▎ 摘　　要

Gold nanoparticles (AuNPs) and reduced graphene oxide (RGO) composite modified carbon paste electrode (CPE) was prepared by electrodepositing AuNPs over the reduced graphene oxide (RGO) modified carbon paste electrode. The composite material was characterised using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and atomic force microscopy (AFM) techniques. The nano composite modified electrode was applied for the determination of total As and for the inorganic speciation of As(III) and As(V) in environmental samples. The linear dynamic range was obtained for the determination of As(III) in the present method from 1gL(-1) to 20 gL(-1) and the limit of detection(LOD) in the standard solution was found to be 0.13 gL(-1) for the 300sec deposition time in 10mL supporting electrolyte solution. This method was applied for the determination of As (III) in water and soil samples. The results were agreed well with the result obtained from the hydride generation atomic absorption spectrometry.