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Endpoint:
adsorption / desorption
Remarks:
adsorption
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Validated QSAR model. Calculation for Hexadecanamide, N-9-octadecenyl-, (Z)-, however the substance is outside of the domain of the training set (log Kow of the training set: -2.11-8.12; log Kow of the component: 14.31).
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Principles of method if other than guideline:
Calculation based on KOCWIN v2.00, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.
GLP compliance:
no
Type of method:
other: calculation
Media:
soil
Type:
log Koc
Value:
8.815
Temp.:
25 °C
Remarks on result:
other: based on log kow
Type:
Koc
Value:
652 900 000
Temp.:
25 °C
Remarks on result:
other: based on log kow

For detailed description on the model and its applicability, see "Any other information on materials and methods incl. tables".

Endpoint:
adsorption / desorption
Remarks:
adsorption
Type of information:
(Q)SAR
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Validated QSAR model. Calculation for Hexadecanamide, N-9-octadecenyl-, (Z)-, however the substance is outside of the domain of the training set (log Kow of the training set: -2.11-9.10; log Kow of the component: 14.31).
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Principles of method if other than guideline:
Calculation based on KOCWIN v2.00, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.
GLP compliance:
no
Type of method:
other: calculation
Media:
soil
Type:
log Koc
Value:
8.643
Temp.:
25 °C
Remarks on result:
other: based on MCI
Type:
Koc
Value:
439 200 000
Temp.:
25 °C
Remarks on result:
other: based on MCI

For detailed description on the model and its applicability, see "Any other information on materials and methods incl. tables".

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
28 Aug - 18 Oct 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-guideline study
Qualifier:
according to
Guideline:
OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))
Qualifier:
according to
Guideline:
EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))
GLP compliance:
yes (incl. certificate)
Remarks:
The Department of Health of the Government of the United Kingdom
Type of method:
HPLC estimation method
Radiolabelling:
no
Test temperature:
30 °C
Details on study design: HPLC method:
EQUIPMENT
- Apparatus: HPLC System: Agilent Technologies 1100 Series, incorporating autosampler
- Type, material and dimension of analytical (guard) column: Cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties: Waters XSelect HSS Cyano 5µm (150 x 4.6 mm id), Flow-rate: 1.0 mL/min, Injection volume: 10 µL
- Detection system: UV detector wavelength: 210 nm

MOBILE PHASES
- Type:
Phase A: methanol:reverse osmosis water (55:45 v/v)
Phase B: THF
- pH: 6.62

DETERMINATION OF DEAD TIME
- Method: The dead time was determined by measuring the retention time of formamide (purity 99.94%, 614 mg/L solution in methanol:water 55:45 v/v)

REFERENCE SUBSTANCES
Solutions of reference standards were prepared in methanol.

- Identity (purity in %, concentration in mg/L): Phenol (99+, 114), Atrazine (98.8, 105), Isoproturon (99.9, 100), Triadimenol (98.4, 133), Linuron (99.7, 98.0), Naphthalene (99+, 129), Endosulfan-diol (99.9, 116), Fenthion (98.3, 146), a-Endosulfan (99.6, 132), Diclofop-methyl (99.2, 124), Phenanthrene (97, 134), DDT (98, 157)


EVALUATION
- Calculation of capacity factors k': k' = (tr - t0) / t0 with tr = retention time and t0 dead time in min.
- Determination of the log Koc value: Log10 Koc = (Log10 k' - A) / B with Koc = adsorption coefficient, k' = capacity factor, A = intercept of the calibration curve, B = slope of the calibration curve
Analytical monitoring:
no
Type:
log Koc
Value:
> 5.63
Type:
Koc
Value:
> 427 000

Tables: Retention times of the dead time and the retention times, capacity factors (k') and log10 Koc values for the reference standards.

Dead Time

Retention Time (mins)

Mean Retention Time (mins)

Injection 1

Injection 2

Formamide

1.955

1.958

1.957

Standard

Retention Time (mins)

Mean Retention Time (mins)

Capacity Factor (k')

Log10 k'

Log10 Koc

Injection 1

Injection 2

Phenol

2.608

2.608

2.608

0.333

-0.478

1.32

Atrazine

3.782

3.785

3.783

0.934

-2.98 x 10-2

1.81

Isoproturon

4.078

4.078

4.078

1.08

3.52 x 10-2

1.86

Triadimenol

5.585

5.582

5.583

1.85

0.268

2.40

Linuron

5.796

5.793

5.795

1.96

0.293

2.59

Naphthalene

4.976

4.978

4.977

1.54

0.189

2.75

Endosulfan-diol

7.334

7.329

7.331

2.75

0.439

3.02

Fenthion

8.794

8.814

8.804

3.50

0.544

3.31

a-Endosulfan

12.783

12.751

12.767

5.53

0.742

4.09

Diclofop-methyl

13.666

13.663

13.664

5.98

0.777

4.20

Phenanthrene

9.634

9.631

9.632

3.92

0.594

4.09

DDT

27.943

27.921

27.932

13.3

1.12

5.63

Table: Retention times, capacity factor and log10 Koc values determined

Injection

Retention Time (mins)

Capacity Factor (k')

Logio k'

Logio Koc

Adsorption Coefficient

1

39.483

>13.3

>1.12

>5.63

>4.27 x 105

2

39.477

>13.3

>1.12

>5.63

>4.27 x 105

As the test item had a high affinity for the stationary phase of the column, the mobile phase was adjusted to 100% THF shortly after the retention time of DDT to elute the sample. As the slope of the calibration curve for the reference standards showed good first order correlation and as the retention times between duplicate injections for each solution were consistent, the HPLC method was considered valid for the determination of adsorption coefficient. Based on the chromatographic data, the test item was considered to be stable during the test procedure.

Description of key information

Log Koc > 5.6, OECD 121,  (log Koc = 8.81 (KOCWIN v2.00))

Key value for chemical safety assessment

Additional information

(Z)-N-Octadec-9-enylhexadecan-1-amide (CAS No. 16260-09-6) is expected to adsorb to suspended solids and sediment based upon a measured log Koc of > 5.6. The adsorption coefficient has been determined to be greater than 4.27E5 (log Koc > 5.6) using the HPLC screening method according to OECD 121. The test substance is highly insoluble in water and as the test item had a high affinity for the stationary phase of the column, the mobile phase was adjusted to 100% tetrahydrofuran shortly after the retention time of DDT to elute the sample. As the slope of the calibration curve for the reference standards showed good first order correlation and as the retention times between duplicate injections for each solution were consistent, the HPLC method was considered valid for the determination of adsorption coefficient. Based on the chromatographic data, the test item was considered to be stable during the test procedure.

Additional information could be gathered using the program EpiSuite (KOCWIN v2.00), log Koc values of 8.64 (MCI method) and 8.81 (based on log Kow) were calculated (Knoell Consult GmbH, 2012).