An analytical method for determination of formaldehyde impurity in glyphosate technical by offline derivatization-high performance liquid chromatography (HPLC) was developed. The sample was resolved in acetonitrile-water and derivatized with 2,4-dinitrophenyl hydrazine at pH 2.0 and then extracted under ultrasonic bath. The derivatized product was separated on a Merk Co. monolithic flash column (4.6 mm150 mm) with mobile phase consisting of acetonitrile: water (5545, V/V) , flow rate of 3 mL/min and detecte...