2-methylpyridine

Toxicity to aquatic plants other than algae

Administrative data

Endpoint:

toxicity to aquatic plants other than algae

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published in peer reviewed literature, minor restrictions in design and/or reporting but otherwise adequate for assessment

Data source

Reference

Reference Type:

publication

Title:

Comparative Chronic Toxicity of Pyridine, α-Picoline, and β-Picoline to Lemna minor L. and Chlorella vulgaris B

Author:

Singh and Chandra

Year:

2005

Bibliographic source:

Bull. Environ. Contam. Toxicol. (2005) 75:482–489

Materials and methods

Test guideline

Qualifier:

no guideline followed

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

2-methylpyridine

EC Number:

203-643-7

EC Name:

2-methylpyridine

Cas Number:

109-06-8

Molecular formula:

C6H7N

IUPAC Name:

2-methylpyridine

Details on test material:

- Name of test material (as cited in study report): α-picoline

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
120 x 15 mm-petri-dish with 100 mL in double strength algal growth medium without EDTA containing different concentrations test substance.

Test organisms

Test organisms (species):

Lemna minor

Details on test organisms:

TEST ORGANISM
- Common name: Duckweed
- Strain: Lemna minor L.
- Source: Collected form pollution free sites. Water samples were taken to confirm that the water bodies were not loden with pollutants.
- Method of cultivation: The duckweed test specimens were selected from the axenic stock culture 24 h before the actual test. Selection criteria were healthy-looking and two fronds of approximately equal size per colony.

ACCLIMATION
- Acclimation period: 4 weeks
- Culture media: double strenght algal growth medium without EDTA

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

14 d

Test conditions

Hardness:

245 ± 14 mg/L

Test temperature:

25 ± 2 °C

pH:

8.1 ± 0.2

Nominal and measured concentrations:

- Nominal concentrations (v/v): 0.00125, 0.0025, 0.005, 0.0125, 0.025, 0.0375, and 0.05%
- Nominal concentrations mg/L: approx. 11.75, 23.5, 47, 117.5, 235, 352.5, and 470 (calculated with the density 0.94 g/cm3)
- Analytical concentrations: not determined

Details on test conditions:

TEST SYSTEM
- Test vessel: 120 x 15 mm-petri-dish
- No. of organisms per vessel: 50 colonies
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3
- Shaking rate: Twice daily by hand

GROWTH MEDIUM
- double strength algal growth medium

OTHER TEST CONDITIONS
- Photoperiod: 12hr light/12 hr dark
- Light intensity and quality: Cool, white and fluorescent. 115 µmol photon / m-2·s-1

EFFECT PARAMETERS MEASURED
- Determination of cell concentrations: Protein content was determined in accordance with method described by Bradford (1976)
- Chlorophyll measurement: Total chlorophyll content was determined by acetone (80%) extraction.
- Biomass: determined by the dry weight method.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

14 d

Dose descriptor:

IC50

Effect conc.:

ca. 836.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Duration:

14 d

Dose descriptor:

IC50

Effect conc.:

ca. 780.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Chlorophyll

Effect concentrations 3

Duration:

14 d

Dose descriptor:

IC50

Effect conc.:

ca. 554.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: protein

Reported statistics and error estimates:

Data were statistically analysed by an overall one-way analysis of variance (ANOVA) and when differences observed were significant, the means were compared by the Tukey-Kramer Multiple Ccomparison Test. IC50 values were graphically estimated.