Pesticides fipronil

In recent years, there has been much discussion about the toxicity of fipronil. It is classified as a World Health Organization (WHO) class II moderately hazardous pesticide.Fipronil is a relatively new insecticide that has not... 

Konwick, B.J. Garrison, A.W. Black, M.C. Avants, J.K. Eisk, A.T, Bioaccumulation, biotransformation, and metabolite formation of fipronil and chiral legacy pesticides in rainbow trout Environ Sci. Technol. 2006, 40, 2930-2936. 

United States Environmental Protection Agency (EPA) (1996) Fipronil Pesticide Fact Sheet. EPA-737-F-96-005. 

The fipronil standard, more than 99% pure, was obtained from Chem Service (West Chester, Pennsylvania, U.S.A.). The fipronil standard solution was prepared in ethyl acetate. Mallinckrodt (Phillipsburg, New Jersey, U.S. A.) supplied all the nanograde solvents for pesticide-residue analyses. Several adsorbents—such as octadecyl silane (35-75 mesh, Supelco), chromossorb (100-120 mesh, Johns Manville), florisil (100-200 mesh, Riedel), silica gel 60 (70-230 mesh, Merck), and XAD-7 (20-60 mesh, Rohm and Haas)—were tested as sorbents in the SPE cartridges. Different modifiers (hexane, acetone, methanol), various temperature (50, 60°C), and pressure conditions (120, 250, and 300 atm) were tested for supercritical fluid extraction. The water was purified with a Millipore Milli Q Plus System (Bedford, Massachusetts, U.S.A.). 

Fig. 1 Chromatogram of fipronil pesticide obtained by gas chromatography/electfwi capture detector at 0.1 mg/L concentration. S = ethyl acetate solvent 1 = fipronil.

Table 1 Extraction recovery (%) and corresponding relative standard deviation (RSD) obtained through liquid-liquid extraction (LEE), solid phase extraction (SPE), and supercritical fluid extraction (SEE) in water samples enriched with 0.1 mg/L of fipronil pesticide.

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