Determination of fumigant residues in cereals and other foodstuffs: A multi-detection scheme for gas chromatography of solvent extracts

The need for sensitive and comprehensive methods for determination of fumigant residues in foodstuffs is discussed. A multi‐detection scheme for the evaluation of such residues is described, in which gas‐liquid chromatography using three types of detector is used to analyse the contents of processed solvent extracts. Factors which affect the efficiency of recovery of such residues are discussed. These include the reactivity and volatility of residual components, the effect of water in solvent extraction, and the problems of multiphase extraction. The performance and specificity of the chosen system are considered in relation to other possible methods. Results are given showing the recovery of a range of 20 compounds as volatile fumigant residues in cereals and other foodstuffs, with sensitivities generally better than 0.1 ppm. The extension of the analytical scheme to include other compounds is indicated.