Electrochemical determination of 2,4-dichlorophenol at beta-cyclodextrin functionalized ionic liquid modified chemical sensor: voltammetric and amperometric studies

摘要

A highly effective approach was developed for the specific detection of 2,4-dichlorophenol (2,4-DCP) in real samples, based on a cyclodextrin functionalized ionic liquid modified carbon paste electrode (beta-CDBIMOTs/CPE). First, systematic optimization procedures were carried out for beta-CD-BIMOTs/CPE by cyclic voltammetry (CV) and chrono-amperometry methods. Second, the optimized methods were applied for the determination of 2,4-DCP in environmental samples. A large increase in the peak currents was observed in CV and chrono-amperometry of 2,4-DCP when using beta-CD-BIMOTs/CPE compared to native cyclodextrin modified carbon paste electrode (beta-CD/CPE) and bare carbon paste electrode (CPE). A comparison of voltammetric behavior between CPE, beta-CD/CPE and beta-CD-BIMOTs/CPE indicated that the combination of ionic liquid and cyclodextrin in the composition of the carbon paste significantly improved the conductivity and compatibility of the sensor. The introduction of beta-CD-BIMOTs as a modifier results in clearly enhanced sensitivity and selectivity towards 2,4-DCP over a wide concentration range of 4 mu mol L-1 to 100 mmol L-1, with a detection limit of 1.2 mmol L-1. The interferences from foreign substances in the peak current response were also studied and caused only minor changes in the signals (< 4.6%). Good repeatability was achieved because of the stability of the modified electrode. The proposed method was applied to the determination of 2,4-DCP in leachates from landfill, mineral water and lake water with recoveries of (85.46-117.68%), (98.72-107.91%) and (89.25-107.46%), respectively.