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

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: sediment simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 308 (Aerobic and Anaerobic Transformation in Aquatic Sediment Systems)

Version / remarks:

2002

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

natural water / sediment: freshwater

Details on source and properties of surface water:

- Location : Calwich Abbey Lake UK, Emperor Lake UK
- Storage conditions: 5 ± 3°C
- pH at time of collection: 7.79 in Calwich Abbey Lake UK, not given for Emperor Lake UK
- Oxygen concentration (% saturation) initial/final: not given
- Water filtered: yes
- Type and size of filter used, if any: Prior to use the sediment was passed through a 2 mm sieve and the water was passed through a 0.2 mm sieve.

Details on source and properties of sediment:

- Location : Calwich Abbey Lake UK, Emperor Lake UK
- Storage conditions: 5 ± 3°C
- Textural classification (i.e. %sand/silt/clay): Silt Loam for Calwich Abbey Lake & Sandy clay loam for Emperor Lake
- Organic carbon (%): 4.4 and 2.8 for CAL and EL respectively
- CEC (meq/100 g): 12.1 and 9.7 for CAL and EL respectively
- Bulk density (g/cm³): not determined
- Sediment samples sieved: yes

Duration of test (contact time):

105 d

Initial conc.:

10 µg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

radiochem. meas.

Details on study design:

TEST CONDITIONS
- Composition of medium:
Calwich Abbey Lake Emperor Lake
Total organic carbon (mg/L) 5.43 8.46
Total nitrogen (mg/L) 3.33 1.01
Total phosphorus (mg/L) 0.02 0.02
Total suspended solids (mg/L) 8.5 46.0
Hardness as CaCO3 (mg/L) 260 46.4

- Test temperature: 12 °C
- pH: pH in water 7.79 (CAL); not determined (EL)
- pH adjusted: no
- CEC (meq/100 g): 12.1 (meq/100 g) (CAL) and 9.7 (meq/100 g) (EL)
- Aeration of dilution water: yes
- Suspended solids concentration: Total suspended solids (mg/L) 10 for CAL & 4 for EL
- Continuous darkness: yes
- Any indication of the test material adsorbing to the walls of the test apparatus: no
- Test performed in closed vessels due to significant volatility of test substance: yes
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: 4. Vessel containing 1 M aqueous potassium hydroxide solution with phenolphthalein indicator (to trap 14CO2)

SAMPLING
- Sampling frequency: Duplicate samples of each aquatic sediment were taken for analysis immediately after test item application and after 1, 7, 14, 29, 60 and 105 days of incubation.
- Sampling method used per analysis type: Trapping media were taken for analysis with the associated samples at sampling. In addition, trapping media associated with all remaining vessels were taken for analysis and replaced with fresh media at 14, 29, 46, 60, 74, 88 and 105 days after application.
- Sample storage before analysis: Aqueous samples and sediment extracts were stored at 5 ± 2°C prior to analysis.

DESCRIPTION OF CONTROL AND/OR BLANK TREATMENT PREPARATION
CONTROL AND BLANK SYSTEM
- same as test item

Compartment:

natural water / sediment: freshwater

% Total extractable:

37.7

% Non extractable:

8.2

% CO2:

40.6

% Other volatiles:

0

% Recovery:

87.3

Remarks on result:

other: 105 d - Emperor Lake

Compartment:

natural water / sediment: freshwater

% Total extractable:

11.7

% Non extractable:

1.4

% CO2:

0

% Other volatiles:

0

% Recovery:

93.3

Remarks on result:

other: 0 d - Emperor Lake

Compartment:

natural water / sediment: freshwater

% Total extractable:

33.6

% Non extractable:

7.3

% CO2:

42

% Other volatiles:

0

% Recovery:

84.8

Remarks on result:

other: 105 d - Calwich Abbey Lake

Compartment:

natural water / sediment: freshwater

% Total extractable:

14

% Non extractable:

1.7

% CO2:

0

% Other volatiles:

0

% Recovery:

96.4

Remarks on result:

other: 0 d - Calwich Abbey Lake

Compartment:

natural water / sediment: freshwater

DT50:

25.2 d

Type:

not specified

Temp.:

12 °C

Remarks on result:

other: Emperor Lake (whole system)

Compartment:

natural water / sediment: freshwater

DT50:

19.6 d

Type:

not specified

Temp.:

12 °C

Remarks on result:

other: Calwich Abbey Lake (whole system)

Transformation products:

no

Remarks:

Test item was degraded to five low level unidentified degradates (≤3.5% applied radioactivity), incorporated into bound (non-extractable) radioactivity and mineralized to carbon dioxide.

Details on transformation products:

Test item was degraded to five low level unidentified degradates (≤3.5% applied radioactivity), incorporated into bound (non-extractable) radioactivity and mineralized to carbon dioxide.

Evaporation of parent compound:

no

Volatile metabolites:

no

Details on results:

TEST CONDITIONS
- Aerobicity, moisture, temperature and other experimental conditions maintained throughout the study: Yes
- Anomalies or problems encountered (if yes): The temperature of the incubation room during the acclimatization phase of the preliminary experiment deviated from the acceptable range of 12 ± 2ºC on several occasions. This deviation occurred between the 10 May 2019 to 14 May 2019 (5 days). The maximum temperature reached was 14.9°C and the maximum duration of temperature excursion from the acceptable range was approximately 10 hours 16 minutes.
This deviation was not considered to have affected the outcome of the study.


MAJOR TRANSFORMATION PRODUCTS
- none

MINOR TRANSFORMATION PRODUCTS
Test item was degraded to two low level unidentified degradates (≤0.5% applied radioactivity), incorporated into bound (non-extractable) radioactivity and mineralized to carbon dioxide.

Microbiological Characterization of the Aquatic Sediments

Start of incubation

 

	Calwich Abbey Lake		Emperor Lake
	Sediment	Water	Sediment	Water
Aerobic bacteria	6.95×10^5	1.15×10^2	3.60×10^6	4.85×10^2
Aerobic bacterial spores	5.95×10^4	10	4.50×10^5	15
Anaerobic bacteria	1.80×10^5	nm	1.17×10^5	nm
Anaerobic bacterial spores	6.25×10^4	nm	1.07×10^5	nm
Actinomycetes	3.85×10^4	<10	1.85×10^4	<10
Fungi	3.65×10^4	<10	2.70×10^2	<10

 

End of incubation (untreated)

 

	Calwich Abbey Lake		Emperor Lake
	Sediment	Water	Sediment	Water
Aerobic bacteria	2.90x10^5	4.40x10^2	8.90x10^5	80
Aerobic bacterial spores	2.75x10^5	25	3.60x10^5	40
Anaerobic bacteria	6.65x10^4	nm	5.20x10^4	nm
Anaerobic bacterial spores	9.55x10^3	nm	3.15x10^4	nm
Actinomycetes	5.85x10^3	<10	2.40x10^4	<10
Fungi	2.00x10^3	<10	3.50x10^4	<10

 

End of incubation (solvent treated)

 

	Calwich Abbey Lake		Emperor Lake
	Sediment	Water	Sediment	Water
Aerobic bacteria	3.30x10^5	50	1.05x10^6	1.05x10^2
Aerobic bacterial spores	3.35x10^4	15	6.40x10^4	25
Anaerobic bacteria	7.10x10^4	nm	5.95x10^4	nm
Anaerobic bacterial spores	6.30x10^4	nm	5.75x10^4	nm
Actinomycetes	6.05x10^3	<10	3.75x10^3	<10
Fungi	1.75x10^3	<10	2.95x10^4	<10

Results are expressed as colony forming units/g

nm          not measured

 

 

 

 

Mean Distribution and Recovery of Radioactivity in Calwich Abbey Lake Aquatic Sediment

	Time after application (days)
	0	1	7	14	29	60	105
Water	80.8	85.1	49.4	12.4	11.6	5.3	1.2
Sediment:
Extract 1	9.7	5.2	21.3	32.7	31.9	25.2	20.0
Extract 2	4.3	2.1	9.2	13.5	11.8	11.2	9.3
Extract 3	-	-	-	4.1	4.7	3.2	3.2
Extract 4	-	-	-	-	-	-	1.2
Vessel Rinse	-	-	-	-	-	-	0.8
Total extractable	14.0	7.2	30.4	50.2	48.4	39.5	33.6
Non-extractable	1.7	0.6	6.0	9.7	7.7	9.2	7.3
Total in sediment	14.7	8.2	36.4	59.9	56.0	48.7	40.8
Organic volatiles	-	nd	nd	nd	nd	0.1	nd
CO2	-	0.6	4.2	12.0	13.4	31.6	42.0
Total recovery	96.4	93.4	90.0	84.3	81.0	85.6	84.8

Results are expressed as % applied radioactivity

-               not applicable

nd           not detected

Extracts 1 – 3    Tetrahydrofuran

Extract 4      Dichloromethane

Vessel rinse     Tetrahydrofuran

 

 

 

Mean Distribution and Recovery of Radioactivity in Emperor Lake Aquatic Sediment

	Time after application (days)
	0	1	7	14	29	60	105
Water	80.2	85.9	42.5	23.0	13.4	4.2	0.3
Sediment:
Extract 1	8.3	6.9	24.3	24.5	24.9	24.5	22.1
Extract 2	3.5	2.7	9.4	16.3	10.0	12.1	9.6
Extract 3	-	-	3.9	7.2	5.4	4.4	4.0
Extract 4	-	-	-	-	0.6	1.4	2.1
Vessel Rinse	-	-	-	-	-	-	0.5
Total extractable	11.7	9.5	37.6	49.0	40.8	42.3	37.7
Non-extractable	1.4	nd	6.8	9.3	9.7	9.8	8.2
Total in sediment	13.1	9.5	44.4	58.2	50.4	52.1	46.0
Organic volatiles	-	nd	nd	nd	nd	nd	nd
CO2	-	0.2	9.6	9.2	24.4	30.0	40.6
Total recovery	93.3	95.6	96.5	90.4	88.2	86.2	87.3

Results are expressed as % applied radioactivity

-               not applicable

nd           not detected

Extracts 1 – 3    Tetrahydrofuran

Extract 4      Dichloromethane

Vessel rinse     Tetrahydrofuran

 

 

 

Mean Proportions of Radioactive Components in Calwich Abbey Lake Aquatic Sediment

Water Phase

 

	Time after application (days)
	0	1	7	14	29^a	60	105
Test item (Rt ~20.3 mins)	77.2	79.7	44.6	2.3	-	NA	NA
Polar (Rt  ~2 - 4 mins)	-	-	1.9	10.2	-
Met 1 (Rt  ~19.0 mins)	-	-	1.3	-	-
Others	3.6	5.4	1.7	-	6.9

 

Sediment Phase

 

	Time after application (days)
	0	1	7	14	29	60	105
Test item (Rt ~20.3 mins)	13.2	7.2	26.9	42.8	42.8	38.7	31.7
Met 2  (Rt ~4.0 mins)	-	-	0.3	1.2	1.0	0.3	-
Met 4  (Rt ~12.0 mins)	-	-	-	0.6	-	-	-
Met 4  (Rt ~19.0 mins)	-	-	0.8	0.9	0.8	-	-
Others	0.8	-	2.0	4.8	3.9	0.5	0.7

 

Total System

 

	Time after application (days)
	0	1	7	14	29	60	105
Test item (Rt ~20.3 mins)	90.3	86.9	71.5	45.0	42.8	38.7	31.7
Polar  (Rt ~2 - 4 mins)	-	-	-	10.2	-	-	-
Met 2  (Rt ~ 4.0 mins)	-	-	2.2	1.2	1.0	0.3	-
Met 4  (Rt ~ 12.0 mins)	-	-	-	0.6	-	-	-
Met 1  (Rt ~ 19.0 mins)	-	-	2.0	0.9	0.8	-	-
Others	4.4	5.4	4.2	4.8	10.8	0.5	0.7

Results are expressed as % applied radioactivity

(a)          From one replicate analysis

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

NA          Not analyzed (insufficient radioactivity, <10% applied radioactivity)

 

 

 

 

Mean Proportions of Radioactive Components in Emperor Lake Aquatic Sediment

Water Phase

 

	Time after application (days)
	0	1	7	14	29^a	60	105
Test item (Rt ~20.3 mins)	77.4	81.1	39.7	19.4	8.0	NA	NA
Polar (Rt ~2 - 4 mins)	-	-	-	0.9	0.5
Met 5 (Rt ~6.0 mins)	-	-	-	-	0.3
Met 1 (Rt ~19.0 mins)	-	-	1.8	0.8	-
Others	2.9	4.8	1.0	2.1	-

 

Sediment Phase

 

	Time after application (days)
	0	1	7	14	29	60	105
Test item (Rt ~20.3 mins)	11.3	8.9	28.2	43.0	35.4	38.2	35.0
Polar (Rt ~2 - 4 mins)	-	-	-	-	-	-	-
Met 2 (Rt ~ 4.0 mins)	-	-	0.5	0.7	0.9	0.6	-
Met 3 (Rt ~ 15.0 mins)	-	-	0.4	-	-	-	-
Met 1 (Rt ~ 19.0 mins)	-	-	1.7	1.7	1.1	0.4	0.3
Others	0.5	0.6	3.1	3.7	2.9	1.8	0.4

 

Total System

 

	Time after application (days)
	0	1	7	14	29	60	105
Test item (Rt ~20.3 mins)	88.6	90.0	67.9	62.4	43.4	38.2	35.0
Polar (Rt ~ 2 - 4 mins)	-	-	-	0.9	0.5	-	-
Met 2 (Rt ~ 4.0 mins)	-	-	0.5	0.7	0.9	0.6	-
Met 5 (Rt ~ 6.0 mins)	-	-	-	-	0.3	-	-
Met 3 (Rt ~ 15.0 mins)	-	-	0.4	-	-	0.4	0.3
Met 1 (Rt ~ 19.0 mins)	-	-	3.5	2.6	1.1	1.8	0.4
Others	2.0	5.4	4.1	5.7	2.9

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

a              From one replicate analysis

NA          Not Analyzed (insufficient radioactivity <10% applied radioactivity)

 

 

 

 

Kinetic Data for the Decline of Test item in Aquatic Sediment Systems

Test item

Aquatic sediment	Compartment	Kinetic model	DT50 (days)	DT90 (days)
Calwich Abbey Lake	water	SFO	5.1	16.8
Emperor Lake	water	DFOP	5.2	>10,000
Calwich Abbey Lake	sediment	SFO	176	583
Emperor Lake	sediment	SFO	426	1410
Calwich Abbey Lake	total system	DFOP	19.6	637
Emperor Lake	total system	DFOP	25.2	911

(note knietic analysis data was not to GLP)

Kinetic models:    SFO = single first order

                                FOMC = first order multi compartment

 

 

 

 

 

Validity criteria:

- Recoveries should range from 90% to 110% for labelled chemicals and from 70% to 110% for non-labelled chemicals.

Observed value:

the sum of radioactivity in the water layer, extractable and non-extractable radioactivity in sediment and volatile radioactivity) were between 81.0% to 95.5%

Validity criteria fulfilled:

yes

Description of key information

DT50 = 19.6 – 25.2 days (OECD 308)

Mineralisation 40.6 – 42% at 105 days (OECD 308)

Additional information

One simulation test is available assessing the biodegradability of (Z)-N-octadec-9-enylhexadecan-1-amide (CAS No. 16260-09-6) in water and sediment (OECD 307). The fate of the substance was investigated in two different water sediment systems; asandy clay loam (Calwich Abbey Lake) and a silt loam(Emperor Lake). The systems were incubated for 105 days in darkness. (Z)-N-octadec-9-enylhexadecan-1-amide dissipated rapidly from the water of aquatic sediment systems with estimated DT50 values of 5.1 days (Calwich Abbey Lake) and 5.2 days (Emperor Lake). Decline in the total water/sediment system corresponded to estimated DT50 values of 19.6 days (Calwich Abbey Lake) and 25.2 days (Emperor Lake).
The substance was degraded to polar material (≤10.2% AR), five low level unidentified transformation products (≤3.5% AR), incorporated into bound (non-extractable) radioactivity and mineralized to carbon dioxide.A mineralisation of the test substance of 40.6% after 105 days were determined in theEmperor lake system. In the Calwich Abbey Lake system the substance 42% of the substance were mineralized to CO2 by day 105. The polar material was shown to be comprised of multiple components with each component representing <10% AR.