DIRECT DETERMINATION OF INDOLE-3-ACETIC-ACID IN PLANT-TISSUES BY ELECTROANALYTICAL TECHNIQUES USING A CARBON-PASTE MODIFIED WITH OV-17 ELECTRODE

The electrochemical behavior of indole-3-acetic acid (IAA) with a sili cone OV-17 modified carbon paste electrode was explored for the determ ination of this compound in plant tissues. Under optimum conditions, t he procedure gave a linear concentration range up to 0.6 mu g mL(-1), with a limit of detection of 0.053 mu g mL(-1), containing the preconc entration solution 0.08 M HAc/Ac- buffer (pH 4) and 0.4 M phosphate bu ffer (pH 12) as a supporting electrolyte in the measurement cell. The accumulation time was 10 minutes and the sweep potentials were carried out with a scan rate of 30 mV s(-1) with a pulse amplitude (Delta E) of 100 mV. This method is available for the determination of IAA in pl ant tissues.