Analysis of the glyphosate herbicide in water,soil and food using derivatising agents

Glyphosate is used widely to control weeds. Glyphosate is a broad spectrum, non-selective, systemic and post-emergent herbicide. Glyphosate excessive use and impact on the environment is promoting the analysis of glyphosate in water, soil and food materials. Methods to analyse glyphosate at low levels are needed because glyphosate has a short half-life due to easy microbial degradation. Glyphosate has a high polarity and solubility in water, has high binding affinity with soil and is non-volatile. The absence of chromophoric groups in the molecular structure makes the detection difficult. Therefore, detection can be achieved by derivatisation, which makes glyphosate more volatile and stable for spectroscopic analysis. Derivatisation is commonly done by alkyl chloroformates, acylating agents, 9-fluoroenylmethylchloroformate, 4-methoxybenzenesulfonylfluoride and o-phthalaldehyde. Immunosensors allow detection at microlevels. Nanocrystals and nanotechnology allow detection at nanolevels. Here, we review methods to derivatise and analyse glyphosate.