A simple and rapid screening method for glyphosate in water using flow-injection with electrochemiluminescence detection

Abstract

A flow-injection (FI) system coupled with the electrochemiluminescence (ECL) detection method for rapid screening of glyphosate (GLY) in water has been developed. A wall-jet type ECL detector coupled with an indium/tin oxide (ITO)-coated glass working electrode was modified from a thin-layer electrochemical cell, and tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)₃²⁺)-based ECL reaction was used for the sensitive detection of GLY. Under optimized conditions, the linear range of the method was 0.03–2.81 mg L⁻¹ GLY with R² = 0.9998 (n = 7). Repeatability was 5.3% (n = 27) and the detection limit (3σ) was 0.03 mg L⁻¹ GLY. Sample throughput was about 100 injections h⁻¹. Possible interference from some multivalent cations can be readily eliminated by passing the acidified water sample through a solid-phase extraction column packed with strong cation-exchange materials before analysis. The method was examined by application to surface waters including tap water and irrigation water.