Determination of carbofuran and its metabolites.

High-performance liquid chromatographic (HPLC) methods for the determination of carbofuran and its metabolites are described. Results obtained for carrot samples by HPLC are compared with those obtained using gas chromatography and nitrogen-specific detection for carbofuran and 3-hydroxy carbofuran and gas chromatography-mass spectrometry with selected ion monitoring for the determination of the three 7-phenol metabolites. The effect upon observed residue levels of conjugate formation by the 3-hydroxy and/or the 7-phenoxy groups of the four metabolites is demonstrated, and appropriate acid hydrolysis techniques are described. Variations in the HPLC parameters for different commodities are presented.