tetraammine platinum (II) hydrogen carbonate

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-compliant, guideline study, available as unpublished report, adequate for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

not specified

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

123439-82-7

Cas Number:

123439-82-7

IUPAC Name:

123439-82-7

Constituent 2

Reference substance name:

Tetrammine platinum (II) hydrogen carbonate

IUPAC Name:

Tetrammine platinum (II) hydrogen carbonate

Test material form:

solid

Remarks:

powder

Details on test material:

- Description: white powder

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples of the algal populations were removed daily and absorbance values determined for each control and treatment group. Furthermore, water samples were taken from the control and each test groups (the three replicates were pooled) at 0 and 72 hours for quantitative analysis.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: An amount of test material (160 mg) was dispersed in culture medium and the volume adjusted to 500 mL to give a 320 mg/L stock solution. The following stock solutions were then prepared by serial dilution: 160, 80, 40, and 20 mg/L.
An aliquot (250 mL) of each stock solution was then separately mixed with 250 mL of algal suspension to give the test concentrantions of 10, 20, 40, 80 and 160 mg/L.
- Controls: test medium without the test item

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: CCAP 276/20
- Source (laboratory, culture collection): liquid cultures of Scenedesmus subspicatus were obtained from the Culture Centre for Algae and Protozoa (CCAP), Institute of Freshwater Ecology, Ferry House, Ambleside, Cumbria.

HOLDING CONDITIONS PRIOR TO TEST
Cultures were maintained in the laboratory by the replenishment of culture medium approximately once per week. The culture was maintained in the laboratory at a temperature of 21 ± 1 °C under continuous illumination (intensity approximately 7000 lux) and constant aeration.

LIFE STAGE OF TEST SPECIES USED
Pre-culture conditions gave an algal suspension in log phase growth characterised by an absorbance of 1.998 (at 665 nm). This suspension was diluted to an absorbance of 0.030 prior to use. At test start the culture contained a nominal cell density of 1000 cells/mL.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

24 °C

pH:

7.6 - 10.2

Nominal and measured concentrations:

Nominal concentrations: 10, 20, 40, 80 and 160 mg test item/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass conical flasks
- Type: covered with aluminium foil
- Fill volume: 100 ml of test solution
- Initial cells density: 50000/mL
- Control end cells density: 2000000/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Photoperiod: continuous illumination
- Light intensity and quality: at approximately 7000 lux
- Test vessels were constantly shaken at 100 rpm

EFFECT PARAMETERS MEASURED: the cell densities of the controls and test concentrations cultures were determined every 24 hours by direct counting with the aid of a haemocytometer and using a spectrophotometer, respectively.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study
- Test concentrations: 0.010, 0.10, 1.0, 10 and 100 mg test item/L
- Results used to determine the conditions for the definitive study: results showed no effect on growth at test concentrations of 0.010, 0.10, 1.0 and 10 mg test item/L. Growth was observed to be reduced at 100 mg test item/L.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

50.64 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

pt

Basis for effect:

biomass

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC50

Remarks:

24-48 h

Effect conc.:

280 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Extrapolated value

Effect concentrations 4

Key result

Duration:

48 h

Dose descriptor:

EC50

Remarks:

24-48 h

Effect conc.:

141.79 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Pt

Basis for effect:

growth rate

Remarks on result:

other: Extrapolated value

Effect concentrations 5

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

40 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 6

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

20.25 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Pt

Basis for effect:

growth rate

Effect concentrations 7

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

17.5 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

Pt

Basis for effect:

growth rate

Remarks on result:

other: self estimated using TRAP v1.30a

Details on results:

The EC50 for growth rate was determined by extrapolation as less than 50 % inhibition occurred over the test concentrations range.

Reported statistics and error estimates:

Statistical analysis of the area under the growth curve was carried out for the control and all test concentrations using one-way analysis of variance. The test concentrations of 60, 80 and 160 mg test item/L were found to be significantly different (p < 0.05) from the control groups.

Any other information on results incl. tables

Table 1. Mean cell density and absorbance values of the control cultures measured every 24 hours

Control	0 h	24 h	48 h	72 h
Mean cell density (cells/mL)	5.87 x 10^4	5.86 x 10^4	2.59 x 10^5	2.10 x 10^6
Mean absorbance value	0.026	0.035	0.149	0.740

Table 2. Inhibition of growth determined by tetraammineplatinum (2 +) hydrogencarbonate to Scenedesmus subspicatus

Nominal concentrations (mg test item/L)	Area under curve at 72 h	% inhibition	Growth rate (24 - 48 h)	% inhibition
Control	11.960	-	0.063	-
10	11.640	3	0.063	0
20	9.752	18	0.060	5
40	9.936	17	0.054	14
80	6.756	44	0.053	16
160	3.484	71	0.044	30

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

Based on nominal concentrations, the 72-hour EC50 of tetraammineplatinum(2+) hydrogencarbonate to Scenedesmus subspicatus was determined to be 100 mg test item/L (50.64 mg Pt/L) for biomass. The 24/48-hour EC50 for growth rate was extrapolated to be 280 mg test item/L corresponding to 141.79 mg Pt/L. The 72h EC10 value was self-calculated as 17.5 mg Pt/L (using TRAP v1.30a).

Executive summary:

A 72-hour algal growth inhibition test was conducted with Scenedesmus subspicatus for tetraammineplatinum(2+) hydrogencarbonate.The study is reliable without restrictions, being GLP-compliant, and having followed standard test guidelines (OECD 201 and EU Method C.3).

Based on a range-finding test, five test concentrations were used and these were analysed using HPLC. Measured test concentrations were found to be in excess of the required 80 % of nominal, and therefore results were based on nominal concentrations. The 72-hour EC50 for biomass was estimated to be 100 mg test item/L (50.64 mg Pt/L), and the 24/48-hour EC50 for growth rate was extrapolated to be 280 mg test item/L corresponding to 141.79 mg Pt/L. The 72-hour NOEC was determined to be 40 mg test item/L (20.25 mg Pt/L). The 72h EC10 value was self-calculated as 17.5 mg Pt/L (using TRAP v1.30a).