Voltammetric behavior of indole-3-butyric acid and a novel approach for its determination in mixture with indole-3-acetic acid using boron-doped diamond electrode as a sensor

Abstract

In the present paper, the voltammetric behavior of indole-3-butyric acid (IBA) is described employing a boron-doped diamond electrode (BDDE). In acidic media, IBA exhibited one well-developed oxidation signal. Two voltammetric methods, linear-sweep (LSV) and differential pulse voltammetry (DPV), were optimized and low limits of quantification obtained (0.79 μg mL−1 for LSV and 0.52 μg mL−1 for DPV). The latter technique with optimized parameters was successfully applied to the determination of IBA in growth stimulation formulas. Moreover, simultaneous voltammetric determination of IBA and other auxin phytohormone, indole-3-acetic acid (IAA), employing BDDE was also examined. Despite their similar structures, a simple method based on DPV and derivatization of a selected part of the obtained curves was developed. It has been proven that simultaneous determination of IBA and IAA is possible at various concentration ratios with satisfactory results. Applicability of the proposed method was verified by successful analysis of the growth stimulation preparation containing IBA or a mixture of the auxins studied.