Degradation of the (R)- and (S)-enantiomers of the herbicides MCPP and dichlorprop in a continuous field-injection experiment.

An aerobic field-injection experiment was performed to study the degradation and migration of different herbicides at trace levels in an aerobic aquifer at Vejen, Denmark. Mecoprop (MCPP) and dichlorprop monitored in a dense network of multilevel samplers were both degraded within a distance of 1 m after a period of 120 days. The study showed that no preferential degradation of the (R)- and (S)-enantiomers of MCPP and of dichlorprop took place as the enantiomeric forms of the phenoxy acids were degraded simultaneously in the aquifer.