Alcohols, C20-22, reaction products with phosphorus oxide (P2O5)

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February 20, 2020 - September 24, 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

as revised in 1997

Deviations:

yes

Remarks:

Deviations are not critical and have no impact on the results presented in this report.

GLP compliance:

yes (incl. QA statement)

Type of method:

batch equilibrium method

Media:

soil

Test material

Test material information

Constituent 1

Test material form:

solid: flakes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch number of test material: 190604011722
- Expiration date of the lot/batch: June 3 rd , 2022
- Purity test date: 2019/06/14

Radiolabelling:

no

Study design

Test temperature:

All experiments were performed at laboratory ambient temperature (temperature between 20°C and 25°C). The temperature was recorded during the experiments.

Batch equilibrium or other method

Analytical monitoring:

yes

Details on sampling:

Adsorption Kinetic:
The samples were collected sequentially at 0.25, 0.50, 1, 2 and 4 hours for five soils.

Tier 3 of OECD 106 test was not conduct in that study (Freundlich adsorption isotherm and Desorption kinetic).

Matrix properties

Matrix properties 1

Matrix no.:

#5

Matrix type:

clay

% Clay:

41.2

% Org. carbon:

1.7

pH:

7.3

CEC:

23.2 meq/100 g soil d.w.

Matrix properties 2

Matrix no.:

#4

Matrix type:

loam

% Clay:

25.9

% Org. carbon:

1.95

pH:

7.4

CEC:

21.2 meq/100 g soil d.w.

Matrix properties 3

Matrix no.:

#3

Matrix type:

sandy loam

% Clay:

7.3

% Org. carbon:

0.65

pH:

6.1

CEC:

6.8 meq/100 g soil d.w.

Matrix properties 4

Matrix no.:

#2

Matrix type:

sandy loam

% Clay:

8.9

% Org. carbon:

1.61

pH:

5.6

CEC:

8.5 meq/100 g soil d.w.

Matrix properties 5

Matrix no.:

#1

Matrix type:

loamy sand

% Clay:

4.1

% Org. carbon:

0.63

pH:

4.7

CEC:

3.7 meq/100 g soil d.w.

Details on matrix:

The supplier of soils is LUFA SPEYER located in Germany.
Sampling date:
#1 = standard soil type n° 2.1: 2019/10/15
#2 = standard soil type n° 2.2: 2019/10/07
#3 = standard soil type n° 2.3: 2019/10/07
#4 = standard soil type n° 2.4: 2019/10/16
#5 = standard soil type n° 6S: 2019/10/21
Sampling site: Country/ State/ Community
Soil 2.1: Germany/ Rheinland- Pfalz/ Dudenhofen
Soil 2.2: Germany/ Rheinland- Pfalz/ Hanhofen
Soil 2.3: Germany/ Rheinland- Pfalz/ Offenbach
Soil 2.4: Germany/ Rheinland- Pfalz/ Leimersheim
Soil 6S: Germany/ Rheinland- Pfalz/ Siebeldingen
Plants:
-Soils 2.1, 2.3 and 6S: sampling year (2019) uncultivated and former years 2018, 2017, 2016, 2015: uncultivated
- Soil 2.2: sampling year (2019) meadow and former years 22018, 2017, 2016, 2015: meadow
- Soil 2.4: sampling year (2019) meadow with apple trees and former years 22018, 2017, 2016, 2015: meadow with apple trees
Fertilization: all soils:
No organic fertilization and none fertilization in 2019, 2018, 2017, 2016 and 2015
Pesticides: all soils
sampling years and 4 former years: none
More details in the attached report (Annex 7.1 Study plan appendix 2).

Details on test conditions:

Tier 1- Preliminary study

The aim of this Tier 1 was to determine the Kd value at equilibrium in order to select the appropriate soil:solution ratio for the Tier -2.
All experiments were performed at laboratory ambient temperature (temperature between 20°C and 25°C). The temperature was recorded during the experiments.
Selection of optimal soil/solution ratios
Two soil types (standard soil type no. 2.1 (Loamy Sand) - 6S (Clay)) and three soil/solution ratios were used.
The soil/solution ratios are as follows:
- 10 g soil and 50 mL aqueous solution of the test item (ratio 1/5),
- 2 g soil and 50 mL aqueous solution of the test item (ratio 1/25)
- 0.5 g soil and 50 mL aqueous solution of the test item (ratio 1/100),

The absolute mass of soil and volume of aqueous solution corresponding to these ratios can be different with respect to laboratory equipments.

STUDY DESIGN:
The soil samples was equilibrated by shaking with a minimum volume of 45 mL of 0.01 M CaCl2 overnight (12h) before the day of experiment. Afterwards, a certain volume of the stock solution of the test item was added in order to adjust the final volume at 50 mL. This volume of the stock solution added should preferably result in an initial concentration of the test item being with the soil (C0: 10 mg/L (initial concentration)) at least two orders of magnitude higher than the detection limit of the analytical method.
The mixture was shaken until adsorption equilibrium was reached. The samples were collected sequentially over a 24 h period of mixing (1, 4, 24 h). Then, the samples were separated by centrifugation, the aqueous phase was analysed according to the validated method.

One control sample with only the test item in 0.01 M CaCl2 solution (no soil) was subjected to precisely the same steps, in order to check the stability of the test item in CaCl2 solution and its possible adsorption on the surfaces of the tests vessels.
A blank run per soil with the same amount of soil and total volume of 50 mL 0.01 M CaCl2 solution (without test item) was subjected to the same procedure. This serves as a background control during the analysis to detect interfering compounds.

The pH of the aqueous phase was measured before and after contact with the soil.

All the experiments, including controls and blanks were performed in duplicate.

The mass balance was performed on both soils and for one soil/solution ratio 1:5 (w:v) after the ratio-finding experiment is completed (measurement of depletion in solution more than 20% at equilibrium). After 24h of equilibrium, the phases were separated by centrifugation and the test item concentration in the aqueous phase was determined. The amount of test item absorbed to the soil was measured after one extraction with a mixture of solvents (Hexan/Aceton (50:50)(v:v).Then, the extracts were quantified according to the validated method by GC/FID. The data was calculated with the calibration curve using for the chemical analysis of test item in aqueous phase.

The quantity of test item in the soil and aqueous phase was determined and the mass balance was calculated. If the mass balance of the test item is less than 90%, the test item is considered to be unstable in the time scale of test which will have to be taken into account for the following tests.

The percentage adsorption was calculated at each time on the basis of the nominal initial concentration and the measured concentration at the sampling time corrected for the value of the blank if relevant. Plots of the percentage adsorption versus time were performed in order to estimate the achievement of equilibrium plateau. The Kd value at equilibrium was also calculated. Based on this Kd value, appropriate soil/solution ratios was selected, so the percentage adsorption reaches above 20 %.

Tier 2- Adsorption kinetics at one concentration

The aim of Tier 2 was to determine the distribution coefficient Kd value at equilibrium, as well as the organic carbon normalized adsorption coefficient Koc and the logarithm based 10 of Koc (logKoc) for the five soils and for C20 Alcohol and C22 Alcohol.

All experiments were performed at laboratory ambient temperature (temperature between 20°C and 25°C). The temperature was recorded during the experiments.

Five soil types and one soil/solution ratio were used. The supplier of soils is LUFA SPEYER located in Germany.

The soil/solution ratio was as follow:
- 0.5 g soil and 50 mL aqueous solution of the test item (ratio 1/100),

STUDY DESIGN
The soil samples were equilibrated by shaking with a minimum volume of 45 mL of 0.01 M CaCl2 overnight (12h) before the day of experiment. Following pre-equilibration, the samples with and without soil were spiked with the test item at a nominal concentration of 10 mg/L and shaken for 4 hours until adsorption equilibrium was reached. The samples were collected sequentially at 0.25, 0.50, 1, 2 and 4 hours.

Then, the samples were separated by centrifugation and then, the aqueous phase was analysed according to the validated method by GC/FID.
One control sample with only the test item in 0.01 M CaCl2 solution (no soil) was subjected to precisely the same steps, in order to check the stability of the test item in CaCl2 solution and its possible adsorption on the surfaces of the tests vessels.
A blank run per soil with the same amount of soil and total volume of 50 mL 0.01 M CaCl2 solution (without test item) was subjected to the same procedure. This serves as a background control during the analysis to detect interfering compounds.

The pH of the aqueous phase was measured before and after contact with the soil.

All the experiments, including controls and blanks were performed in duplicate.

The percentage adsorption was calculated at each time on the basis of the nominal initial concentration and the measured concentration at the sampling time corrected for the value of the blank if relevant. Plots of the percentage adsorption versus time were performed in order to estimate the achievement of equilibrium plateau. The distribution coefficient Kd value at equilibrium, as well as the organic carbon normalized adsorption coefficient Koc (for non-polar organic chemicals) were also calculated.

Duration of adsorption equilibration

Duration of adsorption equilibration 1

Sample No.:

#5

Duration:

4 h

Initial conc. measured:

>= 3.15 - <= 3.69 other: µg/cm3

pH:

7.29

Remarks:

mean concentrations (ti) (aqueous phase) C20 Alcohol (3.69) and C22 Alcohol (3.15)

Duration of adsorption equilibration 2

Sample No.:

#4

Duration:

4 h

Initial conc. measured:

>= 2.55 - <= 2.79 other: µg/cm3

pH:

7.43

Remarks:

mean concentrations (ti) (aqueous phase) C20 Alcohol (2.79) and C22 Alcohol

Duration of adsorption equilibration 3

Sample No.:

#3

Duration:

4 h

Initial conc. measured:

>= 2.84 - <= 2.89 other: µg/cm3

pH:

7.16

Remarks:

mean (ti) concentrations (aqueous phase) C20 Alcohol (2.84) and C22 Alcohol (2.89)

Duration of adsorption equilibration 4

Sample No.:

#1

Duration:

4 h

Initial conc. measured:

>= 2.41 - <= 2.81 other: µg/cm3

pH:

7.16

Remarks:

mean (ti) concentrations (aqueous phase) C20 Alcohol (2.81) C22 Alcohol (2.41)

Duration of adsorption equilibration 5

Sample No.:

#2

Duration:

4 h

Initial conc. measured:

>= 3.05 - <= 3.6 other: µg/cm3

pH:

7.11

Remarks:

mean (ti) concentrations (aqueous phase) C20 Alcohol (3.05) and C22 Alcohol (3.60)

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Key result

Type:

log Koc

Value:

>= 4.1 - <= 4.69

Temp.:

20 °C

% Org. carbon:

>= 0.63 - <= 1.95

Adsorption coefficient 2

Key result

Type:

Koc

Value:

>= 12 472 - <= 49 400 dimensionless

Temp.:

20 °C

% Org. carbon:

>= 0.63 - <= 1.95

Adsorption coefficient 3

Key result

Type:

Kd

Value:

>= 243.2 - <= 321.1 other: cm3/g

Temp.:

20 °C

% Org. carbon:

>= 0.63 - <= 1.95

Results: Batch equilibrium or other method

Adsorption and desorption constants:

See in tables below (other information on results) and in the report attached

Recovery of test material:

See in tables below (other information on results) and in the report attached

Transformation products:

no

Details on results (Batch equilibrium method):

See in tables below (other information on results and overall remarks) and in the report attached.
The relative homogeneity of the results between the different components of the test item “Reaction products between C20/22 (even numbered) alcohol and phosphoric anhydride suggest that the end points determined at this step for each compound can be extrapolate to the test Item itself and those for all the soils.

The Log Koc range of the Reaction products between C20/22 (even numbered) alcohol and phosphoric anhydride is 4.12 to 4.67 depending on the soil.
According the OECD 106 guideline, in general chemicals with Kd ≤ 1 cm3.g-1 are considered to be qualitatively mobile. Whatever the type of soil, the Kd is > 1 cm3.g-1 for both compounds. As C20 Alcohol and C22 Alcohol are relevant and representative constituents of test item. Therefore, the test item is not considered to be qualitatively mobile.

Any other information on results incl. tables

Adsorption Kinetic

The tables below summarize the results of Kd, Koc and Log Koc for the five soils

Matrice	Soil 6S (Clay)				Soil 2.1 (Sand)
	Kd (cm3.g-1)	% OC	Koc	Log Koc	Kd (cm3.g-1)	% OC	Koc	Log Koc
C20 Alcohol	228.5	1.70	13441	4.13	207.1	0.63	32872	4.52
C22 Alcohol	278.5	1.70	16382	4.21	262.0	0.63	41587	4.62

 

Matrice	Soil 2.2 (Loamy sand)				Soil 2.3 (Sandy loam)
	Kd (cm3.g-1)	% OC	Koc	Log Koc	Kd (cm3.g-1)	% OC	Koc	Log Koc
C20 Alcohol	248.7	1.61	15447	4.19	282.2	0.65	43415	4.64
C22 Alcohol	317.1	1.61	19696	4.29	321.1	0.65	49400	4.69

 

Matrice	Soil 2.4 (Loamy )
	Kd (cm3.g-1)	% OC	Koc	Log Koc
C20 Alcohol	243.2	1.95	12472	4.10
C22 Alcohol	262.4	1.95	13456	4.13

 

Whatever the kind of soils with a soil:solution ratio 1:100 (very low), both compounds were strongly adsorbed the soil after 0.25 hour of exposure. During the kinetic, the percentage of adsorption is stable for both compounds.

Kinetic curves were established in order to define the distribution coefficient K_d and to determinate the organic carbon normalized adsorption coefficient K_oc for C20 Alcohol and C22 Alcohol for different kind of soils.

In addition, the relative homogeneity of the results between the different components of the test item “Reaction products between C20/22 ‘even numbered) alcohol and phosphoric anhydride suggest that the end points determined at this step for each compound can be extrapolate to the test Item itself and those for all the soils.

The Log K_oc range of the Reaction products between C20/22 (even numbered) alcohol and phosphoric anhydride is 4.12 to 4.67 depending on the soil.

According the OECD 106 guideline, in general chemicals with K_d ≤ 1 cm3.g-1 are considered to be qualitatively mobile. Whatever the type of soil, the Kd is > 1 cm3.g-1 for both compounds. As C20 Alcohol and C22 Alcohol are relevant and representative constituents of test item. Therefore, the test item is not considered to be qualitatively mobile.

The mobility classification was developed by FAO in order to describe the compound’s sorption using Koc values. (FAO, 2000; USEPA, 2006).

According to the FAO Mobility classification based on Koc, a mobility classification of test item can be performed. The test item is considered to be hardly mobile in the following soil texture (USDA): clay, sandy loam, loamy sand, and loam.

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Whatever the kind of soils with a soil:solution ratio 1:100 (very low), both compounds were strongly adsorbed the soil after 0.25 hour of exposure. During the kinetic, the percentage of adsorption is stable for both compounds.
Kinetic curves were established in order to define the distribution coefficient Kd and to determinate the organic carbon normalized adsorption coefficient Koc for C20 Alcohol and C22 Alcohol for different kind of soils.

In addition, the relative homogeneity of the results between the different components of the test item “Reaction products between C20/22 ‘even numbered) alcohol and phosphoric anhydride suggest that the end points determined at this step for each compound can be extrapolate to the test Item itself and those for all the soils.
The Log Koc range of the Reaction products between C20/22 (even numbered) alcohol and phosphoric anhydride is 4.12 to 4.67 depending on the soil.

According the OECD 106 guideline, in general chemicals with Kd ≤ 1 cm3.g-1 are considered to be qualitatively mobile. Whatever the type of soil, the Kd is > 1 cm3.g-1 for both compounds. As C20 Alcohol and C22 Alcohol are relevant and representative constituents of test item. Therefore, the test item is not considered to be qualitatively mobile.

According to the FAO Mobility classification based on Koc, a mobility classification of test item can be performed. The test item is considered to be hardly mobile in the following soil texture (USDA): clay, sandy loam, loamy sand, and loam.

Executive summary:

The aim of this study was to estimate the adsorption/desorption behaviour of the test item “acetalization product between glucose and C20/22 (even numbered) – alcohol” on soils.

As the test item is an UVCB composed by different chemical structures, the experimentations were performed on one kind of classes of relevant and representative constituents (Alcohol) contained in the test item in agreement with the sponsor. These compounds are presented hereafter: 

Compound to quantify	Kind of classes of compound
C20 Alcohol	Alcohol
C22 Alcohol	Alcohol

The results of this study are summarised below:

Validation of the GC/FID method for determination of C20 Alcohol and C22 Alcohol in the aqueous phase

The method was validated with regard to specificity, linearity, precision and accuracy (recovery rate).

Specificity:No interference was detected at the retention time of C20 Alcohol and C22 Alcohol, in GC/FID in blank matrix samples (soil 6S in solution with 0.01 M CaCl2) extracted with ethyl acetate (the retention times of C20 Alcohol and C22 Alcohol were identified with the analytical reference item).

Linearity: Linearity (response function) was studied by carrying out 10 calibration spots with single determination, over a concentration range from 1.4 to 240 mg/L for the compounds C20 Alcohol and C22 Alcohol. A linear regression and its correlation coefficient were calculated. Both calibrations were found to be linear, with a correlation coefficient (r) of 0.99 or greater.

Precision and accuracy: Precision and accuracy were studied by spiking 2 * 5 blank matrix samples at 2 fortification levels (LOQ: 0.15 mg/L and 10 mg/L) for the compounds C20 Alcohol and C22 Alcohol. Precision was assessed through RSD calculations and Accuracy was assessed through mean recovery calculations. For C20 Alcohol, Mean recovery rate were 98.67 % (n = 10) with a RSD_r of 5.053% and with RSD_R of 12.36% at 0.15 mg/L and 91.80 % (n=10) with a RSDr of 5.911 % and with RSD_R of 6.868% at 10 mg/L. For C22 Alcohol, Mean recovery rate were 97.47% (n = 10) with a RSD_r of 5.496% and with RSD_R of 5.496% at 0.15 mg/L and 87.00 % (n=10) with a RSDr of 7.379 % and with RSD_R of 10.42% at 10 mg/L.

Conclusion: This analytical method for determination of C20 Alcohol and C22 Alcohol in aqueous phase was successfully validated and was fit to purpose.

Adsorption-Desorption using a batch equilibrium method on the test item “Reaction products between C20/22 (even numbered) alcohol and phosphoric anhydride

The adsorption/desorption characteristics of C20 Alcohol and C22 Alcohol were studied in five soils:

• Loamy Sand [pH 4.7; organic carbon 0.63 %],


• Sandy Loam [pH 5.6; organic carbon 1.61 %],


• Sandy loam [pH 7.3; organic carbon 0.65 %],


• Loam [pH 7.4; organic carbon 1.95%]


• Clay [pH 7.3; organic carbon 1.70 %].

Adsorption Kinetic

The adsorption phase of the study was carried out at a nomimal concentration of 10 mg/L with a soil/solution ratio 1:100. The samples were collected sequentially at 0.25, 0.50, 1, 2 and 4 hours for five soils.  The test soils were equilibrated overnight before the day of experiment at ambient temperature (temperature between 20°C and 25 °C). The equilibrating solution used was 0.01 M CaCl2 solution with soil solution ratio of 1:100 for the five soils. The mixtures were separated by centrifugation and the aqueous phases were extracted with Ethyl acetate solvent. The organic phases were evaporated to dryness under nitrogen flux, the silylation reagents were added to the extracts and the supernatants were analysed by GC/FID.

All the experiments were performed in duplicate at laboratory ambient temperature (temperature between 20°C and 25°C).

Whatever the kind of soils with a soil:solution ratio 1:100 (very low), both compounds were strongly adsorbed the soil after 0.25 hour of exposure. During the kinetic, the percentage of adsorption is stable for both compounds

Kinetic curves were established in order to define the distribution coefficient K_d and to determinate the organic carbon normalized adsorption coefficient K_oc for C20 Alcohol and C22 Alcohol for different kind of soils.

The tables (below) summarize the results of K_d ,K_oc and Log K_oc for the kind of soils:

Matrice	Soil 6S (Clay)				Soil 2.1 (Sand)
	Kd (cm3.g-1)	% OC	Koc	Log Koc	Kd (cm3.g-1)	% OC	Koc	Log Koc
C20 Alcohol	228.5	1.70	13441	4.13	207.1	0.63	32872	4.52
C22 Alcohol	278.5	1.70	16382	4.21	262.0	0.63	41587	4.62

 

Matrice	Soil 2.2 (Loamy sand)				Soil 2.3 (Sandy loam)
	Kd (cm3.g-1)	% OC	Koc	Log Koc	Kd (cm3.g-1)	% OC	Koc	Log Koc
C20 Alcohol	248.7	1.61	15447	4.19	282.2	0.65	43415	4.64
C22 Alcohol	317.1	1.61	19696	4.29	321.1	0.65	49400	4.69

Matrice	Soil 2.4 (Loamy )
	Kd (cm3.g-1)	% OC	Koc	Log Koc
C20 Alcohol	243.2	1.95	12472	4.10
C22 Alcohol	262.4	1.95	13456	4.13

In addition, the relative homogeneity of the results between the different components of the test item “Reaction products between C20/22 (even numbered) alcohol and phosphoric anhydride suggest that the end points determined at this step for each compound can be extrapolate to the test Item itself and those for all the soils.

The Log K_oc range of the Reaction products between C20/22 (even numbered) alcohol and phosphoric anhydride is 4.12 to 4.67 depending on the soil.

According the OECD 106 guideline, in general chemicals with K_d ≤ 1 cm3.g-1 are considered to be qualitatively mobile. Whatever the type of soil, the Kd is > 1 cm3.g-1 for both compounds. As C20 Alcohol and C22 Alcohol are relevant and representative constituents of test item. Therefore, the test item is not considered to be qualitatively mobile.

The mobility classification was developed by FAO in order to describe the compound’s sorption using Koc values. (FAO, 2000; USEPA, 2006).

According to the FAO Mobility classification based on Koc, a mobility classification of test item can be performed. The test item is considered to be hardly mobile in the following soil texture (USDA): clay, sandy loam, loamy sand, and loam.