(Z)-pent-2-enenitrile

Phototransformation in water

Administrative data

Endpoint:

phototransformation in water

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study does not follow a particular guideline and is not GLP compliant. However, it is well described both in terms of experimental conditions and results, and allows to scientifically conclude on the results obtained during the algal study.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Study type:

other: Photo-degradation during an OECD 201 algal test

Principles of method if other than guideline:

Test design:
- 2 concentrations were tested: 100 and 500 mg/L
- 1 replicate with algae in the light (per conc.)
- 1 replicate with algae in the dark (per conc.)
- 1 replicate without algae in the light (per conc.)
- 1 replicate without algae in the dark (per conc.)
- Each replicate was divided in 5 test beakers with 50 mL each
- Light exclusion was achieved by completely coverage of the test beakers in the dark. They were completely wrapped in aluminium foil.
- All beakers were incubated at exactly the same conditions used in a normal Algae test
- Sampling after 0, 24, 48, and 72h
- Per sampling one beaker of each replicate was sacrificed (except at 0h where only one beaker representative for all replicates was sacrificed)
- Standby analysis of the test item after 0, 24, 48, 72 h with HPLC
- calibration with test item
- fortified samples with test item
- Standby analysis of total carbon content after 0, 24, 48, 72 h with TOC
- calibration with test item
- fortified samples with test item

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

(Z)-pent-2-enenitrile

EC Number:

247-323-5

EC Name:

(Z)-pent-2-enenitrile

Cas Number:

25899-50-7

Molecular formula:

C5H7N

IUPAC Name:

(2Z)-pent-2-enenitrile

Study design

Radiolabelling:

no

Analytical method:

high-performance liquid chromatography

other: Total Organic Carbon (TOC) analysis

Details on sampling:

- Sampling intervals: Both 2-pentenenitrile (2PN) and TOC were analysed after 0, 24, 48 and 72 hours.
- Sampling method: Each replicate of each treatment was divided in 5 test beakers intended to perform the analyses at the different times. Per sampling time, one beaker of each replicate was sacrificed (except at 0h where only one beaker representative for all replicates was sacrificed).
No further data.

Buffers:

No data

Light source:

other: as for the algae study (OECD 201)

Details on light source:

Neon ligth tubes as for a typical algae study (OECD 201). For futher details on light conditions, please refer to IUCLID section "6.1.5 Toxicity to aquatic algae and cyanobacteria" and the ESR relative to the study of Hoffmann & Deierling (2010).

In the case of treatment performed in the dark, light exclusion was achieved by completely coverage of the test beakers in the dark. They were completely wrapped in aluminium foil.

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test apparatus/vessels: 50 mL beakers
No further data

TEST MEDIUM
The same medium as in the algal test was used. For further details, please refer to IUCLID section "6.1.5 Toxicity to aquatic algae and cyanobacteria" and the ESR relative to the study of Hoffmann & Deierling (2010).

REPLICATION
- No. of replicates: 8 different treatments were applied:
* 100 mg/L 2PN - With Algae - In the light: 1 replicate
* 100 mg/L 2PN - With Algae - In the dark: 1 replicate
* 100 mg/L 2PN - Without Algae - In the light: 1 replicate
* 100 mg/L 2PN - Without Algae - In the dark: 1 replicate
* 500 mg/L 2PN - With Algae - In the light: 1 replicate
* 500 mg/L 2PN - With Algae - In the dark: 1 replicate
* 500 mg/L 2PN - Without Algae - In the light: 1 replicate
* 500 mg/L 2PN - Without Algae - In the dark: 1 replicate

Duration of test at given test condition

Duration of test at given test condition 1

Duration:

72 h

Initial conc. measured:

100 mg/L

Duration of test at given test condition 2

Duration:

72 h

Initial conc. measured:

500 mg/L

Reference substance:

no

Dark controls:

yes

Computational methods:

No data

Results and discussion

Transformation products:

not specified

Details on results:

TOC analysis:
- For an initial concentration of 500 mg/L: In the presence of algae, the TOC content decreased over time regardless the light conditions (light or darkness). In the absence of algae, this decrease is less pronounced, especially in the light.
- For an initial concentration of 100 mg/L: In the presence of algae, the decrease of TOC content was only observed in the light. The same trend was observed in the absence of algae.

HPLC analysis of 2PN:
- For an initial concentration of 500 mg/L: In the presence of algae, the 2PN concentration decreased over time regardless the light conditions (light or darkness). In the absence of algae, this decrease is less important, especially in the light.
- For an initial concentration of 100 mg/L: In the presence of algae, the 2PN concentration decreased over time regardless the light conditions. In the absence of algae, a decrease of the 2PN concentration was also observed, but it was less important than in the presence of algae, especially in the dark.

Any other information on results incl. tables

Table: Results for the determination of the test item in the test samples (HPLC)

Sample description					test item		calculated
	age				found		test item	nominal	% of
[mg/L]	day	[h]	light	algae	[mg/L]	D.F.	[mg/L]	[mg/L]	nominal
100	0	0			72.334	1	72.334	100.000	72
100	1	24	X	X	39.544	1	39.544	100.000	40
100	1	24		X	61.694	1	61.694	100.000	62
100	1	24	X		37.714	1	37.714	100.000	38
100	1	24			66.723	1	66.723	100.000	67
100	2	48	X	X	0.561	1	0.561	100.000	1
100	2	48		X	56.548	1	56.548	100.000	57
100	2	48	X		21.691	1	21.691	100.000	22
100	2	48			55.199	1	55.199	100.000	55
100	3	72	X	X	0.035	1	0.035	100.000	0
100	3	72		X	0.494	1	0.494	100.000	0
100	3	72	X		14.279	1	14.279	100.000	14
100	3	72			63.965	1	63.965	100.000	64
500	0	0			61.134	5	305.670	500.000	61
500	1	24	X	X	44.848	5	224.240	500.000	45
500	1	24		X	55.118	5	275.590	500.000	55
500	1	24	X		42.186	5	210.930	500.000	42
500	1	24			55.123	5	275.615	500.000	55
500	2	48	X	X	24.242	5	121.210	500.000	24
500	2	48		X	60.444	5	302.220	500.000	60
500	2	48	X		18.81	5	94.050	500.000	19
500	2	48			50.838	5	254.190	500.000	51
500	3	72	X	X	21.772	5	108.860	500.000	22
500	3	72		X	51.244	5	256.220	500.000	51
500	3	72	X		15.595	5	77.975	500.000	16
500	3	72			41.419	5	207.095	500.000	41

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Conclusions:

The results from the treatment testing a 100 mg/L concentration in conditions "Light and algae" suggest, at this concentration, the substance adsorbs on algae and undergoes a photo-transformation at the same time.

Executive summary:

Due to the disapearance of the substance in a previous algae study, a specific analytical experiment was conducted. Two different concentrations of the substance were tested (100 and 500 mg/L), with or without algae, in the light or in the dark (1 replicate for each concentration, for each experimental condition). Standby analyses of the test item were realized after 0, 24, 48, and 72 h with HPLC. Standby analyses of total carbon content were conducted after 0, 24, 48, and 72 h with TOC analysis. The measured concentration of 2PN at time 0 was only 63% of nominal, unlike in the main test where it was 92%. It is assumed that the reason is that the test vessels were not properly closed and volatilization of 2PN may have occurred. Seemingly, this may explain the variation in measurements, especially of TOC.

The results from treatment testing a 100 mg/L concentration in conditions "Light and algae" suggest that at this concentration the substance adsorbs on algae and undergoes a photo-transformation at the same time.