Analytical Strategies for the Determination of Herbicides in Water: Advances in Sample Preparation, Separation, and Detection

Herbicides are widely used agrochemicals and are increasingly recognised as contaminants of emerging concern in aquatic environments due to their extensive application, environmental persistence, and potential ecological and human health impacts. Their determination in water presents significant analytical challenges, as these compounds occur at trace to ultra-trace levels and encompass a wide range of chemical properties, including highly polar and ionic species as well as transformation products. This review provides a critical overview of recent advances in separation technologies for the analysis of herbicides in water, based on peer-reviewed studies published between 2020 and 2025 retrieved from the PubMed and Scopus databases. The discussion focuses on developments in sample preparation, extraction strategies, chromatographic separation, and detection techniques, with particular attention to analytical performance and sustainability. The reviewed studies demonstrate that solid-phase extraction remains central to achieving the lowest detection limits, while miniaturised and greener extraction approaches are increasingly adopted to reduce solvent consumption and simplify workflows. Advances in chromatographic separation and detection, especially liquid chromatography coupled to tandem mass spectrometry, have further enhanced sensitivity and selectivity for a broad range of herbicides. Overall, this review highlights current analytical capabilities and emerging trends, outlining future directions for reliable and sustainable monitoring of herbicides in aquatic environments.