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Reference
Endpoint:
adsorption / desorption, other
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
2013
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification
Justification for type of information:
QSAR prediction
1. SOFTWARE: Estimation Programs Interface (EPI) Suite for Microsoft Windows, v4.10 (US EPA, 2012)

2. MODEL (incl. version number): KOCWIN v2.00

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
C8- and the C18-fatty acid derivates:
CCCCCCCC(=O)NCCCN(O)(C)C
CCCCCCCCCCCCCCCCCC(=O)NCCCN(O)(C)C

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF.

5. APPLICABILITY DOMAIN
See attached QPRF

6. ADEQUACY OF THE RESULT
- The model is scientifically valid (see attached QMRF).
- The model estimates the KOC for the uncharged molecule at 25 °C; screening information on adsorption (and desorption) is required for substances manufactured or imported in quantities of 10 t/y or more (see also attached QPRF).
- See attached QPRF for reliability assessment.
Qualifier:
no guideline available
Version / remarks:
Guidance on information requirements and chemical safety assessment
Chapter R.6: QSARs and grouping of chemicals
Principles of method if other than guideline:
Estimation of Koc value by EPIWIN (KOCWIN, v2.0), based on MCI and on LogPow: 1.27
GLP compliance:
no
Type of method:
other: QSAR by KOCWIN (v2.0)
Media:
soil
Test temperature:
25 °C (MCI method)
Details on study design: HPLC method:
Not relevant for QSAR
Analytical monitoring:
not required
Details on sampling:
Not relevant for QSAR
Details on matrix:
Not relevant for QSAR
Details on test conditions:
Not relevant for QSAR
Computational methods:
Not relevant for QSAR
Key result
Type:
Koc
Value:
34.41 L/kg
Temp.:
25 °C
Remarks on result:
other: see further in : any other information on results incl. tables
Adsorption and desorption constants:
Not relevant for QSAR
Recovery of test material:
Not relevant for QSAR
Concentration of test substance at end of adsorption equilibration period:
Not relevant for QSAR
Concentration of test substance at end of desorption equilibration period:
Not relevant for QSAR
Transformation products:
not measured

SMILES : CCCCCCCCCCCCCCCCCC(=O)NCCCN(O)(C)C

MOL FOR: C23 H49 N2 O2

MOL WT : 385.66

Koc Estimate from MCI:

 ---------------------

        First Order Molecular Connectivity Index ........... : 12.955

        Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 7.3530

        Fragment Correction(s):

                 1  N-CO-C (aliphatic carbon) ............ : -1.0277

                 4  Nitrogen to Carbon (aliphatic) (-N-C).. : -0.8509

        Corrected Log Koc .................................. : 5.4743

 

                        Estimated Koc: 2.981e+005 L/kg  <===========

 

SMILES : CCCCCCCC(=O)NCCCN(O)(C)C

MOL FOR: C13 H29 N2 O2

MOL WT : 245.39

Koc Estimate from MCI:

 ---------------------

        First Order Molecular Connectivity Index ........... : 7.955

        Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 4.7465

        Fragment Correction(s):

                 1  N-CO-C (aliphatic carbon) ............ : -1.0277

                 4  Nitrogen to Carbon (aliphatic) (-N-C).. : -0.8509

        Corrected Log Koc .................................. : 2.8678

 

                        Estimated Koc: 737.6 L/kg  <===========

Koc Estimate from Log Kow:

 -------------------------

        Log Kow (User entered  ) ......................... : 1.27

        Non-Corrected Log Koc (0.55313 logKow + 0.9251) .... : 1.6276

        Fragment Correction(s):

                 1  N-CO-C (aliphatic carbon) ............ : -0.0038

                 4  Nitrogen to Carbon (aliphatic) (-N-C).. : -0.0871

        Corrected Log Koc .................................. : 1.5366

 

                        Estimated Koc: 34.41 L/kg  <===========

Amides, coco, N-[3-(dimethylamino)propyl], N-oxides represent a mixture containing C8-, C10-, C12-, C14-, C16-, and C18-alkyl side chains. Based on this and the variable composition of the compound (alkyl chain distribution dependent on origin of the coco fatty acid) the calculation of physico-chemical properties for the mixture is not feasible. To get a hint on the physico-chemical data, the EPIWIN calculation was conducted for the test substance based on the measured log Kow. The soil sorption coefficient Koc calculated using EPIWIN v4.10, PCKOCWIN v2.00 was 34.41 L/kg.

Note that the chemical is a quaternary ammonium compound (QAC). Adsorption of QACs seem to occur mainly by an ion-exchange mechanism and depends on cationic-exchange capacity of the sorbent and variety of other parameters (Boethling, 1994). The EPIWIN training set for Koc estimation did not include any QACs. Therefore, the Koc estimate is outside the program's prediction domain. Due to missing information about the applicability of the calculation model in respect to the substance under investigation the results and the conclusions thereof should be treated with care.

Validity criteria fulfilled:
not applicable
Conclusions:
For complex mixtures (UVCB substances) the assessment of Koc is clearly complicated. Estimation of the individual components Koc values, if appropriate, should be considered. The Koc based on a calculated log Kow of 1.27 was predicted to be 34.41 L/kg.

Description of key information

For complex mixtures (UVCB substances) the assessment of Koc is clearly complicated. Estimation of the individual components Koc values, if appropriate, should be considered.  The Koc based on the measured log Kow was calculated to be 34.41 L/kg.

Key value for chemical safety assessment

Koc at 20 °C:
34.41

Additional information

Experimental data on the adsorption/desorption behaviour of the mixture are not available. However, the C12 -C18 AAAO substance is readily biodegradable and is therefore eliminated during sewage treatment. Further, test substance reaching soil or sediment is expected to rapidly degrade. Still, estimation of the individual components Koc values, if appropriate, should be considered.

Amides, C12 -C18 (even numbered), N-[3 -(dimethylamino) propyl], N'oxides represent a mixture containing C8-, C10-, C12-, C14-, C16-, and C18-alkyl side chains. Based on this and the variable composition of the compound (alkyl chain distribution dependent on origin of the fatty acid) the calculation of physico-chemical properties for the mixture is not feasible. The soil sorption coefficient Koc of the test substance was calculated based on the measured Kow using EPIWIN v4.10, PCKOCWIN v2.00. A soil sorption coefficient of 34.41 L/kg was calculated.

Note that the chemical is a surfactant. The EPIWIN training set for Koc estimation did not include any surfactants. Therefore, the Koc estimate is outside the program's prediction domain. Due to missing information about the applicability of the calculation model in respect to the substance under investigation the results and the conclusions thereof should be treated with care.

[LogKoc: 1.54]