Residue Analysis of Glyphosate and Aminomethylphosphonic Acid (AMPA) in Soybean Using Liquid Chromatography Coupled with Tandem Mass Spectrometry

Glyphosate (N-phosphonomethyl glycine) is one of the most widely used pesticide around the world. It is very well known that glyphosate compound rapidly degrades into aminomethylphosphonic acid (AMPA) metabolite (Fig. 1). Glyphosate is a herbicide with a broad spectrum of activity, very effective even on plant roots with little harmful effects on mammals. Its high efficacy, low toxicity and affordable price, when compared with other pesticides, justify the wide utilization in several crops. Due to the low toxicity of glyphosate, the maximum residues levels (MRLs) established around the world are generally greater than the limits for other pesticides. For example, the Codex Alimentarius Commission and the Environmental Protection Agency/USA established the MRL at 20 mg kg-1 for glyphosate in soybean and the National Health Surveillance Agency (ANVISA) in Brazil set the MRL at 10 mg kg-1.