Analysis of phenolic acids in plant materials using HPLC with amperometric detection at a platinum tubular electrode

Abstract

The suitability of a simple amperometric platinum tubular detector for HPLC analysis of selected phenolic acids in yacon (Smallanthus sonchifolius, Asteraceae) is reported. The detector offers good overall limits of detection for the phenolic acids of interest. Three different types of extracts from yacon leaves were analyzed and compared with respect to their content of phenolic acids. Caffeic acid was found in all yacon extracts, whereas the content of chlorogenic acid depends more on the extraction procedure used. It has been demonstrated that no complicated and sophisticated equipment is needed and HPLC with amperometric detection seems to be a very useful technique for analysis of plant extracts containing phenolic acids.

Smallanthus sonchifolius

“…The following phenolic acids gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid and ferulic acid were detected in the ethyl acetate extract of dried yacon leaves and in the leaf aqueous decoction, and aqueous tea infusion gallic acid and ferulic acid were not detected (Jirovský et al 2003 ).…”

The role of methacrylate polymerized as porous‐layered and nanoparticle‐bound phases for open‐tubular capillary electrochromatography: Substitution of a charged monomer for a bulk monomer

“…With pK a values ranging between 3.59 and 4.64, the eight phenolic acids selected were all from plants, such as yacón leaves [44] and Acanthopanax senticosus roots [45]. The acids were mixed with ethylvanillin, pK a 5 7.6, and used to test the CEC performance in the BMA-MES capillary.…”

Silver Amalgam Tubular Detector Combined with Platinum Auxiliary Electrode for Electrochemical Measurements in Flow Systems

“…Electrochemical detection in flow systems is mostly carried out using one of the three possible arrangements of an electrolytic cell: i) wall-jet [1][2][3][4][5][6][7][8][9][10][11][12][13] (reviews [1,5,6,[9][10][11]); ii) thin-layer [6,[9][10][11]14,15] (reviews [6,[9][10][11]) and iii) cell with flow through (tubular) detector [1,[9][10][11][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] (reviews [1,[9][10]…”

“…Material of the working electrode/detector has a decisive influence on the possibilities and limitations of the used electrochemical method. For the implementation of oxidation processes, most commonly used electrodes are made of less active metals (e. g., Pt [16,17,[19][20][21], Au [7,32], Cu [33], Bi [23,24,34]) or from carbon materials (e. g., graphite [9,18,35,36], boron doped diamond [12][13][14], glassy carbon [3,9,15,37], screen-printed carbon [2,9,10], etc.). Carbon electrodes allow working also at slightly negative potentials.…”