Solid-Phase Extraction and Reversed-Phase Ion-Pair High-Performance Liquid Chromatographic Determination of Chlorophacinone and Diphacinone Residues in Range Grass

Abstract

A reversed-phase ion-pair liquid chromatographic method is developed for the analysis of chlorophacinone and diphacinone in range grass. Chlorophacinone and diphacinone are extracted from range grass with chloroform, and the extracts are subjected to an aminopropyl solid-phase extraction procedure, concentrated, and analyzed by reversed-phase ion-pair high-performance liquid chromatography. Chlorophacinone and diphacinone are detected by ultraviolet absorption at 285 nm. The average recoveries from range grass fortified at 0.10,1.0, and 10.0 µg/g chlorophacinone and diphacinone are 94% ± 3 and 97% ± 6. The limit of detection for chlorophacinone and diphacinone in range grass is estimated to be 0.015 µg/g and 0.013 µg/g, respectively.