The effect of cooking on chlorpyrifos and 3,5,6-trichloro-2-pyridinol levels in chlorpyrifos-fortified produce for use in refining dietary exposure

Various types of produce were fortified with chlorpyrifos and then boiled, baked, canned, or concentrated as appropriate for the type of produce. Both uncooked and cooked samples were analyzed for chlorpyrifos and 3,5,6-trichloro-2-pyridinol, and then, chlorpyrifos cooking factors were calculated by comparing the postcooked concentration to the uncooked concentration. The cooking factors were dependent upon the commodity and cooking procedure: 0.320-1.19 for boiled samples, 0.022-1.18 for baked pulp, and 0.119-0.661 for canned samples. Concentrating chlorpyrifos-fortified orange juice 4-fold resulted in a concentration factor of only 2.6, indicating a loss of chlorpyrifos. Green bean and green pepper plants treated in the greenhouse yielded higher chlorpyrifos concentrations but similar cooking factors to lab-fortified samples. The cooking factors can be used with food consumption databases and modeling tools to refine the dietary exposure according to current product label uses.