Determination of methyl bromide residues in stored foods using automated headspace gas chromatography

An automated gas chromatographic headspace method capable of detecting methyl bromide (MB) down to 0.01 mg kg−1 has been developed and evaluated. The method is suitable for analysing cereals, nuts, seeds and dried fruit. Commodities are extracted with solvent and MB present is derivatised to methyl iodide (MI) which is determined by automated headspace gas chromatography. Results from the method described are compared with those using an established solvent extraction method and show good quantitative agreement. The analytical conditions recommended are likely to be suitable for examination of other commodities for MB residues.