Azinphos-ethyl is an organophosphate insecticide similar to Azinphos-methyl which was developed during World War II as a nerve agent. Due to risk concerns for farm workers and aquatic ecosystems AZM use was phased-out by the EPA in 2012. AZM is on the EURL–SRM list of target pesticides in cereals and feeding stuffs. Azinphos-ethyl was retained on Obelisc R, a mixed-mode HPLC column which contains ionic groups and hydrophobic chain. Method is LC/MS compatible and can be used as a general approach for analyzing azinphos-ethyl and other organophosphate insecticides.