Registration Dossier

Administrative data

Endpoint:
additional ecotoxicological information
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Solubility trials in ecotoxicity test media

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report Date:
2016

Materials and methods

Principles of method if other than guideline:
The study consisted of solubility trials used to determine the maximum solubility of the test item under different treatment regimes, suitable for ecotoxicology tests, with separate analysis of platinum and the organic ligand.
GLP compliance:
no
Type of study / information:
Solublity trial for ecotoxicity studies

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid

Results and discussion

Any other information on results incl. tables

Table 1: Measured DVTMDS (organic ligand) concentrations in aqueous samples

 Sampling date  Incubation time (h)

 Decanted (µg/L)

 Filtered (µg/L)

 Centrifuged (µg/L)

 Stock solution, shaken up (µg/L)

 19_09_2016

 0

48.76

 <LOQ

 2.25

 -

 

 20_09_2016

 24

 2.41

 <LOQ

 <LOQ

7.13

 

 21_09_2016

 48

 <LOQ

 <LOQ

 <LOQ

6.12

 

  22_09_2016

 72

 <LOQ

 <LOQ

 <LOQ

4.13 

 23_09_2016

 96

 <LOQ

 <LOQ

 <LOQ

2.74

 

Table 2 Measured Pt concentrations in aqueous samples

 Sampling date  Incubation time (h)

 Decamted Pt conc  

(µg/L)

 Filtered Pt conc  

(µg/L)

Centrifuged Pt conc  

(µg/L)

 19_09_2016

 45.164

 3.901

 6.474

 

 20_09_2016

 24

 7.466

 4.480

 5.173

 

 21_09_2016

 48

 6.554

 5.377

 9.432

 

22_09_2016 

 72

 9.208

 6.988

 8.123

 

 23_09_2016

 96

 7.025

 5.561

 6.188

 

Applicant's summary and conclusion

Conclusions:
Following 96 hour solubility trials, the organic ligand could only be detected in a very small number of samples at the start of the study and platinum could be detected at very low concentrations.
Executive summary:

96 hour solubility trials were conducted using test media representative of that used in ecotoxicity studies (Cu-free water with adjusted pH 6, as this reflects the lowest pH acceptable for an algae test with the highest expected solubility), and three methods of separation (filtration, centrifugation and settling by gravity) (Kotthoff 2016). Samples were taken at 24 hour intervals; platinum was analysed by ICP-MS and the organic ligand by GC-MS. The study does not follow a standard test guideline and is not GLP-compliant, but is used as supporting information for the ecotoxicity endpoints for this substance.

The organic ligand was only detected at levels >LOQ in one of the centrifuged samples at the start of the test, and was not detected in any of the filtered samples. Platinum was detected at low levels (3.901 - 9.43 µg/L for filtered and centrifuged samples). Concentrations were higher for the decanted samples, but this is believed to be due to the presence of undissolved test item.