(Z)-N-octadecyldocos-13-enamide

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:

09 May 2019 to 12 May 2020

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:

2019

Soil no.:

#4

Soil type:

clay

% Org. C:

3.27

pH:

7.8

CEC:

25.8 meq/100 g soil d.w.

Bulk density (g/cm³):

1.13

% Moisture content:

39.3

Soil no.:

#3

Soil type:

loamy sand

% Org. C:

0.64

pH:

7.6

CEC:

5.1 meq/100 g soil d.w.

Bulk density (g/cm³):

1.37

% Moisture content:

15.5

Soil no.:

#2

Soil type:

sandy loam

% Org. C:

2.59

pH:

6.3

CEC:

16.8 meq/100 g soil d.w.

Bulk density (g/cm³):

1.04

% Moisture content:

33.3

Soil no.:

#1

Soil type:

silt loam

% Org. C:

4.96

pH:

5.8

CEC:

20.4 meq/100 g soil d.w.

Bulk density (g/cm³):

0.94

% Moisture content:

51.4

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:

119 d

Soil No.:

#3

Duration:

119 d

Soil No.:

#2

Duration:

119 d

Soil No.:

#1

Duration:

119 d

Soil No.:

#4

Initial conc.:

1.05 ppm

Based on:

test mat.

Soil No.:

#3

Initial conc.:

1.03 ppm

Based on:

test mat.

Soil No.:

#2

Initial conc.:

1.04 ppm

Based on:

test mat.

Soil No.:

#1

Initial conc.:

1.03 ppm

Based on:

test mat.

Parameter followed for biodegradation estimation:

radiochem. meas.

Soil No.:

#4

Temp.:

12°C

Microbial biomass:

1830 mg C/kg soil

Soil No.:

#3

Temp.:

12°C

Microbial biomass:

804 mg C/kg soil

Soil No.:

#2

Temp.:

12°C

Microbial biomass:

1270 mg C/kg soil

Soil No.:

#1

Temp.:

12°C

Microbial biomass:

821 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: 5 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, 28, 60 and 119 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

% Total extractable:

91.6

% Non extractable:

5

% CO2:

3

% Other volatiles:

0

% Recovery:

99.6

Soil No.:

#4

% Total extractable:

94.5

% Non extractable:

3.1

% CO2:

0

% Other volatiles:

0

% Recovery:

97.6

Soil No.:

#3

% Total extractable:

92

% Non extractable:

3.4

% CO2:

5.7

% Other volatiles:

0

% Recovery:

100

Soil No.:

#3

% Total extractable:

92.3

% Non extractable:

8

% CO2:

0

% Other volatiles:

0

% Recovery:

100

Soil No.:

#2

% Total extractable:

93.5

% Non extractable:

2.7

% CO2:

3.8

% Other volatiles:

0

% Recovery:

100

Soil No.:

#2

% Total extractable:

93.8

% Non extractable:

6.6

% CO2:

0

% Other volatiles:

0

% Recovery:

100

Soil No.:

#1

% Total extractable:

91.8

% Non extractable:

4.6

% CO2:

5

% Other volatiles:

0

% Recovery:

100

Soil No.:

#1

% Total extractable:

96.4

% Non extractable:

1.5

% CO2:

0

% Other volatiles:

0

% Recovery:

97.9

Parent/product:

parent

% Degr.:

0

Parameter:

radiochem. meas.

Sampling time:

119 d

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.

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.

Transformation products:

no

Remarks:

One minor unidentified component was detected and accounted for a mean of ≤1.8% applied radioactivity.

Details on transformation products:

One minor unidentified component was detected and accounted for a mean of ≤1.8% applied radioactivity. Test item was also 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	28	60	119
Extract 1	67.1	64.1	69.9	65.8	67.7	58.8
Extract 2	19.3	18.4	15.8	17.1	14.4	15.7
Extract 3	3.0	4.6	2.7	4.1	3.2	3.9
Extract 4	7.0	10.0	9.8	11.0	10.3	13.4
Total extractable	96.4	97.1	98.2	98.0	95.6	91.8
Non-extractable	1.5	2.3	2.7	2.7	3.0	4.6
Total in soil	97.9	99.4	100.9	100.7	98.6	96.4
Organic volatiles	-	nd	nd	nd	nd	nd
CO2	-	0.4	0.7	1.2	2.6	5.0
Total recovery	97.9	99.8	101.6	101.9	101.2	101.4

Results are expressed as % applied radioactivity

-                               not applicable

nd                           not detected

Extracts 1 to 3      Dichloromethane, ambient temperature

Extract 4                Tetrahydrofuran, ambient temperature

 

 

Mean Proportions of Radioactive Components in Brierlow Soil

	Time after application (days)
	0	7	14	28	60	119
Test item (Rt ~20.6 mins)	91.5	89.2	94.1	92.6	90.2	85.8
Unknown 1 (Rt ~18.4 mins)	1.2	1.3	0.6	-	0.9	1.8
Others (a)	0.6	1.9	0.7	1.3	1.4	0.4

Results are expressed as % applied radioactivity

(a) 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	28	60	119
Extract 1	79.1	75.7	75.5	76.8	75.5	70.4
Extract 2	12.7	11.6	10.8	9.7	10.4	10.8
Extract 3	2.0	3.1	1.9	2.3	2.0	2.7
Extract 4	-	-	7.6	7.6	8.4	9.6
Total extractable	93.8	90.4	95.8	96.4	96.3	93.5
Non-extractable	6.6	9.1	1.9	1.9	2.1	2.7
Total in soil	100.4	99.5	97.7	98.3	98.4	96.2
Organic volatiles	-	nd	nd	nd	nd	nd
CO2	-	0.3	0.6	1.0	2.0	3.8
Total recovery	100.4	99.8	98.3	99.3	100.4	100.0

Results are expressed as % applied radioactivity

-                               not applicable

nd                           not detected

Extracts 1 to 3      Dichloromethane, ambient temperature

Extract 4                Tetrahydrofuran, ambient temperature

 

 

 

Mean Proportions of Radioactive Components in Calke Soil

	Time after application (days)
	0	7	14	28	60	119
Test item (Rt ~20.6 mins)	89.2	84.9	93.1	93.1	92.8	90.6
Unknown 1 (Rt ~18.4 mins)	0.9	0.6	0.5	0.6	0.7	-
Others (a)	1.9	1.8	0.2	0.4	0.8	0.1

Results are expressed as % applied radioactivity

(a) 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 Kennett Soil

	Time after application (days)
	0	7	14	28	60	119
Extract 1	79.5	79.6	80.2	78.3	76.0	65.0
Extract 2	10.5	9.1	8.5	9.0	9.3	10.1
Extract 3	2.3	2.2	2.3	2.9	2.3	3.9
Extract 4	-	-	-	-	7.5	13.0
Total extractable	92.3	90.9	91.0	90.2	95.1	92.0
Non-extractable	8.0	10.5	10.6	11.0	2.2	3.4
Total in soil	100.3	101.4	101.6	101.2	97.3	95.4
Organic volatiles	-	nd	nd	nd	nd	nd
CO2	-	0.3	0.8	1.5	3.3	5.7
Total recovery	100.3	101.7	102.4	102.7	100.6	101.1

Results are expressed as % applied radioactivity

-                               not applicable

nd                           not detected

Extracts 1 to 3      Dichloromethane, ambient temperature

Extract 4                Tetrahydrofuran, ambient temperature

 

 

Mean Proportions of Radioactive Components in Kennett Soil

	Time after application (days)
	0	7	14	28	60	119
Test item (Rt ~20.6 mins)	87.6	86.2	88.3	85.6	89.7	87.8
Unknown 1 (Rt ~18.4 mins)	0.3	1.0	0.4	0.3	0.7	-
Others (a)	2.1	1.6	0.0	1.4	2.4	0.2

Results are expressed as % applied radioactivity

(a) 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 South Witham Soil

	Time after application (days)
	0	7	14	28	60	119
Extract 1	76.0	73.7	75.6	70.6	73.3	54.5
Extract 2	8.0	8.7	9.1	11.7	8.3	11.1
Extract 3	2.0	2.2	1.3	2.6	2.6	3.4
Extract 4	8.5	12.4	9.7	10.8	9.8	22.6
Total extractable	94.5	97.0	95.7	95.7	94.0	91.6
Non-extractable	3.1	3.2	4.9	3.3	4.6	5.0
Total in soil	97.6	100.2	100.6	99.0	98.6	96.6
Organic volatiles	-	nd	nd	nd	nd	nd
CO2	-	0.3	0.5	1.0	1.8	3.0
Total recovery	97.6	100.5	101.1	100.0	100.4	99.6

Results are expressed as % applied radioactivity

-                               not applicable

nd                           not detected

Extracts 1 to 3      Dichloromethane, ambient temperature

Extract 4                Tetrahydrofuran, ambient temperature

 

 

Mean Proportions of Radioactive Components in South Witham Soil

	Time after application (days)
	0	7	14	28	60	119
Test item (Rt ~20.6 mins)	90.6	92.6	94.4	92.5	89.3	88.1
Unknown 1 (Rt ~18.4 mins)	0.7	0.4	-	0.2	0.2	-
Others (a)	1.0	1.9	0.0	0.4	2.0	0.1

Results are expressed as % applied radioactivity

(a) 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

 

Description of key information

There was no significant decline in the levels of test item in the four soils incubated under aerobic conditions. Test item was detected at a mean of between 87.6 and 91.5% applied radioactivity at time zero and between 85.8 and 90.6% after 119 days of incubation. One minor unidentified component was detected and accounted for a mean of ≤1.8% applied radioactivity. Test item was also incorporated into bound (non-extractable) radioactivity and mineralized to carbon dioxide. Only minor degradation is observed. Volatile radioactivity, 14CO2, accounted for a maximum of 5.7 % applied radioactivity after 119 days.

Additional information

The biodegradation in four aerobic soil of (Z)-N-octadecyldocos-13-enamide (CAS 10094-45-8) has been studied in four soils under laboratory conditions at 12°C according to OECD 307 (Covance, 2020). The degradation of 14C-labelled test item was measured in four soils in order to derive DT50-values.

Mean total recoveries of radioactivity (mass balances) for the four soils were between 97.6% and 102.7% applied radioactivity.

The proportion of radioactivity extracted from soil accounted for a mean of ≥ 90.2 % applied radioactivity throughout.  Mean non-extractable radioactivity accounted for a mean of ≤ 11.0 % applied radioactivity throughout. Volatile radioactivity, 14CO2, accounted for a maximum of 5.7 % applied radioactivity after 119 days.

There was no significant decline in the levels of test item in the four soils incubated under aerobic conditions. The test item was detected at a mean of between 87.6 and 91.5% applied radioactivity at time zero and between 85.8 and 90.6% after 119 days of incubation.

One minor unidentified component was detected and accounted for a mean of ≤1.8% applied radioactivity. The test item was also incorporated into bound (non-extractable) radioactivity and mineralized to carbon dioxide.