Determination of amino acids using capillary electrophoresis - contactless conductivity detection in antiviral medicinal plants

Abstract

Medicinal plants are valued due to accumulated polyphenolic compounds, however amines and amino acids are rarely investigated. Compounds containing amino group are considered as biologically active: some of them act as the mediators, other can be the cause of poisoning. In this work capillary electrophoresis coupled with capacitance-to-digital based miniaturized contactless conductivity detector was used for determination of amino acids and other amine group containing substances. Sixteen different medicinal plants were selected for screening. Analytes were separated in acidic (acetic acid solution) background electrolyte ensuring that all amine containing compounds are dissociated and charged positively. After the injection and application of electric field cations start migrating from anode to cathode and are detected by contactless conductivity detector in negative detection mode. Separated compounds were classified as having high, medium and low electrophoretic mobility. Different plant extracts indicated different peak profile. Several amino acids were identified and determined in all plant extracts. The compounds determined and conditions used for this research work will be presented during the conference.