Advances in glyphosate residue analysis for environmental monitoring: From chromatography to immunoassays

Glyphosate, the most widely used herbicide, poses significant ecological and human health risks due to its environmental residues. This paper reviews various advanced techniques for glyphosate detection, including chromatographic methods, spectroscopic techniques, and electrochemical analysis, while evaluating their strengths and limitations. Ion chromatography, using large-capacity columns and ammonium-type membrane suppressors, achieves a detection limit of 0.03 μg/L in drinking water, with recovery rates ranging from 91 % to 118 %, but suffers from interference by salts like NO₂⁻ and SO₄²⁻. High-performance liquid chromatography, following FMOC-cl derivatization, detects glyphosate at 0.6 μg/L in seawater, though the derivatization step increases the relative standard deviation (RSD) to 5 %–8 %. Liquid chromatography-tandem mass spectrometry (LC-MS/MS), without derivatization, achieves a detection limit as low as 0.5 μg/L in soil, with an RSD under 3 %, providing strong resistance to matrix interference. Fluorescence spectrophotometry, with a detection range in the nanomolar scale, can experience 10 %–15 % deviations in fluorescence intensity due to environmental pH fluctuations. Surface-enhanced Raman spectroscopy, using cysteamine-modified silver nanoparticles, lowers the detection limit to 1 mM but faces signal instability. Photoelectrochemical sensors with Fe₃O₄ nanoparticle-based nanozymes detect within the range of 5 × 10⁻¹⁰–1 × 10⁻⁴ M, with recovery rates of 95.9 %–104.5 %, but show a 15 % decay in electrode activity per month. Future research should aim to optimize chromatographic columns, integrate multiple techniques, and employ nanomaterials to improve sensitivity, accuracy, and environmental adaptability