Carbofuran is one of the most acutely toxic insecticides used on field crops. It is banned in Europe, Canada, and as of 2009 was banned in the United States. The EURL included carbofuran as a target pesticide for the EUPT-CF9. Obelisc R was used to retain carbofuran and separate it from impurities. Obelisc R contains embedded ionic and hydrophobic groups which can assist in fine tuning separations. Method is LC/MS compatible and can be used as a general approach for analyzing carbofuran and other phenoxy acids.