Various studies on the fate of pesticides residues have been reported
during the storage and processing, however the fate of
chlorpyrifos in soybeans is not well studied. Zayed, Farghaly,
Mahdy, and Soliman (2007) investigated the fate of the organophosphorus
insecticide dichlorvos in stored faba beans and
soybean at intervals during 30 weeks of storage and found only
15–21% of the actually applied dose remained for both beans.
The persistence of the pesticide residues on other grains has been
investigated for long-term storage. Sasaki, Matsuda, and Saito
(1995) found that the residue levels of organophosphorus pesticides
such as dichlorvos, chlorpyrifos-methyl, fenitrothion, pirimiphos-
methyl and chlorpyrifos applied to corn were declined
continuously over time of storage for 12 weeks.