Voltammetric Antioxidant Analysis in Mineral Oil Samples Immobilized into Boron-Doped Diamond Micropore Array Electrodes

X H Zhang, C A Paddon, Y H Chan, P C Bulman-Page, Paul S Fordred, Steven D Bull, H C Chang, N Rizvi, Frank Marken

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

Mineral oil microdroplets containing the model antioxidant N,N-didodecyl-N',N'-dietliyl-phenylene-diamine (DDPD) are immobilized into a 100 x 100 pore-array (ca. 10 mu m individual pore diameter, 100 mu m pitch) in a boron-doped diamond electrode surface. The robust diamond surface allows pore filling, cleaning, and reuse without damage to the electrode surface. The electrode is immersed into aqueous electrolyte media, and voltammetric responses 1 or the oxidation of DDPD are obtained. In order to further improve the current responses, 20 wt% of carbon nanofibers are co-deposited with the oil into the pore array. Voltammetric signals are consistent with the oxidation of DDPD and the associated transfer of perchlorate anions (in aqueous 0.1 M NaClO4) or the transfer of protons (in aqueous 0.1 M HClO4). From the magnitude of the current response, the DDPD content in the mineral oil can be determined down to less than 1 wt% levels. Perhaps surprisingly, the reversible (or midpoint) potential for the DDPD oxidation in mineral oil (when immersed in 0.1 NaClO4) is shown to be concentration-dependent and to shift to more positive potential values for more dilute DDPD in mineral oil solutions. An extraction mechanism and the formation of a separate organic product phase are proposed to explain this behavior.
Original languageEnglish
Pages (from-to)1341-1347
Number of pages7
JournalElectroanalysis
Volume21
Issue number12
DOIs
Publication statusPublished - Jun 2009

Keywords

  • Antioxidants
  • Sensors
  • Mineral oil
  • Laser-machining
  • Micropore
  • Array electrode
  • Diamond
  • Voltammetry
  • Carbon nanofibers
  • Phenylene-diamine

Fingerprint

Dive into the research topics of 'Voltammetric Antioxidant Analysis in Mineral Oil Samples Immobilized into Boron-Doped Diamond Micropore Array Electrodes'. Together they form a unique fingerprint.

Cite this