Abstract
Phytosterols are problematic analytes when considering their detection, as they rarely possess moieties exhibiting electrochemical/fluorescent activity or sufficient absorbance in UV spectra. In this study, electrochemical oxidation of selected phytosterols was studied in a mixture of acetonitrile and a strong acid, presumably iniciating dehydration of the steroid skeleton.
This chemical reaction activates phytosterols so that their electrochemical oxidation proceeds at reasonable potentials within the potential window of boron doped diamond and glassy carbon electrode. Voltammetric behaviour was studied using inorganic acids (perchloric acid, sulfuric acid and trihydrogenphosphoric acid) as supporting electrolytes.
The stability of the voltammetric response of phytosterols, dependence of peak heights on scan rate and the dependence of the phytosterol signal on the water content in the measured solution was studied.