Electrochemical determination of indole-3-acetic acid and indole-3-butyric acid using HPLC with carbon felt detector
Abstract
Method for the determination of two auxins, indole-3-acetic acid and indole-3-butyric acid, is developed using HPLC with electrochemical detection. As the working electrode, recently developed carbon felt detector with high conversion degree was employed.
Optimum conditions, i.e. separation on 125-4 Lichrospher 100, RP-18 column with mobile phase consisting of buffer pH 4.0 and methanol (40:60, v/v) and detection at potential +1.5V, allow to obtain linear concentration dependences in the concentration range from 1 to 100 mu moldm(-3), with determination limits of 1.1 mu moldm(-3) and 1.8 mu moldm(-3) for indole-3-acetic and -butyric acid, respectively. Applicability of the method was verified by the determination of both analytes in rooting preparation; the results were in agreement with the reference method, although not with the values declared by the manufacturer.