ABSTRACT
One of the most useful procedures for confirming pesticide residue identity is the chemical derivatization gas liquid chromatographic technique (CD-GLC). For confirmation purposes, derivative formation of an o.c. pesticide can be achieved chemically or photochemically. Among various chemical systems used in reactions for confirmation of identity as well as for the analysis of organochlorine pesticide residues in agricultural commodities and in environmental samples, reaction of Dichlorodiphenyltrichloroethane (DDT) and similar compounds with alakli are the most widely used and investigated. Photochemical reaction for confirmation of pesticide residues has been proposed, but it generally results in derivatives with considerably less Electron-Capture Detector (ECD) responses compared with the corresponding parent compounds and hence is a much less sensitive method. In the early 1960s A. K. Kein and J. O. Watts wrote of the need for additional confirmatory evidence to determine small amounts of DDT in butter by GLC/ECD.
