Analytical Method for Diphenyl Ether Herbicides in Fish and Shellfish

Studies on Residual Diphenyl Ether Herbicides in Foods. II

Abstract

The determination of diphenyl ether herbicides, NIP, CNP, chlomethoxynil and TCNP, was achieved according to the procedure for the determination of organochlorine pesticides, which consists of acetonitrile extraction and clean-up by silver nitrate-coated Florisil column chromatography.
The homogenized sample is extracted 3 times with acetonitrile. The extract is diluted with water and re-extracted with n-hexane. After concentration, the n-hexane layer is subjected to silver nitrate-coated Florisil column chromatography. The 2% ethylacetate/n-hexane eluate is concentrated for ECD/GC analysis. Satisfactory gas chromatograms were obtained for most samples.
The average recoveries throughout the procedure were 98% (NIP), 97% (CNP), 91% (chlomethoxynil) and 95% (TCNP).