Abstract
Degradation of the herbicide MCPB-ethyl [ethyl 4-(4-chloro-2-methylphenoxy) butylate] in soils under flooded and upland conditions was investigated by means of GC equipped with an electron capture detector in the laboratory. MCPB-ethyl was degraded rapidly in soil under flooded and upland conditions, and MCPB [4-(4-chloro-2-methylphenoxy) butyric acid] was formed correspondingly. MCPB was also converted slowly to MCPA [(4-chloro-2-methylphenoxy) acetic acid] by β-oxidation of the side chain. In sterilized soil, MCPB-ethyl was moderately stable under both soil conditions. More than 72% of the MCPB-ethyl applied was recovered 28 days after treatment. These results suggest that the degradation process of MCPB-ethyl including hydrolysis of the ester is caused mainly by microorganisms in the soil. Half-life of the total amounts of MCPB-ethyl, MCPB and MCPA was 2-7 days under flooded soil conditions and 3-4 days under upland conditions.
