Ammonium mercaptoacetate

Additional information on environmental fate and behaviour

Administrative data

Endpoint:

additional information on environmental fate and behaviour

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Determination of the reaction rate for the oxidation of ATG in aereated water by HPLC

GLP compliance:

no

Remarks:

The central laboratory was quality audited regarding ISO 9001:2000 by TÜV-Cert in June 2007, audit May 2009.

Test material

Test material information

Constituent 1

Reference substance name:

Ammonium mercaptoacetate

EC Number:

226-540-9

EC Name:

Ammonium mercaptoacetate

Cas Number:

5421-46-5

Molecular formula:

C2H4O2S.H3N

IUPAC Name:

ammonium 2-sulfanylacetate

Details on test material:

- Name of test material (as cited in study report): Ammonium thioglycolate 71%
- Physical state: liquid
- Analytical purity: 71.26 (iodometric)
- Lot/batch No.: 790000007017

Results and discussion

Any other information on results incl. tables

Results

In aerated tap water of Marschacht community (which corresponds to natural occuring surface and ground water) the degradation down to non detectable concentrations of the test material took place in two hours. The concentration of oxidation product diammonium dithiodiglycolate (DADTDG) was measured to 72.0% of the theoretical amount.

Discussion

In aerated tap water - which is comparable to ground water and surface water - the oxidation of the test material was completed after 2 hours with the theoretical amount of 72.0 % of oxidation product detected. The first step of oxidation took place during the preparation of the sample at start point. After one hour ongoing oxidation another unidentified product evolved at later retention time than dithiodiglycolate. The pH value rose with ongoing oxidation staying constant after 24 hours. The unidentified peak is very broad, this is a hint to an alkaline substance. Plotting peak area% against time (pic.9) shows, that this product disappears as well, but slowlier than thioglycolate. The evolving small unidentified peaks at higher retention times are disregarded because of their negligible magnitude.

Applicant's summary and conclusion

Conclusions:

The velocity of degradation of thioglycolate anion in oxygen saturated tap water was such high, that the first sample taken at start point showed already considerable amount of oxidation product. 2 hours later thioglycolate was no longer detectable. The amount of oxidation product increased to 72.0 % of theoretical amount. The evolving product at 6.25 min retention time decreased to 21% of the highest value after 4 days. The estimated t1/2 is 30 h, that means after 12 days this degradation product will be no longer detectable.