Strontium hydrogen phosphate

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:

27 July 2021 - 17 September 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

batch equilibrium method

Media:

soil

Radiolabelling:

no

Test temperature:

21ºC

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 3 mg/L
- Sampling interval: 0, 2, 4, 6, 8, 24 and 48 h (Tier 1); 0, 2, 4, 6, 8 and 24 h (Tier 2)
- Sample storage before analysis: No

Matrix no.:

#1

Matrix type:

silt loam

% Clay:

16

% Silt:

78.2

% Sand:

5.7

% Org. carbon:

1.06

pH:

6.9

CEC:

118 other: mmol/kg

Matrix no.:

#2

Matrix type:

silt loam

% Clay:

23.9

% Silt:

60.6

% Sand:

15.5

% Org. carbon:

4.45

pH:

6.1

CEC:

177 other: mmol/kg

Matrix no.:

#3

Matrix type:

loamy sand

% Clay:

6.5

% Silt:

12.2

% Sand:

81.2

% Org. carbon:

2.89

pH:

5.77

CEC:

102 other: mmol/kg

Matrix no.:

#4

Matrix type:

loam

% Clay:

20.3

% Silt:

46.7

% Sand:

33

% Org. carbon:

2.1

pH:

5.37

CEC:

115 other: mmol/kg

Matrix no.:

#5

Matrix type:

clay

% Clay:

41.9

% Silt:

35.1

% Sand:

23

% Org. carbon:

1.55

CEC:

18.7 other: mmol/kg

Bulk density (g/cm³):

1.291

Details on matrix:

COLLECTION AND STORAGE
- Geographic location:
RefeSol 02-A-02 (matrix#1), RefeSol 03-G-05 (matrix#2), RefeSol 04-A-02 (matrix#3) and RefeSol 05-G (matrix#4): Schmallenberg, Northrhine-Westphalia (Germany)
Lufa 6S (matrix#5): In der unteren Hohnert, Nr 3412, Rheinland-Pfalz/Siebeldingen (germany)
- Collection procedures: For matrix#1, #2, #3 and #4 sampling was conducted using a spade up to 20 cm, several subsamples were taken and unified to a mixed sample.
- Sampling depth (cm): 20
- Storage conditions: The freshly collected soil samples were transported using loosely tied plastic bags (polyethylene bags) to the laboratory. After receiving the soil to the laboratory, it was stored at ambient temperature (20 to 25°C) and kept at air-dried.
- Storage length: N/A
- Soil preparation (e.g.: 2 mm sieved; air dried etc.): the material was air-dried and sieved over a 2 mm sieve. The soil was sterilized (121ºC for a least 2 hours) (matrices #1, #2, #3 and #4)

PROPERTIES
RefeSol 02-A-02 (matrix#1)
- Soil series: Stagnic Luvisol
- Moisture at 1/3 atm (%): 0.35
- Biomass (e.g. in mg microbial C/100 mg, CFU or other): 794 mg microbial/kg

RefeSol 03-G-05 (matrix#2)
- Soil series: Eutric Cambisol
- Moisture at 1/3 atm (%): 0.25
- Biomass (e.g. in mg microbial C/100 mg, CFU or other): 1711 mg microbial/kg

RefeSol 04-A-02 (matrix#3)
- Soil series: Gleyic Podsol
- Moisture at 1/3 atm (%): 0.42
- Biomass (e.g. in mg microbial C/100 mg, CFU or other): 332 mg microbial/kg

RefeSol 05-G (matrix#4)
- Soil series: Berthold Beste
- Moisture at 1/3 atm (%): 0.46
- Biomass (e.g. in mg microbial C/100 mg, CFU or other): 1358 mg microbial/kg

Lufa 6S (matrix#5)
- Soil series: N/A
- Moisture at 1/3 atm (%): 0.26
- Biomass (e.g. in mg microbial C/100 mg, CFU or other): N/A

Details on test conditions:

TEST CONDITIONS
The test was conducted at constant temperature (21ºC). Temperature was monitored during the experiment.

TEST SYSTEM
- Type, size and further details on reaction vessel: Teflon centrifuge tubes.
- Amount of soil and water per treatment: tier 1 (10 g/10 mL; 5 g/25 mL and 1 g/25 mL); tier 2 (10 g/10 mL)
- Soil-water ratio: tier 1 (1:1, 1:5 and 1:25); tier 2 (1:1)
- Number of reaction vessels/concentration: Parallel method:
Tier 1 test: 96 test vessels per soil with three ratios and sampling times of 0hr, 2 hr, 4 hr, 6 hr, 8 hr, 24 hr and 48 hr (including blank, control and treated test vessels).
Tier 2 Test: 28 test vessels per soil with one ratio and sampling times of 0hr, 2 hr, 4 hr, 6 hr, 8 hr and 24 hr (including blank, control and treated test vessels).
- Test performed in closed vessels.
- Method of preparation of test solution: Depending on soil-solution ratio to prepare, soil samples (10, 5 or 1 g) with a measured quantity of minimum of 22.5 mL and 9 mL of 0.01 M CaCl2 solution including moisture content for each soil (i.e. 90% of the final volume solution) were added and pre-equilibrated by shaking at overnight (minimum 12 hours) before the day of the experiment. After shaking, on next day a certain volume of the stock solution of the test item were added in order to adjust final total volume. The test vessels were capped, placed on the incubator shaker and continuously agitated to keep the soil in suspension. The mixture was shaken until predetermined sampling intervals for each test vessel.

Sample No.:

#1

Duration:

48 h

Initial conc. measured:

3.035 other: mg/L in aqueous phase

pH:

6.64

Temp.:

ca. 21 °C

Remarks:

Tier 1_Lufa 6S - Soil to Solution Ratio (1:1). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr, 8 hr and 24 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#2

Duration:

48 h

Initial conc. measured:

3.035 other: mg/L in aqueous phase

pH:

6.34

Temp.:

ca. 21 °C

Remarks:

Tier 1_Lufa 6S - Soil to Solution Ratio (1:5). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr, 8 hr and 24 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#3

Duration:

48 h

Initial conc. measured:

3.035 other: mg/L in aqueous phase

pH:

6.53

Temp.:

ca. 21 °C

Remarks:

Tier 1_Lufa 6S - Soil to Solution Ratio (1:25). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr, 8 hr and 24 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#4

Duration:

48 h

Initial conc. measured:

3.011 other: mg/L in aqueous phase

pH:

6.41

Temp.:

ca. 21 °C

Remarks:

Tier 1_Refesol 03-G-05 - Soil to Solution Ratio (1:1). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr, 8 hr and 24 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#5

Duration:

48 h

Initial conc. measured:

3.011 other: mg/L in aqueous phase

pH:

6.64

Temp.:

ca. 21 °C

Remarks:

Tier 1_Refesol 03-G-05 - Soil to Solution Ratio (1:5). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr, 8 hr and 24 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#6

Duration:

48 h

Initial conc. measured:

3.011 other: mg/L in aqueous phase

pH:

7.14

Temp.:

ca. 21 °C

Remarks:

Tier 1_Refesol 03-G-05 - Soil to Solution Ratio (1:25). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr, 8 hr and 24 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#7

Duration:

24 h

Initial conc. measured:

3 other: mg/L in aqueous phase

pH:

6.68

Temp.:

ca. 21 °C

Remarks:

Tier 2_Lufa 6S - Soil to Solution Ratio (1:1). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr and 8 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#8

Duration:

24 h

Initial conc. measured:

3 other: mg/L in aqueous phase

pH:

6.63

Temp.:

ca. 21 °C

Remarks:

Tier 2_Refesol 03-G-05 - Soil to Solution Ratio (1:1). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr and 8 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#9

Duration:

24 h

Initial conc. measured:

3.029 other: mg/L in aqueous phase

pH:

6.31

Temp.:

ca. 21 °C

Remarks:

Tier 2_Refesol-02-A-02 - Soil to Solution Ratio (1:1). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr and 8 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#10

Duration:

24 h

Initial conc. measured:

3.029 other: mg/L in aqueous phase

pH:

4.75

Temp.:

ca. 21 °C

Remarks:

Tier 2_Refesol 04-A-02 - Soil to Solution Ratio (1:1). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr and 8 hr as well as control and blanck samples were also used at the same conditions.

Sample No.:

#11

Duration:

24 h

Initial conc. measured:

3.029 other: mg/L in aqueous phase

pH:

4.45

Temp.:

ca. 21 °C

Remarks:

Tier 2_Refesol 05-G - Soil to Solution Ratio (1:1). Vessels for interim sampling times of 0hr, 2 hr, 4 hr, 6 hr and 8 hr as well as control and blanck samples were also used at the same conditions.

Computational methods:

- Adsorption coefficient (Kd):
Equilibration time was determined from plots of the percent adsorption (Ati) against time (T). The equilibration time was defined by the point at which this plot reaches a plateau.
Ati (%) = Msads(ti) x100 / m0
Msads(ti) = Mass of test substance adsorbed on soil at the time ti (µg)
m0 = Mass of test item in the test tube at the beginning of the test (µg)

Msads(ti) = mo – (Caqads (ti) x Vo(aq))
Caqads (ti) = Mass concentration of the substance in the aqueous phase at the time ti that the analysis is performed (µg)
Vo(aq) = Initial volume of the aqueous phase in contact with the soil (mL)

The distribution coefficient for adsorption (Kd) for each test concentration was calculated for each test soil using the following equation:
Kd = Csads(eq) / Caqads(eq)
Csads(eq) = Content of the substance adsorbed on the soil at adsorption equilibrium (µg/g)
Caqads(eq) = Mass concentration of the substance in the aqueous phase at adsorption equilibrium (µg/mL)

Csads(eq) = Msads / msoil
Msads = Mass of test substance adsorbed on the soil at the time ti (µg)
msoil = Mass of dry soil taken (g)

- Adsorption coefficient per organic carbon (Koc):
The Kd value was used to calculate Kom and Koc values using the following equations:
Kom = Kd x 100 / % Organic matter
Koc = Kd x 100 / % Organic carbon
Organic Matter (%) = Organic Carbon (%) x 1.724

Sample No.:

#1

Type:

Kd

Value:

3.99 L/kg

pH:

6.68

Temp.:

21 °C

Matrix:

Lufa 6S (ratio 1:1)

% Org. carbon:

1.55

Sample No.:

#1

Type:

other: Kom

Value:

149.44 L/kg

pH:

6.68

Temp.:

21 °C

Matrix:

Lufa 6S (ratio 1:1)

% Org. carbon:

1.55

Sample No.:

#1

Type:

Koc

Value:

257.42 L/kg

pH:

6.68

Temp.:

21 °C

Matrix:

Lufa 6S (ratio 1:1)

% Org. carbon:

1.55

Key result

Sample No.:

#1

Type:

log Koc

Value:

2.41 dimensionless

pH:

6.68

Temp.:

21 °C

Matrix:

Lufa 6S (ratio 1:1)

% Org. carbon:

1.55

Sample No.:

#2

Type:

Kd

Value:

1.9 L/kg

pH:

6.63

Temp.:

21 °C

Matrix:

Refesol 03-G-05 (ratio 1:1)

% Org. carbon:

4.45

Sample No.:

#2

Type:

other: Kom

Value:

24.71 L/kg

pH:

6.63

Temp.:

21 °C

Matrix:

Refesol 03-G-05 (ratio 1:1)

% Org. carbon:

4.45

Sample No.:

#2

Type:

Koc

Value:

42.58 L/kg

pH:

6.63

Temp.:

21 °C

Matrix:

Refesol 03-G-05 (ratio 1:1)

% Org. carbon:

4.45

Key result

Sample No.:

#2

Type:

log Koc

Value:

1.63 dimensionless

pH:

6.63

Temp.:

21 °C

Matrix:

Refesol 03-G-05 (ratio 1:1)

% Org. carbon:

4.45

Sample No.:

#3

Type:

Kd

Value:

0.68 L/kg

pH:

6.31

Temp.:

21 °C

Matrix:

Refesol 02-A-02 (ratio 1:1)

% Org. carbon:

1.06

Sample No.:

#3

Type:

other: Kom

Value:

36.89 L/kg

pH:

6.31

Temp.:

21 °C

Matrix:

Refesol 02-A-02 (ratio 1:1)

% Org. carbon:

1.06

Sample No.:

#3

Type:

Koc

Value:

63.68 L/kg

pH:

6.31

Temp.:

21 °C

Matrix:

Refesol 02-A-02 (ratio 1:1)

% Org. carbon:

1.06

Key result

Sample No.:

#3

Type:

log Koc

Value:

1.8 dimensionless

pH:

6.31

Temp.:

21 °C

Matrix:

Refesol 02-A-02 (ratio 1:1)

% Org. carbon:

1.06

Sample No.:

#4

Type:

Kd

Value:

2.8 L/kg

pH:

4.75

Temp.:

21 °C

Matrix:

Refesol 04-A-02 (ratio 1:1)

% Org. carbon:

2.89

Sample No.:

#4

Type:

other: Kom

Value:

56.13 L/kg

pH:

4.75

Temp.:

21 °C

Matrix:

Refesol 04-A-02 (ratio 1:1)

% Org. carbon:

2.89

Sample No.:

#4

Type:

Koc

Value:

96.71 L/kg

pH:

4.75

Temp.:

21 °C

Matrix:

Refesol 04-A-02 (ratio 1:1)

% Org. carbon:

2.89

Key result

Sample No.:

#4

Type:

log Koc

Value:

1.99 dimensionless

pH:

4.75

Temp.:

21 °C

Matrix:

Refesol 04-A-02 (ratio 1:1)

% Org. carbon:

2.89

Sample No.:

#5

Type:

Kd

Value:

0.16 L/kg

pH:

4.45

Temp.:

21 °C

Matrix:

Refesol 05-G (ratio 1:1)

% Org. carbon:

2.1

Sample No.:

#5

Type:

other: Kom

Value:

4.28 L/kg

pH:

4.45

Temp.:

21 °C

Matrix:

Refesol 05-G (ratio 1:1)

% Org. carbon:

2.1

Sample No.:

#5

Type:

Koc

Value:

7.38 L/kg

pH:

4.45

Temp.:

21 °C

Matrix:

Refesol 05-G (ratio 1:1)

% Org. carbon:

2.1

Key result

Sample No.:

#5

Type:

log Koc

Value:

0.87 dimensionless

pH:

4.45

Temp.:

21 °C

Matrix:

Refesol 05-G (ratio 1:1)

% Org. carbon:

2.1

Adsorption and desorption constants:

Results for different soils and sampling times are included in tables below.

Recovery of test material:

Results for different soils and sampling times are included in tables below.

Concentration of test substance at end of adsorption equilibration period:

Results for different soils and sampling times are included in tables below.

Sample no.:

#1

Duration:

24 h

% Adsorption:

79.94

Remarks on result:

other: Lufa 6S

Sample no.:

#2

Duration:

24 h

% Adsorption:

64.41

Remarks on result:

other: Refesol 03-G-05

Sample no.:

#3

Duration:

24 h

% Adsorption:

40.22

Remarks on result:

other: Refesol 02-A-02

Sample no.:

#4

Duration:

24 h

% Adsorption:

73.58

Remarks on result:

other: Refesol 04-A-02

Sample no.:

#5

Duration:

24 h

% Adsorption:

13.4

Remarks on result:

other: Refesol 05-G

Transformation products:

no

Details on results (Batch equilibrium method):

PRELIMINARY TEST
- Sample purity: 99%
- Weighed soil: 10, 5 or 1 g for soil to solution ratios of 1:1, 1:5 and 1:25 respectively.
- Volume of CaCl2 solution: 10 mL for soil to solution ratio of 1:1 and 25 mL for soil to solution ratio of 1:5 and 1:25.
- Initial test substance concentration: 3 mg/L in aqueous solution.
- Test substance concentration in final solution: see Tables below for different soils, soil to solution ratios and sampling times.
- Analytical test substance concentration in final solution: see Tables below for different soils, soil to solution ratios and sampling times.

MAIN TEST: PERFORMANCE
- Test material stability during adsorption phase: Lufa 6S and Refesol 03-g-05 soils at 1:1 (w/v) soil to solution ratio fortified at concentration of 3.0294 mg/L were used to confirm the stability of the test item under the given conditions of the test. Both aqueous phase and soil pellet extracts were analysed at 48 h. The mass balance for each soil was determined as the sum of the amount of test item in the aqueous solution and the amount of test item extracted from soil and walls of the test vessel. The average mass balance was 93.70% and 93.30% for the Lufa 6S and Refesol 03-G-05 soils at 48 hour, respectively. The obtained mass balance was >90% in both soils, hence the test item was considered to be stable in the scale of the test.
- Experimental conditions maintained throughout the study: Yes
- Buffer/test substance interactions affecting sorption: No
- Further chemical interactions: No
- Buffer-catalyzed degradation of test substance: No

TABLE 2. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR LUFA 6S SOIL TREATED WITH TEST ITEM IN 1:1 RATIO AT 2, 4, 6 AND 8 HOUR FOR TIER 1 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated - R1	0.6	30.354	9.9768	2.0661	20.661	9.693	0.9716	0.47	17.60	30.32	31.93	33.35
2 Hour Test item treated - R2	0.6	30.354	9.9814	1.9802	19.802	10.552	1.0572	0.53	19.85	34.19	34.76
4 Hour Test item treated - R1	0.6	30.354	9.9761	0.8664	8.664	21.690	2.1742	2.51	94.01	161.94	71.46	70.27
4 Hour Test item treated - R2	0.6	30.354	9.9773	0.9387	9.387	20.967	2.1015	2.24	83.90	144.52	69.07
6 Hour Test item treated - R1	0.6	30.354	9.9840	0.8623	8.623	21.731	2.1766	2.52	94.38	162.58	71.59	72.53
6 Hour Test item treated - R2	0.6	30.354	9.9765	0.8057	8.057	22.297	2.2350	2.77	103.75	178.71	73.46
8 Hour Test item treated R1	0.6	30.354	9.9797	0.7753	7.753	22.601	2.2647	2.92	109.36	188.39	74.46	74.69
8 Hour Test item treated - R2	0.6	30.354	9.9836	0.7617	7.617	22.737	2.2774	2.99	111.99	192.90	74.91
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 1.55, OM (%) = 2.67

 

TABLE 3. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR LUFA 6S SOIL TREATED WITH TEST ITEM IN 1:1 RATIO AT 24 AND 48 HOUR FOR TIER 1 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
24 Hour Test item treated R1	0.6	30.354	10.0006	0.6789	6.789	23.565	2.3564	3.47	129.96	223.87	77.63	77.98
24 Hour Test item treated - R2	0.6	30.354	9.9765	0.6580	6.580	23.774	2.3830	3.62	135.58	233.55	78.32
48 Hour Test item treated - R1	0.6	30.354	9.9814	0.6601	6.601	23.753	2.3797	3.61	135.21	232.90	78.25	78.50
48 Hour Test item treated - R2	0.6	30.354	10.0001	0.6454	6.454	23.900	2.3900	3.70	138.58	238.71	78.74
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 1.55, OM (%) = 2.67

 

TABLE 4. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR LUFA 6S SOIL TREATED WITH TEST ITEM IN 1:5 RATIO AT 2, 4 AND 6 HOUR FOR TIER 1 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated - R1	1.5	75.885	4.9881	2.9304	73.260	2.625	0.5263	0.18	6.74	11.61	3.46	2.86
2 Hour Test item   treated - R2	1.5	75.885	4.9874	2.9671	74.178	1.708	0.3424	0.12	4.49	7.74	2.25
4 Hour Test item treated - R1	1.5	75.885	4.9902	1.4814	37.035	38.850	7.7853	5.26	197.00	339.35	51.20	48.23
4 Hour Test item treated - R2	1.5	75.885	4.9886	1.6617	41.543	34.343	6.8842	4.14	155.06	267.10	45.26
6 Hour Test item treated - R1	1.5	75.885	4.9953	1.8639	46.598	29.288	5.8630	3.15	117.98	203.23	38.59	37.65
6 Hour Test item treated - R2	1.5	75.885	4.9886	1.9215	48.038	27.848	5.5822	2.91	108.99	187.74	36.70
Total aq. Vol V0 (aq) = 25 mL, Percent organic matter = OC × 1.724, OC (%) = 1.55, OM (%) = 2.67

 

TABLE 5. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR LUFA 6S SOIL TREATED WITH TEST ITEM, IN 1:5 RATIO AT 8, 24 AND 48 HOUR FOR TIER 1 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
8 Hour Test item treated R1	1.5	75.885	4.9925	1.7643	44.108	31.778	6.3650	3.61	135.21	232.90	41.88	40.45
8 Hour Test item treated - R2	1.5	75.885	4.9929	1.8513	46.283	29.603	5.9289	3.20	119.85	206.45	39.01
24 Hour Test item treated - R1	1.5	75.885	4.9911	2.1394	53.485	22.400	4.4880	2.10	78.65	135.48	29.52	30.51
24 Hour Test item treated - R2	1.5	75.885	4.9928	2.0797	51.993	23.893	4.7854	2.30	86.14	148.39	31.49
48 Hour Test item treated R1	1.5	75.885	5.0050	2.0493	51.233	24.653	4.9256	2.40	89.89	154.84	32.49	34.53
48 Hour Test item treated R2	1.5	75.885	4.9979	1.9257	48.143	27.743	5.5508	2.88	107.87	185.81	36.56
Total aq. Vol V0 (aq) = 25 mL, Percent organic matter = OC × 1.724, OC (%) = 1.55, OM (%) = 2.67

 

TABLE 6. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR LUFA 6S SOIL TREATED WITH TEST ITEM IN 1:25 RATIO AT 2, 4 AND 6 HOUR FOR TIER 1 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated - R1	1.5	75.885	1.0008	2.9891	74.728	1.158	1.1566	0.39	14.61	25.16	1.53	1.75
2 Hour Test item treated - R2	1.5	75.885	1.0018	2.9755	74.388	1.498	1.4948	0.50	18.73	32.26	1.97
4 Hour Test item treated - R1	1.5	75.885	0.9995	2.1981	54.953	20.933	20.9430	9.53	356.93	614.84	27.58	28.31
4 Hour Test item treated - R2	1.5	75.885	0.9989	2.1541	53.853	22.033	22.0568	10.24	383.52	660.65	29.03
6 Hour Test item treated - R1	1.5	75.885	1.0100	2.4820	62.050	13.835	13.6980	5.52	206.74	356.13	18.23	18.87
6 Hour Test item treated - R2	1.5	75.885	0.9989	2.4432	61.080	14.805	14.8213	6.07	227.34	391.61	19.51
Total aq. Vol V0 (aq) = 25 mL, Percent organic matter = OC × 1.724, OC (%) = 1.55, OM (%) = 2.67

 

TABLE 7. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR LUFA 6S SOIL TREATED WITH TEST ITEM IN 1:25 RATIO AT 8, 24 AND 48 HOUR FOR TIER 1 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
8 Hour Test item treated - R1	1.5	75.885	1.0083	2.3343	58.358	17.528	17.3832	7.45	279.03	480.65	23.10	21.76
8 Hour Test item treated - R2	1.5	75.885	1.0126	2.4160	60.400	15.485	15.2923	6.33	237.08	408.39	20.41
24 Hour Test item treated - R1	1.5	75.885	1.0019	2.2211	55.528	20.358	20.3189	9.15	342.70	590.32	26.83	27.62
24 Hour Test item treated - R2	1.5	75.885	1.0024	2.1729	54.323	21.563	21.5109	9.90	370.79	638.71	28.41
48 Hour Test item treated - R1	1.5	75.885	1.0165	2.1499	53.748	22.138	21.7782	10.13	379.40	653.55	29.17	28.38
48 Hour Test item treated - R2	1.5	75.885	1.0107	2.1981	54.953	20.933	20.7109	9.42	352.81	607.74	27.58
Total aq. Vol V0 (aq) = 25 mL, Percent organic matter = OC × 1.724, OC (%) = 1.55, OM (%) = 2.67

 

TABLE 8. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR REFESOL 03-G-05 SOIL TREATED WITH TEST ITEM IN 1:1 RATIO AT 2, 4, 6 AND 8 HOUR FOR TIER 1 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated - R1	0.6	30.114	9.9864	2.1205	21.205	8.909	0.8921	0.42	5.48	9.44	29.58	31.01
2 Hour Test item treated – R2	0.6	30.114	9.9774	2.0346	20.346	9.768	0.9790	0.48	6.26	10.79	32.44
4 Hour Test item treated – R1	0.6	30.114	9.9783	1.3777	13.777	16.337	1.6373	1.19	15.51	26.74	54.25	53.21
4 Hour Test item treated – R2	0.6	30.114	9.9763	1.4406	14.406	15.708	1.5745	1.09	14.21	24.49	52.16
6 Hour Test item treated - R1	0.6	30.114	9.9799	1.5066	15.066	15.048	1.5078	1.00	13.04	22.47	49.97	51.96
6 Hour Test item treated – R2	0.6	30.114	9.9838	1.3872	13.872	16.242	1.6268	1.17	15.25	26.29	53.94
8 Hour Test item treated – R1	0.6	30.114	9.9821	1.2070	12.070	18.044	1.8076	1.50	19.56	33.71	59.92	59.24
8 Hour Test item treated – R2	0.6	30.114	9.9903	1.2478	12.478	17.636	1.7653	1.41	18.38	31.69	58.56
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 4.45, OM (%) = 7.67

 

TABLE 9. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR REFESOL 03-G-05 SOIL TREATED WITH TEST ITEM IN 1:1 RATIO AT 24 AND 48 HOUR FOR TIER 1 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
24 Hour Test item treated - R1	0.6	30.114	9.9804	1.1797	11.797	18.317	1.8353	1.56	20.34	35.06	60.83	60.83
24 Hour Test item treated R2	0.6	30.114	9.9809	1.1797	11.797	18.317	1.8352	1.56	20.34	35.06	60.83
48 Hour Test item treated – R1	0.6	30.114	9.9893	1.1210	11.210	18.904	1.8924	1.69	22.03	37.98	62.77	61.24
48 Hour Test item treated – R2	0.6	30.114	9.9829	1.2132	12.132	17.982	1.8013	1.48	19.30	33.26	59.71
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 4.45, OM (%) = 7.67

 

TABLE 10. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR REFESOL 03-G-05 SOIL TREATED WITH TEST ITEM IN 1:5 RATIO AT 0, 2, 4 AND 6 HOUR FOR TIER 1 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Total aq. Vol V0 (aq) (mL)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated – R1	1.5	75.285	4.9894	2.3207	25.000	58.018	17.268	3.4608	1.49	19.43	33.48	22.94	20.54
2 Hour Test item treated – R2	1.5	75.285	5.0063	2.4652	25.001	61.633	13.653	2.7271	1.11	14.47	24.94	18.13
4 Hour Test item treated – R1	1.5	75.285	4.9909	2.5208	25.000	63.020	12.265	2.4575	0.97	12.65	21.80	16.29	17.27
4 Hour Test item treated – R2	1.5	75.285	5.0065	2.4621	25.001	61.555	13.730	2.7424	1.11	14.47	24.94	18.24
6 Hour Test item treated – R1	1.5	75.285	4.9921	2.4495	25.000	61.238	14.048	2.8139	1.15	14.99	25.84	18.66	20.09
6 Hour Test item treated – R2	1.5	75.285	5.0035	2.3636	25.001	59.092	16.193	3.2363	1.37	17.86	30.79	21.51
Percent organic matter = OC × 1.724, OC (%) = 4.45, OM (%) = 7.67

 

TABLE 11. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR REFESOL 03-G-05 SOIL TREATED WITH TEST ITEM IN 1:5 RATIO AT 8, 24 AND 48 HOUR FOR TIER 1 TEST

Percent organic matter = OC × 1.724, OC (%) = 4.45, OM (%) = 7.67
Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass conc. of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Total aq. Vol V0 (aq) (mL)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption (%)	Ati Average Adsorption (%)
8 Hour Test item treated – R1	1.5	75.285	4.9994	2.4506	25.000	61.265	14.020	2.8043	1.14	14.86	25.62	18.62	17.67
8 Hour Test item treated – R2	1.5	75.285	4.9944	2.5082	25.000	62.705	12.580	2.5188	1.00	13.04	22.47	16.71
24 Hour Test item treated – R1	1.5	75.285	5.0032	2.3804	25.001	59.512	15.773	3.1525	1.32	17.21	29.66	20.95	19.72
24 Hour Test item treated – R2	1.5	75.285	4.9954	2.4548	25.000	61.370	13.915	2.7856	1.13	14.73	25.39	18.48
48 Hour Test item treated – R1	1.5	75.285	4.9940	2.3458	25.000	58.645	16.640	3.3320	1.42	18.51	31.91	22.10	23.04
48 Hour Test item treated – R2	1.5	75.285	4.9980	2.2892	25.000	57.230	18.055	3.6124	1.58	20.60	35.51	23.98

 

TABLE 12. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR REFESOL 03-G-05 SOIL TREATED WITH TEST ITEM IN 1:25 RATIO AT 0, 2, 4 AND 6 HOUR FOR TIER 1 TEST

Percent organic matter = OC × 1.724, OC (%) = 4.45, OM (%) = 7.67
Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Total aq. Vol V0 (aq) (mL)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated – R1	1.5	75.285	1.0058	2.5218	25.001	63.048	12.238	12.1669	4.82	62.84	108.31	16.25	16.25
2 Hour Test item treated – R2	1.5	75.285	1.0065	2.4443	25.001	61.110	14.175	14.0836	5.76	75.10	129.44	18.83
4 Hour Test item treated – R1	1.5	75.285	1.0105	2.3615	25.001	59.040	16.245	16.0763	6.81	88.79	153.03	21.58	21.95
4 Hour Test item treated – R2	1.5	75.285	1.0072	2.3395	25.001	58.490	16.795	16.6751	7.13	92.96	160.22	22.31
6 Hour Test item treated – R1	1.5	75.285	1.0061	2.3353	25.001	58.385	16.900	16.7977	7.19	93.74	161.57	22.45	21.36
6 Hour Test item treated – R2	1.5	75.285	1.0020	2.4013	25.001	60.035	15.250	15.2197	6.34	82.66	142.47	20.26

 

TABLE 13. ADSORPTION COEFFICIENTS (SOIL TO SOLUTION RATIO) FOR REFESOL 03-G-05 SOIL TREATED WITH TEST ITEM IN 1:25 RATIO AT 8, 24 AND 48 HOUR FOR TIER 1 TEST

Percent organic matter = OC × 1.724, OC (%) = 4.45,  OM (%) = 7.67
Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Total aq. Vol V0 (aq) (mL)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
8 Hour Test item treated – R1	1.5	75.285	1.0087	2.2117	25.001	55.295	19.990	19.8179	8.96	116.82	201.35	26.55	26.68
8 Hour Test item treated – R2	1.5	75.285	0.9979	2.2044	25.000	55.110	20.175	20.2175	9.17	119.56	206.07	26.80
24 Hour Test item treated – R1	1.5	75.285	1.0114	2.3269	25.001	58.175	17.110	16.9173	7.27	94.78	163.37	22.73	21.64
24 Hour Test item treated – R2	1.5	75.285	1.0043	2.3929	25.001	59.825	15.460	15.3939	6.43	83.83	144.49	20.54
48 Hour Test item treated – R1	1.5	75.285	1.0136	2.2316	25.001	55.792	19.493	19.2313	8.62	112.39	193.71	25.89	25.56
48 Hour Test item treated – R2	1.5	75.285	1.0013	2.2515	25.001	56.290	18.995	18.9705	8.43	109.91	189.44	25.23

 

TABLE 14. ADSORPTION COEFFICIENTS FOR LUFA 6S SOIL (1:1 RATIO) TREATED WITH TEST ITEM AT 0, 2, 4 AND 6 HOUR FOR TIER 2 TEST

Sample Code	Initial Volume of the Test Solution in Contact with the Soil Vo (mL)	Mass of Test Substance in the Test Tube at the Beginning of the Test m0 (µg)	Mass of Dry Soil Taken msoil (g)	Mass Concentration of the Substance in the Aqueous Phase at Adsorption Equilibrium Caqads (eq) (mg/L)	Test Substance in Aqueous Phase Caqads (eq) x V0 (aq) (µg)	Mass of Test Substance Adsorbed on the Soil at the Time ads ti Ms       (µg)	Content of the    Substance Adsorbed on the Soil at Adsorption Equilibrium ads Cs       (eq) (µg/g)	Kd (mL/g)	Kom (mL/g)	Koc (mL/g)	Ati     Adsorption %	Ati Average Adsorption %
2 Hour Test item treated - R1	0.6	30.0000	9.9809	0.7250	7.2500	22.750	2.2794	3.14	117.60	202.58	75.83	75.40
2 Hour Test item treated - R2	0.6	30.0000	9.9823	0.7512	7.5120	22.488	2.2528	3.00	112.36	193.55	74.96
4 Hour Test item treated - R1	0.6	30.0000	9.9849	0.6684	6.6840	23.316	2.3351	3.49	130.71	225.16	77.72	78.53
4 Hour Test item treated - R2	0.6	30.0000	9.9828	0.6202	6.2020	23.798	2.3839	3.84	143.82	247.74	79.33
6 Hour Test item treated - R1	0.6	30.0000	9.9823	0.6286	6.2860	23.714	2.3756	3.78	141.57	243.87	79.05	79.29
6 Hour Test item treated - R2	0.6	30.0000	9.9829	0.6140	6.1400	23.860	2.3901	3.89	145.69	250.97	79.53
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 1.55, OM (%) = 2.67

 

TABLE 15. ADSORPTION COEFFICIENTS FOR LUFA 6S SOIL (1:1 RATIO) AT 8 AND 24 HOUR FOR TIER 2 TEST

Sample Code	Initial Volume of the Test Solution in Contact with the Soil Vo (mL)	Mass of Test Substance in the Test Tube at the Beginning of the Test m0 (µg)	Mass of Dry Soil Taken msoil (g)	Mass Concentration of the Substance in the Aqueous Phase at Adsorption Equilibrium Caqads (eq) (mg/L)	Test Substance in    Aqueous Phase Caqads (eq) x V0 (aq) (µg)	Mass of Test Substance Adsorbed on the Soil at the Time ti M ^ads (µg) s	Content of the    Substance Adsorbed on the Soil at Adsorption Equilibrium C ^ads (eq) s (µg/g)	Kd (mL/g)	Kom (mL/g)	Koc (mL/g)	Ati     Adsorption %	Ati Average Adsorption %
8 Hour Test item treated - R1	0.6	30.0000	9.9853	0.5899	5.8990	24.101	2.4136	4.09	153.18	263.87	80.34	80.03
8 Hour Test item treated - R2	0.6	30.0000	9.9847	0.6087	6.0870	23.913	2.3950	3.93	147.19	253.55	79.71
24 Hour Test item treated - R1	0.6	30.0000	9.9762	0.5951	5.9510	24.049	2.4106	4.05	151.69	261.29	80.16	79.94
24 Hour Test item treated - R2	0.6	30.0000	9.9871	0.6087	6.0870	23.913	2.3944	3.93	147.19	253.55	79.71
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 1.55, OM (%) = 2.67

 

TABLE 16. ADSORPTION COEFFICIENTS FOR REFESOL 03-G-05 SOIL IN 1:1 RATIO AT 0, 2, 4 AND 6 HOUR FOR TIER 2 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass conc. of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated – R1	0.6	30.0000	9.9759	1.1933	11.933	18.067	1.8111	1.52	19.82	34.16	60.22	59.61
2 Hour Test item treated – R2	0.6	30.0000	9.9801	1.2300	12.300	17.700	1.7735	1.44	18.77	32.36	59.00
4 Hour Test item treated – R1	0.6	30.0000	9.9872	1.0990	10.990	19.010	1.9034	1.73	22.56	38.88	63.37	62.46
4 Hour Test item treated – R2	0.6	30.0000	9.9943	1.1535	11.535	18.465	1.8476	1.60	20.86	35.96	61.55
6 Hour Test item treated – R1	0.6	30.0000	9.9782	1.1483	11.483	18.517	1.8557	1.62	21.12	36.40	61.72	58.69
6 Hour Test item treated – R2	0.6	30.0000	9.9889	1.3306	13.306	16.694	1.6713	1.26	16.43	28.31	55.65
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 4.45, OM (%) = 7.67

 

TABLE 17. ADSORPTION COEFFICIENTS FOR REFESOL 03-G-05 SOIL IN 1:1 RATIO AT 8 AND 24 HOUR FOR TIER 2 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass conc. of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
8 Hour Test item treated R1	0.6	30.0000	9.9967	1.2195	12.195	17.805	1.7811	1.46	19.04	32.81	59.35	62.55
8 Hour Test item treated – R2	0.6	30.0000	9.9876	1.0278	10.278	19.722	1.9746	1.92	25.03	43.15	65.74
24 Hour Test item treated – R1	0.6	30.0000	9.9788	1.0676	10.676	19.324	1.9365	1.81	23.60	40.67	64.41	65.41
24 Hour Test item treated R2	0.6	30.0000	10.0008	1.0079	10.079	19.921	1.9919	1.98	25.81	44.49	66.40
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 4.45, OM (%) = 7.67

 

TABLE 18. ADSORPTION COEFFICIENTS FOR REFESOL 02-A-02 SOIL IN 1:1 RATIO AT 0 AND 2 HOUR FOR TIER 2 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated – R1	0.6	30.294	9.9718	2.4013	24.013	6.281	0.6299	0.26	14.21	24.53	20.73	20.41
2 Hour Test item treated – R2	0.6	30.294	9.9700	2.4212	24.212	6.082	0.6100	0.25	13.66	23.58	20.08
4 Hour Test item treated – R1	0.6	30.294	9.9672	2.4349	24.349	5.945	0.5965	0.24	13.11	22.64	19.62	20.42
4 Hour Test item treated – R2	0.6	30.294	9.9820	2.3867	23.867	6.427	0.6439	0.27	14.75	25.47	21.22
6 Hour Test item treated – R1	0.6	30.294	9.9765	2.0724	20.724	9.570	0.9593	0.46	25.14	43.40	31.59	33.39
6 Hour Test item treated – R2	0.6	30.294	9.9711	1.9634	19.634	10.660	1.0691	0.54	29.51	50.94	35.19
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 1.06, OM (%) = 1.83

 

TABLE 19. ADSORPTION COEFFICIENTS FOR REFESOL 02-A-02 SOIL IN 1:1 RATIO AT 8 AND 24 HOUR FOR TIER 2 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
8 Hour Test item treated – R1	0.6	30.294	9.9752	1.9602	19.602	10.692	1.0719	0.55	30.05	51.89	35.29	34.74
8 Hour Test item treated – R2	0.6	30.294	9.9704	1.9938	19.938	10.356	1.0387	0.52	28.42	49.06	34.18
24 Hour Test item treated – R1	0.6	30.294	9.9695	1.8303	18.303	11.991	1.2028	0.66	36.07	62.26	39.58	40.22
24 Hour Test item treated R2	0.6	30.294	9.9704	1.7916	17.916	12.378	1.2415	0.69	37.70	65.09	40.86
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 1.06, OM (%) = 1.83

 

TABLE 20. ADSORPTION COEFFICIENTS FOR REFESOL 04-A-02 SOIL IN 1:1 RATIO AT 2, 4 AND 6 HOUR FOR TIER 2 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated – R1	0.6	30.294	9.9681	1.4731	14.731	15.563	1.5613	1.06	21.29	36.68	51.37	50.27
2 Hour Test item treated – R2	0.6	30.294	9.9644	1.5401	15.401	14.893	1.4946	0.97	19.48	33.56	49.16
4 Hour Test item treated R1	0.6	30.294	9.9879	1.2478	12.478	17.816	1.7838	1.43	28.71	49.48	58.81	60.70
4 Hour Test item treated – R2	0.6	30.294	9.9600	1.1336	11.336	18.958	1.9034	1.68	33.73	58.13	62.58
6 Hour Test item treated – R1	0.6	30.294	9.9869	1.3379	13.379	16.915	1.6937	1.27	25.50	43.94	55.84	57.12
6 Hour Test item treated – R2	0.6	30.294	9.9606	1.2604	12.604	17.690	1.7760	1.41	28.31	48.79	58.39
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 2.89, OM (%) = 4.98

 

TABLE 21. ADSORPTION COEFFICIENTS FOR REFESOL 04-A-02 SOIL IN 1:1 RATIO AT 8 AND 24 HOUR FOR TIER 2 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
8 Hour Test item treated – R1	0.6	30.294	9.9774	1.3966	13.966	16.328	1.6365	1.17	23.49	40.48	53.90	53.40
8 Hour Test item treated – R2	0.6	30.294	9.9589	1.4270	14.270	16.024	1.6090	1.13	22.69	39.10	52.89
24 Hour Test item treated – R1	0.6	30.294	9.9838	0.8235	8.235	22.059	2.2095	2.68	53.82	92.73	72.82	73.58
24 Hour Test item treated – R2	0.6	30.294	9.9614	0.7774	7.774	22.520	2.2607	2.91	58.43	100.69	74.34
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 2.89, OM (%) = 4.98

 

TABLE 22. ADSORPTION COEFFICIENTS FOR REFESOL 05-G SOIL IN 1:1 RATIO AT 2, 4 AND 6 HOUR FOR TIER 2 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
2 Hour Test item treated – R1	0.6	30.294	9.9752	2.8298	28.298	1.996	0.2001	0.07	1.93	3.33	6.59	7.59
2 Hour Test item treated – R2	0.6	30.294	9.9670	2.7691	27.691	2.603	0.2612	0.09	2.49	4.29	8.59
4 Hour Test item treated R1	0.6	30.294	9.9609	2.7586	27.586	2.708	0.2719	0.10	2.76	4.76	8.94	9.98
4 Hour Test item treated – R2	0.6	30.294	9.9605	2.6957	26.957	3.337	0.3350	0.12	3.31	5.71	11.02
6 Hour Test item treated – R1	0.6	30.294	9.9565	2.8414	28.414	1.880	0.1888	0.07	1.93	3.33	6.21	5.57
6 Hour Test item treated – R2	0.6	30.294	9.9698	2.8801	28.801	1.493	0.1498	0.05	1.38	2.38	4.93
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 2.1, OM (%) = 3.62

 

TABLE 23. ADSORPTION COEFFICIENTS FOR REFESOL 05-G SOIL IN 1:1 RATIO AT 8 AND 24 HOUR FOR TIER 2 TEST

Sample Code	Initial volume of the test solution in contact with the soil Vo (mL)	Mass of test substance in the test tube at the beginning of the test  m0 (µg)	Mass of dry soil taken msoil (g)	Mass concentration of the substance in the aqueous phase at adsorption equilibrium Caq^ads (eq) (mg/L)	Test substance in Aqueous Phase Caq^ads (eq) x V0 (aq) (µg)	Mass of test substance adsorbed on the soil at the time ti Ms^ads(µg)	Content of the substance adsorbed on the soil at adsorption equilibrium Cs^ads (eq) (µg/g)	Kd             (mL/g)	Kom        (mL/g)	Koc          (mL/g)	Ati Adsorption %	Ati Average Adsorption %
8 Hour Test item treated – R1	0.6	30.294	9.9616	2.7397	27.397	2.897	0.2908	0.07	1.93	3.33	6.10	7.38
8 Hour Test item treated – R2	0.6	30.294	9.9689	2.6622	26.622	3.672	0.3683	0.10	2.76	4.76	8.66
24 Hour Test item treated – R1	0.6	30.294	9.9742	2.6444	26.444	3.850	0.3860	0.15	4.14	7.14	12.71	13.40
24 Hour Test item treated – R2	0.6	30.294	9.9605	2.6025	26.025	4.269	0.4286	0.16	4.42	7.62	14.09
Total aq. Vol V0 (aq) = 10 mL, Percent organic matter = OC × 1.724, OC (%) = 2.1, OM (%) = 3.62

 

Validity criteria fulfilled:

yes

Conclusions:

The adsorption behaviour of the test item was investigated in 5 different soil types. As a worst case assumption, the Koc can be considered to be 257.42 mL/g and the resulting log Koc = 2.41, taking the highest value obtained in the 5 soil types.

Executive summary:

The adsorption behaviour of the test item was investigated using the batch equilibrium method according to OECD Guideline 106, under GLP conditions. The following soil types, collected in Germany, were used: Lufa 6S (clay), Refesol 03-G-05 (Silt loam), Refesol 02- A-02 (silt loam), Refesol 04-A-02 (Loamy sand ) and Refesol 05-G (Loam). The test was conducted at constant temperature of 21ºC. For the preliminary experiments (Tier 1 test), the test item at nominal concentration of 3 mg/L in 0.01 M CaCl2 aqueous solution was tested in two different soils (Lufa 6S and Refesol 03-G-05) with soil/solution ratios of 1:1, 1:5 and 1:25 (w/v). The stability of the test substance was demonstrated. No significant adsorption of the test substance on the surface of the test vessel was firstly confirmed. The mass balance for each soil was determined as the sum of the amount of test item in the aqueous solution and the amount of test item extracted from soil and walls of the test vessel. The average mass balance was 93.70% and 93.30% for the Lufa 6S and Refesol 03-G-05 soils at 48 hour, respectively. The obtained mass balance was >90% in both soils, hence the test item was considered to be stable in the scale of the test. Both soils reached the equilibrium within 24-hour of treatment and the percent absorption of the test substance was >50% only for the soil/solution ratio of 1:1. Based on these results, the tier 2 test was conducted for the 5 soil types with equilibration time of 24 h, 1:1 (w/v) soil to solution ratio and the same weight of soil sample, volume of the aqueous phase in contact with the soil and concentration of the test substance used in tier 1. The sorption coefficients Kd, Kom and Koc were calculated for each soil at the tested concentration. The analytical method ICP-MS, validated according to Guidance SANTE/2020/12830, was used for the determination of strontium in the aqueous solutions and soil extracts. The highest values for adsorption coefficients were found for clay type soil (Lufa 6S) with Kd = 3.99 mL/g, Kom = 149.44 mL/g and Koc = 257.42 mL/g. Therefore, as a worst-case assumption, the Koc can be considered to be 257.42 mL/g and the resulting log Koc = 2.41, taking the highest value obtained in the 5 soil types.

Description of key information

Key study: Adsortion using the batch equilibrium method according to OECD 106, GLP study. The adsorption behaviour of the test item was investigated in 5 different soil types. As a worst case assumption, the Koc can be considered to be 257.42 mL/g and the resulting log Koc = 2.41, taking the highest value obtained in the 5 soil types.

Key value for chemical safety assessment

Koc at 20 °C:

257.42