HPLC Retention of Chlorpyrifos-methyl on Primesep 100 and Obelisc R Mixed-Mode Columns

  Chlorpyrifos-methyl, an organophosphate pesticide is 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,  7 min hold
Buffer Gradient AmAc pH 3.0- 30-60 mM, 15 min,  7 min hold
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,  7 min hold
Buffer Gradient AmAc pH 3.0- 20-60 mM, 15 min,  7 min hold
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,  7 min hold
Buffer Gradient AmAc pH 3.0- 20-60 mM, 15 min,  7 min hold
Flow Rate 0.4 ml/min
Detection UV, 270 nm
 

Description

Class of Compounds  Insecticide, Herbicide, Fungicide,  Hydrophobic, Ionizable
Analyzing Compounds Chlorpyrifos-methyl
 

Application Analytes:

Chlorpyrifos-methyl