Oestr-5(10)-ene-3,17-dione

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

9 Mar - 19 Apr 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

other: Chemical Test Methods (China Environmental Science Press, 2004)

Deviations:

yes

Remarks:

Because it was discovered during the adsorption kinetics test that when soil E was at soil to water ratios of 1 : 25 and 1 : 50, the test substance was almost completely adsorbed, the soil to water ratio of 1 : 100 was therefore added for testing soil E.

Qualifier:

according to guideline

Guideline:

other: Guidelines for the Testing of Chemicals (HJ/T 153-2004)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Remarks:

According to GLP standards of China.

Type of method:

batch equilibrium method

Media:

soil

Radiolabelling:

no

Test temperature:

25 ± 1 °C

Analytical monitoring:

yes

Remarks:

HPLC

Details on sampling:

- Sampling interval: 1, 3, 5, 7, and 24 hours

Matrix no.:

#1

Matrix type:

loam

% Org. carbon:

6.54

pH:

7.28

CEC:

28.87 other: cmol/kg

Matrix no.:

#2

Matrix type:

silty clay

% Org. carbon:

1.36

pH:

4.6

CEC:

11.53 other: cmol/kg

Matrix no.:

#3

Matrix type:

silty clay loam

% Org. carbon:

5.36

pH:

6.81

CEC:

22.9 other: cmol/kg

Matrix no.:

#4

Matrix type:

silt loam

% Org. carbon:

1.39

pH:

7.84

CEC:

7.08 other: cmol/kg

Matrix no.:

#5

Matrix type:

silt loam

% Org. carbon:

6.85

pH:

7.96

CEC:

22.13 other: cmol/kg

Details on matrix:

The pH values stated under 'Matrix properties' is for 0.01 mol/L CaCl2 solution.

COLLECTION AND STORAGE
See also 'Any other information on materials and methods incl. tables'
- Collection procedures: 10-15 cm of surface-layer soil was collected and immediately sent to the laboratory under room temperature conditions, and the original nature of the soil was retained as much as possible.
- Soil preparation (e.g.: 2 mm sieved; air dried etc.): The test soil was air dried at room temperature (20-25°C), ground finely and sieved (0.3 mm), and mixed thoroughly. Soil moisture content was measured by gravimetric method after oven drying (105°C). For all subsequent calculations in the test results, soil mass referred to oven-dried mass (dry mass).

Details on test conditions:

TEST CONDITIONS
- Soil suspension pH (before and after contact with the test substance): 4.10 - 7.37

TEST SYSTEM
- Type, size and further details on reaction vessel: 150 mL glass Erlenmeyer flasks with hard stoppers
- Soil/ solution ratios used for the test: 1/5, 1/25, 1/50 and 1/100
- Number of reaction vessels/concentration: 2
- Method of preparation of test solution: Standard stock solution I (1000 mg/L): 0.1019 g test substance was precisely weighed, dissolved with acetonitrile and diluted to 100 mL, yielding test substance standard stock solution I of concentration 1000 mg/L.

Computational methods:

See 'Any other information on materials and methods incl. tables'

Sample No.:

#1

Type:

log Koc

Value:

2.68

Matrix:

#1 (A) Jilin black soil

Sample No.:

#2

Type:

log Koc

Value:

2.75

Matrix:

#2 (B) Jiangxi red soil

Sample No.:

#3

Type:

log Koc

Value:

2.94

Matrix:

#3 (C) Jiangsu rice paddy soil

Sample No.:

#4

Type:

log Koc

Value:

3.13

Matrix:

#4 (D) Shandong loess

Sample No.:

#5

Matrix:

#5 (E) Gansu meadow soil

Remarks on result:

not measured/tested

Remarks:

The test substance was completely adsorbed, it was not possible to calculate the adsorption coefficient, and subsequent testing was not possible for soil E.

Adsorption and desorption constants:

See 'Any other information on results incl. tables'

Recovery of test material:

In analysis of the 0.200 mg/L and 1.00 mg/L spike water sample, mean sample recovery rates were 96.8% and 95.5% and relative standard deviations were 0.789% and 0.397%.

When the spike concentration of test substance in the soil was 10.0 mg/kg, recovery rates for soils A, B, C, D, and E were 88.7 - 101% and relative standard deviations were 0.574 - 1.21%.

Sample no.:

#1

Duration:

24 h

% Adsorption:

99

Remarks on result:

other: determined for soil A (Jilin black soil)

Sample no.:

#2

Duration:

24 h

% Adsorption:

97.1

Remarks on result:

other: determined for soil B (Jiangxi red soil)

Details on results (Batch equilibrium method):

PRELIMINARY TEST
The results of the pre-test revealed that, after shaking at a constant temperature for 24 hours, distribution of the test substance reached equilibrium in the aqueous phase and the soil phase, and the most suitable soil to water ratio for the adsorption test was 1 : 25.


MAIN TEST: PERFORMANCE
- Test material stability during adsorption/desorption phase: in the test period, the test substance was stable in the test system.
- Other observations: The results indicate that the test substance had no pronounced adsorption on the walls of the test vessel.

Freundlich Adsorption Equation and Relevant Parameters:

Soil	Freundlich adsorption equation	KF^ads(µg ^1-1/n(cm^3)^1/ng^-1)	1/n
A	y = 0.7612x + 0.064, R^2 = 0.998	1.16	0.761
B	y =0.9554x - 0.4624, R^2 = 0.9981	0.345	0.955
C	y = 1.0144x + 0.2655, R^2 = 0.9973	1.84	1.01
D	y =0.7657x - 0.3966, R^2 = 0.9996	0.799	1.03

 

Adsorption isotherm test

The adsorption isotherm test revealed that the adsorption isotherms for D5-NAD in A (Jilin black soil), B (Jiangxi red soil), C (Jiangsu rice paddy soil), and D (Shandong loess) conformed relatively well to the Freundlich adsorption equation. Correlation coefficients were all larger than 0.9, Freundlich adsorption coefficients (K_F^ads) were 1.16, 0.345, 1.84, and 0.799 μg-1/n (cm³)1/ng^-1, and 1/n values were 0.761, 0.955, 1.01, and 1.03.

 

Desorption kinetics

The results of the desorption kinetics test revealed that during the 24-hour desorption equilibrium time, in soil systems A (Jilin black soil), B (Jiangxi red soil), C (Jiangsu rice paddy soil), D (Shandong loess), and E (Gansu meadow soil), the test substance was not detected in the supernatant liquid and the test substance was not clearly desorbed in the five soils.

 

 

Validity criteria fulfilled:

yes

Remarks:

According to Chinese guidelines.

Conclusions:

The adsorption distribution coefficient (Kd) of D5-NAD in A (Jilin black soil), B (Jiangxi red soil), C (Jiangsu rice paddy soil), and D (Shandong loess) were 31.3, 7.64, 46.7, and 18.7 cm3g-1. The adsorption coefficient Koc values in order were 479, 562, 872, and 1343 cm3g-1, respectively. Log Koc values were 2.68, 2.75, 2.94, and 3.13. With E (Gansu meadow soil), at the soil to water ratio of 1/100, the test substance was completely adsorbed, it was not possible to calculate the adsorption coefficient, and subsequent testing was not possible for soil E.

Executive summary:

In accordance with the Guidelines for the Testing of Chemicals (HJ/T 153-2004) and Chemical Test Methods (China Environmental Science Press, 2004), and with reference to Adsorption -Desorption Using a Batch Equilibrium Method (OECD TG 106), this test measured the adsorption (adsorption coefficients) of the chemical substance in soils with different properties, to predict the distribution characteristics of this substance under different environmental conditions and its impact on the ecological environment.

The present study selected five soils with different pH, organic carbon content, soil texture, and other physical-chemical properties, collected from Jiangxi, Jiangsu, Jilin, Shandong, and Gansu Provinces in China. The batch equilibrium method was adopted to carry out several tiers of testing, including a pre-test (test 1), an adsorption kinetics test (test 2), and an adsorption isotherm test and desorption kinetics/desorption isotherm (test 3), to determine the adsorption/desorption properties of D5-NAD.

The adsorption distribution coefficient (Kd) of D5-NAD in A (Jilin black soil), B (Jiangxi red soil), C (Jiangsu rice paddy soil), and D (Shandong loess) were 31.3, 7.64, 46.7, and 18.7 cm³g^-1. The adsorption coefficient Koc values in order were 479, 562, 872, and 1343 cm³g^-1, respectively. Log Koc values were 2.68, 2.75, 2.94, and 3.13. With E (Gansu meadow soil), at the soil to water ratio of 1/100, the test substance was completely adsorbed, it was not possible to calculate the adsorption coefficient, and subsequent testing was not possible for soil E.

The results of the desorption kinetics test revealed that during the 24-hour desorption equilibrium time, in soil systems A (Jilin black soil), B (Jiangxi red soil), C (Jiangsu rice paddy soil), D (Shandong loess), and E (Gansu meadow soil), the test substance was not detected in the supernatant liquid and the test substance was not clearly desorbed in the five soils.

Description of key information

In accordance with the Guidelines for the Testing of Chemicals (HJ/T 153-2004) and Chemical Test Methods (China Environmental Science Press, 2004), and with reference to Adsorption -Desorption Using a Batch Equilibrium Method (OECD TG 106), this test measured the adsorption (adsorption coefficients) of the chemical substance in soils with different properties, to predict the distribution characteristics of this substance under different environmental conditions and its impact on the ecological environment.

The present study selected five soils with different pH, organic carbon content, soil texture, and other physical-chemical properties, collected from Jiangxi, Jiangsu, Jilin, Shandong, and Gansu Provinces in China. The batch equilibrium method was adopted to carry out several tiers of testing, including a pre-test (test 1), an adsorption kinetics test (test 2), and an adsorption isotherm test and desorption kinetics/desorption isotherm (test 3), to determine the adsorption/desorption properties of D5-NAD.

The adsorption distribution coefficient (Kd) of D5-NAD in A (Jilin black soil), B (Jiangxi red soil), C (Jiangsu rice paddy soil), and D (Shandong loess) were 31.3, 7.64, 46.7, and 18.7 cm³g^-1. The adsorption coefficient Koc values in order were 479, 562, 872, and 1343 cm³g^-1, respectively. Log Koc values were 2.68, 2.75, 2.94, and 3.13. With E (Gansu meadow soil), at the soil to water ratio of 1/100, the test substance was completely adsorbed, it was not possible to calculate the adsorption coefficient, and subsequent testing was not possible for soil E.

The results of the desorption kinetics test revealed that during the 24-hour desorption equilibrium time, in soil systems A (Jilin black soil), B (Jiangxi red soil), C (Jiangsu rice paddy soil), D (Shandong loess), and E (Gansu meadow soil), the test substance was not detected in the supernatant liquid and the test substance was not clearly desorbed in the five soils.

Key value for chemical safety assessment

Koc at 20 °C:

1 343

Additional information

The key value chosen was determined in soil D (Shandong loess).