Rapid and Sensitive Electrochemical, Spectroscopic and Spectroelectrochemical Detection of Glyphosate and Glufosinate and Their Copper Salts with Screen-printed Electrodes

N-(Phosphonomethyl)glycine (glyphosate), known by the trade name Roundup®, is a broad-spectrum systemic herbicide used to kill various types of weeds. It was first synthesized in 1970 by John E. Franz, a chemist at the Monsanto agrochemical company. Glyphosate's mode of action is to inhibit a plant enzyme involved in the synthesis of some aromatic amino acids (“shikimate way”). The use of Roundup® is currently controversial, as its hazard potential has not been clarified. Glufosinate (2-Amino-4-[hydroxy(methylphosphonoyl)] butanoic acid) was discovered by German and Japanese scientists in a biological process: Species of Streptomyces bacteria produce a tripeptide that consists of two alanine residues and an amino acid that is an analogue of glutamate named phosphinothricin. Phosphinothricin was first synthesized by scientists at Hoechst (now Aventis) in the 1970s as a racemic mixture; this racemic mixture is called glufosinate. This article presents reliable and easily performed spectroscopic and (spectro)electrochemical measurements for identifying glyphosate and glufosinate.