Persistence of glyphosate in seawater. Glyphosate concentrations recorded over time in standard flask experiment 2013. (NERP TE 4.2, AIMS and UQ)

Brief description

This dataset shows the concentrations of the herbicide glyphosate remaining over time in a simulation flask persistence experiment conducted in 2013.

Glyphosate degradation experiments were carried out in flasks according to the OECD methods for ‘‘simulation tests’’. The tests used natural coastal seawater and were carried out in the incubator shakers under 3 conditions: (1) 25°C in the dark, (2) 31°C in the dark and (3) 25°C in the light. The light levels were ~40 µE on a 12:12 light:dark cycle and the flasks shaken at 100 rpm for up to 330 days.

Water samples were taken periodically and analysed by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS).

Reductions in the concentration of Glyphosate were plotted to predict the persistence of this herbicide (its “half-life”).

The emergence of AMPA, a breakdown product of Glyphosate, was also quantified.

The experiment and its results are described in full detail in:
P. Mercurio, F. Flores, J. F. Muller, S. Carter, A. P. Negri AP (2014), Glyphosate persistence in seawater. Marine Pollution Bulletin http://dx.doi.org/10.1016/j.marpolbul.2014.01.021


Data Format:

The data consists of a CSV file containing the results of the 3 treatments. All concentrations in µg/L
D25 = Dark 25 degrees celcius
D31 = Dark 31 degrees celcius
L25 = Light 25 degrees celcius
Uncertainty in the analytical method for repeated inejctions into the LC-MS results in a concentration uncertainty of approximately ± 0.2 µg/L

Notes

Credit
P. Mercurio, F. Flores, J. Mueller, S. Carter

Purpose
The aim of this study was to quantify the persistence of the herbicide Glyphosate in a standard flask experiment. Time it takes for degradation of half of this herbicide is termed the “half-life”. The half-life can be used to help develop environmental risk assessments.