Voltammetric method for the determination of a pyridine herbicide triclopyr (3,5,6-trichloro-2-pyridyloxyacetic acid) is presented for the first time using bare boron-doped diamond electrode. Triclopyr provides one well-developed, pH-independent oxidation signal at ca. +1.9 V (vs. Ag vertical bar AgCl vertical bar KCl (sat.)) contrary to structurally related clopyralid, which is not oxidizable at the working electrode. Britton-Robinson buffer (pH 2.0) was chosen as optimal electrolyte for determination of triclopyr using square wave and differential pulse voltammetry. The latter method provided slightly better detection limit of 0.82 mu mol L (1) and linearity in the concentration range 1.0-108.8 mu mol L (1). Applicability of the proposed method was verified by analysis of pesticide preparation, spiked water and urine with excellent results. (C) 2014 Elsevier Ltd. All rights reserved.