Highly sensitive and selective electrochemical monitoring of nickel in crude oil samples using cathodically pretreated-boron doped diamond electrode

Abstract

Crude oil is a mixture of hydrocarbons found underground in liquid form and is a valuable fuel with a complex chemical structure. Crude oil is known to come from decaying plants and animals as a fossil product that emerged from the anaerobic process millions of years ago. In the formation of oil, it is accepted that crude oil has an organic origin, and most of the crude oil is found in sedimentary rocks, and the sediments have an organic and inorganic content.In this study, a voltammetric method was developed for the analysis of nickel, one of the metals with the highest density as a heavy metal in crude oil. In the developed voltammetric method, the boron-doped diamond electrode was activated in the cathodic direction at −3.0 V in 0.5 M H2SO4 media.As a result of this cathodic activation, nickel gave a very sensitive anodic signal around −0.15 V on the electrode surface. This anodic signal was determined to be linear in the range of 0.05–0.6 μM around −0.15 V in BR (pH 3.0) media by the anodic stripping voltammetry method. The limit of detection and the limit of quantification were determined to be 0.003 μM and 0.01 μM, respectively. The proposed method allowed the selective analysis of nickel in the crude oil sample without any separation and enrichment process.