Methods for pre-concentration and clean-up of glyphosate and aminomethylphosphonic acid from water samples: A review

Glyphosate, the world's most widely applied herbicide, is frequently detected in both surface and groundwater systems along with its metabolite aminomethylphosphonic acid (AMPA). Due to their high polarity, ionic character, and water solubility, detection of trace levels in environmental samples requires effective enrichment prior to instrumental analysis. This review critically examines the current landscape of pre-concentration and clean-up methods developed for glyphosate and AMPA quantification, including solid-phase extraction (SPE), liquid-liquid extraction (LLE), microextraction, and advanced techniques. The effects of sample matrix, pH, and ionic composition on recovery rates and reproducibility are critically discussed, along with method performance metrics such as detection limits and matrix suppression effects. While derivatization remains essential for enhancing determination via GC- or LC-based techniques, it is treated here as a secondary complement to enrichment steps. Advances such as magnetic sorbents, online SPE systems, and environmentally friendly formats are highlighted for their potential to simplify workflows and enhance throughput. Drawing from peer-reviewed studies, this review presents comparative insights into performance metrics such as recovery, reproducibility, and matrix effects across different methods. Rather than prescribing universal best practices, the synthesis allows researchers to make informed choices based on their specific analytical context, instrumentation, and regulatory requirements. Ultimately, the work provides a foundation for selecting appropriate enrichment strategies that align with diverse environmental monitoring objectives and laboratory capabilities.