Degradation of sodium monofluoroacetate (1080) and fluorocitrate in water

Sodium monofluoroacetate (1080) was commonly used to control the brushtail possum (Trichosurus vulpecula) and rabbit (Oryctolagus cuniculus) in New Zealand. In animals, fluorocitrate was the proposed metabolite, but it was unknown if micro-organisms could convert 1080 to fluorocitrate. To determine whether fluorocitrate was formed in the environment, a method was developed for its analysis in water Analysis of fluorocitrate was undertaken using gas chromatography by derivatization with boron trifluoride and trifluoroethanol. Sodium monofluoroacetate was added to aquariums containing stream water and the aquatic plant Myriophyllum triphyllum, at 0.12, 2 and 5 mg per litre, and analysed for 1080 and fluorocitrate. Results showed that 1080 was degraded in stream water by micro-organisms and plants with the formation of fluorocitrate. Both 1080 and fluorocitrate were rapidly degraded, the latter had a lower oral toxicity and, consequently, it was more important to monitor 1080 residues than fluorocitrate.