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.
Azinphos-ethyl Analysis on Mixed-Mode HPLC Columns
Azinphos-ethyl is a highly toxic organophosphate insecticide. Azinphos-ethyl was retained on both Obelisc R and Primesep B2 mixed-mode HPLC columns. Primesep B2 contains embedded basic ion-pairing groups while Obelisc R contains embedded ionic and hydrophobic groups which can assist in fine tuning separations. Method is LC/MS compatible and can be used as a general approach for analyzing azinphos-ethyl and other organophosphate insecticides.
Primesep B2, 2.1x150 mm, 5 µm, 100A
Gradient MeCN - 25-70%, 15 min, 7 min hold
Gradient AmAc pH 3.0- 30-60 mM, 15 min, 7 min hold
UV, 250 nm
Obelisc R, 2.1x150 mm, 5 µm, 100A
Gradient MeCN - 10-70%, 15 min, 7 min hold
Gradient AmAc pH 3.0- 20-60 mM, 15 min, 7 min hold
Controlling Retention of Azinphos-ethyl on Primesep and Obelisc HPLC Columns
Azinphos-ethyl is a toxic pesticide in the organophosphate class. It is currently on the WHO (World Health Organization) hazard classification as class IB, highly hazardous. Azinphos-methyl, a compound with two less carbons is also a pesticide and considered a target pesticide by the EURL (European Union Reference Laboratory) for the EUPT-FF9 2015 a proficiency test for the analysis of a over a hundred pesticides. This compound was separated on two different mixed-mode columns, Primesep 100 and Obelisc R. Primesep 100 is a reverse phase column that contains embedded acidic ion-pairing groups, while Obelisc R retains with long hydrophobic chains and multiple ionic pairing groups on the surface. Method is LC/MS compatible and can be replicated to analyze dozens of other pesticides.