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.

Condition 1

Column Obelisc R, 2.1x150 mm, 5 µm, 100A
Mobile Phase Gradient MeCN - 25-70%, 15 min
Buffer Gradient AmAc pH 3.0- 30-60 mM, 15 min
Flow Rate 0.4 ml/min
Detection UV, 270 nm
 

Condition 2

Column Obelisc R, 2.1x150 mm, 5 µm, 100A
Mobile Phase Gradient MeCN - 10-70%, 15 min
Buffer Gradient AmAc pH 3.0- 20-60 mM, 15 min
Flow Rate 0.4 ml/min
Detection UV, 270 nm
 

Condition 3

Column Primesep 100, 2.1x150 mm, 5 µm, 100A
Mobile Phase Gradient MeCN - 10-70%, 15 min
Buffer Gradient AmAc pH 3.0- 20-60 mM, 15 min
Flow Rate 0.4 ml/min
Detection UV, 270 nm
 

Description

Class of Compounds  Insecticide, Herbicide, Fungicide,  Hydrophobic, Ionizable
Analyzing Compounds Azinphos-ethyl
 

Application Analytes:

Azinphos-ethyl