A Benzocaine‐Induced Local Near‐Surface pH Effect: Influence on the Accuracy of Voltammetric Cocaine Detection

Autor: Karolien De Wael, Nick Sleegers, Anca Florea, Devin Daems, Jonas Schram, Mats de Jong
Rok vydání: 2020
Předmět:
Zdroj: Analysis & Sensing
ISSN: 2629-2742
DOI: 10.1002/anse.202000012
Popis: This work reports on a local induced near‐surface pH effect (pH S ), due to the presence of one analyte, leading to an influence or even suppression of redox signals of a second analyte present in solution. This concept and its impact on voltammetric sensing is illustrated by focusing on the detection of cocaine in the presence of the common adulterant benzocaine. An in‐depth study on the occurring interference mechanism and why it occurs for benzocaine specifically and not for other adulterants was performed through the use of multiple electrochemical strategies. It was concluded that the potential shift and loss of intensity of the square‐wave voltammetric cocaine signal in the presence of benzocaine was caused by a local pH S effect. A cathodic pretreatment strategy was developed to nonetheless allow accurate cocaine detection. The gathered insights are useful to explain unidentified phenomena involving compounds with properties similar to benzocaine in voltammetric electroanalysis.
Databáze: OpenAIRE