Self-assembled sensor based on boron-doped diamond and its application in voltammetric analysis of picloram

Abstract

A self-assembled sensor based on a boron-doped diamond was investigated as a sensitive tool for voltammetric analysis of a member of a pyridine herbicide family - picloram. A cyclic voltammetry and a differential pulse voltammetry were applied for investigation of the voltammetric behaviour and quantification of this herbicide. Picloram yielded one well-developed irreversible oxidation signal at a very positive potential about +1.5 V vs. Ag/AgCl/3 mol L⁻¹ KCl electrode in an acidic medium and 1 mol L⁻¹ H₂SO₄ was chosen as a suitable supporting electrolyte. Operating parameters of differential pulse voltammetry were optimized and the proposed voltammetric method provided a high repeatability (a relative standard deviation of 20 repeated measurements at a concentration level of picloram of 50 µmol L⁻¹ equaled to 2.58%), a linear concentration range from 2.5 to 90.9 µmol L⁻¹ and a low limit of detection (LD = 1.64 µmol L⁻¹). Practical usefulness of the ‘environmentally-green’ electrochemical sensor was verified by an analysis of spiked water samples with satisfactory recoveries.

Keywords:

• boron-doped diamond
• determination
• herbicide
• voltammetry
• limit of detection
• picloram

Acknowledgements

This work was supported by The Ministry of Education, Youth and Sports of the Czech Republic (project No. CZ.1.07/2.3.00/30.0021), the Grant Agency of the Slovak Republic (grant No. 1/0051/13) and the Slovak Research and Development Agency under the Contract Nos. APVV-0797-11 and APVV-0365-12.