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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-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
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

Constituent 1
Chemical structure
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 conditionopen allclose all
Duration:
72 h
Initial conc. measured:
100 mg/L
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.