Sensitive electrochemical detection of picloram utilising a multi-walled carbon nanotube/Cr-based metal-organic framework composite-modified glassy carbon electrode

Abstract

This study describes the utilisation of a glassy carbon electrode modified with a composite of multi-walled carbon nanotube and Cr-based metal-organic framework (MIL-101, Cr-BDC, BDC = 1,4-benzenedicarboxylate) for the sensitive, simple and fast voltammetric determination of picloram in environmental samples. Under optimum conditions, additions of picloram using square wave voltammetry showed linear ranges of picloram concentrations from 24.15 to 3018 µg∙L‒1 (0.1–12.5 μM) and from 3018 to 9658 µg∙L‒1 (12.5–40 μM) with a detection limit of 14.49 µg∙L‒1 (0.06 µM). The method was successfully applied to the determination of picloram in tap and river water samples spiked with picloram without any purification step by the standard addition method. The good recovery values obtained ranging from 97.5% to 105.0% revealed the reliability and accuracy of the method.