Registration Dossier

Environmental fate & pathways

Hydrolysis

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

DOPA-Glycinate is considered to be hydrolytically stable, half-life periods at pH 4, 7 and 9 can be expected to exceed one year at 25°C (OECD guideline 111, GLP)

Key value for chemical safety assessment

Half-life for hydrolysis:
1 yr
at the temperature of:
25 °C

Additional information

Dodecyl-1-14C-labelled DOPA-Glycinate was tested for hydrolysis according to OECD guideline 111 (2002). The test item was dissolved in buffered aqueous media of defined pH-values (pH 4, 7, or 9) and maintained at constant temperature (50 °C) in the darkness. The concentrations of the lead compounds of the test item were measured as a function of time. At 0, 1, 3 and 5 days radioactivity as well as the identity of the components of the test item and potential hydrolysis products were verified by HPLC-MS/MS.

The results of the preliminary test indicated no need for further testing. From day 1 to day 5 of the experiment, recoveries of14C in the test solution decreased from approx. 100 % to 59.3 % (at pH 7) and 58.6 % (at pH 9), respectively, whereas at pH 4 105.6 % of the radioactivity were recovered on day 5. It was clearly demonstrated that the test material had adsorbed onto the walls of the glass vials at pH 7 and 9, but was removable by rinsing the vial walls with acetonitrile/water, leading to total recovery rates of 92.9 and 102% as the sum of the test item solutions and the rinsing solutions. Less than 10 % of the test item hydrolysed in the preliminary test during five days at 50 ± 5 °C. Hence, kH and DT50 or DT90 values could not be established.

In conclusion, DOPA-Glycinate is considered to be hydrolytically stable. The half-life periods at pH 4, 7 and 9 can be expected to exceed one year at 25 °C.