(Z)-N-octadec-9-enylhexadecan-1-amide

Biodegradation in soil

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 May 2020 to 17 May 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 307 (Aerobic and Anaerobic Transformation in Soil)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

laboratory

Radiolabelling:

yes

Oxygen conditions:

aerobic

Soil classification:

not specified

Year:

2020

Soil no.:

#4

Soil type:

clay

% Clay:

38

% Silt:

22

% Sand:

40

% Org. C:

3.4

pH:

7.3

CEC:

23.7 meq/100 g soil d.w.

Bulk density (g/cm³):

1.1

% Moisture content:

33.9

Soil no.:

#3

Soil type:

loamy sand

% Clay:

8

% Silt:

8

% Sand:

84

% Org. C:

0.76

pH:

7.3

CEC:

7.7 meq/100 g soil d.w.

Bulk density (g/cm³):

1.43

% Moisture content:

9.6

Soil no.:

#2

Soil type:

sandy loam

% Clay:

8

% Silt:

18

% Sand:

74

% Org. C:

2.7

pH:

5.4

CEC:

10.7 meq/100 g soil d.w.

Bulk density (g/cm³):

1.11

% Moisture content:

19.1

Soil no.:

#1

Soil type:

silt loam

% Clay:

12

% Silt:

52

% Sand:

36

% Org. C:

3.7

pH:

5.6

CEC:

12.6 meq/100 g soil d.w.

Bulk density (g/cm³):

0.97

% Moisture content:

46

Details on soil characteristics:

SOIL COLLECTION AND STORAGE
- Geographic location:
soil 1 Brierlow, Derbyshire, UK, Grassland field
soil 2 Calke, Derbyshire, UK, Grass meadow
soil 3 Kennett, Cambridgeshire, UK, Agricultural topsoil
soil 4, South Witham, Lincolnshire, UK, Former arable land

- Pesticide use history at the collection site: None within previous 5 years for all four.

Soil No.:

#4

Duration:

120 d

Soil No.:

#3

Duration:

120 d

Soil No.:

#2

Duration:

120 d

Soil No.:

#1

Duration:

120 d

Soil No.:

#4

Initial conc.:

1 ppm

Based on:

test mat.

Soil No.:

#3

Initial conc.:

1 ppm

Based on:

test mat.

Soil No.:

#2

Initial conc.:

1 ppm

Based on:

test mat.

Soil No.:

#1

Initial conc.:

1 ppm

Based on:

test mat.

Parameter followed for biodegradation estimation:

radiochem. meas.

Soil No.:

#4

Temp.:

12°C

Microbial biomass:

954 mg C/kg soil

Soil No.:

#3

Temp.:

12°C

Microbial biomass:

1190 mg C/kg soil

Soil No.:

#2

Temp.:

12°C

Microbial biomass:

814 mg C/kg soil

Soil No.:

#1

Temp.:

12°C

Microbial biomass:

2346 mg C/kg soil

Details on experimental conditions:

EXPERIMENTAL DESIGN
- Soil preincubation conditions (duration, temperature if applicable): stored at 5 +/- 3 °C
- Soil condition: air dried
- Soil (g/replicate): 50 g dry weight
- Control conditions, if used (present differences from other treatments, i.e., sterile/non-sterile, experimental conditions): same conditions without substance
- No. of replication controls, if used: 5
- No. of replication treatments: 14 vessels of each soil
- Test apparatus (Type/material/volume): The soil and solvent were separated by centrifugation. The weight of extract was recorded, and duplicate weighed aliquots (1.0 mL) were taken for LSC.
The soil debris remaining after extraction was air-dried, weighed, homogenized and duplicate weighed aliquots (approximately 0.3 g) were taken for combustion and LSC.
- Details of traps for CO2 and organic volatile, if any: Solid samples were combusted in oxygen using a Harvey OX501 sample oxidizer. Combustion products were absorbed into Oxysolve C-400 combined CO2 sorbent and scintillator (Zinsser Analytic).
- Identity and concentration of co-solvent: Dichloromethane & Tetrahydrofuran approx. 200 mL.

Experimental conditions (in addition to defined fields)
- Moisture maintenance method: addition of purified water
- Continuous darkness: Yes

SAMPLING DETAILS
- Sampling intervals: Duplicate samples of each soil type were taken for analysis immediately after test item application and after 7, 14, 29, 60 and 120 days of incubation.
- Sampling method for soil samples: Extraction of the soil began on the day of sampling. The soil was extracted with a series of solvents (approximately 200 mL) as detailed below by sonicating at ambient temperature for 15 minutes then shaking for 15 minutes at ambient temperature.
- Method of collection of CO2 and volatile organic compounds: Combustion products were absorbed into Oxysolve C-400 combined CO2 sorbent and scintillator (Zinsser Analytic)

Soil No.:

#4

Sampling day(s):

0 d

% Total extractable:

104.7

% Non extractable:

1.7

% Recovery:

106.3

Soil No.:

#4

Sampling day(s):

120 d

% Total extractable:

84.2

% Non extractable:

5.8

% CO2:

11.5

% Recovery:

101.5

Soil No.:

#3

Sampling day(s):

0 d

% Total extractable:

105.1

% Non extractable:

0.9

% Recovery:

106

Soil No.:

#3

Sampling day(s):

120 d

% Total extractable:

87.1

% Non extractable:

5.1

% CO2:

8.5

% Recovery:

100.7

Soil No.:

#2

Sampling day(s):

0 d

% Total extractable:

107.4

% Non extractable:

0.3

% Recovery:

107.7

Soil No.:

#2

Sampling day(s):

120 d

% Total extractable:

77

% Non extractable:

9.7

% CO2:

12.4

% Recovery:

99.1

Soil No.:

#1

Sampling day(s):

0 d

% Total extractable:

104.3

% Non extractable:

1.3

% Recovery:

105.5

Soil No.:

#1

Sampling day(s):

120 d

% Total extractable:

77.1

% Non extractable:

7.1

% CO2:

15.4

% Recovery:

99.6

Soil No.:

#4

DT50:

418 d

Type:

not specified

Temp.:

12 °C

Remarks on result:

not determinable

Remarks:

There was no significant decline in the levels of test item in the four soils incubated under aerobic conditions.

Soil No.:

#3

DT50:

330 d

Temp.:

12 °C

Soil No.:

#2

DT50:

226 d

Temp.:

12 °C

Soil No.:

#1

DT50:

270 d

Temp.:

12 °C

Transformation products:

no

Remarks:

Test item was degraded to up to four low level unidentified transformation products (up to a mean of 2.4% AR), incorporated into bound (non-extractable) radioactivity and mineralized to carbon dioxide.

Details on transformation products:

Test item was degraded to up to four low level unidentified transformation products (up to a mean of 2.4% AR), incorporated into bound (non-extractable) radioactivity and mineralized to carbon dioxide.

Evaporation of parent compound:

no

Volatile metabolites:

no

Residues:

no

Mean Distribution and Recovery of Radioactivity in Brierlow Soil

	Time after application (days)
	0	7	14	29	60	120
Extract 1	80.2	77.2	77.2	74.6	71.6	64.4
Extract 2	20.0	18.2	17.0	16.4	16.5	16.0
Extract 3	4.6	4.2	4.0	3.8	3.9	3.9
Total extractable	104.7	99.5	98.1	94.8	92.0	84.2
Non-extractable	1.7	2.8	2.9	3.6	4.6	5.8
Total in soil	106.3	102.3	101.0	98.3	96.6	90.0
Organic volatiles	-	nd	nd	nd	nd	nd
CO2	-	1.8	3.3	5.1	8.1	11.5
Total recovery	106.3	104.1	104.3	103.4	104.7	101.5

Results are expressed as % applied radioactivity

-                               not applicable

nd                           not detected

Extracts 1 to 3      Tetradydrofuran, ambient temperature

 

 

Mean Proportions of Radioactive Components in Brierlow Soil

	Time after application (days)
	0	7	14	29	60	120
Test item (Rt ~20.3 mins)	100.1	94.4	90.5	87.9	86.3	79.6
Met 4 (Rt ~18.0 mins)	-	-	2.0	-	-	-
Met 1 (Rt ~19.5 mins)	-	-	-	1.1	-	-
Met 2 (Rt ~20.0 mins)	-	-	1.1	0.6	1.5	1.3
Others	4.6	5.2	4.6	4.5	4.2	3.4

Results are expressed as % applied radioactivity

Others Radioactivity distributed throughout regions of the chromatogram other than those specified and which did not contain any discrete radioactive components

-               Not apparent or below the limit of detection

Rt            HPLC retention time of component

 

 

Mean Distribution and Recovery of Radioactivity in Calke Soil

	Time after application (days)
	0	7	14	29	60	120
Extract 1	84.4	78.2	77.2	74.9	73.7	69.2
Extract 2	17.5	17.5	16.3	15.7	15.1	14.7
Extract 3	3.3	3.4	3.1	3.1	3.3	3.2
Total extractable	105.1	99.0	96.5	93.7	92.0	87.1
Non-extractable	0.9	2.8	3.4	4.1	4.7	5.1
Total in soil	106.0	101.8	99.9	97.8	96.7	92.2
Organic volatiles	-	nd	nd	nd	nd	nd
CO2	-	1.0	3.1	5.3	7.3	8.5
Total recovery	106.0	102.8	103.0	103.1	104.0	100.7

Results are expressed as % applied radioactivity

-                               not applicable

nd                           not detected

Extracts 1 to 3       Tetrahydrofuran, ambient temperature

 

 

 

Mean Proportions of Radioactive Components in Calke Soil

	Time after application (days)
	0	7	14	29	60	120
Test item (Rt ~20.3 mins)	101.3	94.1	92.0	86.3	85.6	76.0
Met 5 (Rt ~17.5 mins)	-	-	-	-	-	1.2
Met 4 (Rt ~18.0 mins)	-	-	-	-	-	1.9
Met 1 (Rt ~19.5 mins)	-	-	-	0.6	-	-
Met 2 (Rt ~20.0 mins)	-	-	-	1.3	0.7	1.4
Others	3.9	5.0	4.6	5.6	5.7	6.7

Results are expressed as % applied radioactivity

Others        Radioactivity distributed throughout regions of the chromatogram other than those specified and which did not contain any discrete radioactive components

-               Not apparent or below the limit of detection

 

 

 

Mean Distribution and Recovery of Radioactivity in Kennett Soil

	Time after application (days)
	0	7	14	29	60	120
Extract 1	93.1	90.4	87.9	87.0	81.0	66.8
Extract 2	12.7	12.0	11.4	11.4	10.7	9.0
Extract 3	1.6	1.4	1.4	1.4	1.4	1.2
Total extractable	107.4	103.7	100.7	99.8	93.0	77.0
Non-extractable	0.3	1.1	1.5	2.6	3.9	9.7
Total in soil	107.7	104.8	102.2	102.3	96.8	86.7
Organic volatiles	-	nd	nd	nd	nd	nd
CO2	-	0.6	1.3	2.4	4.9	12.4
Total recovery	107.7	105.4	103.5	104.7	101.7	99.1

Results are expressed as % applied radioactivity

-                               not applicable

nd                           not detected

Extracts 1 to 3      Tetrahydrofuran, ambient temperature

 

 

Mean Proportions of Radioactive Components in Kennett Soil

	Time after application (days)
	0	7	14	29	60	120
Test item (Rt ~20.3 mins)	100.5	97.8	95.5	93.9	84.3	68.9
Met 3 (Rt ~16.0 mins)	-	-	-	-	-	0.6
Met 4 (Rt ~18.0 mins)	-	-	-	-	-	0.8
Met 1 (Rt ~19.5 mins)	-	-	-	1.1	0.5	-
Met 2 (Rt ~20.0 mins)	-	-	-	-	1.5	2.4
Others	6.9	5.9	5.2	4.8	6.8	4.4

Results are expressed as % applied radioactivity

Others        Radioactivity distributed throughout regions of the chromatogram other than those specified and which did not contain any discrete radioactive components

-               Not apparent or below the limit of detection

 

 

Mean Distribution and Recovery of Radioactivity in South Witham Soil

	Time after application (days)
	0	7	14	29	60	120
Extract 1	84.5	80.4	77.6	73.4	71.7	62.4
Extract 2	16.2	14.8	15.5	14.6	12.5	12.2
Extract 3	3.6	3.2	3.4	3.1	2.8	2.5
Total extractable	104.3	98.3	96.5	91.0	86.9	77.1
Non-extractable	1.3	2.4	3.4	4.0	5.2	7.1
Total in soil	105.5	100.6	99.8	95.0	92.1	84.2
Organic volatiles	-	nd	nd	nd	nd	nd
CO2	-	1.2	3.0	5.8	10.2	15.4
Total recovery	105.5	101.8	102.8	100.8	102.3	99.6

Results are expressed as % applied radioactivity

-                               not applicable

nd                           not detected

Extracts 1 to 3      Tetrahydrofuran, ambient temperature

 

 

Mean Proportions of Radioactive Components in South Witham Soil

	Time after application (days)
	0	7	14	29	60	120
Test item (Rt ~20.3 mins)	99.2	92.9	91.8	84.8	81.5	71.5
Met 5 (Rt ~17.5 mins)	-	-	-	-	-	0.5
Met 4 (Rt ~18.0 mins)	-	-	-	-	-	0.7
Met 1 (Rt ~19.5 mins)	-	-	-	1.2	0.5	-
Met 2 (Rt ~20.0 mins)	-	-	-	0.5	0.9	0.6
Others	5.1	5.4	4.7	4.6	4.1	3.8

Results are expressed as % applied radioactivity

Others        Radioactivity distributed throughout regions of the chromatogram other than those specified and which did not contain any discrete radioactive components

-               Not apparent or below the limit of detection

 

Description of key information

DT50 = 226 and 418 days (OECD 307 under aerobic conditions).

Additional information

One simulation tests is available assessing the biodegradability of (Z)-N-octadec-9-enylhexadecan-1-amide (CAS No. 16260-09-6) in soil (OECD 308). The biodegradability of the substance was investigated in four different soils types, a clay loam, a loamy sand, a sandy loam and a silt loam. Total test duration was 120 days. (Z)-N-octadec-9-enylhexadecan-1-amide degraded slowly in four soils incubated under aerobic conditions with estimated DT50 values of between 226 and 418 days.The mineralisation rates of the substance ranged from 8.5% - 15.4% in the four different soil types.(Z)-N-octadec-9-enylhexadecan-1-amide (CAS No. 16260-09-6) was degraded to up to four low level unidentified transformation products (≤2.6% applied radioactivity), incorporated into bound (non-extractable) radioactivity and mineralized to carbon dioxide.