Comparative voltammetric study and determination of carbamate pesticide residues in soil at carbon nanotubes paste electrodes

Abstract

In this investigation, the persistence of carbamate pesticides in soil samples was investigated. A simple and selective differential pulse adsorptive stripping voltammetry was selected for this investigation. Carbon nanotubes paste electrodes were used as working electrodes for differential pulse adsorptive stripping voltammetry and cyclic voltammetry. A symmetric study of the various operational parameters that affect the stripping response was carried out by differential pulse voltammetry. Peak currents were linear over the concentration range of 10^-5 to 10^-10 M with an accumulation potential of -0.6 V and a 70 s accumulation time with lower detec­tion limits of 1.09x10^-7 M, 1.07×10^-7M, 1.09×10^-7 M for chlorphropham, thiodicarb, aldicarb. The relative standard deviation (n=10) and correlation coefficient values were 1.15 %, 0.988; 1.13 %, 0.978; and 1.14 %, 0.987, respectively. Universal buffer with pH range 2.0 - 6.0 was used as sup­porting electrolyte. The solutions with uniform concentration (10^-5 M) were used in all deter­minations. Calculations were made by standard addition method.