Methods of extraction and analysis suited for analysis of aged, unknown residues on wheat, barley, oats, sorghum, rice in husk, milled rice, polished rice and cooked rice are reported for carbaryl, for the pyrethroids bioresmethrin, fenothrin, d-fenothrin and pyrethrum I, and for the organophosphorus insecticides dichlorvos, fenithrothion, methacrifos and pirimiphos-methyl. Fortification studies were performed for each insecticide on each commodity; six regimes were used to extract insecticides that had been applied to grains 3-6 months previously in order to obtain adequate methods of extraction. Amounts of aged residues of dichlorvos, fenitrothion, methacrifos and pirimiphos-methyl, after standing whole grain in methanol or ethanol for 12 hours, were over 90% of the amounts obtained after extracting for 26 or 36 hours and above the levels extracted by hexane. Recoveries of fortified samples extracted by ethanol or methanol from all commodities ranged between 89 and 100%. The organophosphorus insecticides were determined by gas-liquid chromatography (glc) using a phosphorus-specific detector. Residue levels of fenitrothion were also determined colorimetrically, after hydrolysis to 4-nitro-3-methylphenoxide and clean-up by the addition of barium chloride. This method was suitable for determination of residue levels greater than 2 mg/ kg. At least 80% of aged residues of carbaryl was extracted by standing grain in acetone or ethanol for 12 hours. Carbaryl was determined by glc, using electron capture, after derivatization to 2-chloroacetyl-l-naphthol and also semi quantitatively by thin-layer chromatography with 4-nitrobenzenediazonium fluoroborate as the chromogenic reagent. A two phase procedure using dilute alkali, 2-chloroacetic-anhydride and diethyl ether resulted in >95% acetylation of 1-naphthol, 4-cyanophenol and of the acidic phenols 2, 4, 5-trichlorophenol, 4-nitrophenol and 4-nitro-3-methylphenol provided that the pH of the aqueous phase was close to the pKa of the phenol. Over 90% of the amounts of the pyrethroids bioremethrin, fenothrin, d-fenothrin and pyrethrum I extracted from all commodities after 26-36 hours in ethanol, light petroleum or acetone was extracted after 12 hours in light petroleum, with the exception that light petroleum was inadequate for the extraction of these pyrethroids from cooked rice. The pyrethroids, after alkaline hydrolysis, were determined colorimetrically from the reaction of chrysanthemic acid with acidified mercury (II) sulphate. Recoveries of fortified samples were between 89 and 95%.