1-ethyl-2-(3-methylbutyl)cyclopentanol

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:

This study was conducted between 09 January 20017 and 11 March 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Reliability 1 is assigned because the study was conducted according to OECD TG 106 in compliance with GLP, without deviations that influence the quality of the results.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

21 January 2000

Deviations:

no

GLP compliance:

yes

Type of method:

batch equilibrium method

Media:

soil

Specific details on test material used for the study:

Identification: FRET 10-0367
Batch: RDGM38757
Purity: 98.3%
Physical state / appearance: clear, colorless liquid
Expiry date: 01 June 2018
Storage conditions: approximately 4 °C, in the dark

Radiolabelling:

no

Test temperature:

25°C ± 2°C

Analytical monitoring:

yes

Remarks:

Gas chromatography

Details on sampling:

After a 24 hour adsorption period, the samples, controls and blanks were centrifuged at 6000 rpm for 30 minutes and the supernatants isolated for analysis.
An aliquot of each supernatant (15 mL) was taken and an aliquot (5 mL) of iso-octane added. The samples were then shaken for 20 minutes to extract, before allowing the phases to separate and vialling the upper, iso-octane phase for analysis

Details on matrix:

See "Any other information on materials and methods incl. tables" Table 1: Soil Classification and Characteristics

Details on test conditions:

Identification of Optimal Soil to Solution Ratio
Method
Three contrasting soil types were initially investigated using a range of nominal soil to solution ratios in order to identify the ratio at which the percentage of test item adsorbed was optimized for the determination of the distribution coefficient (Kd) and the organic carbon normalized adsorption coefficient (Koc) of the test item.

Testing used a direct method, designed to be compatible with Method 106 of the OECD Guidelines for Testing of Chemicals, 21 January 2000.

Procedure
Aliquots of soil and 0.01M calcium chloride solution were taken in FEP/ETFE (fluorinated ethylene propylene/ethylene tetrafluoroethylene) centrifuge tubes. Aliquots of 0.01M calcium chloride solution required for soil-less controls and solvent only blanks were also taken in these test vessels.
The resulting mixtures were pre-equilibrated by shaking at 25 ± 2”C overnight prior to addition of the test item.

Preparation of stock solution
An aliquot of test item (0.5015 g) was dissolved in 100 mL of acetonitrile. The stock solution was such that a nominal concentration of 5.0 mg/L was obtained when 25 µL was spiked into samples containing 25 mL of aqueous solution.

Addition of test item into samples
Relevant stock solution (25 µL) was added to all samples and soil-less controls.
Each control, sample and blank was then shaken for an adsorption period of 24 hours at 25 ± 2 ºC in the dark.
After a 24 hour adsorption period, the samples, controls and blanks were centrifuged at 6000 rpm for 30 minutes and the supernatants isolated for analysis.
The pH of all solutions was recorded.
 
Analysis of solutions
The concentration of test item in the sample solution was determined by gas chromatography (GC). The GC parameters used are presented above.
Samples
An aliquot of each supernatant (15 mL) was taken and an aliquot (5 mL) of iso-octane added. The samples were then shaken for 20 minutes to extract, before allowing the phases to separate and vialling the upper, iso-octane phase for analysis.
Standards
Duplicate standard solutions of test item were prepared in iso-octane at a nominal concentration of 15 mg/L.
Standard matrix blank
Iso-octane.

Conclusion
The percentage of test item adsorbed after equilibration at 25 ± 2 ºC for 24 hours was investigated using a number of soil to solution ratios. The results are summarized in the following table:
Summary of Influence of Soil to Solution Ratio of Percentage Adsorption

Nominal Soil to Solution Ratio Mean Percentage Test Item Adsorbed (%)
Soil Type 2 Soil Type 5 Soil Type 7
1:10 40.3 12.2 94.9
1:25 20.2 5.10 87.0
1:100 5.77 - 60.7

The experimental results indicated that a soil to solution ratio of 1:4, 1:2 and 1:50 would optimize future analytical results for soil type 2, soil type 5, and soil type 7 respectively. For the remaining two soil types (soil type 3 and soil type 4) a soil to solution ratio of 1:4 was selected for testing based on the organic carbon content of the soils.

Determination of Adsorption Equilibration Time
Method
Testing was continued using the identified optimum soil to solution ratio for each soil type to determine the adsorption equilibration time required until no further significant adsorption of the test item occurred. Testing was carried out using an indirect, parallel method.

Procedure
Aliquots of soil and 0.01M calcium chloride solution were taken in FEP/ETFE (fluorinated ethylene propylene/ethylene tetrafluoroethylene) centrifuge tubes. Aliquots of 0.01M calcium chloride solution required for soil-less controls and solvent only blanks were also taken in these test vessels.

Due to the capacity of necessary apparatus, testing was split into two groups of soil type 2, soil type 3, and soil type 4, and then soil type 5 and soil type 7. For this reason, separate control and solvent only blank preparations are presented within this section. Control solutions A to H and solvent only blank A and B were prepared and analyzed with the soil type 2, soil type 3 and soil type 4 testing. Control solutions I to P and solvent only blank C and D were prepared and analyzed with soil type 5 and soil type 7 testing.
The resulting mixtures were pre-equilibrated by shaking at 25.0 ± 2”C overnight prior to addition of the test item.

Preparation of stock solution for evaluation of soil type 2, soil type 3 and soil type 4
An aliquot of test item (0.5014 g) was dissolved in 100 mL of acetonitrile. The stock solution was such that a nominal concentration of 5.0 mg/L was obtained when 30 µL was spiked into samples containing 30 mL of aqueous solution.

Preparation of stock solution for evaluation of soil type 5 and soil type 7
An aliquot of test item (0.5043 g) was dissolved in 100 mL of acetonitrile. The stock solution was such that a nominal concentration of 5.0 mg/L was obtained when 30 µL was spiked into samples containing 30 mL of aqueous solution.

Addition of test item into samples
Relevant stock solution (30 µL) was added to all samples and soil-less controls.
Each sample was then shaken for its respective adsorption period at 25.0 ± 2 ºC, in the dark.
Duplicate soil-less controls were also removed for analysis at each adsorption equilibrium timepoint.
Solvent blanks and soil only blanks were removed with the 48 hour adsorption equilibrium timepoint samples.
After the relevant adsorption period, the samples, controls and blanks were centrifuged at 6000 rpm for 30 minutes and the supernatants isolated for analysis.
The pH of all solutions was recorded.

Analysis of solutions
The concentration of test item in the sample solution was determined by gas chromatography (GC). The GC parameters used are presented above.
Samples
An aliquot of each supernatant (15 mL) was taken and an aliquot (5 mL) of iso-octane added. The samples were then shaken for 20 minutes to extract, before allowing the phases to separate and vialling the upper, iso-octane phase for analysis.
Standards
Duplicate standard solutions of test item were prepared in iso-octane at a nominal concentration of 15 mg/L.
Standard matrix blank
Iso-octane.

Discussion
Assessing the adsorption equilibration plots which graphically display the observed adsorption properties of the test item up to an equilibration period of 48 hours; approximate adsorption equilibrium was concluded to have been achieved within 24 hours.

However, the actual calculation of adsorption kinetics has been completed using adsorption data generated within the evaluation of the desorption equilibrium time. This was since this procedure used an increased number of samples exposed to a 24 hour adsorption equilibrium time, n = 6 as opposed to n = 2 for each soil type, and thus provided a larger, potentially more statistically robust, data set. This data selection introduced no bias into the study since percentages of adsorption observed remained approximately constant.

Conclusion
The evaluation of adsorption equilibrium time indicated that an adsorption period of 24 hours was sufficient to achieve adsorption equilibrium.

Determination of Desorption Equilibration Time
Method
The desorption equilibration time required until no further significant desorption of the test item from the soil phase occurred was determined. A 24 hour adsorption equilibration period was previously determined to be sufficient for all soil types.

Testing was performed using an indirect, parallel method.

Procedure
Aliquots of soil and 0.01M calcium chloride solution were taken in FEP/ETFE (fluorinated ethylene propylene/ethylene tetrafluoroethylene) centrifuge tubes. Aliquots of 0.01M calcium chloride solution required for soil-less controls and solvent only blanks were also taken in these test vessels.
Due to the capacity of necessary apparatus, testing was split into two groups of soil type 2, soil type 3 and soil type 4, and then soil type 5 and soil type 7. For this reason, separate control and solvent only blank preparations are presented within this section. Control solutions A to C and solvent only blank A and B were prepared and analyzed with the soil type 2, soil type 3 and soil type 4 testing. Control solutions D to F and solvent only blank C and D were prepared and analyzed with soil type 5 and soil type 7 testing.
The resulting mixtures were pre-equilibrated by shaking at 25.0 ± 2 ºC overnight, prior to addition of the test item.

Preparation of stock solution for evaluation of soil type 2, soil type 3 and soil type 4
An aliquot of test item (0.5020 g) was dissolved in 100 mL of acetonitrile. The stock solution was such that a nominal concentration of 5.0 mg/L was obtained when 30 µL was spiked into samples containing 30 mL of aqueous solution.
Preparation of stock solution for evaluation of soil type 5 and soil type 7
An aliquot of test item (0.5029 g) was dissolved in 100 mL of acetonitrile. The stock solution was such that a nominal concentration of 5.0 mg/L was obtained when 30 µL was spiked into samples containing 30 mL of aqueous solution.
Addition of test item into samples
Relevant stock solution (30 µL) was added to all samples and soil-less controls.
Adsorption step
Each sample was shaken at 25.0 ± 2 ºC, in the dark, for 24 hours; the adsorption equilibration period.

Analysis at adsorption equilibrium
After the 24 hour adsorption period, the tubes were centrifuged at 6000 rpm for 30 minutes and the maximum possible volume of aqueous phase removed by decanting into a tared vessel. The mass of supernatant recovered was recorded in each case.
The pH of all solutions was recorded.
The concentration of test item in the adsorption stage sample supernatants was determined by gas chromatography (GC). The GC parameters used are presented above.
Samples
An aliquot of each supernatant (15 mL) was taken and an aliquot (5 mL) of iso-octane added. The samples were then shaken for 20 minutes to extract, before allowing the phases to separate and vialling the upper, iso-octane phase for analysis.
Standards
Duplicate standard solutions of test item were prepared in iso-octane at a nominal concentration of 15 mg/L.
Standard matrix blank
Iso-octane.

Desorption step
The volume of aqueous phase removed from all samples and soil only blanks was replaced with an approximately equal weight (volume) of 0.01M calcium chloride solution and the test vessels returned to shaking at 25.0 ± 2 ºC, in the dark, i.e. the desorption period. On completion of the required desorption equilibration period, the samples were removed for analysis.

Analysis following desorption step
On completion of the relevant desorption period, each soil sample was centrifuged at 6000 rpm for 30 minutes and an aliquot of supernatant extracted for analysis as detailed for the adsorption stage.
All soil only blanks were removed with the 48 hour desorption period samples. Each blank was centrifuged and extracted for analysis as detailed for the samples.
The pH of all solutions was recorded.

Discussion
All soil types showed rapid desorption equilibration, with an approximately equal percentage desorption observed at all timepoints. Therefore, definitive desorption kinetics (see Section 4.5) have been quantified from all timepoint data.

Conclusion
The test item was identified as having reached desorption equilibrium rapidly in the presence of all soil types.

Duration:

24 h

Initial conc. measured:

> 1.77 - < 1.82 other: mg/L

pH:

7

Remarks:

Soil Type 2: Clay Loam

Duration:

24 h

Initial conc. measured:

> 2.08 - < 2.1 other: mg/L

pH:

6.1

Remarks:

Soil Type 3: Silt Loam

Duration:

24 h

Initial conc. measured:

> 1.19 - < 1.2 other: mg/L

pH:

5.3

Remarks:

Soil Type 4: Silt Loam

Duration:

24 h

Initial conc. measured:

> 2.42 - < 2.62 other: mg/L

pH:

6.1

Remarks:

Soil Type 5: Loamy Sand

Duration:

24 h

Initial conc. measured:

> 1.2 - < 1.22 other: mg/L

pH:

3.3

Remarks:

Soil Type 7: Loamy Sand

Duration:

24 h

Conc. of adsorbed test mat.:

0.997 other: mg/L

pH:

7

Temp.:

25 °C

Remarks:

Soil Type 2: Clay Loam

Duration:

24 h

Conc. of adsorbed test mat.:

1.2 other: m/L

pH:

6.3

Temp.:

25 °C

Remarks:

Soil Type 3: Silt Loam

Duration:

24 h

Conc. of adsorbed test mat.:

0.857 other: mg/L

pH:

5.5

Temp.:

25 °C

Remarks:

Soil Type 4: Silt Loam

Duration:

24 h

Conc. of adsorbed test mat.:

1.35 other: mg/L

pH:

3.4

Temp.:

25 °C

Remarks:

Soil Type 5: Loamy Sand

Duration:

24 h

Conc. of adsorbed test mat.:

0.84 other: mg/L

pH:

3.4

Temp.:

25 °C

Remarks:

Soil Type 7: Loamy Sand

Type:

log Koc

Value:

> 2.32 - < 2.36

pH:

7.2

Temp.:

25 °C

Matrix:

Soil type 2 : Clay Loam

% Org. carbon:

3.78

Type:

log Koc

Value:

> 2.35 - < 2.4 dimensionless

pH:

6

Temp.:

25 °C

Matrix:

Soil Type 3: Silt Loam

% Org. carbon:

2.49

Type:

log Koc

Value:

> 2.52 - < 2.54 dimensionless

pH:

4.8

Temp.:

25 °C

Matrix:

Soil Type 4: Silt Loam

% Org. carbon:

3.82

Type:

log Koc

Value:

> 2.28 - < 2.38 dimensionless

pH:

5.6

Temp.:

25 °C

Matrix:

Soil Type 5: Loamy Sand

% Org. carbon:

0.91

Type:

log Koc

Value:

> 2.71 - < 2.84 dimensionless

pH:

3.1

Temp.:

25 °C

Matrix:

Soil Type 7: Loamy Sand

% Org. carbon:

25.5

Details on results (HPLC method):

I

Adsorption and desorption constants:

The distribution coefficient (Kd) and the organic carbon normalized adsorption coefficient (Koc) results are summarized in the following table:

Soil Type Mean Distribution Mean Organic Carbon Normalized Log10 Koc
Coefficient for Adsorption(Kd, cm3/g) Adsorption Coefficient (Koc, cm3/g)
2 8.33 220 2.34
3 5.76 231 2.36
4 13.0 341 2.53
5 1.88 206 2.31
7 180 705 2.85

Overall Kd range: 1.88 to 180 cm3/g
Overall Koc range: 206 to 705 cm3/g
log10 Koc range: 2.31 to 2.85

The distribution coefficient (K_d) and the organic carbon normalized adsorption coefficient (K_oc) at adsorption equilibrium were determined for five different soil types, at 25.0 ± 2 ºC. The results are shown in the following table: 

Soil Type^*	Mean Distribution  Coefficient for Adsorption (Kd,cm^3/g)	Mean Organic Carbon Normalized Adsorption Coefficient (Koc, cm^3/g)	Log10Koc
2	8.33	220	2.34
3	5.76	231	2.36
4	13.0	341	2.53
5	1.88	206	2.31
7	180	705	2.85

Overall K_drange: 1.88 to 180 cm³/g

Overall K_ocrange: 206 to 705 cm³/g
log₁₀K_ocrange:     2.31 to 2.85

The apparent desorption coefficient (K_des) and the organic carbon normalized apparent desorption coefficient at desorption equilibrium were determined for five different soil types at 25.0 ± 2 ºC. The results are shown in the following table: 

  

Soil Type[1]	Observed Mean Percentage Desorption (%)	Mean Apparent Desorption Coefficient (Kdesin cm^3/g)	Mean Organic Carbon Normalized Desorption Coefficient (Kdes (oc)in cm^3/g)	Log10Organic Carbon Normalized Desorption Coefficient (Kdes (oc))
2	25.8	13.5	358	2.55
3	31.2	9.12	366	2.56
4	18.0	18.9	494	2.69
5	37.4	3.39	372	2.57
7	19.5	235	921	2.96

 

Overall K_desrange: 3.39 to 235 cm³/g
Overall organic carbon normalized K_desrange: 358 to 921 cm³/g

Overall log₁₀organic carbon normalized K_desrange: 2.55 to 2.96

From the linearized Freundlich adsorption plots, the Freundlich adsorption coefficient was determined for each soil type. The results and the coefficient of determination (r²) of each plot are shown in the following table:

 

Soil Type[1]	Intercept	Freundlich Adsorption Coefficient K  (µg^1-1/n(cm^3)^1/ng^-1)	Freundlich Exponent	r^2	Organic Carbon Normalized Adsorption Coefficient, K (µg^1-1/n(cm^3)^1/ng^-1)
2	0.942	8.75	0.897	0.9998	231
3	0.769	5.88	0.952	0.9998	236
4	1.13	13.3	0.949	>0.9999	349
5	0.337	2.17	0.901	>0.9999	239
7	2.31	202	0.901	0.9988	790

 

Conclusion

The Freundlich adsorption coefficient at adsorption equilibrium andat 25 ± 2°Chas been determined for five soil types. The results are summarized in the following table:

  

Soil Type^*	Freundlich Adsorption Coefficient K  (µg^1-1/n(cm^3)^1/ng^-1)	Freundlich Exponent	r^2	Organic Carbon Normalized Adsorption Coefficient, K (µg^1-1/n(cm^3)^1/ng^-1)
2	8.75	0.897	0.9998	231
3	5.88	0.952	0.9998	236
4	13.3	0.949	>0.9999	349
5	2.17	0.901	>0.9999	239
7	202	0.901	0.9988	790

 

From the linearized Freundlich desorption plots, the Freundlich desorption coefficient was determined for each soil type. The results and the coefficient of determination (r²) of each plot are shown in the following table:

Soil Type*	Intercept	Freundlich Desorption Coefficient K (µg^1-1/n(cm^3)^1/ng^-1)	Freundlich Exponent	r^2	Organic Carbon Normalized Desorption Coefficient, K (µg^1-1/n(cm^3)^1/ng^-1)
2	0.575	3.76	0.992	>0.9999	99.3
3	0.498	3.15	0.994	0.9999	126
4	0.515	3.27	0.988	0.9999	85.7
5	0.118	1.31	1.01	0.9997	144
7	1.72	52.2	0.999	>0.9999	204

 

 Conclusion

The Freundlich desorption coefficient at desorption equilibrium and 25 ± 2 °C has been determined for five soil types. The results are summarized in the following table:

Table62

Soil Type^*	Freundlich Desorption Coefficient K (µg^1-1/n(cm^3)^1/ng^-1)	Freundlich Exponent	r^2	Organic Carbon Normalized Desorption Coefficient, K (µg^1-1/n(cm^3)^1/ng^-1)
2	3.76	0.992	>0.9999	99.3
3	3.15	0.994	0.9999	126
4	3.27	0.988	0.9999	85.7
5	1.31	1.01	0.9997	144
7	52.2	0.999	>0.9999	204

 

Validity criteria fulfilled:

yes

Conclusions:

The adsorption and desorption behaviour of FRET 10-0367 has been determined with soils of differing pH, organic carbon content and textural classification, using a batch equilibrium method. The experimental procedures were designed to be compatible with Method 106 of the OECD Guidelines for Testing of Chemicals, 21 January 2000.
Adsorption Coefficients. The distribution coefficient (Kd) and organic carbon normalized adsorption coefficient (Koc) were determined at adsorption equilibrium for five different soil types at 25.0 ± 2 °C.
Overall Kd range: 1.88 to 180 cm3/g Overall Koc range: 206 to 705 cm3/g log10 Koc range: 2.31 to 2.85

Desorption Coefficients. The mean apparent desorption coefficient (Kdes) and organic carbon normalized desorption coefficient (Kdes (oc)) were determined at desorption equilibrium for five different soil types at 25.0 ± 2 °C.
Overall Kdes range: 3.39 to 235 cm3/g Overall Kdes (oc) range: 358 to 921 cm3/g Overall log10 Kdes (oc) range: 2.55 to 2.96

Adsorption Isotherms. From the linearized Freundlich adsorption plots generated evaluating five different test item concentrations, at 25 ± 2 °C, the Freundlich adsorption coefficient at adsorption equilibrium was determined for each soil type.
Desorption Isotherms. From the linearized Freundlich desorption plots generated evaluating five different test item concentrations, at 25 ± 2 °C, the Freundlich desorption coefficient at desorption equilibrium was determined for each soil type.

Executive summary:

The adsorption and desorption behaviourofFRET 10-0367 has been determined with soils of differing pH, organic carbon content and textural classification,using a batch equilibrium method. The experimental procedures were designed to be compatible with Method 106 of the OECD Guidelines for Testing of Chemicals, 21 January 2000. 

Adsorption Coefficients. The distribution coefficient (K_d) and organic carbon normalized adsorption coefficient (K_oc) were determined at adsorption equilibrium for five different soil types at 25.0 ± 2°C. The results are shown in the following table:

Soil Type[1]	Mean Distribution  Coefficient for Adsorption (Kd,cm^3/g)	Mean Organic Carbon Normalized Adsorption Coefficient (Koc, cm^3/g)	Log10Koc
2	8.33	220	2.34
3	5.76	231	2.36
4	13.0	341	2.53
5	1.88	206	2.31
7	180	705	2.85

Overall K_drange: 1.88 to 180 cm³/g                   Overall K_ocrange: 206 to 705 cm³/g
log₁₀K_ocrange:     2.31 to 2.85                           

           

Desorption Coefficients. The mean apparent desorption coefficient (K_des) and organic carbon normalized desorption coefficient (K_{des (oc)}) were determined at desorption equilibrium for five different soil types at 25.0 ± 2°C. The results are shown in the following table:

 

Soil Type*	Observed Mean Percentage Desorption (%)	Mean Apparent Desorption Coefficient (Kdesin cm^3/g)	Mean Organic Carbon Normalized Desorption Coefficient (Kdes (oc)in cm^3/g)	Log10Organic Carbon Normalized Desorption Coefficient (Kdes (oc))
2	25.8	13.5	358	2.55
3	31.2	9.12	366	2.56
4	18.0	18.9	494	2.69
5	37.4	3.39	372	2.57
7	19.5	235	921	2.96

Overall K_desrange: 3.39 to 235 cm³/g                Overall K_{des (oc)}range: 358 to 921 cm³/g

Overall log₁₀K_{des (oc)}range: 2.55 to 2.96

 

Adsorption Isotherms. From the linearized Freundlich adsorption plots generated evaluating five different test item concentrations, at 25 ± 2°C, the Freundlich adsorption coefficient at adsorption equilibrium was determined for each soil type. The results and the coefficient of determination (r²) of each plot are shown in the following table:

 

Soil Type^*	Freundlich Adsorption Coefficient K  (µg^1-1/n(cm^3)^1/ng^-1)	Freundlich Exponent	r^2	Organic Carbon Normalized Adsorption Coefficient, K (µg^1-1/n(cm^3)^1/ng^-1)
2	8.75	0.897	0.9998	231
3	5.88	0.952	0.9998	236
4	13.3	0.949	>0.9999	349
5	2.17	0.901	>0.9999	239
7	202	0.901	0.9988	790

 

Desorption Isotherms. From the linearized Freundlich desorption plots generated evaluating five different test item concentrations, at 25 ± 2°C, the Freundlich desorption coefficient at desorption equilibrium was determined for each soil type. The results and the coefficient of determination (r²) of each plot are shown in the following table:

 

Soil Type^*	Freundlich Desorption Coefficient K (µg^1-1/n(cm^3)^1/ng^-1)	Freundlich Exponent	r^2	Organic Carbon Normalized Desorption Coefficient, K (µg^1-1/n(cm^3)^1/ng^-1)
2	3.76	0.992	>0.9999	99.3
3	3.15	0.994	0.9999	126
4	3.27	0.988	0.9999	85.7
5	1.31	1.01	0.9997	144
7	52.2	0.999	>0.9999	204

 

*see "Any other informatioin on Materials and Methods"

Description of key information

The adsorption and desorption behaviour of FRET 10-0367 has been determined with soils of differing pH, organic carbon content and textural classification, using a batch equilibrium method.  The experimental procedures were designed to be compatible with Method 106 of the OECD Guidelines for Testing of Chemicals, 21 January 2000.  

Adsorption Coefficients.  The distribution coefficient (Kd) and organic carbon normalized adsorption coefficient (Koc) were determined at adsorption equilibrium for five different soil types at 25.0 ± 2 °C.

Overall Kd range:  1.88 to 180 cm3/g       Overall Koc range: 206 to 705 cm3/g       log10 Koc range:      2.31 to 2.85

Desorption Coefficients.  The mean apparent desorption coefficient (Kdes) and organic carbon normalized desorption coefficient (Kdes (oc)) were determined at desorption equilibrium for five different soil types at 25.0 ± 2 °C.

Overall Kdes range:  3.39 to 235 cm3/g       Overall Kdes (oc) range: 358 to 921 cm3/g       Overall log10 Kdes (oc) range: 2.55 to 2.96

Adsorption Isotherms.  From the linearized Freundlich adsorption plots generated evaluating five different test item concentrations, at 25 ± 2 °C, the Freundlich adsorption coefficient at adsorption equilibrium was determined for each soil type.

Desorption Isotherms.  From the linearized Freundlich desorption plots generated evaluating five different test item concentrations, at 25 ± 2 °C, the Freundlich desorption coefficient at desorption equilibrium was determined for each soil type.