Fluoroacetic acid

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Fluoroacetic acid
Fluoroacetic Acid V.1.svg
Identifiers
CAS number 144-49-0 YesY
ChemSpider 10205670
Jmol-3D images Image 1
Properties
Molecular formula C2H3FO2
Molar mass 78.04 g mol−1
Appearance White crystals
Density 1.369
Melting point 35.2°C
Boiling point 165°C
Solubility in water Soluble in water and ethanol
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Fluoroacetic acid is a chemical compound with formula CH2FCOOH. The sodium salt, sodium fluoroacetate is used as a pesticide. It inhibits the aconitase step of the citric acid cycle.[1]

Natural Occurrence[edit]

Dichapetalum cymosum

Fluoroacetate occurs naturally in at least 40 plants in Australia, Brazil, and Africa. It was first identified in the poison leaf (gifblaar) Dichapetalum cymosum by Marais in 1944.[2][3] As early as 1904, colonists in Sierra Leone used extracts of Chailletia toxicaria, which also contains fluoroacetic acid or its salts, to poison rats.[4][5][6] Several native Australian plant genera contain the toxin, including: Gastrolobium, Gompholobium, Oxylobium, Nemcia and Acacia.

Fluoroacetate occurrence in Gastrolobium species[edit]

Gastrolobium is a genus of flowering plants in the family Fabaceae. There are over 100 species in this genus, and all but two are native to the south west region of Western Australia, where they are known as "poison peas". Gastrolobium growing in south western Australia are unique in their ability to concentrate fluoroacetate from low fluorine soils.[7] Brush-tailed possums, bush rats and western grey kangaroos native to this region are capable of safely eating plants containing fluoroacetate, but livestock and introduced species from elsewhere in Australia are highly-susceptible to the poison,[8] as are species introduced from outside Australia, such as the red fox. The fact that many Gastrolobium species also have high secondary toxicity to non-native carnivores is thought to have limited the ability of cats to establish populations in locations where the plants form a major part of the understorey vegetation.[9]

The presence of Gastrolobium species in the fields of farmers in Western Australia has often forced these farmers to 'scalp' their land, that is remove the top soil and any poison pea seed which it may contain, and replace it with a new poison pea-free top soil sourced from elsewhere in which to sow crops. Similarly, following bushfires in north-western Queensland cattlemen have to move livestock before the poisonous Gastrolobium grandiflorum emerges from the ashes.[10]

References[edit]

  1. ^ Proudfoot, A. T.; Bradberry, S. M.; Vale, J. A. (2006). "Sodium fluoroacetate poisoning". Toxicology Reviews 25 (4): 213–219. doi:10.2165/00139709-200625040-00002. PMID 17288493. 
  2. ^ Marais, J. C. S. (1943). "The isolation of the toxic principle "K cymonate" from "Gifblaar", Dichapetalum cymosum". Onderstepoort Journal of Veterinary Science and Animal Industry 18: 203. 
  3. ^ Marais, J. C. S. (1944). "Monofluoroacetic acid, the toxic principle of "gifblaar" Dichapetalum cymosum". Onderstepoort Journal of Veterinary Science and Animal Industry 20: 67. 
  4. ^ Renner (1904). "Chemical and Physiological Examination of the Fruit of Chailletia Toxicaria". Jour African Soc.: 109. 
  5. ^ Power, F. B.; Tutin, F. (1906). "Chemical and Physiological Examination of the Fruit of Chailletia toxicaria". Journal of the American Chemical Society 28 (9): 1170–1183. doi:10.1021/ja01975a007. 
  6. ^ Vartiainen, T.; Kauranen, P. (1984). "The determination of traces of fluoroacetic acid by extractive alkylation, pentafluorobenzylation and capillary gas chromatography-mass spectrometry". Analytica Chimica Acta 157 (1): 91–97. doi:10.1016/S0003-2670(00)83609-0. 
  7. ^ Lee, J. (1998). "Deadly plants face threat of extinction". ANU Reporter (Australian National University) 29 (6). Retrieved 2012-08-07. 
  8. ^ McKenzie, R. (1997). "Australian Native Poisonous Plants". Australian Plants Online. Australian Native Plants Society. Retrieved 2012-08-07. 
  9. ^ Short, J.; Atkins, L.; Turner, B. (2005). Diagnosis of Mammal Decline in Western Australia, with Particular Emphasis on the Possible Role of Feral Cats and Poison Peas (pdf). Australia: Wildlife Research and Management Pty. Retrieved 2011-09-26. 
  10. ^ "Death lurks in the ashes on western farms". Townsville Bulletin. September 2011. Retrieved 2011-09-23.