:

soil

Test material

Test material information

Radiolabelling:

no

Study design

Batch equilibrium or other method

Analytical monitoring:

yes

Details on sampling:

Solution Preparation: 0.01 mol/L CaCl2 was prepared by dissolving 1.11 g CaCl2 into 1000 mL ultra water.

Test 1 - Preliminary Study
(1) Solution/soil/solution ratio 5:1
5.0g soil with 25 mL solution (0.01 mol/L CaCl2) was agitated at 160rpm for at least 12 hours at 20-25 0C in order to achieve pre-equilibrium. Then 1.25μL working solution of 2000 mg/L was added to the aqueous phase to achieve a nominal concentration of 1 mg/L. The another 24 hours agitation was run to reach adsorption equilibrium . Both the concentration of aqueous and oil phases were measured on 4th, 6th, 16th and 24th hours to calculate the adsorption percentage and mass balance rate.

(2) Solution/soil/solution ratio 25:1
2.0g soil with 50mL solution (0.01 mol/L CaCl2) was agitated at 160rpm for at least 12 hours at 20-25 0C in order to achieve pre-equilibrium. Then 25μL working solution of 2000 mg/L was added to the aqueous phase to achieve a nominal concentration of 1 mg/L. The another 24 hours agitation was run to reach adsorption equilibrium . Both the concentration of aqueous and oil phases were measured on 4th, 6th, and 24th hours to calculate the adsorption percentage and mass balance rate

(3) Solution/soil/solution ratio 100:1
1.0g soil with 100mL solution (0.01 mol/L CaCl2) was agitated at 160rpm for at least 12 hours at 20-25 0C in order to achieve pre-equilibrium. Then 25μL working solution of 4000 mg/L was added to the aqueous phase to achieve a nominal concentration of 1 mg/L. The another 24 hours agitation was run to reach adsorption equilibrium . Both the concentration of aqueous and oil phases were measured on 4th, 6th, and 24th hours to calculate the adsorption percentage and mass balance rate.

One control sample with only the test substance in 0.01 mol/L CaCl2 solution (no soil) was subjected to precisely the same steps as the test systems.
A blank run per soil with the same amount of soil with 0.01 mol/L CaCl2 solutions (without test substance) were subjected to the same test procedure.

Matrix properties

Matrix properties 1

Matrix no.:

#1

Matrix type:

other: Paddy soil

% Org. carbon:

1.96

pH:

6.88

Matrix properties 2

Matrix no.:

#2

Matrix type:

other: Aquic Brown soil

% Org. carbon:

2.06

pH:

5.47

Matrix properties 3

Matrix no.:

#3

Matrix type:

other: Red soil

% Org. carbon:

1.94

pH:

4.93

Matrix properties 4

Matrix no.:

#4

Matrix type:

other: Black soil

% Org. carbon:

2

pH:

6.54

Matrix properties 5

Matrix no.:

#5

Matrix type:

other: Moisture soil

% Org. carbon:

1.22

pH:

7.87

Details on matrix:

COLLECTION AND STORAGE
- Geographic location: Huai'an - Jiangsu Province, Shenyang - Liaoning Province, Qidong - Hanon
Province, Suihua - Heilongjiang Province and Heze - Shendong Province
- Storage conditions: Room Temperature
- Soil preparation: 2 mm sieved

PROPERTIES
- % sand (thin 0.2 - 0.02): 63.9, 39.9, 16.8, 39.3 and 50.9
- % sand (crude 2 - 0.2): 0.9, 0.8, 0.9, 1.4 and 0.3
- % silt: 17.1, 42.8, 28.5, 25.9 and 24.2
- % clay: 18.1, 16.5, 53.8, 33.4 and 24.6
- pH: 6.88, 5.47, 4.93, 6.54 and 7.87
- Organic carbon (%): 1.96, 2.06, 1.94, 2.00 and 1.22

Results and discussion

Adsorption coefficient

Key result

Type:

Koc

Value:

2.63

Temp.:

40 °C

Results: Batch equilibrium or other method

Mass balance (%) at end of adsorption phase

Mass balance (%) at end of adsorption phase 1

Sample no.:

#1

Duration:

4 h

% Adsorption:

60.1

Mass balance (%) at end of adsorption phase 2

Sample no.:

#2

Duration:

4 h

% Adsorption:

65.3

Mass balance (%) at end of adsorption phase 3

Sample no.:

#3

Duration:

4 h

% Adsorption:

45.8

Mass balance (%) at end of adsorption phase 4

Sample no.:

#4

Duration:

4 h

% Adsorption:

50.6

Mass balance (%) at end of adsorption phase 5

Sample no.:

#5

Duration:

4 h

% Adsorption:

68.4

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item in the water/soil system was severely unstable during the test period but it expressed high adsorption potential in the five soils including black soil, red soil, paddy soil, moisture soil and aquinic-brown soil. The estimated log Koc of the test item was 2.63.  

Executive summary:

A batch equilibrium method was performed on the basis of MEP Guideline for the Testing of Chemicals (2013) No.106 Adsorption/desorption using a batch equilibrium method. The LS/MS/MS instrument was employed to determine the test item E Stage 3 intermediate. The recovery test in 0.01 mol/L CaCl2 solution used 2 concentrations ie. 0.1 g/L and 2mg/L. The mean recovery rate was in the range of 3.8-4.1%. The recovery test in soils used 2 concentrations ie. 0.05 mg/kg and 1mg/kg.The mean recovery rate was in the range of 75.4-103.7% with RSD in the range of 1.5% - 807%. The present analytical method met the validity criteria. However, the test item in the water/soil system was severely unstable during the test period. It expressed high adsorption percentage on the five soils including black soil, red soil, paddy soil, moisture soil and aquic-brown soil. 

Due to the Batch Equilibrium method being unsuitable for the test item, the HPLC method was subsequently employed to measure the Koc of the test item. Six reference items, NaNO3, Phenol, N,N-dimethylbenzamide, Atrazine, Triazophos, γ-HCH and DDT were employed in the HPLC method. The estimated log Koc of the test item was 2.63.