Capillary gas chromatographic analysis of trichlorfon in dosed feed formulations

A method was developed for the analysis of trichlorfon as the intact molecule from feed formulations of the chemical. The method involved isolation of trichlorfon by a simple extraction procedure. Subsequent detection and quantitation of the trichlorfon was by gas chromatography with a DB-1 fused-silica wide-bore capillary column and flame photometric detection. Automated on-column injections were performed. The method was linear in the range 5-75 ng injected on-column and had an average recovery of 86%. The limit of detection for trichlorfon in feed was 1 ppm. The applicability of the method was tested by determining the stability of trichlorfon over a 21-day period in a feed blend of trichlorfon at the 50-ppm concentration level. Mass spectrometric analyses were performed to confirm that trichlorfon could be quantitated as the intact molecule.