摘要：Determination of monofluoroacetic acid was investigated according to the method of the fluorescence of thioindigo, which was formed from the ferricyanide oxidation of a reaction product of monofluoroacetic acid and thiosalicylic acid in the presence of sodium hydroxide. The recommendatory procedure is as follows : To 1 ml of a sample solution containing 20 to 100 μg of monofluoroacetic acid, add 0.5 ml of a thiosalicylic acid reagent (30 mg of thiosalicylic acid was dissolved in 0.5 ml of 1 N NaOH and made up to 10 ml with water), then heat the mixture at 105° for 60 min. To the residue, add 1 ml of 1.5 N NaOH. After heating the mixture at 130°for 80 min, add 7.5 ml of the mixed acid solution and 3 ml of a 2% potassium ferricyanide solution, then shake the mixture for 1 min vigorously. To the solution, add 10 ml of benzene, then shake the mixture for 10 min vigorously. After separation, measure the fluorescence of benzene layer at 580 nm by an excitation at 540 nm. This fluorometric method was applied to the recovery test of monofluoroacetic acid added to plant materials. After extraction with ether and subsequent silicic acid column chromatography, the monofluoroacetic acid separated from plant materials was determined by the method.
