Benzenediamine, ar-methyl-, polymer with 2-methyloxirane and oxirane

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:

from 2021-0125 to 2021-03-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.18 (Adsorption / Desorption Using a Batch Equilibrium Method)

Qualifier:

according to guideline

Guideline:

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

Principles of method if other than guideline:

The Freundlich adsorption isotherm was not determined. The desorption behavior of the test item was not investigated. These deviations from the guideline are on request of the sponsor.
The extraction efficiency of the soil extraction method was lower than 90%. Despite extensive method development for the extraction, this efficiency could not be optimized.
This deviation is considered to have no impact on the quality and integrity of the study.

GLP compliance:

yes (incl. QA statement)

Type of method:

batch equilibrium method

Media:

soil

Specific details on test material used for the study:

Three components, o-TDA-1EO-3PO, o-TDA-2EO-5PO and o-TDA-3EO-6PO, of the UVCB substance oTDA-EO-PO, were selected as being representative and analysed in aqueous phases as well as in soil extracts.

Radiolabelling:

no

Test temperature:

The temperature was in the range of 20 to 25 °C during the course of the study.

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 2 mg/L
- Sampling interval: Tier 2: 2 h, 4 h, 24 h, 48 h and 72 h

Details on matrix:

Standard LUFA soils 2.1, 2.2, 2.3 and 2.4 as well as Eurosoil 2 in contact to 0.01 M CaCl2-solution were used for this study. These matrices have varying adsorption capacities in relation to their content of organic matter, clay, pH and cation exchange capacity. (see table 1)
COLLECTION AND STORAGE
-Origin of soils:
LUFA soils:Landwirtschaftliche Untersuchungs- und Forschungsanstalt LUFA Speyer. Obere Langgasse 40. 67346 Speyer, Germany
Eurosoils: European Commission, Joint Research Centre. Institute for Reference Materials and Measurements IRMM; Retieseweg. B-2440 Geel, Belgium
- Storage conditions:
Eurosoils: Room temperature. in brown glass bottles
LUFA soils: Room temperature. in closed containers
- Soil preparation (e.g.: 2 mm sieved; air dried etc.):

PROPERTIES
Please see table 1 for details

Details on test conditions:

TEST CONDITIONS
- pH: see table 1
- Temperature: 20-25 °C

TEST SYSTEM
- Reaction vessel: 50 mL polypropylene centrifugation tubes
- Water filtered (i.e. yes/no; type of size of filter used, if any):
- Amount of soil/sediment/sludge and water per treatment (if simulation test):
- Soil/sediment/sludge-water ratio (if simulation test):
- Number of reaction vessels/concentration:
- Measuring equipment:
- Test performed in closed vessels due to significant volatility of test substance:
- Test performed in open system:
- Method of preparation of test solution:
- Are the residues from the adsorption phase used for desorption:
- Other:

Sample No.:

#1

Duration:

24 h

Remarks:

o-TDA-2EO-5PO

Sample No.:

#3

Duration:

72 h

Remarks:

o-TDA-3EO-6PO

Sample No.:

#2

Duration:

48 h

Remarks:

o-TDA-1EO-3PO

Sample No.:

#2

Duration:

72 h

Remarks:

o-TDA-2EO-5PO

Sample No.:

#5

Duration:

48 h

Remarks:

o-TDA-2EO-5PO

Sample No.:

#5

Duration:

72 h

Remarks:

o-TDA-1EO-3PO

Sample No.:

#1

Duration:

72 h

Remarks:

o-TDA-3EO-6PO

Key result

Sample No.:

#3

Type:

log Koc

Remarks:

o-TDA-3EO-6PO

Value:

5.35 dimensionless

Matrix:

LUFA 2.3: Sandy loam (see table 1)

% Org. carbon:

0.412

Key result

Sample No.:

#2

Type:

log Koc

Remarks:

o-TDA-1EO-3PO

Value:

5.25 dimensionless

Matrix:

LUFA 2.2: Loamy sand (see table 1)

% Org. carbon:

1.47

Key result

Sample No.:

#2

Type:

log Koc

Remarks:

o-TDA-2EO-5PO

Value:

5.21 dimensionless

Matrix:

LUFA 2.2. loamy sand (see table 1)

% Org. carbon:

1.47

Sample No.:

#5

Type:

log Koc

Remarks:

o-TDA-2EO-5PO

Value:

3.68 dimensionless

Matrix:

Eurosoil 2: Silt loam (see table 1)

% Org. carbon:

3.72

Sample No.:

#5

Type:

log Koc

Remarks:

o-TDA-1EO-3PO

Value:

3.46 dimensionless

Matrix:

Eurosoil 2: Silt loam (see table 1)

% Org. carbon:

3.72

Sample No.:

#1

Type:

log Koc

Remarks:

o-TDA-3EO-6PO

Value:

3.45 dimensionless

Matrix:

LUFA 2.1: Loamy sand (see table 1)

% Org. carbon:

0.718

Adsorption and desorption constants:

see table 3

Recovery of test material:

The recovery rate for soil extracts was below 90%. The extraction efficiency could not be optimized, presumably due to rapid formation of NER. See table 4a-c for details.

Remarks on result:

other: see table 4 a-c

Transformation products:

not specified

Table 2: Tier 2 - Adsorption Kinetics - Results

Applied nominal test item concentration: 2 mg/L; n = 2;
Mobility according to McCall et al. (1980): K_OC 0 – 50 very high, K_OC 50 – 150 high, K_OC 150 – 500 medium, K_OC 500 – 2000 low, K_OC 2000 – 5000 slight, K_OC > 5000 immobile

Matrix	pH Value ^1)	MB [%]	teq [h]	Direct Method			Indirect Method
				Kd [mL/g]	KOC [mL/g]	Mobility according to McCall et al.	Kd [mL/g]	KOC [mL/g]	Mobility according to McCall et al.
o-TDA-1EO-3PO
LUFA 2.1	5.8	26	48	-0.0001	-0.02	very high	138	19263	immobile
LUFA 2.2	6.2	1	48	-0.0002	-0.01	very high	2642	179728	immobile
LUFA 2.3	6.4	8	72	-0.0002	-0.04	very high	590	143086	immobile
LUFA 2.4	7.9	7	72	-0.00008	-0.004	very high	795	42957	immobile
Eurosoil 2	7.5	32	72	-0.00003	-0.001	very high	108	2898	slight
o-TDA-2EO-5PO
LUFA 2.1	5.8	54	24	-0.00006	-0.009	very high	45	6294	immobile
LUFA 2.2	6.2	2	72	0.0004	0.02	very high	2408	163790	immobile
LUFA 2.3	6.4	8	72	0.0004	0.09	very high	643	156075	immobile
LUFA 2.4	7.9	10	72	0.001	0.06	very high	524	28320	immobile
Eurosoil 2	7.5	31	48	0.01	0.3	very high	179	4819	slight
o-TDA-3EO-6PO
LUFA 2.1	5.8	72	72	-0.00004	-0.005	very high	20	2789	slight
LUFA 2.2	6.2	4	48	0.0006	0.04	very high	1745	118720	Immobile
LUFA 2.3	6.4	5	72	0.0004	0.09	very high	927	224884	Immobile
LUFA 2.4	7.9	4	72	0.003	0.2	very high	1502	81206	Immobile
Eurosoil 2	7.5	31	48	0.05	1	very high	429	11534	Immobile

 

Table 3: Kd and KOC Values for the three selected Components after equilibrium time

t_eq              = equilibrium time; time to reach the adsorption plateau

Soil Type	o-TDA-1EO-3PO				o-TDA-2EO-5PO				o-TDA-3EO-6PO
	teq [h]	Kd [ml/g]	KOC [ml/g]	Log  KOC	teq [h]	Kd [ml/g]	KOC [ml/g]	Log  KOC	teq [h]	Kd [ml/g]	KOC [ml/g]	Log  KOC
LUFA 2.1	48	138	19263	4.28	24	45	6294	3.80	72	20	2789	3.45
LUFA 2.2	48	2642	179728	5.25	72	2408	163790	5.21	48	1745	118720	5.07
LUFA 2.3	72	590	143086	5.16	72	643	156075	5.19	72	927	224884	5.35
LUFA 2.4	72	795	42957	4.63	72	524	28320	4.45	72	1502	81206	4.91
Eurosoil 2	72	108	2898	3.46	48	179	4819	3.68	48	429	11534	4.06

 

Table 4: Mass Ballance;

RR   = Recovery Rate, ‘-1%’ is calculated if the amount in the pore water is higher than in the soil extracts

nominal concentration, test item: 2 mg/L, n = 2

a) o-TDA-1EO-3PO

Sampling point [h]	2	4	24	48	72
Soil Type	LUFA 2.1
RR aqueous phase [%]	49	53	30	28	26
RR solid phase [%]	0	0	0	0	0
Mass balance [%]	48	53	30	28	26
Soil Type	LUFA 2.2
RR aqueous phase [%]	63	52	17	3	1
RR solid phase [%]	-1	-1	0	0	0
Mass balance [%]	62	51	17	3	1
Soil Type	LUFA 2.3
RR aqueous phase [%]	84	59	46	15	8
RR solid phase [%]	-1	-1	0	0	0
Mass balance [%]	82	59	45	15	8
Soil Type	LUFA 2.4
RR aqueous phase [%]	59	41	29	10	7
RR solid phase [%]	-1	0	0	0	0
Mass balance [%]	59	41	29	10	7
Soil Type	Eurosoil 2
RR aqueous phase [%]	93	70	44	30	32
RR solid phase [%]	-1	0	0	0	0
Mass balance [%]	92	70	45	31	32

b) o-TDA-2EO-5PO

Sampling point [h]	2	4	24	48	72
Soil Type	LUFA 2.1
RR aqueous phase [%]	84	77	54	51	55
RR solid phase [%]	-1	0	0	0	0
Mass balance [%]	83	76	54	51	55
Soil Type	LUFA 2.2
RR aqueous phase [%]	79	69	30	6	2
RR solid phase [%]	-1	1	0	0	0
Mass balance [%]	79	70	30	6	2
Soil Type	LUFA 2.3
RR aqueous phase [%]	89	90	55	20	7
RR solid phase [%]	1	2	0	0	0
Mass balance [%]	90	91	55	20	8
Soil Type	LUFA 2.4
RR aqueous phase [%]	72	55	35	19	10
RR solid phase [%]	5	6	4	1	0
Mass balance [%]	77	61	39	19	10
Soil Type	Eurosoil 2
RR aqueous phase [%]	69	63	31	23	22
RR solid phase [%]	11	12	11	8	9
Mass balance [%]	80	76	42	31	31

c) o-TDA-3EO-6PO

Sampling point [h]	2	4	24	48	72
Soil Type	LUFA 2.1
RR aqueous phase [%]	90	76	81	63	72
RR solid phase [%]	0	0	1	0	0
Mass balance [%]	89	76	82	63	72
Soil Type	LUFA 2.2
RR aqueous phase [%]	85	73	26	4	2
RR solid phase [%]	1	2	0	0	0
Mass balance [%]	86	76	26	4	2
Soil Type	LUFA 2.3
RR aqueous phase [%]	87	86	40	13	5
RR solid phase [%]	2	3	1	0	0
Mass balance [%]	88	89	41	13	5
Soil Type	LUFA 2.4
RR aqueous phase [%]	74	56	27	10	4
RR solid phase [%]	11	13	6	1	0
Mass balance [%]	85	69	33	12	4
Soil Type	Eurosoil 2
RR aqueous phase [%]	32	32	13	11	10
RR solid phase [%]	35	37	25	20	22
Mass balance [%]	67	69	38	31	32

 

Validity criteria fulfilled:

yes

Conclusions:

It was found that the three selected components had a strong tendency to adsorb on soil and the equilibrium was mainly completely achieved after 72 hours.

Executive summary:

The adsorption behavior of the test item was investigated on five different soils according to OECD guideline 106 and Council Regulation (EC) No. 440/2008, C.18 (Tier 1 and Tier 2). Three components, o-TDA-1EO-3PO, o-TDA-2EO-5PO and o-TDA-3EO-6PO, of the UVCB substance oTDA-EO-PO, were selected as being representative and analysed in aqueous phases as well as in soil extracts. The determination for adsorption kinetics was performed with a nominal test item concentration of 2 mg test item/L. A soil / solution ratio of 1:50 was used. The concentrations of the test item were measured in aqueous phase and soil extracts at defined sampling points. The sampling points were 2 h, 4 h, 24 h, 48 h and 72 h. The test item was analysed via LC-MS/MS. It was found that the three selected components had a strong tendency to adsorb on soil and the equilibrium was mainly completely achieved after 72 hours. The measured log Koc reached from 3.46 (o-TDA-1EO-3PO at Eurosoil 2) to 5.35 (o-TDA-3EO-6PO at LUFA 2.3).

The Freundlich adsorption isotherm was not determined. The desorption behavior of the test item was not investigated. These deviations from the guideline are on request of the sponsor.
The extraction efficiency of the soil extraction method was lower than 90%. Despite extensive method development for the extraction, this efficiency could not be optimized.
This deviation is considered to have no impact on the quality and integrity of the study.

Description of key information

The three representative structures of the UVCB found to have a strong tendency to adsorp to thesoil phase with log Koc values ranging from 3.46 (o-TDA-1EO-3PO at Eurosoil 2) to 5.35 (o-TDA-3EO-6PO at LUFA 2.3) (NLP Polyols Consortium, 2021)..

Additional information

An experimental study according to OECD guideline 106 and Council Regulation (EC) No. 440/2008, C.18 (Batch equilibrium method) with five different soil types was conducted to assess the adsorption behavior of the UVCB substance. Three components, o-TDA-1EO-3PO, o-TDA-2EO-5PO and o-TDA-3EO-6PO, of the UVCB substance oTDA-EO-PO, were selected as being representative and analysed in aqueous phases as well as in soil extracts. The determination for adsorption kinetics was performed with a nominal test item concentration of 2 mg test item/L at 20 -25 °C test temperature. A soil / solution ratio of 1:50 was used. The concentrations of the test item were measured in aqueous phase and soil extracts at defined sampling points. The sampling points were 2 h, 4 h, 24 h, 48 h and 72 h. The test item was analysed via LC-MS/MS. It was found that the three selected components had a strong tendency to adsorb on soil and the equilibrium was mainly completely achieved after 72 hours. The measured log Koc reached from 3.46 (o-TDA-1EO-3PO at Eurosoil 2) to 5.35 (o-TDA-3EO-6PO at LUFA 2.3). The Koc ranged from 2789 to 224884 ml/g (NLP Polyols Consortium, 2021).

These results are expected to provide a more realistic determination of adsorption potential than the HPLC estimation method, which may be confounded by the surface-activity of the test substance components and lack of relevant reference substances (i.e., aromatic, alcohols, ethers, amines) employed in the OECD 121 guideline.Furthermore, because the HPLC method does not account for the cation-exchange mode of adsorption, it may not correctly predict the adsorption of the test substance components which possess cationic amino-groups.