Recent Advances in the Analysis of Herbicides and their Transformation Products in Environmental Samples

Herbicide residues in crop, soil and contamination of groundwater have become a worldwide concern in recent decades as their presence at low concentrations entails an unacceptable risk to human health and non-target organism. The magnitude of exposure and concentration at a particular time may trigger bioaccumulation and bio magnifications of herbicide residues and their degraded products, causing mutagenic, carcinogenic and teratogenic effects on humans, flora and fauna and microbiological living system. These atrocious circumstances have raised concern about their presence in environmental compartments and necessitate the continuous monitoring of herbicide residues in various matrices. However, determining the herbicide residues in the soil and crop is challenging because of the very low concentration of analyte, complicated sample matrices and low maximum residue limit (MRL) imposed by the regulatory agencies. The detection limits imposed by environment quality legislation can only be achieved by using appropriate sample preparation techniques, which comprise isolation and concentration of the analytes with nominal matrix interference, thus allowing its facile detection and quantification through instrumental analysis. In recent years, the requirements for separation and pre-concentration procedures have undergone numerous changes, and various sample preparation methods have been used. The final step in the analytical process involves the identification and quantification of the herbicide residues using suitable instrumentation, and over the years, herbicides have been determined by spectrophotometric, chromatographic, electrochemical, electrophoretic, hyphenated and biosensors. This book chapter provides a comprehensive overview of the novelties and the advantages of different techniques employed for the detection of herbicides and their transformation products in environmental samples.