Amines, N-(C16-18 and C18-unsatd. alkyl)trimethylenedi-, diacetates

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

21-04-2008 till 16-01-2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Test is performed according to the guideline under GLP conditions. The information presented in the report allows reproduction of the test and gives sufficient information in the test substance used. For completeness also the CoA's of both 14C labelled test substance batches are attached.

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

4 soils instead of 5 soils were used

Principles of method if other than guideline:

Test is performed with [1-14C]octadecylpropane-1,3-diamine and not with n-hydrogenatedtallow propane-1,3-diamine.
octadecylpropane-1,3-diamine is the main component of n-hydrogenatedtallow propane-1,3-diamine.

GLP compliance:

yes (incl. QA statement)

Type of method:

batch equilibrium method

Media:

soil

Radiolabelling:

yes

Test temperature:

20 plus minus 2 deg C

Details on study design: HPLC method:

not applicable

Analytical monitoring:

yes

Details on matrix:

Speyer 2.2 Soil
Name: Speyer standard soil type 2.2
Location: Rheinland-Pfalz/Hanhofen, Germany "Grosser Striet", Nr 585
Texture (USDA): Loamy sand
Horizon: 0 - 20 cm
pH-CaC12: 5.4
% organic matter: 3.72
% organic carbon: 2.16
Particle size distribution (USDA):
% clay (<2 micrometer): 6.4
% silt (2 - 50 micrometer): 12.2
%sand (50 - 2000 micrometer): 81.4
CEC (meq1100g): 10
Water holding capacity (%): 48.2
Batch number: F222008
Field sampling date: 15 May 2008
Received from: Landwirtschaftlichte Untersuchungs- und Forschugsanstalt Speyer, Obere Langgasse 40, 67346 Speyer, Germany
Sievedlair dried on: 8 September 2008
Storage: Refrigerated after receipt at Notox, Ambient temperature after sieving/air drying
Expiry date: 15 may 2011

Speyer 2.3 soil
Name Speyer 2.3 soil
Location Germany/ Rheinland-Pfalz/Offenbach "Im Bildgarten", Nr 570
Texture (USDA): Sandy loam
Horizon: 0 - 20 cm
pH-CaCl2: 6.4
% organic matter: 1.69
% organic carbon: 0.98
Particle size distribution (USDA):
% clay (<2 micrometer): 9.4
% silt (2-50 micrometer):29.8
% sand(50-2000 micrometer):60.8
CEC (meq1100g): 8
Water holding capacity (%):34.4
Batch number: F232008
Field sampling date: 13 May 2008
Received from: Landwirtschaftlichte Untersuchungs- und Forschugsanstalt Speyer, Obere Langgasse 40, 67346 Speyer, Germany
Sievedlair dried on: 8 September 2008
Storage: Refrigerated after receipt at Notox, Ambient temperature after sieving/air drying
Expiry date: 13 may 2011

Name: LLM 164 (Cranfield 164)
Location: Farditch Farm, Chelmorton, Buxton, United Kingdom (OSmap reference SK 1050269133)
Texture (USDA): Silty clay loam
Horizon: 10 - 20 cm
pH-CaC12: 6.4
% organic matter: 6.4
% organic carbon: 3.7
Particle size distribution (USDA):
% clay (<2 micrometer): 28
% silt (2 - 50 micrometer): 52
% sand (50 - 2000 micrometer): 20
CEC (meq1100g): 22.8
Water holding capacity (%): 65.7
Batch number: LLM/008/08
Field sampling date: 4 March 2008
Received from: Landlook (Midlands), Jesmond, Leicester Lane, Cubbington Head, Leamington Spa, Warwickshire, CV32 6QY, UK
Sieved on: 10 March 2008
Air dried on: 9 june 2008
Refrigerated after receipt at Notox, Ambient temperature after sieving/air drying
Expiry date: 28 February 2011

Speyer 6S soil
Name: Speyer standard soil type 6S
Location: Germany/Rheinland-Pfalz/Siebdingen "Inder unteren Hohnert", Nr 3412
Texture (USDA): Clay
Horizon: 0 - 20 cm
pH-CaCl2: 7.2
% organic matter: 3.02
% organic carbon: 1.75
Particle size distribution (USDA):
% clay (<2 micrometer): 42.1
% Silt (2 - 50 micrometer): 36.0
% sand (50-2000 micrometer): 21.9
CEC (meq1100g): 22
Water holding capacity (%): 40.7
Batch number: F6S2208
Field sampling date: 28 May 2008
Received from: Landwirtschaftlichte Untersuchungs- und Forschugsanstalt Speyer, Obere Langgasse 40, 67346 Speyer, Germany
Sievedlair dried on: 8 September 2008
Storage: Refrigerated after receipt at Notox, Ambient temperature after sieving/air drying
Expiry date: 28 may 2011

Details on test conditions:

Moisture content was determined: ranging from 1 to 6.2%
Adsorption to testcontainer walls was quantified: Glass between 65 and 83% adsorption; Polyethylene between 9 and 27%; Glass was selected for the final test
The appropriate soil:solution ratio was determined: No difference was observed between 1:50 soil:solution ratio and 1:100. 1:100 was selected for the final test. Adsorption to container walls is negligible in the presence of soil
The equilibrium time for adsorption and desorption was determined:
Adsorption equilibrium was reached after 6 hours. In the final test sampling was performed after 24 hours
Desorption equilibrium was reached after 6 hours. In the final test sampling was performed after 24 hours

The adsorption isotherm was determined at an initial concentration range of: 0.1 to 10.3 mg/L in triplicate

A stock solution (StF) containing 6.46 MBq/mL [1-14C]Octadecylpropane-1,3-diamine (NOTOX substance 183546/B) in methanol was prepared. This is equivalent to 1.03 g/L. Spike solutions were prepared by diluting the stock solution with 0.01 M CaCl2 solution to five different concentrations. The exact concentrations were determined by LSC of three 0.1 mL aliquots and are given in following table:
Concentration in the test (mg/L) RSD (n=3) (%)
Spike A 0.010 5.4
Spike B 0.060 2.1
Spike C 0.211 4.2
Spike D 0.435 2.4
Spike E 1.03 1.5
Slurries (approximately 0.45 g soil and 40.5 mL 0.01 M CaCl2 solution in glass Erlenmeyer flasks were equilibrated at 20 ± 2°C in the dark on a shaker overnight, prior to spiking. The adsorption isotherms experiment was initiated by adding a known volume of approximately 4.5 mL of the different spike solutions to ten pre-equilibrated slurries of each soil (two replicates per concentration). In this way, initial [1-14C]Octadecylpropane-1,3-diamine concentrations of approximately 0.01, 0.06, 0.2, 0.4 and 1.0 mg/L were obtained. For each soil a blank sample was included using a known amount of 0.01 M CaCl2 solution and no test substance. The samples were incubated on a shaker at 20 ± 2°C in the dark. After about 24 hours of
contact time, the slurries were removed from the shaker and allowed to settle down for 30 minutes. The activity in 3 mL of clear supernatant was determined by LSC and the supernatants were decanted and weighed. The decanted supernatant was replaced by an approximately equal, known volume of fresh 0.01 M CaCl2 solution. The slurries were mixed well and placed on a shaker at 20 ± 2°C for 24 hours and activity was determined by LSC in 3
mL of supernatant.

Computational methods:

All calculations were based on formulas given in the OECD guideline. For the purpose of the study, it is considered that the weight of 1 mL
of aqueous solution is 1 g (according to the OECD guideline). All calculations were performed using non-rounded values. Rounded values are reported in the tables. Therefore, minor differences might be observed when calculating the parameters as mentioned in the tables.
The mass balance (determined in the kinetics experiment) was calculated as:
% of applied radioactivity recovered in supernatant after adsorption +
% of applied radioactivity recovered in soil after adsorption (combustion)1 +
% of applied radioactivity recovered in supernatant after desorption2 +
% of applied radioactivity recovered in soil after desorption (combustion) 2 +
% of applied radioactivity recovered in rinsate +
% of applied radioactivity in aliquots of supernatant taken for LSC +
Mass balance (= total)
1. Only applicable when mass balance was determined after the adsorption phase.
2. Only applicable when mass balance was determined after the desorption phase.
Optimisations were performed using the program ModelMaker (AP Benson, Wallingford, Oxfordshire, UK).

Type:

Kd

Value:

530

Temp.:

20 °C

% Org. carbon:

2.16

Remarks on result:

other: Speyer 2.2

Type:

Kd

Value:

250

Temp.:

20 °C

% Org. carbon:

0.98

Remarks on result:

other: Speyer 2.3

Type:

Kd

Value:

450

Temp.:

20 °C

% Org. carbon:

3.7

Remarks on result:

other: Cranfield 164

Type:

Kd

Value:

850

Temp.:

20 °C

% Org. carbon:

1.75

Remarks on result:

other: Speyer S6

Details on results (HPLC method):

not applicable

Adsorption and desorption constants:

Results obtained from the determination of equilibrium time
Kd Kdes
cm3/g cm3/g
Speyer 2.2: 220 380
Speyer 2.3: 480 900
Cranfield 164 610 1390
Speyer 6S 1410 3550
Results presented are average of two replicates

Recovery of test material:

Recovery of the test material was determined during the determination of the equilibrium time.
Distribution of [1-14C] Octadecylpropane-1,3-diamine after adsorption stage

Soil % in solution % adsorption % in rinsate % total
Speyer 2.2 20.4 55.7 10.6 86.8
Speyer 2.3 13.5 78.5 5.9 97.9
Cranfield 164 8.9 89.1 2.5 101
Speyer 6S 6.9 95.3 2.4 105
The % adsorption is determined by combustion of the soil
Distribution of [1-14C] Otadecylpropane-1,3-diamine after desorption stage

Soil % decanted % in solution % adsorption % in rinsate % total
Speyer 2.2 23.7 21.1 43.1 3.6 91.6
Speyer 2.3 14.8 11.9 74.3 4.0 105
Cranfield 164 12.1 8.8 80.1 1.9 103
Speyer 6S 5.1 5.4 95.8 2.1 108

Concentration of test substance at end of adsorption equilibration period:

Speyer 2.2 (soil with the lowest sorption)
at 1.03 mg/L initial, 0.12 mg/L equilibrium ==> Kd = 730 cm3/g
at 0.0097 mg/L initial, 0.0024 mg/L equilibrium ==> Kd = 310 cm3/g

Speyer 6S (soil with highest sorption)
at 1.03 mg/L initial, 0.06 mg/L at equilibrium ==> Kd = 1520 cm3/g
at 0.0097 mg/L initial, 0.0006 mg/L at equilibrium ==> Kd = 1991 cm3/g

Concentration of test substance at end of desorption equilibration period:

Speyer 2.2
at 1.03 mg/L initial, 0.042 equilibrium
at 0.0097 mg/L initial, 0.00045 equilibrium

Speyer 6S
at 1.03 mg/L initial, 0.017 equilibrium
at 0.0097 mg/L initial, 0.00025 equilibrium

Transformation products:

no

Details on results (Batch equilibrium method):

See remarks on results including tables

Statistics:

No specific statistics were applied

Freundlich adsorption isotherm parameters for [1-14C]Octadecylpropane-1,3- diamine

Soil	KF ads (103 cm3/g)	KF,oc ads (103 cm3/g)	KF,om ads (103 cm3/g)	1/n	r2	data points
Speyer 2.2	0.53	12.9	22.3	0.89	0.900	10
Speyer 2.3	0.25	14.3	24.7	0.62	0.917	10
Cranfield 164	0.45	7.0	12.1	0.74	0.996	9
Speyer 6S	0.85	26.2	45.2	0.81	0.950	10

 

Validity criteria fulfilled:

yes

Remarks:

Test is performed with 4 instead of 5 soils. The 4 soils used cover a wide range of soil characteristics

Conclusions:

A reliable, valid and adequate study. Test is completely performed according to OECD guideline 106 under GLP conditions at a concentration range from 0.01 to 1.0 mg/L but on with only 4 soils. The 4 soils used howevercover a wide range of soil characteristics and therefore the coverage of different soil types is considered to be sufficient.

Executive summary:

The adsorption behaviour of [1-14C]Octadecylpropane-1,3-diamine was studied in four soils, including a loamy sand (Speyer 2.2; 2.16% organic carbon [OC]), a sandy loam (Speyer 2.3; 0.98% OC), a silty clay loam (Cranfield 164; 3.7% OC) and a clay (Speyer 6S; 1.75% OC).

Adsorption and desorption kinetics were determined at a nominal initial concentration of approximately 0.9 mg/L. Adsorption and desorption isotherms were determined over a concentration range from 0.01 to 1 mg/L. The adsorption-desorption experiments were carried

out at 20 °C ± 2 °C in the dark on a shaker at a soil:0.01 M CaCl2 solution ratio of 1:100. In the kinetics experiment 87% and 92% of applied activity was recovered for Speyer 2.2 soil at the end of the adsorption phase and desorption phase, respectively. For the other three soils recoveries between 98% and 108% were obtained. As the mass balance after the desorption phase of all soils was >90%, it was concluded that no activity was lost during the timeframe of the experiment.

[1-14C]Octadecylpropane-1,3-diamine adsorption isotherms could be described by the

Freundlich equation. Freundlich adsorption coefficients are summarised in the table below.

Test system	Texture	%oc	pH	CEC	KF,ads 10^3 cm^3/g	KF,oc,ads *10^3 cm^3/g
Speyer 2.2	Loamy sand	2.16	5.4	10	0.53	22.3
Speyer 2.3	Sandy loam	0.98	6.4	8	0.25	24.7
Cranfield 164	Silty clay loam	3.70	6.0	23	0.45	12.1
Speyer 6S	Clay loam	1.75	7.2	22	0.85	45.2

Description of key information

The amines in the test substance will to a large extent be protonated under ambient conditions and will therefore interact with the negative surface of mineral particles or with negative charges of humic substances. The ionic interactions play a more important role than hydrophobic partitioning with organic matter.  The log Koc is therefore considered as a poor predictor of the partitioning behaviour of cationic surfactants in the environment. The sorption test results are therefore not expressed in Koc but in their Kd or Kfads values. The mean KFads value for the four soils of 520 L/kg will be used as a realistic worst-case to derive the distribution constants for the alkyl-1,3-diaminopropanes. This Kd value of 520 L/kg corresponds with a Koc of 10400 L/kg. This latter Koc may be used to derive other Kd values for risk assessment purposes. 
Because ionic interactions play a more important role than hydrophobic partitioning with organic matter, the influence of the chain length on the sorption behaviour is expected to be low, and the experimental results obtained in the test with octadecyl-1,3-diaminopropanes can be taken as representative for the other alkyl-1,3-diaminopropane products as well. Furthermore is an influence of the double bond (in octadecenyl-1,3-diaminopropane) onto sorption is not expected. 
Because there is no principal difference between soil and sediments considering the sorption properties (EU RAR primary alkyl amines, 2008) and because for cationic surfactants the degree of sorption is not related to the organic carbon content, the value for soil will also be used for sediment and suspended particles. For sludge which consists mainly of organic matter the sorption data as observed for soil are not considered to be representative. This is however not a serious problem because the removal by sorption in a waste water treatment plant will be close to what is observed in the waste water treatment simulation test i.e. 4.1% removal. 

Key value for chemical safety assessment

Koc at 20 °C:

10 400

Additional information

In Amines, N-(C16-18 and C18-unsatd. alkyl)trimethylenedi-, diacetates,

the presence of diamines that are strong bases will determine the partitioning process of the substance in the environment. Thus it was considered justified to use the results of Kd or Kfads values obtained with Diamine C16 -18, C18 -saturated-1,3 -diaminopropane (68603-64-5) for read-across to Diamines, 1,3-Propane diamine,N-tallow-,diacetate.

The amines in the test substance will to a large extent be protonated under ambient conditions and will therefore interact with the negative surface of mineral particles or with negative charges of humic substances. The ionic interactions play a more important role than hydrophobic partitioning with organic matter. The log Koc is therefore considered as a poor predictor of the partitioning behaviour of cationic surfactants in the environment. Earlier results showed that using at least three soils with at least one loamy sand and a clay soil, can give as much information as using the full number of soils. These earlier tests also revealed that only rarely linear adsorption isotherms were obtained for cationic surfactants and that extrapolation to lower concentrations based on these non-linear isotherms leads to unrealistic results (e.g. RAR primary fatty amines Oct. 2008). According to the Danish EPA (2004) a more reliable method of extrapolation to lower concentrations, is to use the data originating from the lowest measured concentration and to assume that the coefficient remains constant at lower concentrations

The determination of a Koc from log Kow is not opportune, because the common equations for Koc derivation are not valid for both ionic and surface active substances. Thus only an OECD 106 can be relevant for such substances.

The adsorption behaviour of 1-¹⁴C-labelled n-octadecyl-1,3-diaminopropane was studied in a batch equilibrium experiment according OECD 106 (Corral and Brands, 2009). Three soils collected in(2.2, loamy sand: 6.4% clay, 3.7% organic matter;2.3, sandy loam: 9.4% clay, 1.7% organic matter and Speyer S6, clay: 42.1% clay, 3.0% organic matter) and one in(Cranfield 164, silty clay loam: 28% clay, 6.4% organic matter) were used, encompassing a range of % clay and organic matter. The test substance adsorbed partially onto the container walls which was considered for the determination of the adsorption coefficients. Adsorption kinetics was determined by measurements at different sampling times (up to 48 h), an equilibrium was reached after 6 hours. Desorption occurred to a lesser extent than adsorption. Table 12 presents a summary of the most important soil properties and observed Freundlich constants.

 

Table 12:Soil properties and related Freundlich adsorption coefficients fortest material (CAS number): 68603-64-5

Test system	Texture	% OC	pH	% Clay	Kf^ads (cm^3/g)	KF^Adsoc (10^3cm^3/g)
Speyer2.2	Loamy sand	2.16	5.4	6.4	530	22.3
Speyer2.3	Sandyloam	0.98	6.4	9.4	250	24.7
Cranfield164	Silty clay loam	3.7	6.0	28	450	12.1
Speyer6S	Clay	1.75	7.2	42.1	850	45.2

 

From the data it can be observed that the sorption onto Speyer 6S is much higher than to Cranfield 164 despite of the higher organic matter content in Cranfield 164 soil. This can be explained that ionic interactions play a more important role than hydrophobic partitioning with organic matter. Alkyl ammonium ions can interact with the surface of mineral particles or with negative charges of humic substances. The influence of the chain length on the sorption behaviour is therefore expected to be limited and the experimental results obtained in the test with octadecyl-1,3-diaminopropane can be taken as representative for other alkyl-1,3-diaminopropane products. As well, an influence of the double bond (in octadecenyl-1,3-diaminopropane) onto sorption is not expected.

The concentration used for the determination of the adsorption isotherms range from 0.01 to 1 mg/L. The isotherms observed are not linear but considered to be acceptable for extrapolation to lower concentrations (r²= 0.9). The observed aquatic equilibrium concentrations in the experiment range from 0.3 to 2.6 µg/L.

For the prediction of the partitioning of the Diamines C16-18 in soil, sediment and suspended matter not the K_F^adsbased on organic matter will used but the uncorrected K_F^adsbecause there is no relation between the organic matter concentration and the sorption observed.

The mean K_F^adsvalue for the four soils of 520 L/kg will be used as a realistic worst-case to derive the distribution constants for the alkyl-1,3-diaminopropanes. Because there is no principal difference between soil and sediments considering the sorption properties and because for cationic surfactants the degree of sorption is not related to the organic carbon content, the value for soil will also be used for sediment and suspended particles. For sludge which consists mainly of organic matter the sorption data as observed for soil are not considered to be representative. This is however not a serious problem because the removal by sorption in a waste water treatment plant will be close to what is observed in the waste water treatment simulation test i.e. 4.1% removal.

In table 12 a, the distribution constants used in this assessment are summarized:

                       Table 12a:Distribution constants for alkyl-1,3-diaminopropanes

Kpsoil	520 L^.kg^-1	Ksoil-water	780 m^3.m^-3
Kpsusp	1040 L^.kg^-1	Ksusp-water	261 m^3.m^-3
Kpsed	520 L^.kg^-1	Ksed-water	261 m^3.m^-3

 

With a Kp_suspof 1040 L/kg and a concentration of 15 mg/L suspended matter in surface waters, the adsorbed fraction is calculated as 1.5%.