Differential-Pulsvoltammetrie und cyklische Voltammetrie von Phenols�uren

Analysis of Food by High Performance Liquid Chromatography Coupled with Coulometric Detection and Related Techniques: A Review

The development of single coulometric cells in combination with high performance liquid chromatography to dual cells and to the coulometric electrode array detector is described. An overview is given about the application of these methods in food chemistry. Easily oxidizable compounds, such as phenolic substances, pesticides, or vitamins, can be determined, as well as substances with high oxidation potentials or electroinactive compounds. Substances exhibiting poor electrochemical activity can be transformed to electroactive compounds by precolumn derivatization, postcolumn photochemical reactions, postcolumn enzyme reactors, or by using the oxidative/reductive mode for coulometric electrode array detection. Furthermore, it is shown that the interesting combination of high performance liquid chromatography with electrochemistry and mass spectrometry has opened further possibilities with respect to interpretation of redox reactions, drug metabolism studies, metabolomics, and electrochemical derivatization.

[Determination of phenolic compounds in alcoholic beverages by HPLC with an electrochemical detector]

A method has been developed for the quantitative determination of phenolic lignin degradation products in alcoholic distillates. After diluting the samples with the eluent (1:5-1:10, v/v) the phenolic compounds are separated by high-pressure liquid chromatography and detected by an electrochemical detector at +1.3 V. To identify the compounds the k'-values and the hydrodynamic voltammograms of the samples are compared with those of the standard solution. Several distilled alcoholic beverages were analysed. The content of phenolic compounds was found to vary between 0.15 and 7.7 mg/l. The detection limits were 0.3-0.9 ng.