Simple and sensitive electrochemical determination of higenamine in dietary supplements using a disposable pencil graphite electrode


Talay Pınar P. , Yardım Y. , Şentürk Z.

MONATSHEFTE FUR CHEMIE, vol.151, no.3, pp.301-307, 2020 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 151 Issue: 3
  • Publication Date: 2020
  • Doi Number: 10.1007/s00706-020-02556-y
  • Title of Journal : MONATSHEFTE FUR CHEMIE
  • Page Numbers: pp.301-307

Abstract

In this study, a cheap, rapid, simple, and modification-free electroanalytical methodology based on the disposable pencil graphite electrode is described for the quantification of higenamine (isoquinoline-type alkaloid having three phenolic OHs). At first, the electrochemical oxidation of higenamine was investigated in aqueous solutions by cyclic voltammetry. The electrode process is pH-dependent and controlled by a mixture of diffusion and adsorption processes. Higenamine yielded two well-separated oxidation steps in acidic, neutral, and alkaline media by using square-wave voltammetry. By using the first oxidation peak due to its higher sensitivity, there was an excellent correlation between oxidation peak current at + 0.44 V and higenamine concentration (as hydrochloride salt) in the range of 0.05 to 2.0 mu g cm(-3) (1.63 x 10(-7)-6.5 x 10(-6) mol dm(-3)), with a detection limit of 0.014 mu g cm(-3) (4.55 x 10(-8) mol dm(-3)) in Britton-Robinson buffer at pH 4.0. As an example, the developed approach can be used for the quantification of higenamine in the commercial dietary supplement formulations. Graphic abstract