Highly-sensitive and rapid determination of sunset yellow using functionalized montmorillonite-modified electrode

Food Chem. 2015 Apr 15:173:640-4. doi: 10.1016/j.foodchem.2014.10.075. Epub 2014 Oct 22.

Abstract

Montmorillonite calcium (MMT-Ca) was functionalized with cetyltrimethylammonium bromide (CTAB) via cationic exchange effects. Compared with MMT-Ca, the resulting CTAB functionalized MMT-Ca (CTAB/MMT-Ca) greatly increased the oxidation peak current of sunset yellow, indicative of strong signal enhancement effects. The oxidation mechanism was studied, and one electron was transferred during the oxidation of sunset yellow. The influences of pH value, mass ratio of CTAB to MMT-Ca, amount of CTAB/MMT-Ca, and accumulation time were studied on the oxidation signal of sunset yellow. As a result, a highly-sensitive, rapid and simple electrochemical method was newly developed for the determination of sunset yellow. The linear ranger was from 2.5 to 200 nM, and the detection limit was as low as 0.71 nM after 1-min accumulation. This method was applied in soft drink samples, and the detected results consisted with the values that obtained by high-performance liquid chromatography.

Keywords: Electrochemical detection; Functionalized montmorillonite; High sensitivity; Modified electrode; Sunset yellow.

MeSH terms

  • Azo Compounds / analysis*
  • Bentonite / chemistry*
  • Cetrimonium
  • Cetrimonium Compounds / chemistry
  • Electrochemical Techniques*
  • Electrodes
  • Oxidation-Reduction
  • Sensitivity and Specificity

Substances

  • Azo Compounds
  • Cetrimonium Compounds
  • Bentonite
  • 6-hydroxy-5-((p- sulfophenyl)azo)-2-naphthalenesulfonic acid disodium salt
  • Cetrimonium