Glyphosate is an herbicide used for many plants that can be toxic to humans in high doses. Current methods for measuring glyphosate are slow and expensive. Here we describe a fast and simple method for measuring glyphosate in tea beverages by capillary electrophoresis with on-line formation of copper(Il)-glyphosate complex. The optimum running conditions were found to be 40mM acetate buffer (pH 5.0) containing 5 mM CUSO(4) with an effective voltage of +15 kV using a sulfonated capillary (FunCap-CE Type S) and direct UV detection at 250 nm. Linearity (r(2) > 0.999) was demonstrated in the range 5-1000 mg/l of glyphosate. Good reproducibilities of peak area (relative standard deviation < 1.2%) and migration time (relative standard deviation < 0.2%) were obtained. Recovery of glyphosate was between 98 and 100%. With this method, a tea beverage that was mixed with a glyphosate formulation was successfully analyzed.